/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
* Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
* Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
* Copyright (c) 2008-2021 Ivan Maidanski
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
#include "private/gc_priv.h"
#if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
&& !defined(MSWINCE) && !defined(SN_TARGET_ORBIS) \
&& !defined(SN_TARGET_PSP2) && !defined(__CC_ARM)
# include <sys/types.h>
# if !defined(MSWIN32) && !defined(MSWIN_XBOX1)
# include <unistd.h>
# endif
#endif
#include <stdio.h>
#if defined(MSWINCE) || defined(SN_TARGET_PS3)
# define SIGSEGV 0 /* value is irrelevant */
#else
# include <signal.h>
#endif
#if defined(UNIX_LIKE) || defined(CYGWIN32) || defined(NACL) \
|| defined(SYMBIAN)
# include <fcntl.h>
#endif
#if defined(LINUX) || defined(LINUX_STACKBOTTOM)
# include <ctype.h>
#endif
/* Blatantly OS dependent routines, except for those that are related */
/* to dynamic loading. */
#ifdef AMIGA
# define GC_AMIGA_DEF
# include "extra/AmigaOS.c"
# undef GC_AMIGA_DEF
#endif
#ifdef MACOS
# include <Processes.h>
#endif
#ifdef IRIX5
# include <sys/uio.h>
# include <malloc.h> /* for locking */
#endif
#if defined(MMAP_SUPPORTED) || defined(ADD_HEAP_GUARD_PAGES)
# if defined(USE_MUNMAP) && !defined(USE_MMAP) && !defined(CPPCHECK)
# error Invalid config: USE_MUNMAP requires USE_MMAP
# endif
# include <sys/types.h>
# include <sys/mman.h>
# include <sys/stat.h>
#endif
#if defined(ADD_HEAP_GUARD_PAGES) || defined(LINUX_STACKBOTTOM) \
|| defined(MMAP_SUPPORTED) || defined(NEED_PROC_MAPS)
# include <errno.h>
#endif
#ifdef DARWIN
/* for get_etext and friends */
# include <mach-o/getsect.h>
#endif
#ifdef DJGPP
/* Apparently necessary for djgpp 2.01. May cause problems with */
/* other versions. */
typedef long unsigned int caddr_t;
#endif
#ifdef PCR
# include "il/PCR_IL.h"
# include "th/PCR_ThCtl.h"
# include "mm/PCR_MM.h"
#endif
#if defined(GC_DARWIN_THREADS) && defined(MPROTECT_VDB)
/* Declare GC_mprotect_stop and GC_mprotect_resume as extern "C". */
# include "private/darwin_stop_world.h"
#endif
#if !defined(NO_EXECUTE_PERMISSION)
STATIC GC_bool GC_pages_executable = TRUE;
#else
STATIC GC_bool GC_pages_executable = FALSE;
#endif
#define IGNORE_PAGES_EXECUTABLE 1
/* Undefined on GC_pages_executable real use. */
#if ((defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS) \
|| defined(PROC_VDB) || defined(SOFT_VDB)) && !defined(PROC_READ)) \
|| defined(CPPCHECK)
# define PROC_READ read
/* Should probably call the real read, if read is wrapped. */
#endif
#if defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS)
/* Repeatedly perform a read call until the buffer is filled */
/* up, or we encounter EOF or an error. */
STATIC ssize_t GC_repeat_read(int fd, char *buf, size_t count)
{
size_t num_read = 0;
ASSERT_CANCEL_DISABLED();
while (num_read < count) {
ssize_t result = PROC_READ(fd, buf + num_read, count - num_read);
if (result < 0) return result;
if (result == 0) break;
num_read += result;
}
return num_read;
}
#endif /* LINUX_STACKBOTTOM || NEED_PROC_MAPS */
#ifdef NEED_PROC_MAPS
/* We need to parse /proc/self/maps, either to find dynamic libraries, */
/* and/or to find the register backing store base (IA64). Do it once */
/* here. */
#ifdef THREADS
/* Determine the length of a file by incrementally reading it into a */
/* buffer. This would be silly to use it on a file supporting lseek, */
/* but Linux /proc files usually do not. */
/* As of Linux 4.15.0, lseek(SEEK_END) fails for /proc/self/maps. */
STATIC size_t GC_get_file_len(int f)
{
size_t total = 0;
ssize_t result;
# define GET_FILE_LEN_BUF_SZ 500
char buf[GET_FILE_LEN_BUF_SZ];
do {
result = PROC_READ(f, buf, sizeof(buf));
if (result == -1) return 0;
total += result;
} while (result > 0);
return total;
}
STATIC size_t GC_get_maps_len(void)
{
int f = open("/proc/self/maps", O_RDONLY);
size_t result;
if (f < 0) return 0; /* treat missing file as empty */
result = GC_get_file_len(f);
close(f);
return result;
}
#endif /* THREADS */
/* Copy the contents of /proc/self/maps to a buffer in our address */
/* space. Return the address of the buffer. */
GC_INNER const char * GC_get_maps(void)
{
ssize_t result;
static char *maps_buf = NULL;
static size_t maps_buf_sz = 1;
size_t maps_size;
# ifdef THREADS
size_t old_maps_size = 0;
# endif
/* The buffer is essentially static, so there must be a single client. */
GC_ASSERT(I_HOLD_LOCK());
/* Note that in the presence of threads, the maps file can */
/* essentially shrink asynchronously and unexpectedly as */
/* threads that we already think of as dead release their */
/* stacks. And there is no easy way to read the entire */
/* file atomically. This is arguably a misfeature of the */
/* /proc/self/maps interface. */
/* Since we expect the file can grow asynchronously in rare */
/* cases, it should suffice to first determine */
/* the size (using read), and then to reread the file. */
/* If the size is inconsistent we have to retry. */
/* This only matters with threads enabled, and if we use */
/* this to locate roots (not the default). */
# ifdef THREADS
/* Determine the initial size of /proc/self/maps. */
maps_size = GC_get_maps_len();
if (0 == maps_size)
ABORT("Cannot determine length of /proc/self/maps");
# else
maps_size = 4000; /* Guess */
# endif
/* Read /proc/self/maps, growing maps_buf as necessary. */
/* Note that we may not allocate conventionally, and */
/* thus can't use stdio. */
do {
int f;
while (maps_size >= maps_buf_sz) {
# ifdef LINT2
/* Workaround passing tainted maps_buf to a tainted sink. */
GC_noop1((word)maps_buf);
# else
GC_scratch_recycle_no_gww(maps_buf, maps_buf_sz);
# endif
/* Grow only by powers of 2, since we leak "too small" buffers.*/
while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
maps_buf = GC_scratch_alloc(maps_buf_sz);
if (NULL == maps_buf)
ABORT_ARG1("Insufficient space for /proc/self/maps buffer",
", %lu bytes requested", (unsigned long)maps_buf_sz);
# ifdef THREADS
/* Recompute initial length, since we allocated. */
/* This can only happen a few times per program */
/* execution. */
maps_size = GC_get_maps_len();
if (0 == maps_size)
ABORT("Cannot determine length of /proc/self/maps");
# endif
}
GC_ASSERT(maps_buf_sz >= maps_size + 1);
f = open("/proc/self/maps", O_RDONLY);
if (-1 == f)
ABORT_ARG1("Cannot open /proc/self/maps",
": errno= %d", errno);
# ifdef THREADS
old_maps_size = maps_size;
# endif
maps_size = 0;
do {
result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
if (result < 0) {
ABORT_ARG1("Failed to read /proc/self/maps",
": errno= %d", errno);
}
maps_size += result;
} while ((size_t)result == maps_buf_sz-1);
close(f);
if (0 == maps_size)
ABORT("Empty /proc/self/maps");
# ifdef THREADS
if (maps_size > old_maps_size) {
/* This might be caused by e.g. thread creation. */
WARN("Unexpected asynchronous /proc/self/maps growth"
" (to %" WARN_PRIuPTR " bytes)\n", maps_size);
}
# endif
} while (maps_size >= maps_buf_sz
# ifdef THREADS
|| maps_size < old_maps_size
# endif
);
maps_buf[maps_size] = '\0';
return maps_buf;
}
/*
* GC_parse_map_entry parses an entry from /proc/self/maps so we can
* locate all writable data segments that belong to shared libraries.
* The format of one of these entries and the fields we care about
* is as follows:
* XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
* ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
* start end prot maj_dev
*
* Note that since about august 2003 kernels, the columns no longer have
* fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets
* anywhere, which is safer anyway.
*/
/* Assign various fields of the first line in maps_ptr to (*start), */
/* (*end), (*prot), (*maj_dev) and (*mapping_name). mapping_name may */
/* be NULL. (*prot) and (*mapping_name) are assigned pointers into the */
/* original buffer. */
#if (defined(DYNAMIC_LOADING) && defined(USE_PROC_FOR_LIBRARIES)) \
|| defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR) \
|| (defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS))
GC_INNER const char *GC_parse_map_entry(const char *maps_ptr,
ptr_t *start, ptr_t *end,
const char **prot, unsigned *maj_dev,
const char **mapping_name)
{
const unsigned char *start_start, *end_start, *maj_dev_start;
const unsigned char *p; /* unsigned for isspace, isxdigit */
if (maps_ptr == NULL || *maps_ptr == '\0') {
return NULL;
}
p = (const unsigned char *)maps_ptr;
while (isspace(*p)) ++p;
start_start = p;
GC_ASSERT(isxdigit(*start_start));
*start = (ptr_t)strtoul((const char *)start_start, (char **)&p, 16);
GC_ASSERT(*p=='-');
++p;
end_start = p;
GC_ASSERT(isxdigit(*end_start));
*end = (ptr_t)strtoul((const char *)end_start, (char **)&p, 16);
GC_ASSERT(isspace(*p));
while (isspace(*p)) ++p;
GC_ASSERT(*p == 'r' || *p == '-');
*prot = (const char *)p;
/* Skip past protection field to offset field */
while (!isspace(*p)) ++p;
while (isspace(*p)) p++;
GC_ASSERT(isxdigit(*p));
/* Skip past offset field, which we ignore */
while (!isspace(*p)) ++p;
while (isspace(*p)) p++;
maj_dev_start = p;
GC_ASSERT(isxdigit(*maj_dev_start));
*maj_dev = strtoul((const char *)maj_dev_start, NULL, 16);
if (mapping_name != NULL) {
while (*p && *p != '\n' && *p != '/' && *p != '[') p++;
*mapping_name = (const char *)p;
}
while (*p && *p++ != '\n');
return (const char *)p;
}
#endif /* REDIRECT_MALLOC || DYNAMIC_LOADING || IA64 || ... */
#if defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR)
/* Try to read the backing store base from /proc/self/maps. */
/* Return the bounds of the writable mapping with a 0 major device, */
/* which includes the address passed as data. */
/* Return FALSE if there is no such mapping. */
GC_INNER GC_bool GC_enclosing_mapping(ptr_t addr, ptr_t *startp,
ptr_t *endp)
{
const char *prot;
ptr_t my_start, my_end;
unsigned int maj_dev;
const char *maps_ptr = GC_get_maps();
for (;;) {
maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end,
&prot, &maj_dev, 0);
if (NULL == maps_ptr) break;
if (prot[1] == 'w' && maj_dev == 0
&& (word)my_end > (word)addr && (word)my_start <= (word)addr) {
*startp = my_start;
*endp = my_end;
return TRUE;
}
}
return FALSE;
}
#endif /* IA64 || INCLUDE_LINUX_THREAD_DESCR */
#if defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS)
/* Find the text(code) mapping for the library whose name, after */
/* stripping the directory part, starts with nm. */
GC_INNER GC_bool GC_text_mapping(char *nm, ptr_t *startp, ptr_t *endp)
{
size_t nm_len = strlen(nm);
const char *prot, *map_path;
ptr_t my_start, my_end;
unsigned int maj_dev;
const char *maps_ptr = GC_get_maps();
for (;;) {
maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end,
&prot, &maj_dev, &map_path);
if (NULL == maps_ptr) break;
if (prot[0] == 'r' && prot[1] == '-' && prot[2] == 'x') {
const char *p = map_path;
/* Set p to point just past last slash, if any. */
while (*p != '\0' && *p != '\n' && *p != ' ' && *p != '\t') ++p;
while ((word)p >= (word)map_path && *p != '/') --p;
++p;
if (strncmp(nm, p, nm_len) == 0) {
*startp = my_start;
*endp = my_end;
return TRUE;
}
}
}
return FALSE;
}
#endif /* REDIRECT_MALLOC */
#ifdef IA64
static ptr_t backing_store_base_from_proc(void)
{
ptr_t my_start, my_end;
if (!GC_enclosing_mapping(GC_save_regs_in_stack(), &my_start, &my_end)) {
GC_COND_LOG_PRINTF("Failed to find backing store base from /proc\n");
return 0;
}
return my_start;
}
#endif
#endif /* NEED_PROC_MAPS */
#if defined(SEARCH_FOR_DATA_START)
/* The x86 case can be handled without a search. The Alpha case */
/* used to be handled differently as well, but the rules changed */
/* for recent Linux versions. This seems to be the easiest way to */
/* cover all versions. */
# if defined(LINUX) || defined(HURD)
/* Some Linux distributions arrange to define __data_start. Some */
/* define data_start as a weak symbol. The latter is technically */
/* broken, since the user program may define data_start, in which */
/* case we lose. Nonetheless, we try both, preferring __data_start.*/
/* We assume gcc-compatible pragmas. */
EXTERN_C_BEGIN
# pragma weak __data_start
# pragma weak data_start
extern int __data_start[], data_start[];
EXTERN_C_END
# endif /* LINUX */
ptr_t GC_data_start = NULL;
GC_INNER void GC_init_linux_data_start(void)
{
ptr_t data_end = DATAEND;
# if (defined(LINUX) || defined(HURD)) && defined(USE_PROG_DATA_START)
/* Try the easy approaches first: */
/* However, this may lead to wrong data start value if libgc */
/* code is put into a shared library (directly or indirectly) */
/* which is linked with -Bsymbolic-functions option. Thus, */
/* the following is not used by default. */
if (COVERT_DATAFLOW(__data_start) != 0) {
GC_data_start = (ptr_t)(__data_start);
} else {
GC_data_start = (ptr_t)(data_start);
}
if (COVERT_DATAFLOW(GC_data_start) != 0) {
if ((word)GC_data_start > (word)data_end)
ABORT_ARG2("Wrong __data_start/_end pair",
": %p .. %p", (void *)GC_data_start, (void *)data_end);
return;
}
# ifdef DEBUG_ADD_DEL_ROOTS
GC_log_printf("__data_start not provided\n");
# endif
# endif /* LINUX */
if (GC_no_dls) {
/* Not needed, avoids the SIGSEGV caused by */
/* GC_find_limit which complicates debugging. */
GC_data_start = data_end; /* set data root size to 0 */
return;
}
GC_data_start = (ptr_t)GC_find_limit(data_end, FALSE);
}
#endif /* SEARCH_FOR_DATA_START */
#ifdef ECOS
# ifndef ECOS_GC_MEMORY_SIZE
# define ECOS_GC_MEMORY_SIZE (448 * 1024)
# endif /* ECOS_GC_MEMORY_SIZE */
/* TODO: This is a simple way of allocating memory which is */
/* compatible with ECOS early releases. Later releases use a more */
/* sophisticated means of allocating memory than this simple static */
/* allocator, but this method is at least bound to work. */
static char ecos_gc_memory[ECOS_GC_MEMORY_SIZE];
static char *ecos_gc_brk = ecos_gc_memory;
static void *tiny_sbrk(ptrdiff_t increment)
{
void *p = ecos_gc_brk;
ecos_gc_brk += increment;
if ((word)ecos_gc_brk > (word)(ecos_gc_memory + sizeof(ecos_gc_memory))) {
ecos_gc_brk -= increment;
return NULL;
}
return p;
}
# define sbrk tiny_sbrk
#endif /* ECOS */
#if defined(NETBSD) && defined(__ELF__)
ptr_t GC_data_start = NULL;
EXTERN_C_BEGIN
extern char **environ;
EXTERN_C_END
GC_INNER void GC_init_netbsd_elf(void)
{
/* This may need to be environ, without the underscore, for */
/* some versions. */
GC_data_start = (ptr_t)GC_find_limit(&environ, FALSE);
}
#endif /* NETBSD */
#if defined(ADDRESS_SANITIZER) && (defined(UNIX_LIKE) \
|| defined(NEED_FIND_LIMIT) || defined(MPROTECT_VDB)) \
&& !defined(CUSTOM_ASAN_DEF_OPTIONS)
EXTERN_C_BEGIN
GC_API const char *__asan_default_options(void);
EXTERN_C_END
/* To tell ASan to allow GC to use its own SIGBUS/SEGV handlers. */
/* The function is exported just to be visible to ASan library. */
GC_API const char *__asan_default_options(void)
{
return "allow_user_segv_handler=1";
}
#endif
#ifdef OPENBSD
static struct sigaction old_segv_act;
STATIC JMP_BUF GC_jmp_buf_openbsd;
STATIC void GC_fault_handler_openbsd(int sig GC_ATTR_UNUSED)
{
LONGJMP(GC_jmp_buf_openbsd, 1);
}
# ifdef GC_OPENBSD_UTHREADS
# include <sys/syscall.h>
EXTERN_C_BEGIN
extern sigset_t __syscall(quad_t, ...);
EXTERN_C_END
/* Don't use GC_find_limit() because siglongjmp() outside of the */
/* signal handler by-passes our userland pthreads lib, leaving */
/* SIGSEGV and SIGPROF masked. Instead, use this custom one that */
/* works-around the issues. */
/* Return the first non-addressable location > p or bound. */
/* Requires the allocation lock. */
STATIC ptr_t GC_find_limit_openbsd(ptr_t p, ptr_t bound)
{
static volatile ptr_t result;
/* Safer if static, since otherwise it may not be */
/* preserved across the longjmp. Can safely be */
/* static since it's only called with the */
/* allocation lock held. */
struct sigaction act;
word pgsz = (word)sysconf(_SC_PAGESIZE);
GC_ASSERT((word)bound >= pgsz);
GC_ASSERT(I_HOLD_LOCK());
act.sa_handler = GC_fault_handler_openbsd;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_NODEFER | SA_RESTART;
/* act.sa_restorer is deprecated and should not be initialized. */
sigaction(SIGSEGV, &act, &old_segv_act);
if (SETJMP(GC_jmp_buf_openbsd) == 0) {
result = (ptr_t)((word)p & ~(pgsz-1));
for (;;) {
if ((word)result >= (word)bound - pgsz) {
result = bound;
break;
}
result += pgsz; /* no overflow expected */
GC_noop1((word)(*result));
}
}
# ifdef THREADS
/* Due to the siglongjump we need to manually unmask SIGPROF. */
__syscall(SYS_sigprocmask, SIG_UNBLOCK, sigmask(SIGPROF));
# endif
sigaction(SIGSEGV, &old_segv_act, 0);
return(result);
}
# endif /* GC_OPENBSD_UTHREADS */
static volatile int firstpass;
/* Return first addressable location > p or bound. */
/* Requires the allocation lock. */
STATIC ptr_t GC_skip_hole_openbsd(ptr_t p, ptr_t bound)
{
static volatile ptr_t result;
struct sigaction act;
word pgsz = (word)sysconf(_SC_PAGESIZE);
GC_ASSERT((word)bound >= pgsz);
GC_ASSERT(I_HOLD_LOCK());
act.sa_handler = GC_fault_handler_openbsd;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_NODEFER | SA_RESTART;
/* act.sa_restorer is deprecated and should not be initialized. */
sigaction(SIGSEGV, &act, &old_segv_act);
firstpass = 1;
result = (ptr_t)((word)p & ~(pgsz-1));
if (SETJMP(GC_jmp_buf_openbsd) != 0 || firstpass) {
firstpass = 0;
if ((word)result >= (word)bound - pgsz) {
result = bound;
} else {
result += pgsz; /* no overflow expected */
GC_noop1((word)(unsigned char)(*result));
}
}
sigaction(SIGSEGV, &old_segv_act, 0);
return(result);
}
#endif /* OPENBSD */
# ifdef OS2
# include <stddef.h>
# if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
struct exe_hdr {
unsigned short magic_number;
unsigned short padding[29];
long new_exe_offset;
};
#define E_MAGIC(x) (x).magic_number
#define EMAGIC 0x5A4D
#define E_LFANEW(x) (x).new_exe_offset
struct e32_exe {
unsigned char magic_number[2];
unsigned char byte_order;
unsigned char word_order;
unsigned long exe_format_level;
unsigned short cpu;
unsigned short os;
unsigned long padding1[13];
unsigned long object_table_offset;
unsigned long object_count;
unsigned long padding2[31];
};
#define E32_MAGIC1(x) (x).magic_number[0]
#define E32MAGIC1 'L'
#define E32_MAGIC2(x) (x).magic_number[1]
#define E32MAGIC2 'X'
#define E32_BORDER(x) (x).byte_order
#define E32LEBO 0
#define E32_WORDER(x) (x).word_order
#define E32LEWO 0
#define E32_CPU(x) (x).cpu
#define E32CPU286 1
#define E32_OBJTAB(x) (x).object_table_offset
#define E32_OBJCNT(x) (x).object_count
struct o32_obj {
unsigned long size;
unsigned long base;
unsigned long flags;
unsigned long pagemap;
unsigned long mapsize;
unsigned long reserved;
};
#define O32_FLAGS(x) (x).flags
#define OBJREAD 0x0001L
#define OBJWRITE 0x0002L
#define OBJINVALID 0x0080L
#define O32_SIZE(x) (x).size
#define O32_BASE(x) (x).base
# else /* IBM's compiler */
/* A kludge to get around what appears to be a header file bug */
# ifndef WORD
# define WORD unsigned short
# endif
# ifndef DWORD
# define DWORD unsigned long
# endif
# define EXE386 1
# include <newexe.h>
# include <exe386.h>
# endif /* __IBMC__ */
# define INCL_DOSEXCEPTIONS
# define INCL_DOSPROCESS
# define INCL_DOSERRORS
# define INCL_DOSMODULEMGR
# define INCL_DOSMEMMGR
# include <os2.h>
# endif /* OS/2 */
/* Find the page size */
GC_INNER size_t GC_page_size = 0;
#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
# ifndef VER_PLATFORM_WIN32_CE
# define VER_PLATFORM_WIN32_CE 3
# endif
# if defined(MSWINCE) && defined(THREADS)
GC_INNER GC_bool GC_dont_query_stack_min = FALSE;
# endif
GC_INNER SYSTEM_INFO GC_sysinfo;
GC_INNER void GC_setpagesize(void)
{
GetSystemInfo(&GC_sysinfo);
# if defined(CYGWIN32) && (defined(MPROTECT_VDB) || defined(USE_MUNMAP))
/* Allocations made with mmap() are aligned to the allocation */
/* granularity, which (at least on Win64) is not the */
/* same as the page size. Probably a separate variable could */
/* be added to distinguish the allocation granularity from the */
/* actual page size, but in practice there is no good reason to */
/* make allocations smaller than dwAllocationGranularity, so we */
/* just use it instead of the actual page size here (as Cygwin */
/* itself does in many cases). */
GC_page_size = (size_t)GC_sysinfo.dwAllocationGranularity;
GC_ASSERT(GC_page_size >= (size_t)GC_sysinfo.dwPageSize);
# else
GC_page_size = (size_t)GC_sysinfo.dwPageSize;
# endif
# if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION)
{
OSVERSIONINFO verInfo;
/* Check the current WinCE version. */
verInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
if (!GetVersionEx(&verInfo))
ABORT("GetVersionEx failed");
if (verInfo.dwPlatformId == VER_PLATFORM_WIN32_CE &&
verInfo.dwMajorVersion < 6) {
/* Only the first 32 MB of address space belongs to the */
/* current process (unless WinCE 6.0+ or emulation). */
GC_sysinfo.lpMaximumApplicationAddress = (LPVOID)((word)32 << 20);
# ifdef THREADS
/* On some old WinCE versions, it's observed that */
/* VirtualQuery calls don't work properly when used to */
/* get thread current stack committed minimum. */
if (verInfo.dwMajorVersion < 5)
GC_dont_query_stack_min = TRUE;
# endif
}
}
# endif
}
# ifndef CYGWIN32
# define is_writable(prot) ((prot) == PAGE_READWRITE \
|| (prot) == PAGE_WRITECOPY \
|| (prot) == PAGE_EXECUTE_READWRITE \
|| (prot) == PAGE_EXECUTE_WRITECOPY)
/* Return the number of bytes that are writable starting at p. */
/* The pointer p is assumed to be page aligned. */
/* If base is not 0, *base becomes the beginning of the */
/* allocation region containing p. */
STATIC word GC_get_writable_length(ptr_t p, ptr_t *base)
{
MEMORY_BASIC_INFORMATION buf;
word result;
word protect;
result = VirtualQuery(p, &buf, sizeof(buf));
if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
if (base != 0) *base = (ptr_t)(buf.AllocationBase);
protect = buf.Protect & ~(word)(PAGE_GUARD | PAGE_NOCACHE);
if (!is_writable(protect)) {
return(0);
}
if (buf.State != MEM_COMMIT) return(0);
return(buf.RegionSize);
}
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
ptr_t trunc_sp;
word size;
/* Set page size if it is not ready (so client can use this */
/* function even before GC is initialized). */
if (!GC_page_size) GC_setpagesize();
trunc_sp = (ptr_t)((word)GC_approx_sp() & ~(word)(GC_page_size-1));
/* FIXME: This won't work if called from a deeply recursive */
/* client code (and the committed stack space has grown). */
size = GC_get_writable_length(trunc_sp, 0);
GC_ASSERT(size != 0);
sb -> mem_base = trunc_sp + size;
return GC_SUCCESS;
}
# else /* CYGWIN32 */
/* An alternate version for Cygwin (adapted from Dave Korn's */
/* gcc version of boehm-gc). */
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
# ifdef X86_64
sb -> mem_base = ((NT_TIB*)NtCurrentTeb())->StackBase;
# else
void * _tlsbase;
__asm__ ("movl %%fs:4, %0"
: "=r" (_tlsbase));
sb -> mem_base = _tlsbase;
# endif
return GC_SUCCESS;
}
# endif /* CYGWIN32 */
# define HAVE_GET_STACK_BASE
#else /* !MSWIN32 */
GC_INNER void GC_setpagesize(void)
{
# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(SOFT_VDB) \
|| defined(USE_MMAP)
GC_page_size = (size_t)GETPAGESIZE();
# if !defined(CPPCHECK)
if (0 == GC_page_size)
ABORT("getpagesize failed");
# endif
# else
/* It's acceptable to fake it. */
GC_page_size = HBLKSIZE;
# endif
}
#endif /* !MSWIN32 */
#ifdef HAIKU
# include <kernel/OS.h>
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
thread_info th;
get_thread_info(find_thread(NULL),&th);
sb->mem_base = th.stack_end;
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* HAIKU */
#ifdef OS2
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
PTIB ptib; /* thread information block */
PPIB ppib;
if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
WARN("DosGetInfoBlocks failed\n", 0);
return GC_UNIMPLEMENTED;
}
sb->mem_base = ptib->tib_pstacklimit;
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* OS2 */
# ifdef AMIGA
# define GC_AMIGA_SB
# include "extra/AmigaOS.c"
# undef GC_AMIGA_SB
# define GET_MAIN_STACKBASE_SPECIAL
# endif /* AMIGA */
# if defined(NEED_FIND_LIMIT) \
|| (defined(UNIX_LIKE) && !defined(NO_DEBUGGING)) \
|| (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS)) \
|| (defined(WRAP_MARK_SOME) && defined(__GNUC__))
typedef void (*GC_fault_handler_t)(int);
# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
|| defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
|| defined(NETBSD)
static struct sigaction old_segv_act;
# if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \
|| defined(HURD) || defined(NETBSD) || defined(FREEBSD)
static struct sigaction old_bus_act;
# endif
# elif !defined(OPENBSD)
static GC_fault_handler_t old_segv_handler;
# ifdef HAVE_SIGBUS
static GC_fault_handler_t old_bus_handler;
# endif
# endif
GC_INNER void GC_set_and_save_fault_handler(GC_fault_handler_t h)
{
# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
|| defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
|| defined(NETBSD) || defined(OPENBSD)
struct sigaction act;
act.sa_handler = h;
# ifdef SIGACTION_FLAGS_NODEFER_HACK
/* Was necessary for Solaris 2.3 and very temporary */
/* NetBSD bugs. */
act.sa_flags = SA_RESTART | SA_NODEFER;
# else
act.sa_flags = SA_RESTART;
# endif
(void) sigemptyset(&act.sa_mask);
/* act.sa_restorer is deprecated and should not be initialized. */
# ifdef GC_IRIX_THREADS
/* Older versions have a bug related to retrieving and */
/* and setting a handler at the same time. */
(void) sigaction(SIGSEGV, 0, &old_segv_act);
(void) sigaction(SIGSEGV, &act, 0);
# else
(void) sigaction(SIGSEGV, &act, &old_segv_act);
# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
|| defined(HPUX) || defined(HURD) || defined(NETBSD) \
|| defined(FREEBSD)
/* Under Irix 5.x or HP/UX, we may get SIGBUS. */
/* Pthreads doesn't exist under Irix 5.x, so we */
/* don't have to worry in the threads case. */
(void) sigaction(SIGBUS, &act, &old_bus_act);
# endif
# endif /* !GC_IRIX_THREADS */
# else
old_segv_handler = signal(SIGSEGV, h);
# ifdef HAVE_SIGBUS
old_bus_handler = signal(SIGBUS, h);
# endif
# endif
# if defined(CPPCHECK) && defined(ADDRESS_SANITIZER)
GC_noop1((word)&__asan_default_options);
# endif
}
# endif /* NEED_FIND_LIMIT || UNIX_LIKE */
# if defined(NEED_FIND_LIMIT) \
|| (defined(WRAP_MARK_SOME) && defined(__GNUC__)) \
|| (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS))
/* Some tools to implement HEURISTIC2 */
# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
GC_INNER JMP_BUF GC_jmp_buf;
STATIC void GC_fault_handler(int sig GC_ATTR_UNUSED)
{
LONGJMP(GC_jmp_buf, 1);
}
GC_INNER void GC_setup_temporary_fault_handler(void)
{
/* Handler is process-wide, so this should only happen in */
/* one thread at a time. */
GC_ASSERT(I_HOLD_LOCK());
GC_set_and_save_fault_handler(GC_fault_handler);
}
GC_INNER void GC_reset_fault_handler(void)
{
# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
|| defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
|| defined(NETBSD) || defined(OPENBSD)
(void) sigaction(SIGSEGV, &old_segv_act, 0);
# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
|| defined(HPUX) || defined(HURD) || defined(NETBSD) \
|| defined(FREEBSD)
(void) sigaction(SIGBUS, &old_bus_act, 0);
# endif
# else
(void) signal(SIGSEGV, old_segv_handler);
# ifdef HAVE_SIGBUS
(void) signal(SIGBUS, old_bus_handler);
# endif
# endif
}
/* Return the first non-addressable location > p (up) or */
/* the smallest location q s.t. [q,p) is addressable (!up). */
/* We assume that p (up) or p-1 (!up) is addressable. */
/* Requires allocation lock. */
GC_ATTR_NO_SANITIZE_ADDR
STATIC ptr_t GC_find_limit_with_bound(ptr_t p, GC_bool up, ptr_t bound)
{
static volatile ptr_t result;
/* Safer if static, since otherwise it may not be */
/* preserved across the longjmp. Can safely be */
/* static since it's only called with the */
/* allocation lock held. */
GC_ASSERT(up ? (word)bound >= MIN_PAGE_SIZE
: (word)bound <= ~(word)MIN_PAGE_SIZE);
GC_ASSERT(I_HOLD_LOCK());
GC_setup_temporary_fault_handler();
if (SETJMP(GC_jmp_buf) == 0) {
result = (ptr_t)((word)p & ~(word)(MIN_PAGE_SIZE-1));
for (;;) {
if (up) {
if ((word)result >= (word)bound - MIN_PAGE_SIZE) {
result = bound;
break;
}
result += MIN_PAGE_SIZE; /* no overflow expected */
} else {
if ((word)result <= (word)bound + MIN_PAGE_SIZE) {
result = bound - MIN_PAGE_SIZE;
/* This is to compensate */
/* further result increment (we */
/* do not modify "up" variable */
/* since it might be clobbered */
/* by setjmp otherwise). */
break;
}
result -= MIN_PAGE_SIZE; /* no underflow expected */
}
GC_noop1((word)(unsigned char)(*result));
}
}
GC_reset_fault_handler();
if (!up) {
result += MIN_PAGE_SIZE;
}
return(result);
}
void * GC_find_limit(void * p, int up)
{
return GC_find_limit_with_bound((ptr_t)p, (GC_bool)up,
up ? (ptr_t)GC_WORD_MAX : 0);
}
# endif /* NEED_FIND_LIMIT || USE_PROC_FOR_LIBRARIES */
#ifdef HPUX_MAIN_STACKBOTTOM
# include <sys/param.h>
# include <sys/pstat.h>
STATIC ptr_t GC_hpux_main_stack_base(void)
{
struct pst_vm_status vm_status;
int i = 0;
while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
if (vm_status.pst_type == PS_STACK)
return (ptr_t)vm_status.pst_vaddr;
}
/* Old way to get the stack bottom. */
# ifdef STACK_GROWS_UP
return (ptr_t)GC_find_limit(GC_approx_sp(), /* up= */ FALSE);
# else /* not HP_PA */
return (ptr_t)GC_find_limit(GC_approx_sp(), TRUE);
# endif
}
#endif /* HPUX_MAIN_STACKBOTTOM */
#ifdef HPUX_STACKBOTTOM
#include <sys/param.h>
#include <sys/pstat.h>
GC_INNER ptr_t GC_get_register_stack_base(void)
{
struct pst_vm_status vm_status;
int i = 0;
while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
if (vm_status.pst_type == PS_RSESTACK) {
return (ptr_t) vm_status.pst_vaddr;
}
}
/* old way to get the register stackbottom */
return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
& ~(word)(BACKING_STORE_ALIGNMENT-1));
}
#endif /* HPUX_STACK_BOTTOM */
#ifdef LINUX_STACKBOTTOM
# include <sys/types.h>
# include <sys/stat.h>
# define STAT_SKIP 27 /* Number of fields preceding startstack */
/* field in /proc/self/stat */
# ifdef USE_LIBC_PRIVATES
EXTERN_C_BEGIN
# pragma weak __libc_stack_end
extern ptr_t __libc_stack_end;
# ifdef IA64
# pragma weak __libc_ia64_register_backing_store_base
extern ptr_t __libc_ia64_register_backing_store_base;
# endif
EXTERN_C_END
# endif
# ifdef IA64
GC_INNER ptr_t GC_get_register_stack_base(void)
{
ptr_t result;
# ifdef USE_LIBC_PRIVATES
if (0 != &__libc_ia64_register_backing_store_base
&& 0 != __libc_ia64_register_backing_store_base) {
/* Glibc 2.2.4 has a bug such that for dynamically linked */
/* executables __libc_ia64_register_backing_store_base is */
/* defined but uninitialized during constructor calls. */
/* Hence we check for both nonzero address and value. */
return __libc_ia64_register_backing_store_base;
}
# endif
result = backing_store_base_from_proc();
if (0 == result) {
result = (ptr_t)GC_find_limit(GC_save_regs_in_stack(), FALSE);
/* This works better than a constant displacement heuristic. */
}
return result;
}
# endif /* IA64 */
STATIC ptr_t GC_linux_main_stack_base(void)
{
/* We read the stack bottom value from /proc/self/stat. We do this */
/* using direct I/O system calls in order to avoid calling malloc */
/* in case REDIRECT_MALLOC is defined. */
# define STAT_BUF_SIZE 4096
char stat_buf[STAT_BUF_SIZE];
int f;
word result;
ssize_t i, buf_offset = 0, len;
/* First try the easy way. This should work for glibc 2.2 */
/* This fails in a prelinked ("prelink" command) executable */
/* since the correct value of __libc_stack_end never */
/* becomes visible to us. The second test works around */
/* this. */
# ifdef USE_LIBC_PRIVATES
if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
# if defined(IA64)
/* Some versions of glibc set the address 16 bytes too */
/* low while the initialization code is running. */
if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
return __libc_stack_end + 0x10;
} /* Otherwise it's not safe to add 16 bytes and we fall */
/* back to using /proc. */
# elif defined(SPARC)
/* Older versions of glibc for 64-bit SPARC do not set this */
/* variable correctly, it gets set to either zero or one. */
if (__libc_stack_end != (ptr_t) (unsigned long)0x1)
return __libc_stack_end;
# else
return __libc_stack_end;
# endif
}
# endif
f = open("/proc/self/stat", O_RDONLY);
if (-1 == f)
ABORT_ARG1("Could not open /proc/self/stat", ": errno= %d", errno);
len = GC_repeat_read(f, stat_buf, sizeof(stat_buf));
if (len < 0)
ABORT_ARG1("Failed to read /proc/self/stat",
": errno= %d", errno);
close(f);
/* Skip the required number of fields. This number is hopefully */
/* constant across all Linux implementations. */
for (i = 0; i < STAT_SKIP; ++i) {
while (buf_offset < len && isspace(stat_buf[buf_offset++])) {
/* empty */
}
while (buf_offset < len && !isspace(stat_buf[buf_offset++])) {
/* empty */
}
}
/* Skip spaces. */
while (buf_offset < len && isspace(stat_buf[buf_offset])) {
buf_offset++;
}
/* Find the end of the number and cut the buffer there. */
for (i = 0; buf_offset + i < len; i++) {
if (!isdigit(stat_buf[buf_offset + i])) break;
}
if (buf_offset + i >= len) ABORT("Could not parse /proc/self/stat");
stat_buf[buf_offset + i] = '\0';
result = (word)STRTOULL(&stat_buf[buf_offset], NULL, 10);
if (result < 0x100000 || (result & (sizeof(word) - 1)) != 0)
ABORT_ARG1("Absurd stack bottom value",
": 0x%lx", (unsigned long)result);
return (ptr_t)result;
}
#endif /* LINUX_STACKBOTTOM */
#ifdef FREEBSD_STACKBOTTOM
/* This uses an undocumented sysctl call, but at least one expert */
/* believes it will stay. */
# include <unistd.h>
# include <sys/types.h>
# include <sys/sysctl.h>
STATIC ptr_t GC_freebsd_main_stack_base(void)
{
int nm[2] = {CTL_KERN, KERN_USRSTACK};
ptr_t base;
size_t len = sizeof(ptr_t);
int r = sysctl(nm, 2, &base, &len, NULL, 0);
if (r) ABORT("Error getting main stack base");
return base;
}
#endif /* FREEBSD_STACKBOTTOM */
#if defined(ECOS) || defined(NOSYS)
ptr_t GC_get_main_stack_base(void)
{
return STACKBOTTOM;
}
# define GET_MAIN_STACKBASE_SPECIAL
#elif defined(SYMBIAN)
EXTERN_C_BEGIN
extern int GC_get_main_symbian_stack_base(void);
EXTERN_C_END
ptr_t GC_get_main_stack_base(void)
{
return (ptr_t)GC_get_main_symbian_stack_base();
}
# define GET_MAIN_STACKBASE_SPECIAL
#elif defined(EMSCRIPTEN)
# if defined(USE_EMSCRIPTEN_SCAN_STACK) && defined(EMSCRIPTEN_ASYNCIFY)
/* According to the documentation, emscripten_scan_stack() is only */
/* guaranteed to be available when building with ASYNCIFY. */
# include <emscripten.h>
static void *emscripten_stack_base;
static void scan_stack_cb(void *begin, void *end)
{
(void)begin;
emscripten_stack_base = end;
}
# else
# include <emscripten/stack.h>
# endif
ptr_t GC_get_main_stack_base(void)
{
# if defined(USE_EMSCRIPTEN_SCAN_STACK) && defined(EMSCRIPTEN_ASYNCIFY)
emscripten_scan_stack(scan_stack_cb);
return (ptr_t)emscripten_stack_base;
# else
return (ptr_t)emscripten_stack_get_base();
# endif
}
# define GET_MAIN_STACKBASE_SPECIAL
#elif !defined(AMIGA) && !defined(HAIKU) && !defined(OS2) \
&& !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) \
&& !defined(GC_OPENBSD_THREADS) \
&& (!defined(GC_SOLARIS_THREADS) || defined(_STRICT_STDC))
# if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \
&& (defined(THREADS) || defined(USE_GET_STACKBASE_FOR_MAIN))
# include <pthread.h>
# ifdef HAVE_PTHREAD_NP_H
# include <pthread_np.h> /* for pthread_attr_get_np() */
# endif
# elif defined(DARWIN) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
/* We could use pthread_get_stackaddr_np even in case of a */
/* single-threaded gclib (there is no -lpthread on Darwin). */
# include <pthread.h>
# undef STACKBOTTOM
# define STACKBOTTOM (ptr_t)pthread_get_stackaddr_np(pthread_self())
# endif
ptr_t GC_get_main_stack_base(void)
{
ptr_t result;
# if (defined(HAVE_PTHREAD_ATTR_GET_NP) \
|| defined(HAVE_PTHREAD_GETATTR_NP)) \
&& (defined(USE_GET_STACKBASE_FOR_MAIN) \
|| (defined(THREADS) && !defined(REDIRECT_MALLOC)))
pthread_attr_t attr;
void *stackaddr;
size_t size;
# ifdef HAVE_PTHREAD_ATTR_GET_NP
if (pthread_attr_init(&attr) == 0
&& (pthread_attr_get_np(pthread_self(), &attr) == 0
? TRUE : (pthread_attr_destroy(&attr), FALSE)))
# else /* HAVE_PTHREAD_GETATTR_NP */
if (pthread_getattr_np(pthread_self(), &attr) == 0)
# endif
{
if (pthread_attr_getstack(&attr, &stackaddr, &size) == 0
&& stackaddr != NULL) {
(void)pthread_attr_destroy(&attr);
# ifdef STACK_GROWS_DOWN
stackaddr = (char *)stackaddr + size;
# endif
return (ptr_t)stackaddr;
}
(void)pthread_attr_destroy(&attr);
}
WARN("pthread_getattr_np or pthread_attr_getstack failed"
" for main thread\n", 0);
# endif
# ifdef STACKBOTTOM
result = STACKBOTTOM;
# else
# ifdef HEURISTIC1
# define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
# ifdef STACK_GROWS_DOWN
result = (ptr_t)(((word)GC_approx_sp() + STACKBOTTOM_ALIGNMENT_M1)
& ~(word)STACKBOTTOM_ALIGNMENT_M1);
# else
result = (ptr_t)((word)GC_approx_sp()
& ~(word)STACKBOTTOM_ALIGNMENT_M1);
# endif
# elif defined(HPUX_MAIN_STACKBOTTOM)
result = GC_hpux_main_stack_base();
# elif defined(LINUX_STACKBOTTOM)
result = GC_linux_main_stack_base();
# elif defined(FREEBSD_STACKBOTTOM)
result = GC_freebsd_main_stack_base();
# elif defined(HEURISTIC2)
{
ptr_t sp = GC_approx_sp();
# ifdef STACK_GROWS_DOWN
result = (ptr_t)GC_find_limit(sp, TRUE);
# if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK)
if ((word)result > (word)HEURISTIC2_LIMIT
&& (word)sp < (word)HEURISTIC2_LIMIT) {
result = HEURISTIC2_LIMIT;
}
# endif
# else
result = (ptr_t)GC_find_limit(sp, FALSE);
# if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK)
if ((word)result < (word)HEURISTIC2_LIMIT
&& (word)sp > (word)HEURISTIC2_LIMIT) {
result = HEURISTIC2_LIMIT;
}
# endif
# endif
}
# elif defined(STACK_NOT_SCANNED) || defined(CPPCHECK)
result = NULL;
# else
# error None of HEURISTIC* and *STACKBOTTOM defined!
# endif
# if defined(STACK_GROWS_DOWN) && !defined(CPPCHECK)
if (result == 0)
result = (ptr_t)(signed_word)(-sizeof(ptr_t));
# endif
# endif
# if !defined(CPPCHECK)
GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)result);
# endif
return(result);
}
# define GET_MAIN_STACKBASE_SPECIAL
#endif /* !AMIGA, !HAIKU, !OPENBSD, !OS2, !Windows */
#if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \
&& defined(THREADS) && !defined(HAVE_GET_STACK_BASE)
# include <pthread.h>
# ifdef HAVE_PTHREAD_NP_H
# include <pthread_np.h>
# endif
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
{
pthread_attr_t attr;
size_t size;
# ifdef IA64
DCL_LOCK_STATE;
# endif
# ifdef HAVE_PTHREAD_ATTR_GET_NP
if (pthread_attr_init(&attr) != 0)
ABORT("pthread_attr_init failed");
if (pthread_attr_get_np(pthread_self(), &attr) != 0) {
WARN("pthread_attr_get_np failed\n", 0);
(void)pthread_attr_destroy(&attr);
return GC_UNIMPLEMENTED;
}
# else /* HAVE_PTHREAD_GETATTR_NP */
if (pthread_getattr_np(pthread_self(), &attr) != 0) {
WARN("pthread_getattr_np failed\n", 0);
return GC_UNIMPLEMENTED;
}
# endif
if (pthread_attr_getstack(&attr, &(b -> mem_base), &size) != 0) {
ABORT("pthread_attr_getstack failed");
}
(void)pthread_attr_destroy(&attr);
# ifdef STACK_GROWS_DOWN
b -> mem_base = (char *)(b -> mem_base) + size;
# endif
# ifdef IA64
/* We could try backing_store_base_from_proc, but that's safe */
/* only if no mappings are being asynchronously created. */
/* Subtracting the size from the stack base doesn't work for at */
/* least the main thread. */
LOCK();
{
IF_CANCEL(int cancel_state;)
ptr_t bsp;
ptr_t next_stack;
DISABLE_CANCEL(cancel_state);
bsp = GC_save_regs_in_stack();
next_stack = GC_greatest_stack_base_below(bsp);
if (0 == next_stack) {
b -> reg_base = GC_find_limit(bsp, FALSE);
} else {
/* Avoid walking backwards into preceding memory stack and */
/* growing it. */
b -> reg_base = GC_find_limit_with_bound(bsp, FALSE, next_stack);
}
RESTORE_CANCEL(cancel_state);
}
UNLOCK();
# elif defined(E2K)
b -> reg_base = NULL;
# endif
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* THREADS && (HAVE_PTHREAD_ATTR_GET_NP || HAVE_PTHREAD_GETATTR_NP) */
#if defined(GC_DARWIN_THREADS) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
# include <pthread.h>
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
{
/* pthread_get_stackaddr_np() should return stack bottom (highest */
/* stack address plus 1). */
b->mem_base = pthread_get_stackaddr_np(pthread_self());
GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)b->mem_base);
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* GC_DARWIN_THREADS */
#ifdef GC_OPENBSD_THREADS
# include <sys/signal.h>
# include <pthread.h>
# include <pthread_np.h>
/* Find the stack using pthread_stackseg_np(). */
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
stack_t stack;
if (pthread_stackseg_np(pthread_self(), &stack))
ABORT("pthread_stackseg_np(self) failed");
sb->mem_base = stack.ss_sp;
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* GC_OPENBSD_THREADS */
#if defined(GC_SOLARIS_THREADS) && !defined(_STRICT_STDC)
# include <thread.h>
# include <signal.h>
# include <pthread.h>
/* These variables are used to cache ss_sp value for the primordial */
/* thread (it's better not to call thr_stksegment() twice for this */
/* thread - see JDK bug #4352906). */
static pthread_t stackbase_main_self = 0;
/* 0 means stackbase_main_ss_sp value is unset. */
static void *stackbase_main_ss_sp = NULL;
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
{
stack_t s;
pthread_t self = pthread_self();
if (self == stackbase_main_self)
{
/* If the client calls GC_get_stack_base() from the main thread */
/* then just return the cached value. */
b -> mem_base = stackbase_main_ss_sp;
GC_ASSERT(b -> mem_base != NULL);
return GC_SUCCESS;
}
if (thr_stksegment(&s)) {
/* According to the manual, the only failure error code returned */
/* is EAGAIN meaning "the information is not available due to the */
/* thread is not yet completely initialized or it is an internal */
/* thread" - this shouldn't happen here. */
ABORT("thr_stksegment failed");
}
/* s.ss_sp holds the pointer to the stack bottom. */
GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)s.ss_sp);
if (!stackbase_main_self && thr_main() != 0)
{
/* Cache the stack bottom pointer for the primordial thread */
/* (this is done during GC_init, so there is no race). */
stackbase_main_ss_sp = s.ss_sp;
stackbase_main_self = self;
}
b -> mem_base = s.ss_sp;
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* GC_SOLARIS_THREADS */
#ifdef GC_RTEMS_PTHREADS
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
{
sb->mem_base = rtems_get_stack_bottom();
return GC_SUCCESS;
}
# define HAVE_GET_STACK_BASE
#endif /* GC_RTEMS_PTHREADS */
#ifndef HAVE_GET_STACK_BASE
# ifdef NEED_FIND_LIMIT
/* Retrieve the stack bottom. */
/* Using the GC_find_limit version is risky. */
/* On IA64, for example, there is no guard page between the */
/* stack of one thread and the register backing store of the */
/* next. Thus this is likely to identify way too large a */
/* "stack" and thus at least result in disastrous performance. */
/* TODO: Implement better strategies here. */
GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
{
IF_CANCEL(int cancel_state;)
DCL_LOCK_STATE;
LOCK();
DISABLE_CANCEL(cancel_state); /* May be unnecessary? */
# ifdef STACK_GROWS_DOWN
b -> mem_base = GC_find_limit(GC_approx_sp(), TRUE);
# else
b -> mem_base = GC_find_limit(GC_approx_sp(), FALSE);
# endif
# ifdef IA64
b -> reg_base = GC_find_limit(GC_save_regs_in_stack(), FALSE);
# elif defined(E2K)
b -> reg_base = NULL;
# endif
RESTORE_CANCEL(cancel_state);
UNLOCK();
return GC_SUCCESS;
}
# else
GC_API int GC_CALL GC_get_stack_base(
struct GC_stack_base *b GC_ATTR_UNUSED)
{
# if defined(GET_MAIN_STACKBASE_SPECIAL) && !defined(THREADS) \
&& !defined(IA64)
b->mem_base = GC_get_main_stack_base();
return GC_SUCCESS;
# else
return GC_UNIMPLEMENTED;
# endif
}
# endif /* !NEED_FIND_LIMIT */
#endif /* !HAVE_GET_STACK_BASE */
#ifndef GET_MAIN_STACKBASE_SPECIAL
/* This is always called from the main thread. Default implementation. */
ptr_t GC_get_main_stack_base(void)
{
struct GC_stack_base sb;
if (GC_get_stack_base(&sb) != GC_SUCCESS)
ABORT("GC_get_stack_base failed");
GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)sb.mem_base);
return (ptr_t)sb.mem_base;
}
#endif /* !GET_MAIN_STACKBASE_SPECIAL */
/* Register static data segment(s) as roots. If more data segments are */
/* added later then they need to be registered at that point (as we do */
/* with SunOS dynamic loading), or GC_mark_roots needs to check for */
/* them (as we do with PCR). Called with allocator lock held. */
# ifdef OS2
void GC_register_data_segments(void)
{
PTIB ptib;
PPIB ppib;
HMODULE module_handle;
# define PBUFSIZ 512
UCHAR path[PBUFSIZ];
FILE * myexefile;
struct exe_hdr hdrdos; /* MSDOS header. */
struct e32_exe hdr386; /* Real header for my executable */
struct o32_obj seg; /* Current segment */
int nsegs;
# if defined(CPPCHECK)
hdrdos.padding[0] = 0; /* to prevent "field unused" warnings */
hdr386.exe_format_level = 0;
hdr386.os = 0;
hdr386.padding1[0] = 0;
hdr386.padding2[0] = 0;
seg.pagemap = 0;
seg.mapsize = 0;
seg.reserved = 0;
# endif
if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
ABORT("DosGetInfoBlocks failed");
}
module_handle = ppib -> pib_hmte;
if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
ABORT("DosQueryModuleName failed");
}
myexefile = fopen(path, "rb");
if (myexefile == 0) {
ABORT_ARG1("Failed to open executable", ": %s", path);
}
if (fread((char *)(&hdrdos), 1, sizeof(hdrdos), myexefile)
< sizeof(hdrdos)) {
ABORT_ARG1("Could not read MSDOS header", " from: %s", path);
}
if (E_MAGIC(hdrdos) != EMAGIC) {
ABORT_ARG1("Bad DOS magic number", " in file: %s", path);
}
if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
ABORT_ARG1("Bad DOS magic number", " in file: %s", path);
}
if (fread((char *)(&hdr386), 1, sizeof(hdr386), myexefile)
< sizeof(hdr386)) {
ABORT_ARG1("Could not read OS/2 header", " from: %s", path);
}
if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
ABORT_ARG1("Bad OS/2 magic number", " in file: %s", path);
}
if (E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
ABORT_ARG1("Bad byte order in executable", " file: %s", path);
}
if (E32_CPU(hdr386) == E32CPU286) {
ABORT_ARG1("GC cannot handle 80286 executables", ": %s", path);
}
if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
SEEK_SET) != 0) {
ABORT_ARG1("Seek to object table failed", " in file: %s", path);
}
for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
int flags;
if (fread((char *)(&seg), 1, sizeof(seg), myexefile) < sizeof(seg)) {
ABORT_ARG1("Could not read obj table entry", " from file: %s", path);
}
flags = O32_FLAGS(seg);
if (!(flags & OBJWRITE)) continue;
if (!(flags & OBJREAD)) continue;
if (flags & OBJINVALID) {
GC_err_printf("Object with invalid pages?\n");
continue;
}
GC_add_roots_inner((ptr_t)O32_BASE(seg),
(ptr_t)(O32_BASE(seg)+O32_SIZE(seg)), FALSE);
}
(void)fclose(myexefile);
}
# else /* !OS2 */
# if defined(GWW_VDB)
# ifndef MEM_WRITE_WATCH
# define MEM_WRITE_WATCH 0x200000
# endif
# ifndef WRITE_WATCH_FLAG_RESET
# define WRITE_WATCH_FLAG_RESET 1
# endif
/* Since we can't easily check whether ULONG_PTR and SIZE_T are */
/* defined in Win32 basetsd.h, we define own ULONG_PTR. */
# define GC_ULONG_PTR word
typedef UINT (WINAPI * GetWriteWatch_type)(
DWORD, PVOID, GC_ULONG_PTR /* SIZE_T */,
PVOID *, GC_ULONG_PTR *, PULONG);
static FARPROC GetWriteWatch_func;
static DWORD GetWriteWatch_alloc_flag;
# define GC_GWW_AVAILABLE() (GetWriteWatch_func != 0)
static void detect_GetWriteWatch(void)
{
static GC_bool done;
HMODULE hK32;
if (done)
return;
# if defined(MPROTECT_VDB)
{
char * str = GETENV("GC_USE_GETWRITEWATCH");
# if defined(GC_PREFER_MPROTECT_VDB)
if (str == NULL || (*str == '0' && *(str + 1) == '\0')) {
/* GC_USE_GETWRITEWATCH is unset or set to "0". */
done = TRUE; /* falling back to MPROTECT_VDB strategy. */
/* This should work as if GWW_VDB is undefined. */
return;
}
# else
if (str != NULL && *str == '0' && *(str + 1) == '\0') {
/* GC_USE_GETWRITEWATCH is set "0". */
done = TRUE; /* falling back to MPROTECT_VDB strategy. */
return;
}
# endif
}
# endif
# ifdef MSWINRT_FLAVOR
{
MEMORY_BASIC_INFORMATION memInfo;
SIZE_T result = VirtualQuery((void*)(word)GetProcAddress,
&memInfo, sizeof(memInfo));
if (result != sizeof(memInfo))
ABORT("Weird VirtualQuery result");
hK32 = (HMODULE)memInfo.AllocationBase;
}
# else
hK32 = GetModuleHandle(TEXT("kernel32.dll"));
# endif
if (hK32 != (HMODULE)0 &&
(GetWriteWatch_func = GetProcAddress(hK32, "GetWriteWatch")) != 0) {
/* Also check whether VirtualAlloc accepts MEM_WRITE_WATCH, */
/* as some versions of kernel32.dll have one but not the */
/* other, making the feature completely broken. */
void * page;
GC_ASSERT(GC_page_size != 0);
page = VirtualAlloc(NULL, GC_page_size, MEM_WRITE_WATCH | MEM_RESERVE,
PAGE_READWRITE);
if (page != NULL) {
PVOID pages[16];
GC_ULONG_PTR count = 16;
DWORD page_size;
/* Check that it actually works. In spite of some */
/* documentation it actually seems to exist on Win2K. */
/* This test may be unnecessary, but ... */
if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)(
WRITE_WATCH_FLAG_RESET, page,
GC_page_size, pages, &count,
&page_size) != 0) {
/* GetWriteWatch always fails. */
GetWriteWatch_func = 0;
} else {
GetWriteWatch_alloc_flag = MEM_WRITE_WATCH;
}
VirtualFree(page, 0 /* dwSize */, MEM_RELEASE);
} else {
/* GetWriteWatch will be useless. */
GetWriteWatch_func = 0;
}
}
done = TRUE;
}
# else
# define GetWriteWatch_alloc_flag 0
# endif /* !GWW_VDB */
# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
# ifdef MSWIN32
/* Unfortunately, we have to handle win32s very differently from NT, */
/* Since VirtualQuery has very different semantics. In particular, */
/* under win32s a VirtualQuery call on an unmapped page returns an */
/* invalid result. Under NT, GC_register_data_segments is a no-op */
/* and all real work is done by GC_register_dynamic_libraries. Under */
/* win32s, we cannot find the data segments associated with dll's. */
/* We register the main data segment here. */
GC_INNER GC_bool GC_no_win32_dlls = FALSE;
/* This used to be set for gcc, to avoid dealing with */
/* the structured exception handling issues. But we now have */
/* assembly code to do that right. */
GC_INNER GC_bool GC_wnt = FALSE;
/* This is a Windows NT derivative, i.e. NT, Win2K, XP or later. */
GC_INNER void GC_init_win32(void)
{
# if defined(_WIN64) || (defined(_MSC_VER) && _MSC_VER >= 1800)
/* MS Visual Studio 2013 deprecates GetVersion, but on the other */
/* hand it cannot be used to target pre-Win2K. */
GC_wnt = TRUE;
# else
/* Set GC_wnt. If we're running under win32s, assume that no */
/* DLLs will be loaded. I doubt anyone still runs win32s, but... */
DWORD v = GetVersion();
GC_wnt = !(v & 0x80000000);
GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3);
# endif
# ifdef USE_MUNMAP
if (GC_no_win32_dlls) {
/* Turn off unmapping for safety (since may not work well with */
/* GlobalAlloc). */
GC_unmap_threshold = 0;
}
# endif
}
/* Return the smallest address a such that VirtualQuery */
/* returns correct results for all addresses between a and start. */
/* Assumes VirtualQuery returns correct information for start. */
STATIC ptr_t GC_least_described_address(ptr_t start)
{
MEMORY_BASIC_INFORMATION buf;
LPVOID limit = GC_sysinfo.lpMinimumApplicationAddress;
ptr_t p = (ptr_t)((word)start & ~(word)(GC_page_size-1));
GC_ASSERT(GC_page_size != 0);
for (;;) {
size_t result;
LPVOID q = (LPVOID)(p - GC_page_size);
if ((word)q > (word)p /* underflow */ || (word)q < (word)limit) break;
result = VirtualQuery(q, &buf, sizeof(buf));
if (result != sizeof(buf) || buf.AllocationBase == 0) break;
p = (ptr_t)(buf.AllocationBase);
}
return p;
}
# endif /* MSWIN32 */
# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC)
/* We maintain a linked list of AllocationBase values that we know */
/* correspond to malloc heap sections. Currently this is only called */
/* during a GC. But there is some hope that for long running */
/* programs we will eventually see most heap sections. */
/* In the long run, it would be more reliable to occasionally walk */
/* the malloc heap with HeapWalk on the default heap. But that */
/* apparently works only for NT-based Windows. */
STATIC size_t GC_max_root_size = 100000; /* Appr. largest root size. */
/* In the long run, a better data structure would also be nice ... */
STATIC struct GC_malloc_heap_list {
void * allocation_base;
struct GC_malloc_heap_list *next;
} *GC_malloc_heap_l = 0;
/* Is p the base of one of the malloc heap sections we already know */
/* about? */
STATIC GC_bool GC_is_malloc_heap_base(void *p)
{
struct GC_malloc_heap_list *q = GC_malloc_heap_l;
while (0 != q) {
if (q -> allocation_base == p) return TRUE;
q = q -> next;
}
return FALSE;
}
STATIC void *GC_get_allocation_base(void *p)
{
MEMORY_BASIC_INFORMATION buf;
size_t result = VirtualQuery(p, &buf, sizeof(buf));
if (result != sizeof(buf)) {
ABORT("Weird VirtualQuery result");
}
return buf.AllocationBase;
}
GC_INNER void GC_add_current_malloc_heap(void)
{
struct GC_malloc_heap_list *new_l = (struct GC_malloc_heap_list *)
malloc(sizeof(struct GC_malloc_heap_list));
void *candidate;
if (NULL == new_l) return;
new_l -> allocation_base = NULL;
/* to suppress maybe-uninitialized gcc warning */
candidate = GC_get_allocation_base(new_l);
if (GC_is_malloc_heap_base(candidate)) {
/* Try a little harder to find malloc heap. */
size_t req_size = 10000;
do {
void *p = malloc(req_size);
if (0 == p) {
free(new_l);
return;
}
candidate = GC_get_allocation_base(p);
free(p);
req_size *= 2;
} while (GC_is_malloc_heap_base(candidate)
&& req_size < GC_max_root_size/10 && req_size < 500000);
if (GC_is_malloc_heap_base(candidate)) {
free(new_l);
return;
}
}
GC_COND_LOG_PRINTF("Found new system malloc AllocationBase at %p\n",
candidate);
new_l -> allocation_base = candidate;
new_l -> next = GC_malloc_heap_l;
GC_malloc_heap_l = new_l;
}
/* Free all the linked list nodes. Could be invoked at process exit */
/* to avoid memory leak complains of a dynamic code analysis tool. */
STATIC void GC_free_malloc_heap_list(void)
{
struct GC_malloc_heap_list *q = GC_malloc_heap_l;
GC_malloc_heap_l = NULL;
while (q != NULL) {
struct GC_malloc_heap_list *next = q -> next;
free(q);
q = next;
}
}
# endif /* USE_WINALLOC && !REDIRECT_MALLOC */
/* Is p the start of either the malloc heap, or of one of our */
/* heap sections? */
GC_INNER GC_bool GC_is_heap_base(void *p)
{
int i;
# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC)
if (GC_root_size > GC_max_root_size)
GC_max_root_size = GC_root_size;
if (GC_is_malloc_heap_base(p))
return TRUE;
# endif
for (i = 0; i < (int)GC_n_heap_bases; i++) {
if (GC_heap_bases[i] == p) return TRUE;
}
return FALSE;
}
#ifdef MSWIN32
STATIC void GC_register_root_section(ptr_t static_root)
{
MEMORY_BASIC_INFORMATION buf;
LPVOID p;
char * base;
char * limit;
if (!GC_no_win32_dlls) return;
p = base = limit = GC_least_described_address(static_root);
while ((word)p < (word)GC_sysinfo.lpMaximumApplicationAddress) {
size_t result = VirtualQuery(p, &buf, sizeof(buf));
DWORD protect;
if (result != sizeof(buf) || buf.AllocationBase == 0
|| GC_is_heap_base(buf.AllocationBase)) break;
if ((word)p > GC_WORD_MAX - buf.RegionSize) break; /* overflow */
protect = buf.Protect;
if (buf.State == MEM_COMMIT
&& is_writable(protect)) {
if ((char *)p != limit) {
if (base != limit) GC_add_roots_inner(base, limit, FALSE);
base = (char *)p;
}
limit = (char *)p + buf.RegionSize;
}
p = (char *)p + buf.RegionSize;
}
if (base != limit) GC_add_roots_inner(base, limit, FALSE);
}
#endif /* MSWIN32 */
void GC_register_data_segments(void)
{
# ifdef MSWIN32
GC_register_root_section((ptr_t)&GC_pages_executable);
/* any other GC global variable would fit too. */
# endif
}
# else /* !OS2 && !Windows */
# if (defined(SVR4) || defined(AIX) || defined(DGUX) \
|| (defined(LINUX) && defined(SPARC))) && !defined(PCR)
ptr_t GC_SysVGetDataStart(size_t max_page_size, ptr_t etext_addr)
{
word text_end = ((word)(etext_addr) + sizeof(word) - 1)
& ~(word)(sizeof(word) - 1);
/* etext rounded to word boundary */
word next_page = ((text_end + (word)max_page_size - 1)
& ~((word)max_page_size - 1));
word page_offset = (text_end & ((word)max_page_size - 1));
volatile ptr_t result = (char *)(next_page + page_offset);
/* Note that this isn't equivalent to just adding */
/* max_page_size to &etext if &etext is at a page boundary */
GC_setup_temporary_fault_handler();
if (SETJMP(GC_jmp_buf) == 0) {
/* Try writing to the address. */
# ifdef AO_HAVE_fetch_and_add
volatile AO_t zero = 0;
(void)AO_fetch_and_add((volatile AO_t *)result, zero);
# else
/* Fallback to non-atomic fetch-and-store. */
char v = *result;
# if defined(CPPCHECK)
GC_noop1((word)&v);
# endif
*result = v;
# endif
GC_reset_fault_handler();
} else {
GC_reset_fault_handler();
/* We got here via a longjmp. The address is not readable. */
/* This is known to happen under Solaris 2.4 + gcc, which */
/* places string constants in the text segment, but after */
/* etext. Use plan B. Note that we now know there is a gap */
/* between text and data segments, so plan A brought us */
/* something. */
result = (char *)GC_find_limit(DATAEND, FALSE);
}
return (/* no volatile */ ptr_t)result;
}
# endif
#ifdef DATASTART_USES_BSDGETDATASTART
/* It's unclear whether this should be identical to the above, or */
/* whether it should apply to non-x86 architectures. */
/* For now we don't assume that there is always an empty page after */
/* etext. But in some cases there actually seems to be slightly more. */
/* This also deals with holes between read-only data and writable data. */
GC_INNER ptr_t GC_FreeBSDGetDataStart(size_t max_page_size,
ptr_t etext_addr)
{
word text_end = ((word)(etext_addr) + sizeof(word) - 1)
& ~(word)(sizeof(word) - 1);
/* etext rounded to word boundary */
volatile word next_page = (text_end + (word)max_page_size - 1)
& ~((word)max_page_size - 1);
volatile ptr_t result = (ptr_t)text_end;
GC_setup_temporary_fault_handler();
if (SETJMP(GC_jmp_buf) == 0) {
/* Try reading at the address. */
/* This should happen before there is another thread. */
for (; next_page < (word)DATAEND; next_page += (word)max_page_size)
GC_noop1((word)(*(volatile unsigned char *)next_page));
GC_reset_fault_handler();
} else {
GC_reset_fault_handler();
/* As above, we go to plan B */
result = (ptr_t)GC_find_limit(DATAEND, FALSE);
}
return(result);
}
#endif /* DATASTART_USES_BSDGETDATASTART */
#ifdef AMIGA
# define GC_AMIGA_DS
# include "extra/AmigaOS.c"
# undef GC_AMIGA_DS
#elif defined(OPENBSD)
/* Depending on arch alignment, there can be multiple holes */
/* between DATASTART and DATAEND. Scan in DATASTART .. DATAEND */
/* and register each region. */
void GC_register_data_segments(void)
{
ptr_t region_start = DATASTART;
if ((word)region_start - 1U >= (word)DATAEND)
ABORT_ARG2("Wrong DATASTART/END pair",
": %p .. %p", (void *)region_start, (void *)DATAEND);
for (;;) {
# ifdef GC_OPENBSD_UTHREADS
ptr_t region_end = GC_find_limit_openbsd(region_start, DATAEND);
# else
ptr_t region_end = GC_find_limit_with_bound(region_start, TRUE, DATAEND);
# endif
GC_add_roots_inner(region_start, region_end, FALSE);
if ((word)region_end >= (word)DATAEND)
break;
region_start = GC_skip_hole_openbsd(region_end, DATAEND);
}
}
# else /* !OS2 && !Windows && !AMIGA && !OPENBSD */
# if !defined(PCR) && !defined(MACOS) && defined(REDIRECT_MALLOC) \
&& defined(GC_SOLARIS_THREADS)
EXTERN_C_BEGIN
extern caddr_t sbrk(int);
EXTERN_C_END
# endif
void GC_register_data_segments(void)
{
# if !defined(DYNAMIC_LOADING) && defined(GC_DONT_REGISTER_MAIN_STATIC_DATA)
/* Avoid even referencing DATASTART and DATAEND as they are */
/* unnecessary and cause linker errors when bitcode is enabled. */
/* GC_register_data_segments() is not called anyway. */
# elif !defined(PCR) && !defined(MACOS)
# if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
/* As of Solaris 2.3, the Solaris threads implementation */
/* allocates the data structure for the initial thread with */
/* sbrk at process startup. It needs to be scanned, so that */
/* we don't lose some malloc allocated data structures */
/* hanging from it. We're on thin ice here ... */
GC_ASSERT(DATASTART);
{
ptr_t p = (ptr_t)sbrk(0);
if ((word)DATASTART < (word)p)
GC_add_roots_inner(DATASTART, p, FALSE);
}
# else
if ((word)DATASTART - 1U >= (word)DATAEND) {
/* Subtract one to check also for NULL */
/* without a compiler warning. */
ABORT_ARG2("Wrong DATASTART/END pair",
": %p .. %p", (void *)DATASTART, (void *)DATAEND);
}
GC_add_roots_inner(DATASTART, DATAEND, FALSE);
# ifdef GC_HAVE_DATAREGION2
if ((word)DATASTART2 - 1U >= (word)DATAEND2)
ABORT_ARG2("Wrong DATASTART/END2 pair",
": %p .. %p", (void *)DATASTART2, (void *)DATAEND2);
GC_add_roots_inner(DATASTART2, DATAEND2, FALSE);
# endif
# endif
# endif
# if defined(MACOS)
{
# if defined(THINK_C)
extern void* GC_MacGetDataStart(void);
/* globals begin above stack and end at a5. */
GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
(ptr_t)LMGetCurrentA5(), FALSE);
# else
# if defined(__MWERKS__)
# if !__POWERPC__
extern void* GC_MacGetDataStart(void);
/* MATTHEW: Function to handle Far Globals (CW Pro 3) */
# if __option(far_data)
extern void* GC_MacGetDataEnd(void);
# endif
/* globals begin above stack and end at a5. */
GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
(ptr_t)LMGetCurrentA5(), FALSE);
/* MATTHEW: Handle Far Globals */
# if __option(far_data)
/* Far globals follow the QD globals: */
GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
(ptr_t)GC_MacGetDataEnd(), FALSE);
# endif
# else
extern char __data_start__[], __data_end__[];
GC_add_roots_inner((ptr_t)&__data_start__,
(ptr_t)&__data_end__, FALSE);
# endif /* __POWERPC__ */
# endif /* __MWERKS__ */
# endif /* !THINK_C */
}
# endif /* MACOS */
/* Dynamic libraries are added at every collection, since they may */
/* change. */
}
# endif /* !AMIGA */
# endif /* !MSWIN32 && !MSWINCE */
# endif /* !OS2 */
/*
* Auxiliary routines for obtaining memory from OS.
*/
# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
&& !defined(USE_WINALLOC) && !defined(MACOS) && !defined(DOS4GW) \
&& !defined(NINTENDO_SWITCH) && !defined(NONSTOP) \
&& !defined(SN_TARGET_ORBIS) && !defined(SN_TARGET_PS3) \
&& !defined(SN_TARGET_PSP2) && !defined(RTEMS) && !defined(__CC_ARM)
# define SBRK_ARG_T ptrdiff_t
#if defined(MMAP_SUPPORTED)
#ifdef USE_MMAP_FIXED
# define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
/* Seems to yield better performance on Solaris 2, but can */
/* be unreliable if something is already mapped at the address. */
#else
# define GC_MMAP_FLAGS MAP_PRIVATE
#endif
#ifdef USE_MMAP_ANON
# define zero_fd -1
# if defined(MAP_ANONYMOUS) && !defined(CPPCHECK)
# define OPT_MAP_ANON MAP_ANONYMOUS
# else
# define OPT_MAP_ANON MAP_ANON
# endif
#else
static int zero_fd = -1;
# define OPT_MAP_ANON 0
#endif
# ifndef MSWIN_XBOX1
# if defined(SYMBIAN) && !defined(USE_MMAP_ANON)
EXTERN_C_BEGIN
extern char *GC_get_private_path_and_zero_file(void);
EXTERN_C_END
# endif
STATIC ptr_t GC_unix_mmap_get_mem(size_t bytes)
{
void *result;
static ptr_t last_addr = HEAP_START;
# ifndef USE_MMAP_ANON
static GC_bool initialized = FALSE;
if (!EXPECT(initialized, TRUE)) {
# ifdef SYMBIAN
char *path = GC_get_private_path_and_zero_file();
if (path != NULL) {
zero_fd = open(path, O_RDWR | O_CREAT, 0644);
free(path);
}
# else
zero_fd = open("/dev/zero", O_RDONLY);
# endif
if (zero_fd == -1)
ABORT("Could not open /dev/zero");
if (fcntl(zero_fd, F_SETFD, FD_CLOEXEC) == -1)
WARN("Could not set FD_CLOEXEC for /dev/zero\n", 0);
initialized = TRUE;
}
# endif
GC_ASSERT(GC_page_size != 0);
if (bytes & (GC_page_size - 1)) ABORT("Bad GET_MEM arg");
result = mmap(last_addr, bytes, (PROT_READ | PROT_WRITE)
| (GC_pages_executable ? PROT_EXEC : 0),
GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
# undef IGNORE_PAGES_EXECUTABLE
if (EXPECT(MAP_FAILED == result, FALSE)) {
if (HEAP_START == last_addr && GC_pages_executable
&& (EACCES == errno || EPERM == errno))
ABORT("Cannot allocate executable pages");
return NULL;
}
last_addr = (ptr_t)(((word)result + bytes + GC_page_size - 1)
& ~(word)(GC_page_size - 1));
# if !defined(LINUX)
if (last_addr == 0) {
/* Oops. We got the end of the address space. This isn't */
/* usable by arbitrary C code, since one-past-end pointers */
/* don't work, so we discard it and try again. */
munmap(result, ~GC_page_size - (size_t)result + 1);
/* Leave last page mapped, so we can't repeat. */
return GC_unix_mmap_get_mem(bytes);
}
# else
GC_ASSERT(last_addr != 0);
# endif
if (((word)result % HBLKSIZE) != 0)
ABORT(
"GC_unix_get_mem: Memory returned by mmap is not aligned to HBLKSIZE.");
return((ptr_t)result);
}
# endif /* !MSWIN_XBOX1 */
#endif /* MMAP_SUPPORTED */
#if defined(USE_MMAP)
ptr_t GC_unix_get_mem(size_t bytes)
{
return GC_unix_mmap_get_mem(bytes);
}
#else /* !USE_MMAP */
STATIC ptr_t GC_unix_sbrk_get_mem(size_t bytes)
{
ptr_t result;
# ifdef IRIX5
/* Bare sbrk isn't thread safe. Play by malloc rules. */
/* The equivalent may be needed on other systems as well. */
__LOCK_MALLOC();
# endif
{
ptr_t cur_brk = (ptr_t)sbrk(0);
SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
GC_ASSERT(GC_page_size != 0);
if ((SBRK_ARG_T)bytes < 0) {
result = 0; /* too big */
goto out;
}
if (lsbs != 0) {
if ((ptr_t)sbrk((SBRK_ARG_T)GC_page_size - lsbs) == (ptr_t)(-1)) {
result = 0;
goto out;
}
}
# ifdef ADD_HEAP_GUARD_PAGES
/* This is useful for catching severe memory overwrite problems that */
/* span heap sections. It shouldn't otherwise be turned on. */
{
ptr_t guard = (ptr_t)sbrk((SBRK_ARG_T)GC_page_size);
if (mprotect(guard, GC_page_size, PROT_NONE) != 0)
ABORT("ADD_HEAP_GUARD_PAGES: mprotect failed");
}
# endif /* ADD_HEAP_GUARD_PAGES */
result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
if (result == (ptr_t)(-1)) result = 0;
}
out:
# ifdef IRIX5
__UNLOCK_MALLOC();
# endif
return(result);
}
ptr_t GC_unix_get_mem(size_t bytes)
{
# if defined(MMAP_SUPPORTED)
/* By default, we try both sbrk and mmap, in that order. */
static GC_bool sbrk_failed = FALSE;
ptr_t result = 0;
if (GC_pages_executable) {
/* If the allocated memory should have the execute permission */
/* then sbrk() cannot be used. */
return GC_unix_mmap_get_mem(bytes);
}
if (!sbrk_failed) result = GC_unix_sbrk_get_mem(bytes);
if (0 == result) {
sbrk_failed = TRUE;
result = GC_unix_mmap_get_mem(bytes);
}
if (0 == result) {
/* Try sbrk again, in case sbrk memory became available. */
result = GC_unix_sbrk_get_mem(bytes);
}
return result;
# else /* !MMAP_SUPPORTED */
return GC_unix_sbrk_get_mem(bytes);
# endif
}
#endif /* !USE_MMAP */
# endif /* UN*X */
# ifdef OS2
void * os2_alloc(size_t bytes)
{
void * result;
if (DosAllocMem(&result, bytes, (PAG_READ | PAG_WRITE | PAG_COMMIT)
| (GC_pages_executable ? PAG_EXECUTE : 0))
!= NO_ERROR) {
return(0);
}
/* FIXME: What's the purpose of this recursion? (Probably, if */
/* DosAllocMem returns memory at 0 address then just retry once.) */
if (result == 0) return(os2_alloc(bytes));
return(result);
}
# endif /* OS2 */
#ifdef MSWIN_XBOX1
ptr_t GC_durango_get_mem(size_t bytes)
{
if (0 == bytes) return NULL;
return (ptr_t)VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_TOP_DOWN,
PAGE_READWRITE);
}
#elif defined(MSWINCE)
ptr_t GC_wince_get_mem(size_t bytes)
{
ptr_t result = 0; /* initialized to prevent warning. */
word i;
GC_ASSERT(GC_page_size != 0);
bytes = ROUNDUP_PAGESIZE(bytes);
/* Try to find reserved, uncommitted pages */
for (i = 0; i < GC_n_heap_bases; i++) {
if (((word)(-(signed_word)GC_heap_lengths[i])
& (GC_sysinfo.dwAllocationGranularity-1))
>= bytes) {
result = GC_heap_bases[i] + GC_heap_lengths[i];
break;
}
}
if (i == GC_n_heap_bases) {
/* Reserve more pages */
size_t res_bytes =
SIZET_SAT_ADD(bytes, (size_t)GC_sysinfo.dwAllocationGranularity-1)
& ~((size_t)GC_sysinfo.dwAllocationGranularity-1);
/* If we ever support MPROTECT_VDB here, we will probably need to */
/* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
/* never spans regions. It seems to be OK for a VirtualFree */
/* argument to span regions, so we should be OK for now. */
result = (ptr_t) VirtualAlloc(NULL, res_bytes,
MEM_RESERVE | MEM_TOP_DOWN,
GC_pages_executable ? PAGE_EXECUTE_READWRITE :
PAGE_READWRITE);
if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
/* If I read the documentation correctly, this can */
/* only happen if HBLKSIZE > 64 KB or not a power of 2. */
if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
if (result == NULL) return NULL;
GC_heap_bases[GC_n_heap_bases] = result;
GC_heap_lengths[GC_n_heap_bases] = 0;
GC_n_heap_bases++;
}
/* Commit pages */
result = (ptr_t) VirtualAlloc(result, bytes, MEM_COMMIT,
GC_pages_executable ? PAGE_EXECUTE_READWRITE :
PAGE_READWRITE);
# undef IGNORE_PAGES_EXECUTABLE
if (result != NULL) {
if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
GC_heap_lengths[i] += bytes;
}
return(result);
}
#elif defined(USE_WINALLOC) /* && !MSWIN_XBOX1 */ || defined(CYGWIN32)
# ifdef USE_GLOBAL_ALLOC
# define GLOBAL_ALLOC_TEST 1
# else
# define GLOBAL_ALLOC_TEST GC_no_win32_dlls
# endif
# if (defined(GC_USE_MEM_TOP_DOWN) && defined(USE_WINALLOC)) \
|| defined(CPPCHECK)
DWORD GC_mem_top_down = MEM_TOP_DOWN;
/* Use GC_USE_MEM_TOP_DOWN for better 64-bit */
/* testing. Otherwise all addresses tend to */
/* end up in first 4 GB, hiding bugs. */
# else
# define GC_mem_top_down 0
# endif /* !GC_USE_MEM_TOP_DOWN */
ptr_t GC_win32_get_mem(size_t bytes)
{
ptr_t result;
# ifndef USE_WINALLOC
result = GC_unix_get_mem(bytes);
# else
# if defined(MSWIN32) && !defined(MSWINRT_FLAVOR)
if (GLOBAL_ALLOC_TEST) {
/* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
/* There are also unconfirmed rumors of other */
/* problems, so we dodge the issue. */
result = (ptr_t)GlobalAlloc(0, SIZET_SAT_ADD(bytes, HBLKSIZE));
/* Align it at HBLKSIZE boundary. */
result = (ptr_t)(((word)result + HBLKSIZE - 1)
& ~(word)(HBLKSIZE - 1));
} else
# endif
/* else */ {
/* VirtualProtect only works on regions returned by a */
/* single VirtualAlloc call. Thus we allocate one */
/* extra page, which will prevent merging of blocks */
/* in separate regions, and eliminate any temptation */
/* to call VirtualProtect on a range spanning regions. */
/* This wastes a small amount of memory, and risks */
/* increased fragmentation. But better alternatives */
/* would require effort. */
# ifdef MPROTECT_VDB
/* We can't check for GC_incremental here (because */
/* GC_enable_incremental() might be called some time */
/* later after the GC initialization). */
# ifdef GWW_VDB
# define VIRTUAL_ALLOC_PAD (GC_GWW_AVAILABLE() ? 0 : 1)
# else
# define VIRTUAL_ALLOC_PAD 1
# endif
# else
# define VIRTUAL_ALLOC_PAD 0
# endif
/* Pass the MEM_WRITE_WATCH only if GetWriteWatch-based */
/* VDBs are enabled and the GetWriteWatch function is */
/* available. Otherwise we waste resources or possibly */
/* cause VirtualAlloc to fail (observed in Windows 2000 */
/* SP2). */
result = (ptr_t) VirtualAlloc(NULL,
SIZET_SAT_ADD(bytes, VIRTUAL_ALLOC_PAD),
GetWriteWatch_alloc_flag
| (MEM_COMMIT | MEM_RESERVE)
| GC_mem_top_down,
GC_pages_executable ? PAGE_EXECUTE_READWRITE :
PAGE_READWRITE);
# undef IGNORE_PAGES_EXECUTABLE
}
# endif /* USE_WINALLOC */
if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
/* If I read the documentation correctly, this can */
/* only happen if HBLKSIZE > 64 KB or not a power of 2. */
if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
if (0 != result) GC_heap_bases[GC_n_heap_bases++] = result;
return(result);
}
#endif /* USE_WINALLOC || CYGWIN32 */
#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) \
|| defined(MSWIN_XBOX1)
GC_API void GC_CALL GC_win32_free_heap(void)
{
# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC) \
&& !defined(MSWIN_XBOX1)
GC_free_malloc_heap_list();
# endif
# if (defined(USE_WINALLOC) && !defined(MSWIN_XBOX1) \
&& !defined(MSWINCE)) || defined(CYGWIN32)
# ifndef MSWINRT_FLAVOR
# ifndef CYGWIN32
if (GLOBAL_ALLOC_TEST)
# endif
{
while (GC_n_heap_bases-- > 0) {
# ifdef CYGWIN32
/* FIXME: Is it OK to use non-GC free() here? */
# else
GlobalFree(GC_heap_bases[GC_n_heap_bases]);
# endif
GC_heap_bases[GC_n_heap_bases] = 0;
}
return;
}
# endif /* !MSWINRT_FLAVOR */
# ifndef CYGWIN32
/* Avoiding VirtualAlloc leak. */
while (GC_n_heap_bases > 0) {
VirtualFree(GC_heap_bases[--GC_n_heap_bases], 0, MEM_RELEASE);
GC_heap_bases[GC_n_heap_bases] = 0;
}
# endif
# endif /* USE_WINALLOC || CYGWIN32 */
}
#endif /* Windows */
#ifdef AMIGA
# define GC_AMIGA_AM
# include "extra/AmigaOS.c"
# undef GC_AMIGA_AM
#endif
#if defined(HAIKU)
# include <stdlib.h>
ptr_t GC_haiku_get_mem(size_t bytes)
{
void* mem;
GC_ASSERT(GC_page_size != 0);
if (posix_memalign(&mem, GC_page_size, bytes) == 0)
return mem;
return NULL;
}
#endif /* HAIKU */
#if (defined(USE_MUNMAP) || defined(MPROTECT_VDB)) && !defined(USE_WINALLOC)
# define ABORT_ON_REMAP_FAIL(C_msg_prefix, start_addr, len) \
ABORT_ARG3(C_msg_prefix " failed", \
" at %p (length %lu), errno= %d", \
(void *)(start_addr), (unsigned long)(len), errno)
#endif
#ifdef USE_MUNMAP
/* For now, this only works on Win32/WinCE and some Unix-like */
/* systems. If you have something else, don't define */
/* USE_MUNMAP. */
#if !defined(NN_PLATFORM_CTR) && !defined(MSWIN32) && !defined(MSWINCE) \
&& !defined(MSWIN_XBOX1)
# include <unistd.h>
# ifdef SN_TARGET_PS3
# include <sys/memory.h>
# else
# include <sys/mman.h>
# endif
# include <sys/stat.h>
# include <sys/types.h>
#endif
/* Compute a page aligned starting address for the unmap */
/* operation on a block of size bytes starting at start. */
/* Return 0 if the block is too small to make this feasible. */
STATIC ptr_t GC_unmap_start(ptr_t start, size_t bytes)
{
ptr_t result = (ptr_t)(((word)start + GC_page_size - 1)
& ~(word)(GC_page_size - 1));
GC_ASSERT(GC_page_size != 0);
if ((word)(result + GC_page_size) > (word)(start + bytes)) return 0;
return result;
}
/* Under Win32/WinCE we commit (map) and decommit (unmap) */
/* memory using VirtualAlloc and VirtualFree. These functions */
/* work on individual allocations of virtual memory, made */
/* previously using VirtualAlloc with the MEM_RESERVE flag. */
/* The ranges we need to (de)commit may span several of these */
/* allocations; therefore we use VirtualQuery to check */
/* allocation lengths, and split up the range as necessary. */
/* We assume that GC_remap is called on exactly the same range */
/* as a previous call to GC_unmap. It is safe to consistently */
/* round the endpoints in both places. */
static void block_unmap_inner(ptr_t start_addr, size_t len)
{
if (0 == start_addr) return;
# ifdef USE_WINALLOC
while (len != 0) {
MEMORY_BASIC_INFORMATION mem_info;
word free_len;
if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
!= sizeof(mem_info))
ABORT("Weird VirtualQuery result");
free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
ABORT("VirtualFree failed");
GC_unmapped_bytes += free_len;
start_addr += free_len;
len -= free_len;
}
# else
/* We immediately remap it to prevent an intervening mmap from */
/* accidentally grabbing the same address space. */
if (len != 0) {
# ifdef SN_TARGET_PS3
ps3_free_mem(start_addr, len);
# elif defined(AIX) || defined(CYGWIN32) || defined(HAIKU) \
|| (defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE)) \
|| defined(HPUX)
/* On AIX, mmap(PROT_NONE) fails with ENOMEM unless the */
/* environment variable XPG_SUS_ENV is set to ON. */
/* On Cygwin, calling mmap() with the new protection flags on */
/* an existing memory map with MAP_FIXED is broken. */
/* However, calling mprotect() on the given address range */
/* with PROT_NONE seems to work fine. */
/* On Linux, low RLIMIT_AS value may lead to mmap failure. */
# if defined(LINUX) && !defined(FORCE_MPROTECT_BEFORE_MADVISE)
/* On Linux, at least, madvise() should be sufficient. */
# else
if (mprotect(start_addr, len, PROT_NONE))
ABORT_ON_REMAP_FAIL("unmap: mprotect", start_addr, len);
# endif
# if !defined(CYGWIN32)
/* On Linux (and some other platforms probably), */
/* mprotect(PROT_NONE) is just disabling access to */
/* the pages but not returning them to OS. */
if (madvise(start_addr, len, MADV_DONTNEED) == -1)
ABORT_ON_REMAP_FAIL("unmap: madvise", start_addr, len);
# endif
# elif defined(EMSCRIPTEN)
/* Nothing to do, mmap(PROT_NONE) is not supported and */
/* mprotect() is just a no-op. */
# else
void * result = mmap(start_addr, len, PROT_NONE,
MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
zero_fd, 0/* offset */);
if (EXPECT(MAP_FAILED == result, FALSE))
ABORT_ON_REMAP_FAIL("unmap: mmap", start_addr, len);
if (result != (void *)start_addr)
ABORT("unmap: mmap() result differs from start_addr");
# if defined(CPPCHECK) || defined(LINT2)
/* Explicitly store the resource handle to a global variable. */
GC_noop1((word)result);
# endif
# endif
GC_unmapped_bytes += len;
}
# endif
}
GC_INNER void GC_unmap(ptr_t start, size_t bytes)
{
ptr_t start_addr = GC_unmap_start(start, bytes);
ptr_t end_addr = GC_unmap_end(start, bytes);
block_unmap_inner(start_addr, (size_t)(end_addr - start_addr));
}
GC_INNER void GC_remap(ptr_t start, size_t bytes)
{
ptr_t start_addr = GC_unmap_start(start, bytes);
ptr_t end_addr = GC_unmap_end(start, bytes);
word len = end_addr - start_addr;
if (0 == start_addr) return;
/* FIXME: Handle out-of-memory correctly (at least for Win32) */
# ifdef USE_WINALLOC
while (len != 0) {
MEMORY_BASIC_INFORMATION mem_info;
word alloc_len;
ptr_t result;
if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
!= sizeof(mem_info))
ABORT("Weird VirtualQuery result");
alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
result = (ptr_t)VirtualAlloc(start_addr, alloc_len, MEM_COMMIT,
GC_pages_executable
? PAGE_EXECUTE_READWRITE
: PAGE_READWRITE);
if (result != start_addr) {
if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY ||
GetLastError() == ERROR_OUTOFMEMORY) {
ABORT("Not enough memory to process remapping");
} else {
ABORT("VirtualAlloc remapping failed");
}
}
# ifdef LINT2
GC_noop1((word)result);
# endif
GC_unmapped_bytes -= alloc_len;
start_addr += alloc_len;
len -= alloc_len;
}
# undef IGNORE_PAGES_EXECUTABLE
# else
/* It was already remapped with PROT_NONE. */
{
# if !defined(SN_TARGET_PS3) && !defined(FORCE_MPROTECT_BEFORE_MADVISE) \
&& defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE)
/* Nothing to unprotect as madvise() is just a hint. */
# elif defined(NACL) || defined(NETBSD)
/* NaCl does not expose mprotect, but mmap should work fine. */
/* In case of NetBSD, mprotect fails (unlike mmap) even */
/* without PROT_EXEC if PaX MPROTECT feature is enabled. */
void *result = mmap(start_addr, len, (PROT_READ | PROT_WRITE)
| (GC_pages_executable ? PROT_EXEC : 0),
MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
zero_fd, 0 /* offset */);
if (EXPECT(MAP_FAILED == result, FALSE))
ABORT_ON_REMAP_FAIL("remap: mmap", start_addr, len);
if (result != (void *)start_addr)
ABORT("remap: mmap() result differs from start_addr");
# if defined(CPPCHECK) || defined(LINT2)
GC_noop1((word)result);
# endif
# undef IGNORE_PAGES_EXECUTABLE
# else
if (mprotect(start_addr, len, (PROT_READ | PROT_WRITE)
| (GC_pages_executable ? PROT_EXEC : 0)))
ABORT_ON_REMAP_FAIL("remap: mprotect", start_addr, len);
# undef IGNORE_PAGES_EXECUTABLE
# endif /* !NACL */
}
GC_unmapped_bytes -= len;
# endif
}
/* Two adjacent blocks have already been unmapped and are about to */
/* be merged. Unmap the whole block. This typically requires */
/* that we unmap a small section in the middle that was not previously */
/* unmapped due to alignment constraints. */
GC_INNER void GC_unmap_gap(ptr_t start1, size_t bytes1, ptr_t start2,
size_t bytes2)
{
ptr_t start1_addr = GC_unmap_start(start1, bytes1);
ptr_t end1_addr = GC_unmap_end(start1, bytes1);
ptr_t start2_addr = GC_unmap_start(start2, bytes2);
ptr_t start_addr = end1_addr;
ptr_t end_addr = start2_addr;
GC_ASSERT(start1 + bytes1 == start2);
if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
block_unmap_inner(start_addr, (size_t)(end_addr - start_addr));
}
#endif /* USE_MUNMAP */
/* Routine for pushing any additional roots. In THREADS */
/* environment, this is also responsible for marking from */
/* thread stacks. */
#ifndef THREADS
# if defined(EMSCRIPTEN) && defined(EMSCRIPTEN_ASYNCIFY)
# include <emscripten.h>
static void scan_regs_cb(void *begin, void *end)
{
GC_push_all_stack((ptr_t)begin, (ptr_t)end);
}
STATIC void GC_CALLBACK GC_default_push_other_roots(void)
{
/* Note: this needs -sASYNCIFY linker flag. */
emscripten_scan_registers(scan_regs_cb);
}
# else
# define GC_default_push_other_roots 0
# endif
#else /* THREADS */
# ifdef PCR
PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
{
struct PCR_ThCtl_TInfoRep info;
PCR_ERes result;
info.ti_stkLow = info.ti_stkHi = 0;
result = PCR_ThCtl_GetInfo(t, &info);
GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
return(result);
}
/* Push the contents of an old object. We treat this as stack */
/* data only because that makes it robust against mark stack */
/* overflow. */
PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
{
GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
return(PCR_ERes_okay);
}
extern struct PCR_MM_ProcsRep * GC_old_allocator;
/* defined in pcr_interface.c. */
STATIC void GC_CALLBACK GC_default_push_other_roots(void)
{
/* Traverse data allocated by previous memory managers. */
if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
GC_push_old_obj, 0)
!= PCR_ERes_okay) {
ABORT("Old object enumeration failed");
}
/* Traverse all thread stacks. */
if (PCR_ERes_IsErr(
PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
|| PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
ABORT("Thread stack marking failed");
}
}
# elif defined(SN_TARGET_PS3)
STATIC void GC_CALLBACK GC_default_push_other_roots(void)
{
ABORT("GC_default_push_other_roots is not implemented");
}
void GC_push_thread_structures(void)
{
ABORT("GC_push_thread_structures is not implemented");
}
# else /* GC_PTHREADS, or GC_WIN32_THREADS, etc. */
STATIC void GC_CALLBACK GC_default_push_other_roots(void)
{
GC_push_all_stacks();
}
# endif
#endif /* THREADS */
GC_push_other_roots_proc GC_push_other_roots = GC_default_push_other_roots;
GC_API void GC_CALL GC_set_push_other_roots(GC_push_other_roots_proc fn)
{
GC_push_other_roots = fn;
}
GC_API GC_push_other_roots_proc GC_CALL GC_get_push_other_roots(void)
{
return GC_push_other_roots;
}
#if defined(SOFT_VDB) && !defined(NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK) \
|| (defined(GLIBC_2_19_TSX_BUG) && defined(PARALLEL_MARK))
GC_INNER int GC_parse_version(int *pminor, const char *pverstr) {
char *endp;
unsigned long value = strtoul(pverstr, &endp, 10);
int major = (int)value;
if (major < 0 || (char *)pverstr == endp || (unsigned)major != value) {
/* Parse error. */
return -1;
}
if (*endp != '.') {
/* No minor part. */
*pminor = -1;
} else {
value = strtoul(endp + 1, &endp, 10);
*pminor = (int)value;
if (*pminor < 0 || (unsigned)(*pminor) != value) {
return -1;
}
}
return major;
}
#endif
/*
* Routines for accessing dirty bits on virtual pages.
* There are six ways to maintain this information:
* DEFAULT_VDB: A simple dummy implementation that treats every page
* as possibly dirty. This makes incremental collection
* useless, but the implementation is still correct.
* Manual VDB: Stacks and static data are always considered dirty.
* Heap pages are considered dirty if GC_dirty(p) has been
* called on some pointer p pointing to somewhere inside
* an object on that page. A GC_dirty() call on a large
* object directly dirties only a single page, but for the
* manual VDB we are careful to treat an object with a dirty
* page as completely dirty.
* In order to avoid races, an object must be marked dirty
* after it is written, and a reference to the object
* must be kept on a stack or in a register in the interim.
* With threads enabled, an object directly reachable from the
* stack at the time of a collection is treated as dirty.
* In single-threaded mode, it suffices to ensure that no
* collection can take place between the pointer assignment
* and the GC_dirty() call.
* PCR_VDB: Use PPCRs virtual dirty bit facility.
* PROC_VDB: Use the /proc facility for reading dirty bits. Only
* works under some SVR4 variants. Even then, it may be
* too slow to be entirely satisfactory. Requires reading
* dirty bits for entire address space. Implementations tend
* to assume that the client is a (slow) debugger.
* SOFT_VDB: Use the /proc facility for reading soft-dirty PTEs.
* Works on Linux 3.18+ if the kernel is properly configured.
* The proposed implementation iterates over GC_heap_sects and
* GC_static_roots examining the soft-dirty bit of the words
* in /proc/self/pagemap corresponding to the pages of the
* sections; finally all soft-dirty bits of the process are
* cleared (by writing some special value to
* /proc/self/clear_refs file). In case the soft-dirty bit is
* not supported by the kernel, MPROTECT_VDB may be defined as
* a fallback strategy.
* MPROTECT_VDB:Protect pages and then catch the faults to keep track of
* dirtied pages. The implementation (and implementability)
* is highly system dependent. This usually fails when system
* calls write to a protected page. We prevent the read system
* call from doing so. It is the clients responsibility to
* make sure that other system calls are similarly protected
* or write only to the stack.
* GWW_VDB: Use the Win32 GetWriteWatch functions, if available, to
* read dirty bits. In case it is not available (because we
* are running on Windows 95, Windows 2000 or earlier),
* MPROTECT_VDB may be defined as a fallback strategy.
*/
#if (defined(CHECKSUMS) && (defined(GWW_VDB) || defined(SOFT_VDB))) \
|| defined(PROC_VDB)
/* Add all pages in pht2 to pht1. */
STATIC void GC_or_pages(page_hash_table pht1, page_hash_table pht2)
{
unsigned i;
for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
}
#endif /* CHECKSUMS && (GWW_VDB || SOFT_VDB) || PROC_VDB */
#ifdef GWW_VDB
# define GC_GWW_BUF_LEN (MAXHINCR * HBLKSIZE / 4096 /* x86 page size */)
/* Still susceptible to overflow, if there are very large allocations, */
/* and everything is dirty. */
static PVOID gww_buf[GC_GWW_BUF_LEN];
# ifndef MPROTECT_VDB
# define GC_gww_dirty_init GC_dirty_init
# endif
GC_INNER GC_bool GC_gww_dirty_init(void)
{
detect_GetWriteWatch();
return GC_GWW_AVAILABLE();
}
GC_INLINE void GC_gww_read_dirty(GC_bool output_unneeded)
{
word i;
if (!output_unneeded)
BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
for (i = 0; i != GC_n_heap_sects; ++i) {
GC_ULONG_PTR count;
do {
PVOID * pages = gww_buf;
DWORD page_size;
count = GC_GWW_BUF_LEN;
/* GetWriteWatch is documented as returning non-zero when it */
/* fails, but the documentation doesn't explicitly say why it */
/* would fail or what its behavior will be if it fails. It */
/* does appear to fail, at least on recent Win2K instances, if */
/* the underlying memory was not allocated with the appropriate */
/* flag. This is common if GC_enable_incremental is called */
/* shortly after GC initialization. To avoid modifying the */
/* interface, we silently work around such a failure, it only */
/* affects the initial (small) heap allocation. If there are */
/* more dirty pages than will fit in the buffer, this is not */
/* treated as a failure; we must check the page count in the */
/* loop condition. Since each partial call will reset the */
/* status of some pages, this should eventually terminate even */
/* in the overflow case. */
if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)(
WRITE_WATCH_FLAG_RESET,
GC_heap_sects[i].hs_start,
GC_heap_sects[i].hs_bytes,
pages, &count, &page_size) != 0) {
static int warn_count = 0;
struct hblk * start = (struct hblk *)GC_heap_sects[i].hs_start;
static struct hblk *last_warned = 0;
size_t nblocks = divHBLKSZ(GC_heap_sects[i].hs_bytes);
if (i != 0 && last_warned != start && warn_count++ < 5) {
last_warned = start;
WARN("GC_gww_read_dirty unexpectedly failed at %p: "
"Falling back to marking all pages dirty\n", start);
}
if (!output_unneeded) {
unsigned j;
for (j = 0; j < nblocks; ++j) {
word hash = PHT_HASH(start + j);
set_pht_entry_from_index(GC_grungy_pages, hash);
}
}
count = 1; /* Done with this section. */
} else /* succeeded */ if (!output_unneeded) {
PVOID * pages_end = pages + count;
while (pages != pages_end) {
struct hblk * h = (struct hblk *) *pages++;
struct hblk * h_end = (struct hblk *) ((char *) h + page_size);
do {
set_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h));
} while ((word)(++h) < (word)h_end);
}
}
} while (count == GC_GWW_BUF_LEN);
/* FIXME: It's unclear from Microsoft's documentation if this loop */
/* is useful. We suspect the call just fails if the buffer fills */
/* up. But that should still be handled correctly. */
}
# ifdef CHECKSUMS
GC_ASSERT(!output_unneeded);
GC_or_pages(GC_written_pages, GC_grungy_pages);
# endif
}
#elif defined(SOFT_VDB)
static int clear_refs_fd = -1;
# define GC_GWW_AVAILABLE() (clear_refs_fd != -1)
#else
# define GC_GWW_AVAILABLE() FALSE
#endif /* !GWW_VDB && !SOFT_VDB */
#ifdef DEFAULT_VDB
/* All of the following assume the allocation lock is held. */
/* The client asserts that unallocated pages in the heap are never */
/* written. */
/* Initialize virtual dirty bit implementation. */
GC_INNER GC_bool GC_dirty_init(void)
{
GC_VERBOSE_LOG_PRINTF("Initializing DEFAULT_VDB...\n");
/* GC_dirty_pages and GC_grungy_pages are already cleared. */
return TRUE;
}
#endif /* DEFAULT_VDB */
#ifndef GC_DISABLE_INCREMENTAL
# if !defined(THREADS) || defined(HAVE_LOCKFREE_AO_OR)
# define async_set_pht_entry_from_index(db, index) \
set_pht_entry_from_index_concurrent(db, index)
# elif defined(AO_HAVE_test_and_set_acquire)
/* We need to lock around the bitmap update (in the write fault */
/* handler or GC_dirty) in order to avoid the risk of losing a bit. */
/* We do this with a test-and-set spin lock if possible. */
GC_INNER volatile AO_TS_t GC_fault_handler_lock = AO_TS_INITIALIZER;
static void async_set_pht_entry_from_index(volatile page_hash_table db,
size_t index)
{
GC_acquire_dirty_lock();
set_pht_entry_from_index(db, index);
GC_release_dirty_lock();
}
# else
# error No test_and_set operation: Introduces a race.
# endif /* THREADS && !AO_HAVE_test_and_set_acquire */
#endif /* !GC_DISABLE_INCREMENTAL */
#ifdef MPROTECT_VDB
/*
* This implementation maintains dirty bits itself by catching write
* faults and keeping track of them. We assume nobody else catches
* SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
* This means that clients must ensure that system calls don't write
* to the write-protected heap. Probably the best way to do this is to
* ensure that system calls write at most to pointer-free objects in the
* heap, and do even that only if we are on a platform on which those
* are not protected.
* We assume the page size is a multiple of HBLKSIZE.
* We prefer them to be the same. We avoid protecting pointer-free
* objects only if they are the same.
*/
# ifdef DARWIN
/* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
decrease the likelihood of some of the problems described below. */
# include <mach/vm_map.h>
STATIC mach_port_t GC_task_self = 0;
# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
if (vm_protect(GC_task_self, (vm_address_t)(addr), (vm_size_t)(len), \
FALSE, VM_PROT_READ \
| ((allow_write) ? VM_PROT_WRITE : 0) \
| (GC_pages_executable ? VM_PROT_EXECUTE : 0)) \
== KERN_SUCCESS) {} else ABORT(C_msg_prefix \
"vm_protect() failed")
# elif !defined(USE_WINALLOC)
# include <sys/mman.h>
# include <signal.h>
# if !defined(CYGWIN32) && !defined(HAIKU)
# include <sys/syscall.h>
# endif
# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
if (mprotect((caddr_t)(addr), (size_t)(len), \
PROT_READ | ((allow_write) ? PROT_WRITE : 0) \
| (GC_pages_executable ? PROT_EXEC : 0)) >= 0) { \
} else if (GC_pages_executable) { \
ABORT_ON_REMAP_FAIL(C_msg_prefix \
"mprotect vdb executable pages", \
addr, len); \
} else ABORT_ON_REMAP_FAIL(C_msg_prefix "mprotect vdb", addr, len)
# undef IGNORE_PAGES_EXECUTABLE
# else /* USE_WINALLOC */
# ifndef MSWINCE
# include <signal.h>
# endif
static DWORD protect_junk;
# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
if (VirtualProtect(addr, len, \
GC_pages_executable ? \
((allow_write) ? PAGE_EXECUTE_READWRITE : \
PAGE_EXECUTE_READ) : \
(allow_write) ? PAGE_READWRITE : \
PAGE_READONLY, \
&protect_junk)) { \
} else ABORT_ARG1(C_msg_prefix "VirtualProtect failed", \
": errcode= 0x%X", (unsigned)GetLastError())
# endif /* USE_WINALLOC */
# define PROTECT(addr, len) PROTECT_INNER(addr, len, FALSE, "")
# define UNPROTECT(addr, len) PROTECT_INNER(addr, len, TRUE, "un-")
# if defined(MSWIN32)
typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_HNDLR_PTR;
# undef SIG_DFL
# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER)((signed_word)-1)
# elif defined(MSWINCE)
typedef LONG (WINAPI *SIG_HNDLR_PTR)(struct _EXCEPTION_POINTERS *);
# undef SIG_DFL
# define SIG_DFL (SIG_HNDLR_PTR) (-1)
# elif defined(DARWIN)
typedef void (* SIG_HNDLR_PTR)();
# else
typedef void (* SIG_HNDLR_PTR)(int, siginfo_t *, void *);
typedef void (* PLAIN_HNDLR_PTR)(int);
# endif
#ifndef DARWIN
STATIC SIG_HNDLR_PTR GC_old_segv_handler = 0;
/* Also old MSWIN32 ACCESS_VIOLATION filter */
# if defined(FREEBSD) || defined(HPUX) || defined(HURD) || defined(LINUX)
STATIC SIG_HNDLR_PTR GC_old_bus_handler = 0;
# ifndef LINUX
STATIC GC_bool GC_old_bus_handler_used_si = FALSE;
# endif
# endif
# if !defined(MSWIN32) && !defined(MSWINCE)
STATIC GC_bool GC_old_segv_handler_used_si = FALSE;
# endif /* !MSWIN32 */
#endif /* !DARWIN */
#ifdef THREADS
/* This function is used only by the fault handler. Potential data */
/* race between this function and GC_install_header, GC_remove_header */
/* should not be harmful because the added or removed header should */
/* be already unprotected. */
GC_ATTR_NO_SANITIZE_THREAD
static GC_bool is_header_found_async(void *addr)
{
# ifdef HASH_TL
hdr *result;
GET_HDR((ptr_t)addr, result);
return result != NULL;
# else
return HDR_INNER(addr) != NULL;
# endif
}
#else
# define is_header_found_async(addr) (HDR(addr) != NULL)
#endif /* !THREADS */
#ifndef DARWIN
# if !defined(MSWIN32) && !defined(MSWINCE)
# include <errno.h>
# if defined(FREEBSD) || defined(HURD) || defined(HPUX)
# define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
# else
# define SIG_OK (sig == SIGSEGV)
/* Catch SIGSEGV but ignore SIGBUS. */
# endif
# if defined(FREEBSD)
# ifndef SEGV_ACCERR
# define SEGV_ACCERR 2
# endif
# if defined(AARCH64) || defined(ARM32) || defined(MIPS) \
|| __FreeBSD__ >= 7
# define CODE_OK (si -> si_code == SEGV_ACCERR)
# elif defined(POWERPC)
# define AIM /* Pretend that we're AIM. */
# include <machine/trap.h>
# define CODE_OK (si -> si_code == EXC_DSI \
|| si -> si_code == SEGV_ACCERR)
# else
# define CODE_OK (si -> si_code == BUS_PAGE_FAULT \
|| si -> si_code == SEGV_ACCERR)
# endif
# elif defined(OSF1)
# define CODE_OK (si -> si_code == 2 /* experimentally determined */)
# elif defined(IRIX5)
# define CODE_OK (si -> si_code == EACCES)
# elif defined(CYGWIN32) || defined(HAIKU) || defined(HURD)
# define CODE_OK TRUE
# elif defined(LINUX)
# define CODE_OK TRUE
/* Empirically c.trapno == 14, on IA32, but is that useful? */
/* Should probably consider alignment issues on other */
/* architectures. */
# elif defined(HPUX)
# define CODE_OK (si -> si_code == SEGV_ACCERR \
|| si -> si_code == BUS_ADRERR \
|| si -> si_code == BUS_UNKNOWN \
|| si -> si_code == SEGV_UNKNOWN \
|| si -> si_code == BUS_OBJERR)
# elif defined(SUNOS5SIGS)
# define CODE_OK (si -> si_code == SEGV_ACCERR)
# endif
# ifndef NO_GETCONTEXT
# include <ucontext.h>
# endif
STATIC void GC_write_fault_handler(int sig, siginfo_t *si, void *raw_sc)
# else
# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode \
== STATUS_ACCESS_VIOLATION)
# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] \
== 1) /* Write fault */
STATIC LONG WINAPI GC_write_fault_handler(
struct _EXCEPTION_POINTERS *exc_info)
# endif /* MSWIN32 || MSWINCE */
{
# if !defined(MSWIN32) && !defined(MSWINCE)
char *addr = (char *)si->si_addr;
# else
char * addr = (char *) (exc_info -> ExceptionRecord
-> ExceptionInformation[1]);
# endif
if (SIG_OK && CODE_OK) {
struct hblk * h = (struct hblk *)((word)addr
& ~(word)(GC_page_size-1));
GC_bool in_allocd_block;
size_t i;
GC_ASSERT(GC_page_size != 0);
# ifdef CHECKSUMS
GC_record_fault(h);
# endif
# ifdef SUNOS5SIGS
/* Address is only within the correct physical page. */
in_allocd_block = FALSE;
for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
if (is_header_found_async(&h[i])) {
in_allocd_block = TRUE;
break;
}
}
# else
in_allocd_block = is_header_found_async(addr);
# endif
if (!in_allocd_block) {
/* FIXME - We should make sure that we invoke the */
/* old handler with the appropriate calling */
/* sequence, which often depends on SA_SIGINFO. */
/* Heap blocks now begin and end on page boundaries */
SIG_HNDLR_PTR old_handler;
# if defined(MSWIN32) || defined(MSWINCE)
old_handler = GC_old_segv_handler;
# else
GC_bool used_si;
# if defined(FREEBSD) || defined(HURD) || defined(HPUX)
if (sig == SIGBUS) {
old_handler = GC_old_bus_handler;
used_si = GC_old_bus_handler_used_si;
} else
# endif
/* else */ {
old_handler = GC_old_segv_handler;
used_si = GC_old_segv_handler_used_si;
}
# endif
if (old_handler == (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
# if !defined(MSWIN32) && !defined(MSWINCE)
ABORT_ARG1("Unexpected bus error or segmentation fault",
" at %p", (void *)addr);
# else
return(EXCEPTION_CONTINUE_SEARCH);
# endif
} else {
/*
* FIXME: This code should probably check if the
* old signal handler used the traditional style and
* if so call it using that style.
*/
# if defined(MSWIN32) || defined(MSWINCE)
return((*old_handler)(exc_info));
# else
if (used_si)
((SIG_HNDLR_PTR)old_handler) (sig, si, raw_sc);
else
/* FIXME: should pass nonstandard args as well. */
((PLAIN_HNDLR_PTR)(signed_word)old_handler)(sig);
return;
# endif
}
}
UNPROTECT(h, GC_page_size);
/* We need to make sure that no collection occurs between */
/* the UNPROTECT and the setting of the dirty bit. Otherwise */
/* a write by a third thread might go unnoticed. Reversing */
/* the order is just as bad, since we would end up unprotecting */
/* a page in a GC cycle during which it's not marked. */
/* Currently we do this by disabling the thread stopping */
/* signals while this handler is running. An alternative might */
/* be to record the fact that we're about to unprotect, or */
/* have just unprotected a page in the GC's thread structure, */
/* and then to have the thread stopping code set the dirty */
/* flag, if necessary. */
for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
word index = PHT_HASH(h+i);
async_set_pht_entry_from_index(GC_dirty_pages, index);
}
/* The write may not take place before dirty bits are read. */
/* But then we'll fault again ... */
# if defined(MSWIN32) || defined(MSWINCE)
return(EXCEPTION_CONTINUE_EXECUTION);
# else
return;
# endif
}
# if defined(MSWIN32) || defined(MSWINCE)
return EXCEPTION_CONTINUE_SEARCH;
# else
ABORT_ARG1("Unexpected bus error or segmentation fault",
" at %p", (void *)addr);
# endif
}
# if defined(GC_WIN32_THREADS) && !defined(CYGWIN32)
GC_INNER void GC_set_write_fault_handler(void)
{
SetUnhandledExceptionFilter(GC_write_fault_handler);
}
# endif
# ifdef SOFT_VDB
static GC_bool soft_dirty_init(void);
# endif
GC_INNER GC_bool GC_dirty_init(void)
{
# if !defined(MSWIN32) && !defined(MSWINCE)
struct sigaction act, oldact;
# endif
# ifdef COUNT_PROTECTED_REGIONS
GC_ASSERT(GC_page_size != 0);
if ((signed_word)(GC_heapsize / (word)GC_page_size)
>= ((signed_word)GC_UNMAPPED_REGIONS_SOFT_LIMIT
- GC_num_unmapped_regions) * 2) {
GC_COND_LOG_PRINTF("Cannot turn on GC incremental mode"
" as heap contains too many pages\n");
return FALSE;
}
# endif
# if !defined(MSWIN32) && !defined(MSWINCE)
act.sa_flags = SA_RESTART | SA_SIGINFO;
act.sa_sigaction = GC_write_fault_handler;
(void)sigemptyset(&act.sa_mask);
# if defined(THREADS) && !defined(GC_OPENBSD_UTHREADS) \
&& !defined(GC_WIN32_THREADS) && !defined(NACL)
/* Arrange to postpone the signal while we are in a write fault */
/* handler. This effectively makes the handler atomic w.r.t. */
/* stopping the world for GC. */
(void)sigaddset(&act.sa_mask, GC_get_suspend_signal());
# endif
# endif /* !MSWIN32 */
GC_VERBOSE_LOG_PRINTF(
"Initializing mprotect virtual dirty bit implementation\n");
if (GC_page_size % HBLKSIZE != 0) {
ABORT("Page size not multiple of HBLKSIZE");
}
# ifdef GWW_VDB
if (GC_gww_dirty_init()) {
GC_COND_LOG_PRINTF("Using GetWriteWatch()\n");
return TRUE;
}
# elif defined(SOFT_VDB)
if (soft_dirty_init()) {
GC_COND_LOG_PRINTF("Using soft-dirty bit feature\n");
return TRUE;
}
# endif
# ifdef MSWIN32
GC_old_segv_handler = SetUnhandledExceptionFilter(
GC_write_fault_handler);
if (GC_old_segv_handler != NULL) {
GC_COND_LOG_PRINTF("Replaced other UnhandledExceptionFilter\n");
} else {
GC_old_segv_handler = SIG_DFL;
}
# elif defined(MSWINCE)
/* MPROTECT_VDB is unsupported for WinCE at present. */
/* FIXME: implement it (if possible). */
# else
/* act.sa_restorer is deprecated and should not be initialized. */
# if defined(GC_IRIX_THREADS)
sigaction(SIGSEGV, 0, &oldact);
sigaction(SIGSEGV, &act, 0);
# else
{
int res = sigaction(SIGSEGV, &act, &oldact);
if (res != 0) ABORT("Sigaction failed");
}
# endif
if (oldact.sa_flags & SA_SIGINFO) {
GC_old_segv_handler = oldact.sa_sigaction;
GC_old_segv_handler_used_si = TRUE;
} else {
GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler;
GC_old_segv_handler_used_si = FALSE;
}
if (GC_old_segv_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) {
WARN("Previously ignored segmentation violation!?\n", 0);
GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL;
}
if (GC_old_segv_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
GC_VERBOSE_LOG_PRINTF("Replaced other SIGSEGV handler\n");
}
# if defined(HPUX) || defined(LINUX) || defined(HURD) \
|| (defined(FREEBSD) && defined(SUNOS5SIGS))
sigaction(SIGBUS, &act, &oldact);
if ((oldact.sa_flags & SA_SIGINFO) != 0) {
GC_old_bus_handler = oldact.sa_sigaction;
# if !defined(LINUX)
GC_old_bus_handler_used_si = TRUE;
# endif
} else {
GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler;
}
if (GC_old_bus_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) {
WARN("Previously ignored bus error!?\n", 0);
# if !defined(LINUX)
GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL;
# else
/* GC_old_bus_handler is not used by GC_write_fault_handler. */
# endif
} else if (GC_old_bus_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n");
}
# endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
# endif /* !MSWIN32 && !MSWINCE */
# if defined(CPPCHECK) && defined(ADDRESS_SANITIZER)
GC_noop1((word)&__asan_default_options);
# endif
return TRUE;
}
#endif /* !DARWIN */
GC_API int GC_CALL GC_incremental_protection_needs(void)
{
GC_ASSERT(GC_is_initialized);
# if defined(GWW_VDB) || defined(SOFT_VDB)
/* Only if the incremental mode is already switched on. */
if (GC_GWW_AVAILABLE())
return GC_PROTECTS_NONE;
# endif
if (GC_page_size == HBLKSIZE) {
return GC_PROTECTS_POINTER_HEAP;
} else {
return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
}
}
#define HAVE_INCREMENTAL_PROTECTION_NEEDS
#define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
#define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
STATIC void GC_protect_heap(void)
{
unsigned i;
GC_bool protect_all =
(0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
GC_ASSERT(GC_page_size != 0);
for (i = 0; i < GC_n_heap_sects; i++) {
ptr_t start = GC_heap_sects[i].hs_start;
size_t len = GC_heap_sects[i].hs_bytes;
if (protect_all) {
PROTECT(start, len);
} else {
struct hblk * current;
struct hblk * current_start; /* Start of block to be protected. */
struct hblk * limit;
GC_ASSERT(PAGE_ALIGNED(len));
GC_ASSERT(PAGE_ALIGNED(start));
current_start = current = (struct hblk *)start;
limit = (struct hblk *)(start + len);
while ((word)current < (word)limit) {
hdr * hhdr;
word nhblks;
GC_bool is_ptrfree;
GC_ASSERT(PAGE_ALIGNED(current));
GET_HDR(current, hhdr);
if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
/* This can happen only if we're at the beginning of a */
/* heap segment, and a block spans heap segments. */
/* We will handle that block as part of the preceding */
/* segment. */
GC_ASSERT(current_start == current);
current_start = ++current;
continue;
}
if (HBLK_IS_FREE(hhdr)) {
GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
nhblks = divHBLKSZ(hhdr -> hb_sz);
is_ptrfree = TRUE; /* dirty on alloc */
} else {
nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
is_ptrfree = IS_PTRFREE(hhdr);
}
if (is_ptrfree) {
if ((word)current_start < (word)current) {
PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
}
current_start = (current += nhblks);
} else {
current += nhblks;
}
}
if ((word)current_start < (word)current) {
PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
}
}
}
}
# if defined(CAN_HANDLE_FORK) && defined(DARWIN) && defined(THREADS) \
|| defined(COUNT_PROTECTED_REGIONS)
/* Remove protection for the entire heap not updating GC_dirty_pages. */
STATIC void GC_unprotect_all_heap(void)
{
unsigned i;
GC_ASSERT(I_HOLD_LOCK());
GC_ASSERT(GC_auto_incremental);
for (i = 0; i < GC_n_heap_sects; i++) {
UNPROTECT(GC_heap_sects[i].hs_start, GC_heap_sects[i].hs_bytes);
}
}
# endif /* CAN_HANDLE_FORK && DARWIN && THREADS || COUNT_PROTECTED_REGIONS */
# ifdef COUNT_PROTECTED_REGIONS
GC_INNER void GC_handle_protected_regions_limit(void)
{
GC_ASSERT(GC_page_size != 0);
/* To prevent exceeding the limit of vm.max_map_count, the most */
/* trivial (though highly restrictive) way is to turn off the */
/* incremental collection mode (based on mprotect) once the */
/* number of pages in the heap reaches that limit. */
if (GC_auto_incremental && !GC_GWW_AVAILABLE()
&& (signed_word)(GC_heapsize / (word)GC_page_size)
>= ((signed_word)GC_UNMAPPED_REGIONS_SOFT_LIMIT
- GC_num_unmapped_regions) * 2) {
GC_unprotect_all_heap();
# ifdef DARWIN
GC_task_self = 0;
# endif
GC_incremental = FALSE;
WARN("GC incremental mode is turned off"
" to prevent hitting VM maps limit\n", 0);
}
}
# endif /* COUNT_PROTECTED_REGIONS */
#endif /* MPROTECT_VDB */
#if !defined(THREADS) && (defined(PROC_VDB) || defined(SOFT_VDB))
static pid_t saved_proc_pid; /* pid used to compose /proc file names */
#endif
#ifdef PROC_VDB
/* This implementation assumes a Solaris 2.X like /proc */
/* pseudo-file-system from which we can read page modified bits. This */
/* facility is far from optimal (e.g. we would like to get the info for */
/* only some of the address space), but it avoids intercepting system */
/* calls. */
# include <errno.h>
# include <sys/types.h>
# include <sys/signal.h>
# include <sys/syscall.h>
# include <sys/stat.h>
# ifdef GC_NO_SYS_FAULT_H
/* This exists only to check PROC_VDB code compilation (on Linux). */
# define PG_MODIFIED 1
struct prpageheader {
int dummy[2]; /* pr_tstamp */
unsigned long pr_nmap;
unsigned long pr_npage;
};
struct prasmap {
char *pr_vaddr;
size_t pr_npage;
char dummy1[64+8]; /* pr_mapname, pr_offset */
unsigned pr_mflags;
unsigned pr_pagesize;
int dummy2[2];
};
# else
# include <sys/fault.h>
# include <sys/procfs.h>
# endif
# define INITIAL_BUF_SZ 16384
STATIC size_t GC_proc_buf_size = INITIAL_BUF_SZ;
STATIC char *GC_proc_buf = NULL;
STATIC int GC_proc_fd = -1;
static GC_bool proc_dirty_open_files(void)
{
char buf[40];
pid_t pid = getpid();
(void)snprintf(buf, sizeof(buf), "/proc/%ld/pagedata", (long)pid);
buf[sizeof(buf) - 1] = '\0';
GC_proc_fd = open(buf, O_RDONLY);
if (-1 == GC_proc_fd) {
WARN("/proc open failed; cannot enable GC incremental mode\n", 0);
return FALSE;
}
if (syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC) == -1)
WARN("Could not set FD_CLOEXEC for /proc\n", 0);
# ifndef THREADS
saved_proc_pid = pid; /* updated on success only */
# endif
return TRUE;
}
# ifdef CAN_HANDLE_FORK
GC_INNER void GC_dirty_update_child(void)
{
if (-1 == GC_proc_fd)
return; /* GC incremental mode is off */
close(GC_proc_fd);
if (!proc_dirty_open_files())
GC_incremental = FALSE; /* should be safe to turn it off */
}
# endif /* CAN_HANDLE_FORK */
GC_INNER GC_bool GC_dirty_init(void)
{
if (GC_bytes_allocd != 0 || GC_bytes_allocd_before_gc != 0) {
memset(GC_written_pages, 0xff, sizeof(page_hash_table));
GC_VERBOSE_LOG_PRINTF(
"Allocated %lu bytes: all pages may have been written\n",
(unsigned long)(GC_bytes_allocd + GC_bytes_allocd_before_gc));
}
if (!proc_dirty_open_files())
return FALSE;
GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
if (GC_proc_buf == NULL)
ABORT("Insufficient space for /proc read");
return TRUE;
}
GC_INLINE void GC_proc_read_dirty(GC_bool output_unneeded)
{
int nmaps;
char * bufp = GC_proc_buf;
int i;
# ifndef THREADS
/* If the current pid differs from the saved one, then we are in */
/* the forked (child) process, the current /proc file should be */
/* closed, the new one should be opened with the updated path. */
/* Note, this is not needed for multi-threaded case because */
/* fork_child_proc() reopens the file right after fork. */
if (getpid() != saved_proc_pid
&& (-1 == GC_proc_fd /* no need to retry */
|| (close(GC_proc_fd), !proc_dirty_open_files()))) {
/* Failed to reopen the file. Punt! */
if (!output_unneeded)
memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
memset(GC_written_pages, 0xff, sizeof(page_hash_table));
return;
}
# endif
BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
/* Retry with larger buffer. */
size_t new_size = 2 * GC_proc_buf_size;
char *new_buf;
WARN("/proc read failed: GC_proc_buf_size= %" WARN_PRIuPTR "\n",
GC_proc_buf_size);
new_buf = GC_scratch_alloc(new_size);
if (new_buf != 0) {
GC_scratch_recycle_no_gww(bufp, GC_proc_buf_size);
GC_proc_buf = bufp = new_buf;
GC_proc_buf_size = new_size;
}
if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
WARN("Insufficient space for /proc read\n", 0);
/* Punt: */
if (!output_unneeded)
memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
memset(GC_written_pages, 0xff, sizeof(page_hash_table));
return;
}
}
/* Copy dirty bits into GC_grungy_pages */
nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
# ifdef DEBUG_DIRTY_BITS
GC_log_printf("Proc VDB read: pr_nmap= %u, pr_npage= %lu\n",
nmaps, ((struct prpageheader *)bufp)->pr_npage);
# endif
# if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK)
GC_noop1(((struct prpageheader *)bufp)->dummy[0]);
# endif
bufp += sizeof(struct prpageheader);
for (i = 0; i < nmaps; i++) {
struct prasmap * map = (struct prasmap *)bufp;
ptr_t vaddr = (ptr_t)(map -> pr_vaddr);
unsigned long npages = map -> pr_npage;
unsigned pagesize = map -> pr_pagesize;
ptr_t limit;
# if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK)
GC_noop1(map->dummy1[0] + map->dummy2[0]);
# endif
# ifdef DEBUG_DIRTY_BITS
GC_log_printf(
"pr_vaddr= %p, npage= %lu, mflags= 0x%x, pagesize= 0x%x\n",
(void *)vaddr, npages, map->pr_mflags, pagesize);
# endif
bufp += sizeof(struct prasmap);
limit = vaddr + pagesize * npages;
for (; (word)vaddr < (word)limit; vaddr += pagesize) {
if ((*bufp++) & PG_MODIFIED) {
struct hblk * h;
ptr_t next_vaddr = vaddr + pagesize;
# ifdef DEBUG_DIRTY_BITS
GC_log_printf("dirty page at: %p\n", (void *)vaddr);
# endif
for (h = (struct hblk *)vaddr;
(word)h < (word)next_vaddr; h++) {
word index = PHT_HASH(h);
set_pht_entry_from_index(GC_grungy_pages, index);
}
}
}
bufp = (char *)(((word)bufp + (sizeof(long)-1))
& ~(word)(sizeof(long)-1));
}
# ifdef DEBUG_DIRTY_BITS
GC_log_printf("Proc VDB read done\n");
# endif
/* Update GC_written_pages (even if output_unneeded). */
GC_or_pages(GC_written_pages, GC_grungy_pages);
}
#endif /* PROC_VDB */
#ifdef SOFT_VDB
# ifndef VDB_BUF_SZ
# define VDB_BUF_SZ 16384
# endif
static int open_proc_fd(pid_t pid, const char *proc_filename, int mode)
{
int f;
char buf[40];
(void)snprintf(buf, sizeof(buf), "/proc/%ld/%s", (long)pid,
proc_filename);
buf[sizeof(buf) - 1] = '\0';
f = open(buf, mode);
if (-1 == f) {
WARN("/proc/self/%s open failed; cannot enable GC incremental mode\n",
proc_filename);
} else if (fcntl(f, F_SETFD, FD_CLOEXEC) == -1) {
WARN("Could not set FD_CLOEXEC for /proc\n", 0);
}
return f;
}
# include <stdint.h> /* for uint64_t */
typedef uint64_t pagemap_elem_t;
static pagemap_elem_t *soft_vdb_buf;
static int pagemap_fd;
static GC_bool soft_dirty_open_files(void)
{
pid_t pid = getpid();
clear_refs_fd = open_proc_fd(pid, "clear_refs", O_WRONLY);
if (-1 == clear_refs_fd)
return FALSE;
pagemap_fd = open_proc_fd(pid, "pagemap", O_RDONLY);
if (-1 == pagemap_fd) {
close(clear_refs_fd);
clear_refs_fd = -1;
return FALSE;
}
# ifndef THREADS
saved_proc_pid = pid; /* updated on success only */
# endif
return TRUE;
}
# ifdef CAN_HANDLE_FORK
GC_INNER void GC_dirty_update_child(void)
{
if (-1 == clear_refs_fd)
return; /* GC incremental mode is off */
close(clear_refs_fd);
close(pagemap_fd);
if (!soft_dirty_open_files())
GC_incremental = FALSE;
}
# endif /* CAN_HANDLE_FORK */
/* Clear soft-dirty bits from the task's PTEs. */
static void clear_soft_dirty_bits(void)
{
ssize_t res = write(clear_refs_fd, "4\n", 2);
if (res != 2)
ABORT_ARG1("Failed to write to /proc/self/clear_refs",
": errno= %d", res < 0 ? errno : 0);
}
/* The bit 55 of the 64-bit qword of pagemap file is the soft-dirty one. */
# define PM_SOFTDIRTY_MASK ((pagemap_elem_t)1 << 55)
static GC_bool detect_soft_dirty_supported(ptr_t vaddr)
{
off_t fpos;
pagemap_elem_t buf[1];
GC_ASSERT(GC_page_size != 0);
*vaddr = 1; /* make it dirty */
fpos = (off_t)((word)vaddr / GC_page_size * sizeof(pagemap_elem_t));
for (;;) {
/* Read the relevant PTE from the pagemap file. */
if (lseek(pagemap_fd, fpos, SEEK_SET) == (off_t)(-1))
return FALSE;
if (PROC_READ(pagemap_fd, buf, sizeof(buf)) != (int)sizeof(buf))
return FALSE;
/* Is the soft-dirty bit unset? */
if ((buf[0] & PM_SOFTDIRTY_MASK) == 0) return FALSE;
if (0 == *vaddr) break;
/* Retry to check that writing to clear_refs works as expected. */
/* This malfunction of the soft-dirty bits implementation is */
/* observed on some Linux kernels on Power9 (e.g. in Fedora 36). */
clear_soft_dirty_bits();
*vaddr = 0;
}
return TRUE; /* success */
}
# ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK
# include <sys/utsname.h>
# include <string.h> /* for strcmp() */
/* Ensure the linux (kernel) major/minor version is as given or higher. */
static GC_bool ensure_min_linux_ver(int major, int minor) {
struct utsname info;
int actual_major;
int actual_minor = -1;
if (uname(&info) == -1) {
return FALSE; /* uname() failed, should not happen actually. */
}
if (strcmp(info.sysname, "Linux")) {
WARN("Cannot ensure Linux version as running on other OS: %s\n",
info.sysname);
return FALSE;
}
actual_major = GC_parse_version(&actual_minor, info.release);
return actual_major > major
|| (actual_major == major && actual_minor >= minor);
}
# endif
# ifdef MPROTECT_VDB
static GC_bool soft_dirty_init(void)
# else
GC_INNER GC_bool GC_dirty_init(void)
# endif
{
# ifdef MPROTECT_VDB
char * str = GETENV("GC_USE_GETWRITEWATCH");
# ifdef GC_PREFER_MPROTECT_VDB
if (str == NULL || (*str == '0' && *(str + 1) == '\0'))
return FALSE; /* the environment variable is unset or set to "0" */
# else
if (str != NULL && *str == '0' && *(str + 1) == '\0')
return FALSE; /* the environment variable is set "0" */
# endif
# endif
GC_ASSERT(NULL == soft_vdb_buf);
# ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK
if (!ensure_min_linux_ver(3, 18)) {
GC_COND_LOG_PRINTF(
"Running on old kernel lacking correct soft-dirty bit support\n");
return FALSE;
}
# endif
if (!soft_dirty_open_files())
return FALSE;
soft_vdb_buf = (pagemap_elem_t *)GC_scratch_alloc(VDB_BUF_SZ);
if (NULL == soft_vdb_buf)
ABORT("Insufficient space for /proc pagemap buffer");
if (!detect_soft_dirty_supported((ptr_t)soft_vdb_buf)) {
GC_COND_LOG_PRINTF("Soft-dirty bit is not supported by kernel\n");
/* Release the resources. */
GC_scratch_recycle_no_gww(soft_vdb_buf, VDB_BUF_SZ);
soft_vdb_buf = NULL;
close(clear_refs_fd);
clear_refs_fd = -1;
close(pagemap_fd);
return FALSE;
}
return TRUE;
}
static off_t pagemap_buf_fpos; /* valid only if pagemap_buf_len > 0 */
static size_t pagemap_buf_len;
/* Read bytes from /proc/self/pagemap at given file position. */
/* len - the maximum number of bytes to read; (*pres) - amount of */
/* bytes actually read, always bigger than 0 but never exceeds len; */
/* next_fpos_hint - the file position of the next bytes block to read */
/* ahead if possible (0 means no information provided). */
static const pagemap_elem_t *pagemap_buffered_read(size_t *pres,
off_t fpos, size_t len,
off_t next_fpos_hint)
{
ssize_t res;
size_t ofs;
GC_ASSERT(len > 0);
if (pagemap_buf_fpos <= fpos
&& fpos < pagemap_buf_fpos + (off_t)pagemap_buf_len) {
/* The requested data is already in the buffer. */
ofs = (size_t)(fpos - pagemap_buf_fpos);
res = (ssize_t)(pagemap_buf_fpos + pagemap_buf_len - fpos);
} else {
off_t aligned_pos = fpos & ~(off_t)(GC_page_size < VDB_BUF_SZ
? GC_page_size-1 : VDB_BUF_SZ-1);
for (;;) {
size_t count;
if ((0 == pagemap_buf_len
|| pagemap_buf_fpos + (off_t)pagemap_buf_len != aligned_pos)
&& lseek(pagemap_fd, aligned_pos, SEEK_SET) == (off_t)(-1))
ABORT_ARG2("Failed to lseek /proc/self/pagemap",
": offset= %lu, errno= %d", (unsigned long)fpos, errno);
/* How much to read at once? */
ofs = (size_t)(fpos - aligned_pos);
GC_ASSERT(ofs < VDB_BUF_SZ);
if (next_fpos_hint > aligned_pos
&& next_fpos_hint - aligned_pos < VDB_BUF_SZ) {
count = VDB_BUF_SZ;
} else {
count = len + ofs;
if (count > VDB_BUF_SZ)
count = VDB_BUF_SZ;
}
GC_ASSERT(count % sizeof(pagemap_elem_t) == 0);
res = PROC_READ(pagemap_fd, soft_vdb_buf, count);
if (res > (ssize_t)ofs)
break;
if (res <= 0)
ABORT_ARG1("Failed to read /proc/self/pagemap",
": errno= %d", res < 0 ? errno : 0);
/* Retry (once) w/o page-alignment. */
aligned_pos = fpos;
}
/* Save the buffer (file window) position and size. */
pagemap_buf_fpos = aligned_pos;
pagemap_buf_len = (size_t)res;
res -= (ssize_t)ofs;
}
GC_ASSERT(ofs % sizeof(pagemap_elem_t) == 0);
*pres = (size_t)res < len ? (size_t)res : len;
return &soft_vdb_buf[ofs / sizeof(pagemap_elem_t)];
}
static void soft_set_grungy_pages(ptr_t start, ptr_t limit,
ptr_t next_start_hint)
{
word vaddr = (word)start & ~(word)(GC_page_size-1);
off_t next_fpos_hint;
GC_ASSERT(modHBLKSZ((word)start) == 0);
GC_ASSERT(GC_page_size != 0);
next_fpos_hint = (off_t)((word)next_start_hint / GC_page_size
* sizeof(pagemap_elem_t));
while (vaddr < (word)limit) {
size_t res;
word limit_buf;
const pagemap_elem_t *bufp = pagemap_buffered_read(&res,
(off_t)(vaddr / GC_page_size * sizeof(pagemap_elem_t)),
(size_t)(((word)limit - vaddr + GC_page_size-1) / GC_page_size
* sizeof(pagemap_elem_t)),
next_fpos_hint);
if (res % sizeof(pagemap_elem_t) != 0) {
/* Punt: */
memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
WARN("Incomplete read of pagemap, not multiple of entry size\n", 0);
break;
}
limit_buf = vaddr + (res / sizeof(pagemap_elem_t)) * GC_page_size;
for (; vaddr < limit_buf; vaddr += GC_page_size, bufp++)
if ((*bufp & PM_SOFTDIRTY_MASK) != 0) {
struct hblk * h;
word next_vaddr = vaddr + GC_page_size;
if (EXPECT(next_vaddr > (word)limit, FALSE))
next_vaddr = (word)limit;
/* If the bit is set, the respective PTE was written to */
/* since clearing the soft-dirty bits. */
# ifdef DEBUG_DIRTY_BITS
GC_log_printf("dirty page at: %p\n", (void *)vaddr);
# endif
h = (struct hblk *)vaddr;
if (EXPECT(vaddr < (word)start, FALSE))
h = (struct hblk *)start;
for (; (word)h < next_vaddr; h++) {
word index = PHT_HASH(h);
set_pht_entry_from_index(GC_grungy_pages, index);
}
}
/* Read the next portion of pagemap file if incomplete. */
}
}
GC_INLINE void GC_soft_read_dirty(GC_bool output_unneeded)
{
# ifndef THREADS
/* Similar as for GC_proc_read_dirty. */
if (getpid() != saved_proc_pid
&& (-1 == clear_refs_fd /* no need to retry */
|| (close(clear_refs_fd), close(pagemap_fd),
!soft_dirty_open_files()))) {
/* Failed to reopen the files. */
if (!output_unneeded) {
/* Punt: */
memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
# ifdef CHECKSUMS
memset(GC_written_pages, 0xff, sizeof(page_hash_table));
# endif
}
return;
}
# endif
if (!output_unneeded) {
word i;
BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
pagemap_buf_len = 0; /* invalidate soft_vdb_buf */
for (i = 0; i != GC_n_heap_sects; ++i) {
ptr_t start = GC_heap_sects[i].hs_start;
soft_set_grungy_pages(start, start + GC_heap_sects[i].hs_bytes,
i < GC_n_heap_sects-1 ?
GC_heap_sects[i+1].hs_start : NULL);
}
# ifdef CHECKSUMS
GC_or_pages(GC_written_pages, GC_grungy_pages);
# endif
# ifndef NO_VDB_FOR_STATIC_ROOTS
for (i = 0; (int)i < n_root_sets; ++i) {
soft_set_grungy_pages((ptr_t)HBLKPTR(GC_static_roots[i].r_start),
GC_static_roots[i].r_end,
(int)i < n_root_sets-1 ?
GC_static_roots[i+1].r_start : NULL);
}
# endif
}
clear_soft_dirty_bits();
}
#endif /* SOFT_VDB */
#ifdef PCR_VDB
# include "vd/PCR_VD.h"
# define NPAGES (32*1024) /* 128 MB */
PCR_VD_DB GC_grungy_bits[NPAGES];
STATIC ptr_t GC_vd_base = NULL;
/* Address corresponding to GC_grungy_bits[0] */
/* HBLKSIZE aligned. */
GC_INNER GC_bool GC_dirty_init(void)
{
/* For the time being, we assume the heap generally grows up */
GC_vd_base = GC_heap_sects[0].hs_start;
if (GC_vd_base == 0) {
ABORT("Bad initial heap segment");
}
if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
!= PCR_ERes_okay) {
ABORT("Dirty bit initialization failed");
}
return TRUE;
}
#endif /* PCR_VDB */
#ifndef GC_DISABLE_INCREMENTAL
GC_INNER GC_bool GC_manual_vdb = FALSE;
/* Manually mark the page containing p as dirty. Logically, this */
/* dirties the entire object. */
GC_INNER void GC_dirty_inner(const void *p)
{
word index = PHT_HASH(p);
# if defined(MPROTECT_VDB)
/* Do not update GC_dirty_pages if it should be followed by the */
/* page unprotection. */
GC_ASSERT(GC_manual_vdb);
# endif
async_set_pht_entry_from_index(GC_dirty_pages, index);
}
/* Retrieve system dirty bits for the heap to a local buffer (unless */
/* output_unneeded). Restore the systems notion of which pages are */
/* dirty. We assume that either the world is stopped or it is OK to */
/* lose dirty bits while it's happening (as in GC_enable_incremental).*/
GC_INNER void GC_read_dirty(GC_bool output_unneeded)
{
if (GC_manual_vdb
# if defined(MPROTECT_VDB)
|| !GC_GWW_AVAILABLE()
# endif
) {
if (!output_unneeded)
BCOPY((/* no volatile */ void *)GC_dirty_pages, GC_grungy_pages,
sizeof(GC_dirty_pages));
BZERO((/* no volatile */ void *)GC_dirty_pages,
sizeof(GC_dirty_pages));
# ifdef MPROTECT_VDB
if (!GC_manual_vdb)
GC_protect_heap();
# endif
return;
}
# ifdef GWW_VDB
GC_gww_read_dirty(output_unneeded);
# elif defined(PROC_VDB)
GC_proc_read_dirty(output_unneeded);
# elif defined(SOFT_VDB)
GC_soft_read_dirty(output_unneeded);
# elif defined(PCR_VDB)
/* lazily enable dirty bits on newly added heap sects */
{
static int onhs = 0;
int nhs = GC_n_heap_sects;
for (; onhs < nhs; onhs++) {
PCR_VD_WriteProtectEnable(
GC_heap_sects[onhs].hs_start,
GC_heap_sects[onhs].hs_bytes);
}
}
if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
!= PCR_ERes_okay) {
ABORT("Dirty bit read failed");
}
# endif
}
# if !defined(NO_VDB_FOR_STATIC_ROOTS) && !defined(PROC_VDB)
GC_INNER GC_bool GC_is_vdb_for_static_roots(void)
{
if (GC_manual_vdb) return FALSE;
# if defined(MPROTECT_VDB)
/* Currently used only in conjunction with SOFT_VDB. */
return GC_GWW_AVAILABLE();
# else
GC_ASSERT(GC_incremental);
return TRUE;
# endif
}
# endif
/* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
/* If the actual page size is different, this returns TRUE if any */
/* of the pages overlapping h are dirty. This routine may err on the */
/* side of labeling pages as dirty (and this implementation does). */
GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
{
word index;
# ifdef PCR_VDB
if (!GC_manual_vdb) {
if ((word)h < (word)GC_vd_base
|| (word)h >= (word)(GC_vd_base + NPAGES * HBLKSIZE)) {
return TRUE;
}
return GC_grungy_bits[h-(struct hblk*)GC_vd_base] & PCR_VD_DB_dirtyBit;
}
# elif defined(DEFAULT_VDB)
if (!GC_manual_vdb)
return TRUE;
# elif defined(PROC_VDB)
/* Unless manual VDB is on, the bitmap covers all process memory. */
if (GC_manual_vdb)
# endif
{
if (NULL == HDR(h))
return TRUE;
}
index = PHT_HASH(h);
return get_pht_entry_from_index(GC_grungy_pages, index);
}
# if defined(CHECKSUMS) || defined(PROC_VDB)
/* Could any valid GC heap pointer ever have been written to this page? */
GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h)
{
# if defined(GWW_VDB) || defined(PROC_VDB) || defined(SOFT_VDB)
word index;
# ifdef MPROTECT_VDB
if (!GC_GWW_AVAILABLE())
return TRUE;
# endif
# if defined(PROC_VDB)
if (GC_manual_vdb)
# endif
{
if (NULL == HDR(h))
return TRUE;
}
index = PHT_HASH(h);
return get_pht_entry_from_index(GC_written_pages, index);
# else
/* TODO: implement me for MANUAL_VDB. */
(void)h;
return TRUE;
# endif
}
# endif /* CHECKSUMS || PROC_VDB */
/* We expect block h to be written shortly. Ensure that all pages */
/* containing any part of the n hblks starting at h are no longer */
/* protected. If is_ptrfree is false, also ensure that they will */
/* subsequently appear to be dirty. Not allowed to call GC_printf */
/* (and the friends) here, see Win32 GC_stop_world for the details. */
GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
GC_bool is_ptrfree)
{
# ifdef PCR_VDB
(void)is_ptrfree;
if (!GC_auto_incremental)
return;
PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
# elif defined(MPROTECT_VDB)
struct hblk * h_trunc; /* Truncated to page boundary */
struct hblk * h_end; /* Page boundary following block end */
struct hblk * current;
if (!GC_auto_incremental || GC_GWW_AVAILABLE())
return;
GC_ASSERT(GC_page_size != 0);
h_trunc = (struct hblk *)((word)h & ~(word)(GC_page_size-1));
h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size - 1)
& ~(word)(GC_page_size - 1));
/* Note that we cannot examine GC_dirty_pages to check */
/* whether the page at h_trunc has already been marked */
/* dirty as there could be a hash collision. */
for (current = h_trunc; (word)current < (word)h_end; ++current) {
word index = PHT_HASH(current);
if (!is_ptrfree || (word)current < (word)h
|| (word)current >= (word)(h + nblocks)) {
async_set_pht_entry_from_index(GC_dirty_pages, index);
}
}
UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
# else
/* Ignore write hints. They don't help us here. */
(void)h; (void)nblocks; (void)is_ptrfree;
# endif
}
#endif /* !GC_DISABLE_INCREMENTAL */
#if defined(MPROTECT_VDB) && defined(DARWIN)
/* The following sources were used as a "reference" for this exception
handling code:
1. Apple's mach/xnu documentation
2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
omnigroup's macosx-dev list.
www.omnigroup.com/mailman/archive/macosx-dev/2000-June/014178.html
3. macosx-nat.c from Apple's GDB source code.
*/
/* The bug that caused all this trouble should now be fixed. This should
eventually be removed if all goes well. */
/* #define BROKEN_EXCEPTION_HANDLING */
#include <mach/mach.h>
#include <mach/mach_error.h>
#include <mach/exception.h>
#include <mach/task.h>
EXTERN_C_BEGIN
/* Some of the following prototypes are missing in any header, although */
/* they are documented. Some are in mach/exc.h file. */
extern boolean_t
exc_server(mach_msg_header_t *, mach_msg_header_t *);
extern kern_return_t
exception_raise(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
exception_data_t, mach_msg_type_number_t);
extern kern_return_t
exception_raise_state(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
exception_data_t, mach_msg_type_number_t,
thread_state_flavor_t*, thread_state_t,
mach_msg_type_number_t, thread_state_t,
mach_msg_type_number_t*);
extern kern_return_t
exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
exception_type_t, exception_data_t,
mach_msg_type_number_t, thread_state_flavor_t*,
thread_state_t, mach_msg_type_number_t,
thread_state_t, mach_msg_type_number_t*);
GC_API_OSCALL kern_return_t
catch_exception_raise(mach_port_t exception_port, mach_port_t thread,
mach_port_t task, exception_type_t exception,
exception_data_t code,
mach_msg_type_number_t code_count);
GC_API_OSCALL kern_return_t
catch_exception_raise_state(mach_port_name_t exception_port,
int exception, exception_data_t code,
mach_msg_type_number_t codeCnt, int flavor,
thread_state_t old_state, int old_stateCnt,
thread_state_t new_state, int new_stateCnt);
GC_API_OSCALL kern_return_t
catch_exception_raise_state_identity(mach_port_name_t exception_port,
mach_port_t thread, mach_port_t task, int exception,
exception_data_t code, mach_msg_type_number_t codeCnt,
int flavor, thread_state_t old_state, int old_stateCnt,
thread_state_t new_state, int new_stateCnt);
EXTERN_C_END
/* These should never be called, but just in case... */
GC_API_OSCALL kern_return_t
catch_exception_raise_state(mach_port_name_t exception_port GC_ATTR_UNUSED,
int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED,
mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED,
thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED,
thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED)
{
ABORT_RET("Unexpected catch_exception_raise_state invocation");
return(KERN_INVALID_ARGUMENT);
}
GC_API_OSCALL kern_return_t
catch_exception_raise_state_identity(
mach_port_name_t exception_port GC_ATTR_UNUSED,
mach_port_t thread GC_ATTR_UNUSED, mach_port_t task GC_ATTR_UNUSED,
int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED,
mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED,
thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED,
thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED)
{
ABORT_RET("Unexpected catch_exception_raise_state_identity invocation");
return(KERN_INVALID_ARGUMENT);
}
#define MAX_EXCEPTION_PORTS 16
static struct {
mach_msg_type_number_t count;
exception_mask_t masks[MAX_EXCEPTION_PORTS];
exception_handler_t ports[MAX_EXCEPTION_PORTS];
exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
} GC_old_exc_ports;
STATIC struct ports_s {
void (*volatile os_callback[3])(void);
mach_port_t exception;
# if defined(THREADS)
mach_port_t reply;
# endif
} GC_ports = {
{
/* This is to prevent stripping these routines as dead. */
(void (*)(void))catch_exception_raise,
(void (*)(void))catch_exception_raise_state,
(void (*)(void))catch_exception_raise_state_identity
},
# ifdef THREADS
0, /* for 'exception' */
# endif
0
};
typedef struct {
mach_msg_header_t head;
} GC_msg_t;
typedef enum {
GC_MP_NORMAL,
GC_MP_DISCARDING,
GC_MP_STOPPED
} GC_mprotect_state_t;
#ifdef THREADS
/* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, but it */
/* is not documented. Use the source and see if they should be OK. */
# define ID_STOP 1
# define ID_RESUME 2
/* This value is only used on the reply port. */
# define ID_ACK 3
STATIC GC_mprotect_state_t GC_mprotect_state = GC_MP_NORMAL;
/* The following should ONLY be called when the world is stopped. */
STATIC void GC_mprotect_thread_notify(mach_msg_id_t id)
{
struct buf_s {
GC_msg_t msg;
mach_msg_trailer_t trailer;
} buf;
mach_msg_return_t r;
/* remote, local */
buf.msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
buf.msg.head.msgh_size = sizeof(buf.msg);
buf.msg.head.msgh_remote_port = GC_ports.exception;
buf.msg.head.msgh_local_port = MACH_PORT_NULL;
buf.msg.head.msgh_id = id;
r = mach_msg(&buf.msg.head, MACH_SEND_MSG | MACH_RCV_MSG | MACH_RCV_LARGE,
sizeof(buf.msg), sizeof(buf), GC_ports.reply,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (r != MACH_MSG_SUCCESS)
ABORT("mach_msg failed in GC_mprotect_thread_notify");
if (buf.msg.head.msgh_id != ID_ACK)
ABORT("Invalid ack in GC_mprotect_thread_notify");
}
/* Should only be called by the mprotect thread */
STATIC void GC_mprotect_thread_reply(void)
{
GC_msg_t msg;
mach_msg_return_t r;
/* remote, local */
msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
msg.head.msgh_size = sizeof(msg);
msg.head.msgh_remote_port = GC_ports.reply;
msg.head.msgh_local_port = MACH_PORT_NULL;
msg.head.msgh_id = ID_ACK;
r = mach_msg(&msg.head, MACH_SEND_MSG, sizeof(msg), 0, MACH_PORT_NULL,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
if (r != MACH_MSG_SUCCESS)
ABORT("mach_msg failed in GC_mprotect_thread_reply");
}
GC_INNER void GC_mprotect_stop(void)
{
GC_mprotect_thread_notify(ID_STOP);
}
GC_INNER void GC_mprotect_resume(void)
{
GC_mprotect_thread_notify(ID_RESUME);
}
# ifdef CAN_HANDLE_FORK
GC_INNER void GC_dirty_update_child(void)
{
GC_ASSERT(I_HOLD_LOCK());
if (0 == GC_task_self) return; /* GC incremental mode is off */
GC_ASSERT(GC_mprotect_state == GC_MP_NORMAL);
GC_task_self = mach_task_self(); /* needed by UNPROTECT() */
GC_unprotect_all_heap();
/* Restore the old task exception ports. */
/* TODO: Should we do it in fork_prepare/parent_proc? */
if (GC_old_exc_ports.count > 0) {
/* TODO: Should we check GC_old_exc_ports.count<=1? */
if (task_set_exception_ports(GC_task_self, GC_old_exc_ports.masks[0],
GC_old_exc_ports.ports[0], GC_old_exc_ports.behaviors[0],
GC_old_exc_ports.flavors[0]) != KERN_SUCCESS)
ABORT("task_set_exception_ports failed (in child)");
}
/* TODO: Re-enable incremental mode in child. */
GC_task_self = 0;
GC_incremental = FALSE;
}
# endif /* CAN_HANDLE_FORK */
#else
/* The compiler should optimize away any GC_mprotect_state computations */
# define GC_mprotect_state GC_MP_NORMAL
#endif /* !THREADS */
struct mp_reply_s {
mach_msg_header_t head;
char data[256];
};
struct mp_msg_s {
mach_msg_header_t head;
mach_msg_body_t msgh_body;
char data[1024];
};
STATIC void *GC_mprotect_thread(void *arg)
{
mach_msg_return_t r;
/* These two structures contain some private kernel data. We don't */
/* need to access any of it so we don't bother defining a proper */
/* struct. The correct definitions are in the xnu source code. */
struct mp_reply_s reply;
struct mp_msg_s msg;
mach_msg_id_t id;
if ((word)arg == GC_WORD_MAX) return 0; /* to prevent a compiler warning */
# if defined(CPPCHECK)
reply.data[0] = 0; /* to prevent "field unused" warnings */
msg.data[0] = 0;
# endif
# if defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID)
(void)pthread_setname_np("GC-mprotect");
# endif
# if defined(THREADS) && !defined(GC_NO_THREADS_DISCOVERY)
GC_darwin_register_mach_handler_thread(mach_thread_self());
# endif
for (;;) {
r = mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE |
(GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT
: 0), 0, sizeof(msg), GC_ports.exception,
GC_mprotect_state == GC_MP_DISCARDING ? 0
: MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
# if defined(THREADS)
if (GC_mprotect_state == GC_MP_DISCARDING) {
if (r == MACH_RCV_TIMED_OUT) {
GC_mprotect_state = GC_MP_STOPPED;
GC_mprotect_thread_reply();
continue;
}
if (r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
ABORT("Out of order mprotect thread request");
}
# endif /* THREADS */
if (r != MACH_MSG_SUCCESS) {
ABORT_ARG2("mach_msg failed",
": errcode= %d (%s)", (int)r, mach_error_string(r));
}
switch (id) {
# if defined(THREADS)
case ID_STOP:
if (GC_mprotect_state != GC_MP_NORMAL)
ABORT("Called mprotect_stop when state wasn't normal");
GC_mprotect_state = GC_MP_DISCARDING;
break;
case ID_RESUME:
if (GC_mprotect_state != GC_MP_STOPPED)
ABORT("Called mprotect_resume when state wasn't stopped");
GC_mprotect_state = GC_MP_NORMAL;
GC_mprotect_thread_reply();
break;
# endif /* THREADS */
default:
/* Handle the message (calls catch_exception_raise) */
if (!exc_server(&msg.head, &reply.head))
ABORT("exc_server failed");
/* Send the reply */
r = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0,
MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE,
MACH_PORT_NULL);
if (r != MACH_MSG_SUCCESS) {
/* This will fail if the thread dies, but the thread */
/* shouldn't die... */
# ifdef BROKEN_EXCEPTION_HANDLING
GC_err_printf("mach_msg failed with %d %s while sending "
"exc reply\n", (int)r, mach_error_string(r));
# else
ABORT("mach_msg failed while sending exception reply");
# endif
}
} /* switch */
} /* for */
}
/* All this SIGBUS code shouldn't be necessary. All protection faults should
be going through the mach exception handler. However, it seems a SIGBUS is
occasionally sent for some unknown reason. Even more odd, it seems to be
meaningless and safe to ignore. */
#ifdef BROKEN_EXCEPTION_HANDLING
/* Updates to this aren't atomic, but the SIGBUS'es seem pretty rare. */
/* Even if this doesn't get updated property, it isn't really a problem. */
STATIC int GC_sigbus_count = 0;
STATIC void GC_darwin_sigbus(int num, siginfo_t *sip, void *context)
{
if (num != SIGBUS)
ABORT("Got a non-sigbus signal in the sigbus handler");
/* Ugh... some seem safe to ignore, but too many in a row probably means
trouble. GC_sigbus_count is reset for each mach exception that is
handled */
if (GC_sigbus_count >= 8) {
ABORT("Got more than 8 SIGBUSs in a row!");
} else {
GC_sigbus_count++;
WARN("Ignoring SIGBUS\n", 0);
}
}
#endif /* BROKEN_EXCEPTION_HANDLING */
GC_INNER GC_bool GC_dirty_init(void)
{
kern_return_t r;
mach_port_t me;
pthread_t thread;
pthread_attr_t attr;
exception_mask_t mask;
# if defined(CAN_HANDLE_FORK) && !defined(THREADS)
if (GC_handle_fork) {
/* To both support GC incremental mode and GC functions usage in */
/* the forked child, pthread_atfork should be used to install */
/* handlers that switch off GC_incremental in the child */
/* gracefully (unprotecting all pages and clearing */
/* GC_mach_handler_thread). For now, we just disable incremental */
/* mode if fork() handling is requested by the client. */
WARN("Can't turn on GC incremental mode as fork()"
" handling requested\n", 0);
return FALSE;
}
# endif
GC_VERBOSE_LOG_PRINTF("Initializing mach/darwin mprotect"
" virtual dirty bit implementation\n");
# ifdef BROKEN_EXCEPTION_HANDLING
WARN("Enabling workarounds for various darwin "
"exception handling bugs\n", 0);
# endif
if (GC_page_size % HBLKSIZE != 0) {
ABORT("Page size not multiple of HBLKSIZE");
}
GC_task_self = me = mach_task_self();
GC_ASSERT(me != 0);
r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.exception);
/* TODO: WARN and return FALSE in case of a failure. */
if (r != KERN_SUCCESS)
ABORT("mach_port_allocate failed (exception port)");
r = mach_port_insert_right(me, GC_ports.exception, GC_ports.exception,
MACH_MSG_TYPE_MAKE_SEND);
if (r != KERN_SUCCESS)
ABORT("mach_port_insert_right failed (exception port)");
# if defined(THREADS)
r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.reply);
if(r != KERN_SUCCESS)
ABORT("mach_port_allocate failed (reply port)");
# endif
/* The exceptions we want to catch. */
mask = EXC_MASK_BAD_ACCESS;
r = task_get_exception_ports(me, mask, GC_old_exc_ports.masks,
&GC_old_exc_ports.count, GC_old_exc_ports.ports,
GC_old_exc_ports.behaviors,
GC_old_exc_ports.flavors);
if (r != KERN_SUCCESS)
ABORT("task_get_exception_ports failed");
r = task_set_exception_ports(me, mask, GC_ports.exception, EXCEPTION_DEFAULT,
GC_MACH_THREAD_STATE);
if (r != KERN_SUCCESS)
ABORT("task_set_exception_ports failed");
if (pthread_attr_init(&attr) != 0)
ABORT("pthread_attr_init failed");
if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0)
ABORT("pthread_attr_setdetachedstate failed");
/* This will call the real pthread function, not our wrapper. */
if (GC_inner_pthread_create(&thread, &attr, GC_mprotect_thread, NULL) != 0)
ABORT("pthread_create failed");
(void)pthread_attr_destroy(&attr);
/* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
# ifdef BROKEN_EXCEPTION_HANDLING
{
struct sigaction sa, oldsa;
sa.sa_handler = (SIG_HNDLR_PTR)GC_darwin_sigbus;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART|SA_SIGINFO;
/* sa.sa_restorer is deprecated and should not be initialized. */
if (sigaction(SIGBUS, &sa, &oldsa) < 0)
ABORT("sigaction failed");
if (oldsa.sa_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n");
}
}
# endif /* BROKEN_EXCEPTION_HANDLING */
# if defined(CPPCHECK)
GC_noop1((word)GC_ports.os_callback[0]);
# endif
return TRUE;
}
/* The source code for Apple's GDB was used as a reference for the */
/* exception forwarding code. This code is similar to be GDB code only */
/* because there is only one way to do it. */
STATIC kern_return_t GC_forward_exception(mach_port_t thread, mach_port_t task,
exception_type_t exception,
exception_data_t data,
mach_msg_type_number_t data_count)
{
unsigned int i;
kern_return_t r;
mach_port_t port;
exception_behavior_t behavior;
thread_state_flavor_t flavor;
thread_state_data_t thread_state;
mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
for (i = 0; i < GC_old_exc_ports.count; i++) {
if ((GC_old_exc_ports.masks[i] & ((exception_mask_t)1 << exception)) != 0)
break;
}
if (i == GC_old_exc_ports.count)
ABORT("No handler for exception!");
port = GC_old_exc_ports.ports[i];
behavior = GC_old_exc_ports.behaviors[i];
flavor = GC_old_exc_ports.flavors[i];
if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
r = thread_get_state(thread, flavor, thread_state, &thread_state_count);
if (r != KERN_SUCCESS)
ABORT("thread_get_state failed in forward_exception");
}
switch (behavior) {
case EXCEPTION_STATE:
r = exception_raise_state(port, thread, task, exception, data,
data_count, &flavor, thread_state,
thread_state_count, thread_state,
&thread_state_count);
break;
case EXCEPTION_STATE_IDENTITY:
r = exception_raise_state_identity(port, thread, task, exception, data,
data_count, &flavor, thread_state,
thread_state_count, thread_state,
&thread_state_count);
break;
/* case EXCEPTION_DEFAULT: */ /* default signal handlers */
default: /* user-supplied signal handlers */
r = exception_raise(port, thread, task, exception, data, data_count);
}
if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
r = thread_set_state(thread, flavor, thread_state, thread_state_count);
if (r != KERN_SUCCESS)
ABORT("thread_set_state failed in forward_exception");
}
return r;
}
#define FWD() GC_forward_exception(thread, task, exception, code, code_count)
#ifdef ARM32
# define DARWIN_EXC_STATE ARM_EXCEPTION_STATE
# define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE_COUNT
# define DARWIN_EXC_STATE_T arm_exception_state_t
# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far)
#elif defined(AARCH64)
# define DARWIN_EXC_STATE ARM_EXCEPTION_STATE64
# define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE64_COUNT
# define DARWIN_EXC_STATE_T arm_exception_state64_t
# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far)
#elif defined(POWERPC)
# if CPP_WORDSZ == 32
# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE
# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE_COUNT
# define DARWIN_EXC_STATE_T ppc_exception_state_t
# else
# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE64
# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE64_COUNT
# define DARWIN_EXC_STATE_T ppc_exception_state64_t
# endif
# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(dar)
#elif defined(I386) || defined(X86_64)
# if CPP_WORDSZ == 32
# if defined(i386_EXCEPTION_STATE_COUNT) \
&& !defined(x86_EXCEPTION_STATE32_COUNT)
/* Use old naming convention for 32-bit x86. */
# define DARWIN_EXC_STATE i386_EXCEPTION_STATE
# define DARWIN_EXC_STATE_COUNT i386_EXCEPTION_STATE_COUNT
# define DARWIN_EXC_STATE_T i386_exception_state_t
# else
# define DARWIN_EXC_STATE x86_EXCEPTION_STATE32
# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE32_COUNT
# define DARWIN_EXC_STATE_T x86_exception_state32_t
# endif
# else
# define DARWIN_EXC_STATE x86_EXCEPTION_STATE64
# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE64_COUNT
# define DARWIN_EXC_STATE_T x86_exception_state64_t
# endif
# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(faultvaddr)
#elif !defined(CPPCHECK)
# error FIXME for non-arm/ppc/x86 darwin
#endif
/* This violates the namespace rules but there isn't anything that can */
/* be done about it. The exception handling stuff is hard coded to */
/* call this. catch_exception_raise, catch_exception_raise_state and */
/* and catch_exception_raise_state_identity are called from OS. */
GC_API_OSCALL kern_return_t
catch_exception_raise(mach_port_t exception_port GC_ATTR_UNUSED,
mach_port_t thread, mach_port_t task GC_ATTR_UNUSED,
exception_type_t exception, exception_data_t code,
mach_msg_type_number_t code_count GC_ATTR_UNUSED)
{
kern_return_t r;
char *addr;
thread_state_flavor_t flavor = DARWIN_EXC_STATE;
mach_msg_type_number_t exc_state_count = DARWIN_EXC_STATE_COUNT;
DARWIN_EXC_STATE_T exc_state;
if (exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
# ifdef DEBUG_EXCEPTION_HANDLING
/* We aren't interested, pass it on to the old handler */
GC_log_printf("Exception: 0x%x Code: 0x%x 0x%x in catch...\n",
exception, code_count > 0 ? code[0] : -1,
code_count > 1 ? code[1] : -1);
# endif
return FWD();
}
r = thread_get_state(thread, flavor, (natural_t*)&exc_state,
&exc_state_count);
if (r != KERN_SUCCESS) {
/* The thread is supposed to be suspended while the exception */
/* handler is called. This shouldn't fail. */
# ifdef BROKEN_EXCEPTION_HANDLING
GC_err_printf("thread_get_state failed in catch_exception_raise\n");
return KERN_SUCCESS;
# else
ABORT("thread_get_state failed in catch_exception_raise");
# endif
}
/* This is the address that caused the fault */
addr = (char*) exc_state.DARWIN_EXC_STATE_DAR;
if (!is_header_found_async(addr)) {
/* Ugh... just like the SIGBUS problem above, it seems we get */
/* a bogus KERN_PROTECTION_FAILURE every once and a while. We wait */
/* till we get a bunch in a row before doing anything about it. */
/* If a "real" fault ever occurs it'll just keep faulting over and */
/* over and we'll hit the limit pretty quickly. */
# ifdef BROKEN_EXCEPTION_HANDLING
static char *last_fault;
static int last_fault_count;
if (addr != last_fault) {
last_fault = addr;
last_fault_count = 0;
}
if (++last_fault_count < 32) {
if (last_fault_count == 1)
WARN("Ignoring KERN_PROTECTION_FAILURE at %p\n", addr);
return KERN_SUCCESS;
}
GC_err_printf("Unexpected KERN_PROTECTION_FAILURE at %p; aborting...\n",
(void *)addr);
/* Can't pass it along to the signal handler because that is */
/* ignoring SIGBUS signals. We also shouldn't call ABORT here as */
/* signals don't always work too well from the exception handler. */
EXIT();
# else /* BROKEN_EXCEPTION_HANDLING */
/* Pass it along to the next exception handler
(which should call SIGBUS/SIGSEGV) */
return FWD();
# endif /* !BROKEN_EXCEPTION_HANDLING */
}
# ifdef BROKEN_EXCEPTION_HANDLING
/* Reset the number of consecutive SIGBUSs */
GC_sigbus_count = 0;
# endif
GC_ASSERT(GC_page_size != 0);
if (GC_mprotect_state == GC_MP_NORMAL) { /* common case */
struct hblk * h = (struct hblk *)((word)addr & ~(word)(GC_page_size-1));
size_t i;
# ifdef CHECKSUMS
GC_record_fault(h);
# endif
UNPROTECT(h, GC_page_size);
for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
word index = PHT_HASH(h+i);
async_set_pht_entry_from_index(GC_dirty_pages, index);
}
} else if (GC_mprotect_state == GC_MP_DISCARDING) {
/* Lie to the thread for now. No sense UNPROTECT()ing the memory
when we're just going to PROTECT() it again later. The thread
will just fault again once it resumes */
} else {
/* Shouldn't happen, i don't think */
GC_err_printf("KERN_PROTECTION_FAILURE while world is stopped\n");
return FWD();
}
return KERN_SUCCESS;
}
#undef FWD
#ifndef NO_DESC_CATCH_EXCEPTION_RAISE
/* These symbols should have REFERENCED_DYNAMICALLY (0x10) bit set to */
/* let strip know they are not to be stripped. */
__asm__(".desc _catch_exception_raise, 0x10");
__asm__(".desc _catch_exception_raise_state, 0x10");
__asm__(".desc _catch_exception_raise_state_identity, 0x10");
#endif
#endif /* DARWIN && MPROTECT_VDB */
#ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
GC_API int GC_CALL GC_incremental_protection_needs(void)
{
GC_ASSERT(GC_is_initialized);
return GC_PROTECTS_NONE;
}
#endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
#ifdef ECOS
/* Undo sbrk() redirection. */
# undef sbrk
#endif
/* If value is non-zero then allocate executable memory. */
GC_API void GC_CALL GC_set_pages_executable(int value)
{
GC_ASSERT(!GC_is_initialized);
/* Even if IGNORE_PAGES_EXECUTABLE is defined, GC_pages_executable is */
/* touched here to prevent a compiler warning. */
GC_pages_executable = (GC_bool)(value != 0);
}
/* Returns non-zero if the GC-allocated memory is executable. */
/* GC_get_pages_executable is defined after all the places */
/* where GC_get_pages_executable is undefined. */
GC_API int GC_CALL GC_get_pages_executable(void)
{
# ifdef IGNORE_PAGES_EXECUTABLE
return 1; /* Always allocate executable memory. */
# else
return (int)GC_pages_executable;
# endif
}
/* Call stack save code for debugging. Should probably be in */
/* mach_dep.c, but that requires reorganization. */
/* I suspect the following works for most *nix x86 variants, so */
/* long as the frame pointer is explicitly stored. In the case of gcc, */
/* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
#if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
# include <features.h>
struct frame {
struct frame *fr_savfp;
long fr_savpc;
# if NARGS > 0
long fr_arg[NARGS]; /* All the arguments go here. */
# endif
};
#endif
#if defined(SPARC)
# if defined(LINUX)
# include <features.h>
# if defined(SAVE_CALL_CHAIN)
struct frame {
long fr_local[8];
long fr_arg[6];
struct frame *fr_savfp;
long fr_savpc;
# ifndef __arch64__
char *fr_stret;
# endif
long fr_argd[6];
long fr_argx[0];
};
# endif
# elif defined (DRSNX)
# include <sys/sparc/frame.h>
# elif defined(OPENBSD)
# include <frame.h>
# elif defined(FREEBSD) || defined(NETBSD)
# include <machine/frame.h>
# else
# include <sys/frame.h>
# endif
# if NARGS > 6
# error We only know how to get the first 6 arguments
# endif
#endif /* SPARC */
#ifdef NEED_CALLINFO
/* Fill in the pc and argument information for up to NFRAMES of my */
/* callers. Ignore my frame and my callers frame. */
#ifdef LINUX
# include <unistd.h>
#endif
#endif /* NEED_CALLINFO */
#if defined(GC_HAVE_BUILTIN_BACKTRACE)
# ifdef _MSC_VER
# include "private/msvc_dbg.h"
# else
# include <execinfo.h>
# endif
#endif
#ifdef SAVE_CALL_CHAIN
#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
&& defined(GC_HAVE_BUILTIN_BACKTRACE)
#ifdef REDIRECT_MALLOC
/* Deal with possible malloc calls in backtrace by omitting */
/* the infinitely recursing backtrace. */
# ifdef THREADS
__thread /* If your compiler doesn't understand this */
/* you could use something like pthread_getspecific. */
# endif
GC_bool GC_in_save_callers = FALSE;
# if defined(THREADS) && defined(DBG_HDRS_ALL)
# include "private/dbg_mlc.h"
/* A dummy version of GC_save_callers() which does not call */
/* backtrace(). */
GC_INNER void GC_save_callers_no_unlock(struct callinfo info[NFRAMES])
{
GC_ASSERT(I_HOLD_LOCK());
info[0].ci_pc = (word)(&GC_save_callers_no_unlock);
BZERO(&info[1], sizeof(void *) * (NFRAMES - 1));
}
# endif
#endif /* REDIRECT_MALLOC */
GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
{
void * tmp_info[NFRAMES + 1];
int npcs, i;
GC_ASSERT(I_HOLD_LOCK());
/* backtrace may call dl_iterate_phdr which is also */
/* used by GC_register_dynamic_libraries, and */
/* dl_iterate_phdr is not guaranteed to be reentrant. */
GC_STATIC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
# ifdef REDIRECT_MALLOC
if (GC_in_save_callers) {
info[0].ci_pc = (word)(&GC_save_callers);
for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0;
return;
}
GC_in_save_callers = TRUE;
/* backtrace() might call a redirected malloc. */
UNLOCK();
npcs = backtrace((void **)tmp_info, NFRAMES + 1);
LOCK();
# else
npcs = backtrace((void **)tmp_info, NFRAMES + 1);
# endif
/* We retrieve NFRAMES+1 pc values, but discard the first one, since */
/* it points to our own frame. */
i = 0;
if (npcs > 1) {
i = npcs - 1;
BCOPY(&tmp_info[1], info, (unsigned)i * sizeof(void *));
}
for (; i < NFRAMES; ++i) info[i].ci_pc = 0;
# ifdef REDIRECT_MALLOC
GC_in_save_callers = FALSE;
# endif
}
#else /* No builtin backtrace; do it ourselves */
#if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC)
# define FR_SAVFP fr_fp
# define FR_SAVPC fr_pc
#else
# define FR_SAVFP fr_savfp
# define FR_SAVPC fr_savpc
#endif
#if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
# define BIAS 2047
#else
# define BIAS 0
#endif
GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
{
struct frame *frame;
struct frame *fp;
int nframes = 0;
# ifdef I386
/* We assume this is turned on only with gcc as the compiler. */
asm("movl %%ebp,%0" : "=r"(frame));
fp = frame;
# else
frame = (struct frame *)GC_save_regs_in_stack();
fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
#endif
for (; !((word)fp HOTTER_THAN (word)frame)
# ifndef THREADS
&& !((word)GC_stackbottom HOTTER_THAN (word)fp)
# elif defined(STACK_GROWS_UP)
&& fp != NULL
# endif
&& nframes < NFRAMES;
fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
# if NARGS > 0
int i;
# endif
info[nframes].ci_pc = fp->FR_SAVPC;
# if NARGS > 0
for (i = 0; i < NARGS; i++) {
info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
}
# endif /* NARGS > 0 */
}
if (nframes < NFRAMES) info[nframes].ci_pc = 0;
}
#endif /* No builtin backtrace */
#endif /* SAVE_CALL_CHAIN */
#ifdef NEED_CALLINFO
/* Print info to stderr. We do NOT hold the allocation lock */
GC_INNER void GC_print_callers(struct callinfo info[NFRAMES])
{
int i;
static int reentry_count = 0;
DCL_LOCK_STATE;
/* FIXME: This should probably use a different lock, so that we */
/* become callable with or without the allocation lock. */
LOCK();
++reentry_count;
UNLOCK();
# if NFRAMES == 1
GC_err_printf("\tCaller at allocation:\n");
# else
GC_err_printf("\tCall chain at allocation:\n");
# endif
for (i = 0; i < NFRAMES; i++) {
# if defined(LINUX) && !defined(SMALL_CONFIG)
GC_bool stop = FALSE;
# endif
if (0 == info[i].ci_pc)
break;
# if NARGS > 0
{
int j;
GC_err_printf("\t\targs: ");
for (j = 0; j < NARGS; j++) {
if (j != 0) GC_err_printf(", ");
GC_err_printf("%d (0x%X)", ~(info[i].ci_arg[j]),
~(info[i].ci_arg[j]));
}
GC_err_printf("\n");
}
# endif
if (reentry_count > 1) {
/* We were called during an allocation during */
/* a previous GC_print_callers call; punt. */
GC_err_printf("\t\t##PC##= 0x%lx\n",
(unsigned long)info[i].ci_pc);
continue;
}
{
char buf[40];
char *name;
# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
&& !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
char **sym_name =
backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
if (sym_name != NULL) {
name = sym_name[0];
} else
# endif
/* else */ {
(void)snprintf(buf, sizeof(buf), "##PC##= 0x%lx",
(unsigned long)info[i].ci_pc);
buf[sizeof(buf) - 1] = '\0';
name = buf;
}
# if defined(LINUX) && !defined(SMALL_CONFIG)
/* Try for a line number. */
do {
FILE *pipe;
# define EXE_SZ 100
static char exe_name[EXE_SZ];
# define CMD_SZ 200
char cmd_buf[CMD_SZ];
# define RESULT_SZ 200
static char result_buf[RESULT_SZ];
size_t result_len;
char *old_preload;
# define PRELOAD_SZ 200
char preload_buf[PRELOAD_SZ];
static GC_bool found_exe_name = FALSE;
static GC_bool will_fail = FALSE;
/* Try to get it via a hairy and expensive scheme. */
/* First we get the name of the executable: */
if (will_fail)
break;
if (!found_exe_name) {
int ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
if (ret_code < 0 || ret_code >= EXE_SZ
|| exe_name[0] != '/') {
will_fail = TRUE; /* Don't try again. */
break;
}
exe_name[ret_code] = '\0';
found_exe_name = TRUE;
}
/* Then we use popen to start addr2line -e <exe> <addr> */
/* There are faster ways to do this, but hopefully this */
/* isn't time critical. */
(void)snprintf(cmd_buf, sizeof(cmd_buf),
"/usr/bin/addr2line -f -e %s 0x%lx",
exe_name, (unsigned long)info[i].ci_pc);
cmd_buf[sizeof(cmd_buf) - 1] = '\0';
old_preload = GETENV("LD_PRELOAD");
if (0 != old_preload) {
size_t old_len = strlen(old_preload);
if (old_len >= PRELOAD_SZ) {
will_fail = TRUE;
break;
}
BCOPY(old_preload, preload_buf, old_len + 1);
unsetenv ("LD_PRELOAD");
}
pipe = popen(cmd_buf, "r");
if (0 != old_preload
&& 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
WARN("Failed to reset LD_PRELOAD\n", 0);
}
if (NULL == pipe) {
will_fail = TRUE;
break;
}
result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe);
(void)pclose(pipe);
if (0 == result_len) {
will_fail = TRUE;
break;
}
if (result_buf[result_len - 1] == '\n') --result_len;
result_buf[result_len] = 0;
if (result_buf[0] == '?'
|| (result_buf[result_len-2] == ':'
&& result_buf[result_len-1] == '0'))
break;
/* Get rid of embedded newline, if any. Test for "main" */
{
char * nl = strchr(result_buf, '\n');
if (nl != NULL
&& (word)nl < (word)(result_buf + result_len)) {
*nl = ':';
}
if (strncmp(result_buf, "main",
nl != NULL
? (size_t)((word)nl /* a cppcheck workaround */
- COVERT_DATAFLOW(result_buf))
: result_len) == 0) {
stop = TRUE;
}
}
if (result_len < RESULT_SZ - 25) {
/* Add in hex address */
(void)snprintf(&result_buf[result_len],
sizeof(result_buf) - result_len,
" [0x%lx]", (unsigned long)info[i].ci_pc);
result_buf[sizeof(result_buf) - 1] = '\0';
}
# if defined(CPPCHECK)
GC_noop1((unsigned char)name[0]);
/* name computed previously is discarded */
# endif
name = result_buf;
} while (0);
# endif /* LINUX */
GC_err_printf("\t\t%s\n", name);
# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
&& !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
if (sym_name != NULL)
free(sym_name); /* May call GC_[debug_]free; that's OK */
# endif
}
# if defined(LINUX) && !defined(SMALL_CONFIG)
if (stop)
break;
# endif
}
LOCK();
--reentry_count;
UNLOCK();
}
#endif /* NEED_CALLINFO */
#if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
/* Dump /proc/self/maps to GC_stderr, to enable looking up names for */
/* addresses in FIND_LEAK output. */
void GC_print_address_map(void)
{
const char *maps = GC_get_maps();
GC_err_printf("---------- Begin address map ----------\n");
GC_err_puts(maps);
GC_err_printf("---------- End address map ----------\n");
}
#endif /* LINUX && ELF */
