* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.

/*
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 1997 by Silicon Graphics. All rights reserved.
* Copyright (c) 2009-2021 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"

/*
* This is incredibly OS specific code for tracking down data sections in
* dynamic libraries. There appears to be no way of doing this quickly
* without groveling through undocumented data structures. We would argue
* that this is a bug in the design of the dlopen interface. THIS CODE
* MAY BREAK IN FUTURE OS RELEASES. If this matters to you, don't hesitate
* to let your vendor know ...
*
* None of this is safe with dlclose and incremental collection.
* But then not much of anything is safe in the presence of dlclose.
*/

#if !defined(MACOS) && !defined(GC_NO_TYPES) && !defined(SN_TARGET_PSP2) \
&& !defined(_WIN32_WCE) && !defined(__CC_ARM)
# include <sys/types.h>
#endif

/* BTL: avoid circular redefinition of dlopen if GC_SOLARIS_THREADS defined */
#undef GC_MUST_RESTORE_REDEFINED_DLOPEN
#if defined(GC_PTHREADS) && !defined(GC_NO_DLOPEN) \
&& !defined(GC_NO_THREAD_REDIRECTS) && !defined(GC_USE_LD_WRAP)
/* To support threads in Solaris, gc.h interposes on dlopen by */
/* defining "dlopen" to be "GC_dlopen", which is implemented below. */
/* However, both GC_FirstDLOpenedLinkMap() and GC_dlopen() use the */
/* real system dlopen() in their implementation. We first remove */
/* gc.h's dlopen definition and restore it later, after GC_dlopen(). */
# undef dlopen
# define GC_MUST_RESTORE_REDEFINED_DLOPEN
#endif /* !GC_NO_DLOPEN */

/* A user-supplied routine (custom filter) that might be called to */
/* determine whether a DSO really needs to be scanned by the GC. */
/* 0 means no filter installed. May be unused on some platforms. */
/* FIXME: Add filter support for more platforms. */
STATIC GC_has_static_roots_func GC_has_static_roots = 0;

#if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE) \
|| defined(CYGWIN32)) && !defined(PCR)

#if !defined(DARWIN) && !defined(SCO_ELF) && !defined(SOLARISDL) \
&& !defined(AIX) && !defined(DGUX) && !defined(IRIX5) && !defined(HPUX) \
&& !defined(CYGWIN32) && !defined(MSWIN32) && !defined(MSWINCE) \
&& !(defined(ALPHA) && defined(OSF1)) \
&& !(defined(FREEBSD) && defined(__ELF__)) \
&& !(defined(LINUX) && defined(__ELF__)) \
&& !(defined(NETBSD) && defined(__ELF__)) \
&& !(defined(OPENBSD) && (defined(__ELF__) || defined(M68K))) \
&& !defined(HAIKU) && !defined(HURD) && !defined(NACL) \
&& !defined(CPPCHECK)
# error We only know how to find data segments of dynamic libraries for above.
# error Additional SVR4 variants might not be too hard to add.
#endif

#include <stdio.h>
#ifdef SOLARISDL
# include <sys/elf.h>
# include <dlfcn.h>
# include <link.h>
#endif

#if defined(NETBSD)
# include <sys/param.h>
# include <dlfcn.h>
# include <machine/elf_machdep.h>
# define ELFSIZE ARCH_ELFSIZE
#endif

#if defined(OPENBSD)
# include <sys/param.h>
# if (OpenBSD >= 200519) && !defined(HAVE_DL_ITERATE_PHDR)
# define HAVE_DL_ITERATE_PHDR
# endif
#endif /* OPENBSD */

#if defined(SCO_ELF) || defined(DGUX) || defined(HURD) || defined(NACL) \
|| (defined(__ELF__) && (defined(LINUX) || defined(FREEBSD) \
|| defined(NETBSD) || defined(OPENBSD)))
# include <stddef.h>
# if !defined(OPENBSD) && !defined(HOST_ANDROID)
/* OpenBSD does not have elf.h file; link.h below is sufficient. */
/* Exclude Android because linker.h below includes its own version. */
# include <elf.h>
# endif
# ifdef HOST_ANDROID
/* If you don't need the "dynamic loading" feature, you may build */
/* the collector with -D IGNORE_DYNAMIC_LOADING. */
# ifdef BIONIC_ELFDATA_REDEF_BUG
/* Workaround a problem in Bionic (as of Android 4.2) which has */
/* mismatching ELF_DATA definitions in sys/exec_elf.h and */
/* asm/elf.h included from linker.h file (similar to EM_ALPHA). */
# include <asm/elf.h>
# include <linux/elf-em.h>
# undef ELF_DATA
# undef EM_ALPHA
# endif
# include <link.h>
# if !defined(GC_DONT_DEFINE_LINK_MAP) && !(__ANDROID_API__ >= 21)
/* link_map and r_debug are defined in link.h of NDK r10+. */
/* bionic/linker/linker.h defines them too but the header */
/* itself is a C++ one starting from Android 4.3. */
struct link_map {
uintptr_t l_addr;
char* l_name;
uintptr_t l_ld;
struct link_map* l_next;
struct link_map* l_prev;
};
struct r_debug {
int32_t r_version;
struct link_map* r_map;
void (*r_brk)(void);
int32_t r_state;
uintptr_t r_ldbase;
};
# endif
# else
EXTERN_C_BEGIN /* Workaround missing extern "C" around _DYNAMIC */
/* symbol in link.h of some Linux hosts. */
# include <link.h>
EXTERN_C_END
# endif
#endif

/* Newer versions of GNU/Linux define this macro. We
* define it similarly for any ELF systems that don't. */
# ifndef ElfW
# if defined(FREEBSD)
# if __ELF_WORD_SIZE == 32
# define ElfW(type) Elf32_##type
# else
# define ElfW(type) Elf64_##type
# endif
# elif defined(NETBSD) || defined(OPENBSD)
# if ELFSIZE == 32
# define ElfW(type) Elf32_##type
# elif ELFSIZE == 64
# define ElfW(type) Elf64_##type
# else
# error Missing ELFSIZE define
# endif
# else
# if !defined(ELF_CLASS) || ELF_CLASS == ELFCLASS32
# define ElfW(type) Elf32_##type
# else
# define ElfW(type) Elf64_##type
# endif
# endif
# endif

#if defined(SOLARISDL) && !defined(USE_PROC_FOR_LIBRARIES)

EXTERN_C_BEGIN
extern ElfW(Dyn) _DYNAMIC;
EXTERN_C_END

STATIC struct link_map *
GC_FirstDLOpenedLinkMap(void)
{
ElfW(Dyn) *dp;
static struct link_map * cachedResult = 0;
static ElfW(Dyn) *dynStructureAddr = 0;
/* BTL: added to avoid Solaris 5.3 ld.so _DYNAMIC bug */

# ifdef SUNOS53_SHARED_LIB
/* BTL: Avoid the Solaris 5.3 bug that _DYNAMIC isn't being set */
/* up properly in dynamically linked .so's. This means we have */
/* to use its value in the set of original object files loaded */
/* at program startup. */
if( dynStructureAddr == 0 ) {
void* startupSyms = dlopen(0, RTLD_LAZY);
dynStructureAddr = (ElfW(Dyn)*)(word)dlsym(startupSyms, "_DYNAMIC");
}
# else
dynStructureAddr = &_DYNAMIC;
# endif

if (0 == COVERT_DATAFLOW(dynStructureAddr)) {
/* _DYNAMIC symbol not resolved. */
return(0);
}
if (cachedResult == 0) {
int tag;
for( dp = ((ElfW(Dyn) *)(&_DYNAMIC)); (tag = dp->d_tag) != 0; dp++ ) {
if (tag == DT_DEBUG) {
struct r_debug *rd = (struct r_debug *)dp->d_un.d_ptr;
if (rd != NULL) {
struct link_map *lm = rd->r_map;
if (lm != NULL)
cachedResult = lm->l_next; /* might be NULL */
}
break;
}
}
}
return cachedResult;
}

#endif /* SOLARISDL ... */

/* BTL: added to fix circular dlopen definition if GC_SOLARIS_THREADS defined */
# ifdef GC_MUST_RESTORE_REDEFINED_DLOPEN
# define dlopen GC_dlopen
# endif

# if defined(SOLARISDL)

/* Add dynamic library data sections to the root set. */
# if !defined(PCR) && !defined(GC_SOLARIS_THREADS) && defined(THREADS) \
&& !defined(CPPCHECK)
# error Fix mutual exclusion with dlopen
# endif

# ifndef USE_PROC_FOR_LIBRARIES
GC_INNER void GC_register_dynamic_libraries(void)
{
struct link_map *lm;

for (lm = GC_FirstDLOpenedLinkMap(); lm != 0; lm = lm->l_next) {
ElfW(Ehdr) * e;
ElfW(Phdr) * p;
unsigned long offset;
char * start;
int i;

e = (ElfW(Ehdr) *) lm->l_addr;
p = ((ElfW(Phdr) *)(((char *)(e)) + e->e_phoff));
offset = ((unsigned long)(lm->l_addr));
for( i = 0; i < (int)e->e_phnum; i++, p++ ) {
switch( p->p_type ) {
case PT_LOAD:
{
if( !(p->p_flags & PF_W) ) break;
start = ((char *)(p->p_vaddr)) + offset;
GC_add_roots_inner(start, start + p->p_memsz, TRUE);
}
break;
default:
break;
}
}
}
}

# endif /* !USE_PROC_FOR_LIBRARIES */
# endif /* SOLARISDL */

#if defined(SCO_ELF) || defined(DGUX) || defined(HURD) || defined(NACL) \
|| (defined(__ELF__) && (defined(LINUX) || defined(FREEBSD) \
|| defined(NETBSD) || defined(OPENBSD)))

#ifdef USE_PROC_FOR_LIBRARIES

#include <string.h>

#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#define MAPS_BUF_SIZE (32*1024)

/* Sort an array of HeapSects by start address. */
/* Unfortunately at least some versions of */
/* Linux qsort end up calling malloc by way of sysconf, and hence can't */
/* be used in the collector. Hence we roll our own. Should be */
/* reasonably fast if the array is already mostly sorted, as we expect */
/* it to be. */
static void sort_heap_sects(struct HeapSect *base, size_t number_of_elements)
{
signed_word n = (signed_word)number_of_elements;
signed_word nsorted = 1;

while (nsorted < n) {
signed_word i;

while (nsorted < n &&
(word)base[nsorted-1].hs_start < (word)base[nsorted].hs_start)
++nsorted;
if (nsorted == n) break;
GC_ASSERT((word)base[nsorted-1].hs_start > (word)base[nsorted].hs_start);
i = nsorted - 1;
while (i >= 0 && (word)base[i].hs_start > (word)base[i+1].hs_start) {
struct HeapSect tmp = base[i];
base[i] = base[i+1];
base[i+1] = tmp;
--i;
}
GC_ASSERT((word)base[nsorted-1].hs_start < (word)base[nsorted].hs_start);
++nsorted;
}
}

STATIC void GC_register_map_entries(const char *maps)
{
const char *prot;
ptr_t start, end;
unsigned int maj_dev;
ptr_t least_ha, greatest_ha;
unsigned i;

GC_ASSERT(I_HOLD_LOCK());
sort_heap_sects(GC_our_memory, GC_n_memory);
least_ha = GC_our_memory[0].hs_start;
greatest_ha = GC_our_memory[GC_n_memory-1].hs_start
+ GC_our_memory[GC_n_memory-1].hs_bytes;

for (;;) {
maps = GC_parse_map_entry(maps, &start, &end, &prot, &maj_dev, 0);
if (NULL == maps) break;

if (prot[1] == 'w') {
/* This is a writable mapping. Add it to */
/* the root set unless it is already otherwise */
/* accounted for. */
if ((word)start <= (word)GC_stackbottom
&& (word)end >= (word)GC_stackbottom) {
/* Stack mapping; discard */
continue;
}
# ifdef THREADS
/* This may fail, since a thread may already be */
/* unregistered, but its thread stack may still be there. */
/* That can fail because the stack may disappear while */
/* we're marking. Thus the marker is, and has to be */
/* prepared to recover from segmentation faults. */

if (GC_segment_is_thread_stack(start, end)) continue;

/* FIXME: NPTL squirrels */
/* away pointers in pieces of the stack segment that we */
/* don't scan. We work around this */
/* by treating anything allocated by libpthread as */
/* uncollectible, as we do in some other cases. */
/* A specifically identified problem is that */
/* thread stacks contain pointers to dynamic thread */
/* vectors, which may be reused due to thread caching. */
/* They may not be marked if the thread is still live. */
/* This specific instance should be addressed by */
/* INCLUDE_LINUX_THREAD_DESCR, but that doesn't quite */
/* seem to suffice. */
/* We currently trace entire thread stacks, if they are */
/* are currently cached but unused. This is */
/* very suboptimal for performance reasons. */
# endif
/* We no longer exclude the main data segment. */
if ((word)end <= (word)least_ha
|| (word)start >= (word)greatest_ha) {
/* The easy case; just trace entire segment */
GC_add_roots_inner(start, end, TRUE);
continue;
}
/* Add sections that don't belong to us. */
i = 0;
while ((word)(GC_our_memory[i].hs_start
+ GC_our_memory[i].hs_bytes) < (word)start)
++i;
GC_ASSERT(i < GC_n_memory);
if ((word)GC_our_memory[i].hs_start <= (word)start) {
start = GC_our_memory[i].hs_start
+ GC_our_memory[i].hs_bytes;
++i;
}
while (i < GC_n_memory
&& (word)GC_our_memory[i].hs_start < (word)end
&& (word)start < (word)end) {
if ((word)start < (word)GC_our_memory[i].hs_start)
GC_add_roots_inner(start,
GC_our_memory[i].hs_start, TRUE);
start = GC_our_memory[i].hs_start
+ GC_our_memory[i].hs_bytes;
++i;
}
if ((word)start < (word)end)
GC_add_roots_inner(start, end, TRUE);
} else if (prot[0] == '-' && prot[1] == '-' && prot[2] == '-') {
/* Even roots added statically might disappear partially */
/* (e.g. the roots added by INCLUDE_LINUX_THREAD_DESCR). */
GC_remove_roots_subregion(start, end);
}
}
}

GC_INNER void GC_register_dynamic_libraries(void)
{
GC_register_map_entries(GC_get_maps());
}

/* We now take care of the main data segment ourselves: */
GC_INNER GC_bool GC_register_main_static_data(void)
{
return FALSE;
}

# define HAVE_REGISTER_MAIN_STATIC_DATA

#else /* !USE_PROC_FOR_LIBRARIES */

/* The following is the preferred way to walk dynamic libraries */
/* for glibc 2.2.4+. Unfortunately, it doesn't work for older */
/* versions. Thanks to Jakub Jelinek for most of the code. */

#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
|| (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)) \
|| defined(HOST_ANDROID) /* Are others OK here, too? */
# ifndef HAVE_DL_ITERATE_PHDR
# define HAVE_DL_ITERATE_PHDR
# endif
# ifdef HOST_ANDROID
/* Android headers might have no such definition for some targets. */
EXTERN_C_BEGIN
extern int dl_iterate_phdr(int (*cb)(struct dl_phdr_info *,
size_t, void *),
void *data);
EXTERN_C_END
# endif
#endif /* __GLIBC__ >= 2 || HOST_ANDROID */

#if defined(__DragonFly__) || defined(__FreeBSD_kernel__) \
|| (defined(FREEBSD) && __FreeBSD__ >= 7)
/* On the FreeBSD system, any target system at major version 7 shall */
/* have dl_iterate_phdr; therefore, we need not make it weak as below. */
# ifndef HAVE_DL_ITERATE_PHDR
# define HAVE_DL_ITERATE_PHDR
# endif
# define DL_ITERATE_PHDR_STRONG
#elif defined(HAVE_DL_ITERATE_PHDR)
/* We have the header files for a glibc that includes dl_iterate_phdr.*/
/* It may still not be available in the library on the target system. */
/* Thus we also treat it as a weak symbol. */
EXTERN_C_BEGIN
# pragma weak dl_iterate_phdr
EXTERN_C_END
#endif

#if defined(HAVE_DL_ITERATE_PHDR)

# ifdef PT_GNU_RELRO
/* Instead of registering PT_LOAD sections directly, we keep them */
/* in a temporary list, and filter them by excluding PT_GNU_RELRO */
/* segments. Processing PT_GNU_RELRO sections with */
/* GC_exclude_static_roots instead would be superficially cleaner. But */
/* it runs into trouble if a client registers an overlapping segment, */
/* which unfortunately seems quite possible. */

# define MAX_LOAD_SEGS MAX_ROOT_SETS

static struct load_segment {
ptr_t start;
ptr_t end;
/* Room for a second segment if we remove a RELRO segment */
/* from the middle. */
ptr_t start2;
ptr_t end2;
} load_segs[MAX_LOAD_SEGS];

static int n_load_segs;
static GC_bool load_segs_overflow;
# endif /* PT_GNU_RELRO */

STATIC int GC_register_dynlib_callback(struct dl_phdr_info * info,
size_t size, void * ptr)
{
const ElfW(Phdr) * p;
ptr_t start, end;
int i;

/* Make sure struct dl_phdr_info is at least as big as we need. */
if (size < offsetof (struct dl_phdr_info, dlpi_phnum)
+ sizeof (info->dlpi_phnum))
return -1;

p = info->dlpi_phdr;
for (i = 0; i < (int)info->dlpi_phnum; i++, p++) {
if (p->p_type == PT_LOAD) {
GC_has_static_roots_func callback = GC_has_static_roots;
if ((p->p_flags & PF_W) == 0) continue;

start = (ptr_t)p->p_vaddr + info->dlpi_addr;
end = start + p->p_memsz;
if (callback != 0 && !callback(info->dlpi_name, start, p->p_memsz))
continue;
# ifdef PT_GNU_RELRO
# if CPP_WORDSZ == 64
/* TODO: GC_push_all eventually does the correct */
/* rounding to the next multiple of ALIGNMENT, so, most */
/* probably, we should remove the corresponding assertion */
/* check in GC_add_roots_inner along with this code line. */
/* start pointer value may require aligning. */
start = (ptr_t)((word)start & ~(word)(sizeof(word) - 1));
# endif
if (n_load_segs >= MAX_LOAD_SEGS) {
if (!load_segs_overflow) {
WARN("Too many PT_LOAD segments;"
" registering as roots directly...\n", 0);
load_segs_overflow = TRUE;
}
GC_add_roots_inner(start, end, TRUE);
} else {
load_segs[n_load_segs].start = start;
load_segs[n_load_segs].end = end;
load_segs[n_load_segs].start2 = 0;
load_segs[n_load_segs].end2 = 0;
++n_load_segs;
}
# else
GC_add_roots_inner(start, end, TRUE);
# endif /* !PT_GNU_RELRO */
}
}

# ifdef PT_GNU_RELRO
p = info->dlpi_phdr;
for (i = 0; i < (int)info->dlpi_phnum; i++, p++) {
if (p->p_type == PT_GNU_RELRO) {
/* This entry is known to be constant and will eventually be */
/* remapped as read-only. However, the address range covered */
/* by this entry is typically a subset of a previously */
/* encountered "LOAD" segment, so we need to exclude it. */
int j;

start = (ptr_t)p->p_vaddr + info->dlpi_addr;
end = start + p->p_memsz;
for (j = n_load_segs; --j >= 0; ) {
if ((word)start >= (word)load_segs[j].start
&& (word)start < (word)load_segs[j].end) {
if (load_segs[j].start2 != 0) {
WARN("More than one GNU_RELRO segment per load one\n",0);
} else {
GC_ASSERT((word)end <=
(((word)load_segs[j].end + GC_page_size - 1) &
~(word)(GC_page_size - 1)));
/* Remove from the existing load segment */
load_segs[j].end2 = load_segs[j].end;
load_segs[j].end = start;
load_segs[j].start2 = end;
/* Note that start2 may be greater than end2 because of */
/* p->p_memsz value multiple of page size. */
}
break;
}
if (0 == j && 0 == GC_has_static_roots)
WARN("Failed to find PT_GNU_RELRO segment"
" inside PT_LOAD region\n", 0);
/* No warning reported in case of the callback is present */
/* because most likely the segment has been excluded. */
}
}
}
# endif

*(int *)ptr = 1; /* Signal that we were called */
return 0;
}

/* Do we need to separately register the main static data segment? */
GC_INNER GC_bool GC_register_main_static_data(void)
{
# ifdef DL_ITERATE_PHDR_STRONG
/* If dl_iterate_phdr is not a weak symbol then don't test against */
/* zero (otherwise a compiler might issue a warning). */
return FALSE;
# else
return 0 == COVERT_DATAFLOW(dl_iterate_phdr);
# endif
}

/* Return TRUE if we succeed, FALSE if dl_iterate_phdr wasn't there. */
STATIC GC_bool GC_register_dynamic_libraries_dl_iterate_phdr(void)
{
int did_something;
if (GC_register_main_static_data())
return FALSE;

# ifdef PT_GNU_RELRO
{
static GC_bool excluded_segs = FALSE;
n_load_segs = 0;
load_segs_overflow = FALSE;
if (!EXPECT(excluded_segs, TRUE)) {
GC_exclude_static_roots_inner((ptr_t)load_segs,
(ptr_t)load_segs + sizeof(load_segs));
excluded_segs = TRUE;
}
}
# endif

did_something = 0;
dl_iterate_phdr(GC_register_dynlib_callback, &did_something);
if (did_something) {
# ifdef PT_GNU_RELRO
int i;

for (i = 0; i < n_load_segs; ++i) {
if ((word)load_segs[i].end > (word)load_segs[i].start) {
GC_add_roots_inner(load_segs[i].start, load_segs[i].end, TRUE);
}
if ((word)load_segs[i].end2 > (word)load_segs[i].start2) {
GC_add_roots_inner(load_segs[i].start2, load_segs[i].end2, TRUE);
}
}
# endif
} else {
ptr_t datastart, dataend;
# ifdef DATASTART_IS_FUNC
static ptr_t datastart_cached = (ptr_t)GC_WORD_MAX;

/* Evaluate DATASTART only once. */
if (datastart_cached == (ptr_t)GC_WORD_MAX) {
datastart_cached = DATASTART;
}
datastart = datastart_cached;
# else
datastart = DATASTART;
# endif
# ifdef DATAEND_IS_FUNC
{
static ptr_t dataend_cached = 0;
/* Evaluate DATAEND only once. */
if (dataend_cached == 0) {
dataend_cached = DATAEND;
}
dataend = dataend_cached;
}
# else
dataend = DATAEND;
# endif
if (NULL == *(char * volatile *)&datastart
|| (word)datastart > (word)dataend)
ABORT_ARG2("Wrong DATASTART/END pair",
": %p .. %p", (void *)datastart, (void *)dataend);

/* dl_iterate_phdr may forget the static data segment in */
/* statically linked executables. */
GC_add_roots_inner(datastart, dataend, TRUE);
# ifdef GC_HAVE_DATAREGION2
if ((word)DATASTART2 - 1U >= (word)DATAEND2) {
/* Subtract one to check also for NULL */
/* without a compiler warning. */
ABORT_ARG2("Wrong DATASTART/END2 pair",
": %p .. %p", (void *)DATASTART2, (void *)DATAEND2);
}
GC_add_roots_inner(DATASTART2, DATAEND2, TRUE);
# endif
}
return TRUE;
}

# define HAVE_REGISTER_MAIN_STATIC_DATA

#else /* !HAVE_DL_ITERATE_PHDR */

/* Dynamic loading code for Linux running ELF. Somewhat tested on
* Linux/x86, untested but hopefully should work on Linux/Alpha.
* This code was derived from the Solaris/ELF support. Thanks to
* whatever kind soul wrote that. - Patrick Bridges */

/* This doesn't necessarily work in all cases, e.g. with preloaded
* dynamic libraries. */

# if defined(NETBSD) || defined(OPENBSD)
# include <sys/exec_elf.h>
/* for compatibility with 1.4.x */
# ifndef DT_DEBUG
# define DT_DEBUG 21
# endif
# ifndef PT_LOAD
# define PT_LOAD 1
# endif
# ifndef PF_W
# define PF_W 2
# endif
# elif !defined(HOST_ANDROID)
# include <elf.h>
# endif

# ifndef HOST_ANDROID
# include <link.h>
# endif

#endif /* !HAVE_DL_ITERATE_PHDR */

EXTERN_C_BEGIN
#ifdef __GNUC__
# pragma weak _DYNAMIC
#endif
extern ElfW(Dyn) _DYNAMIC[];
EXTERN_C_END

STATIC struct link_map *
GC_FirstDLOpenedLinkMap(void)
{
static struct link_map *cachedResult = 0;

if (0 == COVERT_DATAFLOW(_DYNAMIC)) {
/* _DYNAMIC symbol not resolved. */
return(0);
}
if( cachedResult == 0 ) {
# if defined(NETBSD) && defined(RTLD_DI_LINKMAP)
# if defined(CPPCHECK)
# define GC_RTLD_DI_LINKMAP 2
# else
# define GC_RTLD_DI_LINKMAP RTLD_DI_LINKMAP
# endif
struct link_map *lm = NULL;
if (!dlinfo(RTLD_SELF, GC_RTLD_DI_LINKMAP, &lm) && lm != NULL) {
/* Now lm points link_map object of libgc. Since it */
/* might not be the first dynamically linked object, */
/* try to find it (object next to the main object). */
while (lm->l_prev != NULL) {
lm = lm->l_prev;
}
cachedResult = lm->l_next;
}
# else
ElfW(Dyn) *dp;
int tag;

for( dp = _DYNAMIC; (tag = dp->d_tag) != 0; dp++ ) {
if (tag == DT_DEBUG) {
struct r_debug *rd = (struct r_debug *)dp->d_un.d_ptr;
/* d_ptr could be null if libs are linked statically. */
if (rd != NULL) {
struct link_map *lm = rd->r_map;
if (lm != NULL)
cachedResult = lm->l_next; /* might be NULL */
}
break;
}
}
# endif /* !NETBSD || !RTLD_DI_LINKMAP */
}
return cachedResult;
}

GC_INNER void GC_register_dynamic_libraries(void)
{
struct link_map *lm;

# ifdef HAVE_DL_ITERATE_PHDR
if (GC_register_dynamic_libraries_dl_iterate_phdr()) {
return;
}
# endif
for (lm = GC_FirstDLOpenedLinkMap(); lm != 0; lm = lm->l_next)
{
ElfW(Ehdr) * e;
ElfW(Phdr) * p;
unsigned long offset;
char * start;
int i;

e = (ElfW(Ehdr) *) lm->l_addr;
# ifdef HOST_ANDROID
if (e == NULL)
continue;
# endif
p = ((ElfW(Phdr) *)(((char *)(e)) + e->e_phoff));
offset = ((unsigned long)(lm->l_addr));
for( i = 0; i < (int)e->e_phnum; i++, p++ ) {
switch( p->p_type ) {
case PT_LOAD:
{
if( !(p->p_flags & PF_W) ) break;
start = ((char *)(p->p_vaddr)) + offset;
GC_add_roots_inner(start, start + p->p_memsz, TRUE);
}
break;
default:
break;
}
}
}
}

#endif /* !USE_PROC_FOR_LIBRARIES */

#endif /* LINUX */

#if defined(IRIX5) || (defined(USE_PROC_FOR_LIBRARIES) && !defined(LINUX))

#include <sys/procfs.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <elf.h>
#include <errno.h>
#include <signal.h> /* Only for the following test. */
#ifndef _sigargs
# define IRIX6
#endif

/* We use /proc to track down all parts of the address space that are */
/* mapped by the process, and throw out regions we know we shouldn't */
/* worry about. This may also work under other SVR4 variants. */
GC_INNER void GC_register_dynamic_libraries(void)
{
static int fd = -1;
char buf[30];
static prmap_t * addr_map = 0;
static int current_sz = 0; /* Number of records currently in addr_map */
int needed_sz = 0; /* Required size of addr_map */
int i;
long flags;
ptr_t start;
ptr_t limit;
ptr_t heap_start = HEAP_START;
ptr_t heap_end = heap_start;

# ifdef SOLARISDL
# define MA_PHYS 0
# endif /* SOLARISDL */

if (fd < 0) {
(void)snprintf(buf, sizeof(buf), "/proc/%ld", (long)getpid());
buf[sizeof(buf) - 1] = '\0';
fd = open(buf, O_RDONLY);
if (fd < 0) {
ABORT("/proc open failed");
}
}
if (ioctl(fd, PIOCNMAP, &needed_sz) < 0) {
ABORT_ARG2("/proc PIOCNMAP ioctl failed",
": fd= %d, errno= %d", fd, errno);
}
if (needed_sz >= current_sz) {
GC_scratch_recycle_no_gww(addr_map,
(size_t)current_sz * sizeof(prmap_t));
current_sz = needed_sz * 2 + 1;
/* Expansion, plus room for 0 record */
addr_map = (prmap_t *)GC_scratch_alloc(
(size_t)current_sz * sizeof(prmap_t));
if (addr_map == NULL)
ABORT("Insufficient memory for address map");
}
if (ioctl(fd, PIOCMAP, addr_map) < 0) {
ABORT_ARG3("/proc PIOCMAP ioctl failed",
": errcode= %d, needed_sz= %d, addr_map= %p",
errno, needed_sz, (void *)addr_map);
}
if (GC_n_heap_sects > 0) {
heap_end = GC_heap_sects[GC_n_heap_sects-1].hs_start
+ GC_heap_sects[GC_n_heap_sects-1].hs_bytes;
if ((word)heap_end < (word)GC_scratch_last_end_ptr)
heap_end = GC_scratch_last_end_ptr;
}
for (i = 0; i < needed_sz; i++) {
flags = addr_map[i].pr_mflags;
if ((flags & (MA_BREAK | MA_STACK | MA_PHYS
| MA_FETCHOP | MA_NOTCACHED)) != 0) goto irrelevant;
if ((flags & (MA_READ | MA_WRITE)) != (MA_READ | MA_WRITE))
goto irrelevant;
/* The latter test is empirically useless in very old Irix */
/* versions. Other than the */
/* main data and stack segments, everything appears to be */
/* mapped readable, writable, executable, and shared(!!). */
/* This makes no sense to me. - HB */
start = (ptr_t)(addr_map[i].pr_vaddr);
if (GC_roots_present(start)) goto irrelevant;
if ((word)start < (word)heap_end && (word)start >= (word)heap_start)
goto irrelevant;

limit = start + addr_map[i].pr_size;
/* The following seemed to be necessary for very old versions */
/* of Irix, but it has been reported to discard relevant */
/* segments under Irix 6.5. */
# ifndef IRIX6
if (addr_map[i].pr_off == 0 && strncmp(start, ELFMAG, 4) == 0) {
/* Discard text segments, i.e. 0-offset mappings against */
/* executable files which appear to have ELF headers. */
caddr_t arg;
int obj;
# define MAP_IRR_SZ 10
static ptr_t map_irr[MAP_IRR_SZ];
/* Known irrelevant map entries */
static int n_irr = 0;
struct stat buf;
int j;

for (j = 0; j < n_irr; j++) {
if (map_irr[j] == start) goto irrelevant;
}
arg = (caddr_t)start;
obj = ioctl(fd, PIOCOPENM, &arg);
if (obj >= 0) {
fstat(obj, &buf);
close(obj);
if ((buf.st_mode & 0111) != 0) {
if (n_irr < MAP_IRR_SZ) {
map_irr[n_irr++] = start;
}
goto irrelevant;
}
}
}
# endif /* !IRIX6 */
GC_add_roots_inner(start, limit, TRUE);
irrelevant: ;
}
/* Don't keep cached descriptor, for now. Some kernels don't like us */
/* to keep a /proc file descriptor around during kill -9. */
/* Otherwise, it should also require FD_CLOEXEC and proper handling */
/* at fork (i.e. close because of the pid change). */
if (close(fd) < 0) ABORT("Couldn't close /proc file");
fd = -1;
}

# endif /* USE_PROC_FOR_LIBRARIES || IRIX5 */

# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)

# include <stdlib.h>

/* We traverse the entire address space and register all segments */
/* that could possibly have been written to. */
STATIC void GC_cond_add_roots(char *base, char * limit)
{
# ifdef GC_WIN32_THREADS
char * curr_base = base;
char * next_stack_lo;
char * next_stack_hi;

if (base == limit) return;
for(;;) {
GC_get_next_stack(curr_base, limit, &next_stack_lo, &next_stack_hi);
if ((word)next_stack_lo >= (word)limit) break;
if ((word)next_stack_lo > (word)curr_base)
GC_add_roots_inner(curr_base, next_stack_lo, TRUE);
curr_base = next_stack_hi;
}
if ((word)curr_base < (word)limit)
GC_add_roots_inner(curr_base, limit, TRUE);
# else
char * stack_top
= (char *)((word)GC_approx_sp() &
~(word)(GC_sysinfo.dwAllocationGranularity - 1));

if (base == limit) return;
if ((word)limit > (word)stack_top
&& (word)base < (word)GC_stackbottom) {
/* Part of the stack; ignore it. */
return;
}
GC_add_roots_inner(base, limit, TRUE);
# endif
}

#ifdef DYNAMIC_LOADING
/* GC_register_main_static_data is not needed unless DYNAMIC_LOADING. */
GC_INNER GC_bool GC_register_main_static_data(void)
{
# if defined(MSWINCE) || defined(CYGWIN32)
/* Do we need to separately register the main static data segment? */
return FALSE;
# else
return GC_no_win32_dlls;
# endif
}
# define HAVE_REGISTER_MAIN_STATIC_DATA
#endif /* DYNAMIC_LOADING */

# ifdef DEBUG_VIRTUALQUERY
void GC_dump_meminfo(MEMORY_BASIC_INFORMATION *buf)
{
GC_printf("BaseAddress= 0x%lx, AllocationBase= 0x%lx,"
" RegionSize= 0x%lx(%lu)\n",
buf -> BaseAddress, buf -> AllocationBase,
buf -> RegionSize, buf -> RegionSize);
GC_printf("\tAllocationProtect= 0x%lx, State= 0x%lx, Protect= 0x%lx, "
"Type= 0x%lx\n", buf -> AllocationProtect, buf -> State,
buf -> Protect, buf -> Type);
}
# endif /* DEBUG_VIRTUALQUERY */

# if defined(MSWINCE) || defined(CYGWIN32)
/* FIXME: Should we really need to scan MEM_PRIVATE sections? */
/* For now, we don't add MEM_PRIVATE sections to the data roots for */
/* WinCE because otherwise SEGV fault sometimes happens to occur in */
/* GC_mark_from() (and, even if we use WRAP_MARK_SOME, WinCE prints */
/* a "Data Abort" message to the debugging console). */
/* To workaround that, use -DGC_REGISTER_MEM_PRIVATE. */
# define GC_wnt TRUE
# endif

GC_INNER void GC_register_dynamic_libraries(void)
{
MEMORY_BASIC_INFORMATION buf;
DWORD protect;
LPVOID p;
char * base;
char * limit;

# ifdef MSWIN32
if (GC_no_win32_dlls) return;
# endif
p = GC_sysinfo.lpMinimumApplicationAddress;
base = limit = (char *)p;
while ((word)p < (word)GC_sysinfo.lpMaximumApplicationAddress) {
size_t result = VirtualQuery(p, &buf, sizeof(buf));

# ifdef MSWINCE
if (result == 0) {
if ((word)p > GC_WORD_MAX - GC_sysinfo.dwAllocationGranularity)
break; /* overflow */
/* Page is free; advance to the next possible allocation base. */
p = (LPVOID)(((DWORD)p + GC_sysinfo.dwAllocationGranularity)
& ~(GC_sysinfo.dwAllocationGranularity-1));
} else
# endif
/* else */ {
if (result != sizeof(buf)) {
ABORT("Weird VirtualQuery result");
}
if ((word)p > GC_WORD_MAX - buf.RegionSize) break; /* overflow */

protect = buf.Protect;
if (buf.State == MEM_COMMIT
&& (protect == PAGE_EXECUTE_READWRITE
|| protect == PAGE_EXECUTE_WRITECOPY
|| protect == PAGE_READWRITE
|| protect == PAGE_WRITECOPY)
&& (buf.Type == MEM_IMAGE
# ifdef GC_REGISTER_MEM_PRIVATE
|| (protect == PAGE_READWRITE && buf.Type == MEM_PRIVATE)
# else
/* There is some evidence that we cannot always */
/* ignore MEM_PRIVATE sections under Windows ME */
/* and predecessors. Hence we now also check for */
/* that case. */
|| (!GC_wnt && buf.Type == MEM_PRIVATE)
# endif
)
&& !GC_is_heap_base(buf.AllocationBase)) {
# ifdef DEBUG_VIRTUALQUERY
GC_dump_meminfo(&buf);
# endif
if ((char *)p != limit) {
GC_cond_add_roots(base, limit);
base = (char *)p;
}
limit = (char *)p + buf.RegionSize;
}
p = (char *)p + buf.RegionSize;
}
}
GC_cond_add_roots(base, limit);
}

#endif /* MSWIN32 || MSWINCE || CYGWIN32 */

#if defined(ALPHA) && defined(OSF1)

#include <loader.h>

EXTERN_C_BEGIN
extern char *sys_errlist[];
extern int sys_nerr;
extern int errno;
EXTERN_C_END

GC_INNER void GC_register_dynamic_libraries(void)
{
ldr_module_t moduleid = LDR_NULL_MODULE;
ldr_process_t mypid = ldr_my_process(); /* obtain id of this process */

/* For each module */
while (TRUE) {
ldr_module_info_t moduleinfo;
size_t modulereturnsize;
ldr_region_t region;
ldr_region_info_t regioninfo;
size_t regionreturnsize;
int status = ldr_next_module(mypid, &moduleid);
/* Get the next (first) module */

/* Any more modules? */
if (moduleid == LDR_NULL_MODULE)
break; /* No more modules */

/* Check status AFTER checking moduleid because */
/* of a bug in the non-shared ldr_next_module stub. */
if (status != 0) {
ABORT_ARG3("ldr_next_module failed",
": status= %d, errcode= %d (%s)", status, errno,
errno < sys_nerr ? sys_errlist[errno] : "");
}

/* Get the module information */
status = ldr_inq_module(mypid, moduleid, &moduleinfo,
sizeof(moduleinfo), &modulereturnsize);
if (status != 0 )
ABORT("ldr_inq_module failed");

/* is module for the main program (i.e. nonshared portion)? */
if (moduleinfo.lmi_flags & LDR_MAIN)
continue; /* skip the main module */

# ifdef DL_VERBOSE
GC_log_printf("---Module---\n");
GC_log_printf("Module ID: %ld\n", moduleinfo.lmi_modid);
GC_log_printf("Count of regions: %d\n", moduleinfo.lmi_nregion);
GC_log_printf("Flags for module: %016lx\n", moduleinfo.lmi_flags);
GC_log_printf("Module pathname: \"%s\"\n", moduleinfo.lmi_name);
# endif

/* For each region in this module */
for (region = 0; region < moduleinfo.lmi_nregion; region++) {
/* Get the region information */
status = ldr_inq_region(mypid, moduleid, region, &regioninfo,
sizeof(regioninfo), &regionreturnsize);
if (status != 0 )
ABORT("ldr_inq_region failed");

/* only process writable (data) regions */
if (! (regioninfo.lri_prot & LDR_W))
continue;

# ifdef DL_VERBOSE
GC_log_printf("--- Region ---\n");
GC_log_printf("Region number: %ld\n", regioninfo.lri_region_no);
GC_log_printf("Protection flags: %016x\n", regioninfo.lri_prot);
GC_log_printf("Virtual address: %p\n", regioninfo.lri_vaddr);
GC_log_printf("Mapped address: %p\n", regioninfo.lri_mapaddr);
GC_log_printf("Region size: %ld\n", regioninfo.lri_size);
GC_log_printf("Region name: \"%s\"\n", regioninfo.lri_name);
# endif

/* register region as a garbage collection root */
GC_add_roots_inner((char *)regioninfo.lri_mapaddr,
(char *)regioninfo.lri_mapaddr + regioninfo.lri_size,
TRUE);

}
}
}
#endif

#if defined(HPUX)

#include <errno.h>
#include <dl.h>

EXTERN_C_BEGIN
extern char *sys_errlist[];
extern int sys_nerr;
EXTERN_C_END

GC_INNER void GC_register_dynamic_libraries(void)
{
int index = 1; /* Ordinal position in shared library search list */

/* For each dynamic library loaded */
while (TRUE) {
struct shl_descriptor *shl_desc; /* Shared library info, see dl.h */
int status = shl_get(index, &shl_desc);
/* Get info about next shared library */

/* Check if this is the end of the list or if some error occurred */
if (status != 0) {
# ifdef GC_HPUX_THREADS
/* I've seen errno values of 0. The man page is not clear */
/* as to whether errno should get set on a -1 return. */
break;
# else
if (errno == EINVAL) {
break; /* Moved past end of shared library list --> finished */
} else {
ABORT_ARG3("shl_get failed",
": status= %d, errcode= %d (%s)", status, errno,
errno < sys_nerr ? sys_errlist[errno] : "");
}
# endif
}

# ifdef DL_VERBOSE
GC_log_printf("---Shared library---\n");
GC_log_printf("filename= \"%s\"\n", shl_desc->filename);
GC_log_printf("index= %d\n", index);
GC_log_printf("handle= %08x\n", (unsigned long) shl_desc->handle);
GC_log_printf("text seg.start= %08x\n", shl_desc->tstart);
GC_log_printf("text seg.end= %08x\n", shl_desc->tend);
GC_log_printf("data seg.start= %08x\n", shl_desc->dstart);
GC_log_printf("data seg.end= %08x\n", shl_desc->dend);
GC_log_printf("ref.count= %lu\n", shl_desc->ref_count);
# endif

/* register shared library's data segment as a garbage collection root */
GC_add_roots_inner((char *) shl_desc->dstart,
(char *) shl_desc->dend, TRUE);

index++;
}
}
#endif /* HPUX */

#ifdef AIX
# include <alloca.h>
# include <sys/ldr.h>
# include <sys/errno.h>
GC_INNER void GC_register_dynamic_libraries(void)
{
int ldibuflen = 8192;

for (;;) {
int len;
struct ld_info *ldi;
# if defined(CPPCHECK)
char ldibuf[ldibuflen];
# else
char *ldibuf = alloca(ldibuflen);
# endif

len = loadquery(L_GETINFO, ldibuf, ldibuflen);
if (len < 0) {
if (errno != ENOMEM) {
ABORT("loadquery failed");
}
ldibuflen *= 2;
continue;
}

ldi = (struct ld_info *)ldibuf;
while (ldi) {
len = ldi->ldinfo_next;
GC_add_roots_inner(
ldi->ldinfo_dataorg,
(ptr_t)(unsigned long)ldi->ldinfo_dataorg
+ ldi->ldinfo_datasize,
TRUE);
ldi = len ? (struct ld_info *)((char *)ldi + len) : 0;
}
break;
}
}
#endif /* AIX */

#ifdef DARWIN

/* __private_extern__ hack required for pre-3.4 gcc versions. */
#ifndef __private_extern__
# define __private_extern__ extern
# include <mach-o/dyld.h>
# undef __private_extern__
#else
# include <mach-o/dyld.h>
#endif
#include <mach-o/getsect.h>

/*#define DARWIN_DEBUG*/

/* Writable sections generally available on Darwin. */
STATIC const struct dyld_sections_s {
const char *seg;
const char *sect;
} GC_dyld_sections[] = {
{ SEG_DATA, SECT_DATA },
/* Used by FSF GCC, but not by OS X system tools, so far. */
{ SEG_DATA, "__static_data" },
{ SEG_DATA, SECT_BSS },
{ SEG_DATA, SECT_COMMON },
/* FSF GCC - zero-sized object sections for targets */
/*supporting section anchors. */
{ SEG_DATA, "__zobj_data" },
{ SEG_DATA, "__zobj_bss" }
};

/* Additional writable sections: */
/* GCC on Darwin constructs aligned sections "on demand", where */
/* the alignment size is embedded in the section name. */
/* Furthermore, there are distinctions between sections */
/* containing private vs. public symbols. It also constructs */
/* sections specifically for zero-sized objects, when the */
/* target supports section anchors. */
STATIC const char * const GC_dyld_add_sect_fmts[] = {
"__bss%u",
"__pu_bss%u",
"__zo_bss%u",
"__zo_pu_bss%u"
};

/* Currently, mach-o will allow up to the max of 2^15 alignment */
/* in an object file. */
#ifndef L2_MAX_OFILE_ALIGNMENT
# define L2_MAX_OFILE_ALIGNMENT 15
#endif

STATIC const char *GC_dyld_name_for_hdr(const struct GC_MACH_HEADER *hdr)
{
unsigned long i, c;
c = _dyld_image_count();
for (i = 0; i < c; i++)
if ((const struct GC_MACH_HEADER *)_dyld_get_image_header(i) == hdr)
return _dyld_get_image_name(i);
return NULL;
}

/* This should never be called by a thread holding the lock. */
STATIC void GC_dyld_image_add(const struct GC_MACH_HEADER *hdr,
intptr_t slide)
{
unsigned long start, end;
unsigned i, j;
const struct GC_MACH_SECTION *sec;
const char *name;
GC_has_static_roots_func callback = GC_has_static_roots;
DCL_LOCK_STATE;

if (GC_no_dls) return;
# ifdef DARWIN_DEBUG
name = GC_dyld_name_for_hdr(hdr);
# else
name = callback != 0 ? GC_dyld_name_for_hdr(hdr) : NULL;
# endif
for (i = 0; i < sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]); i++) {
sec = GC_GETSECTBYNAME(hdr, GC_dyld_sections[i].seg,
GC_dyld_sections[i].sect);
if (sec == NULL || sec->size < sizeof(word))
continue;
start = slide + sec->addr;
end = start + sec->size;
LOCK();
/* The user callback is called holding the lock. */
if (callback == 0 || callback(name, (void*)start, (size_t)sec->size)) {
# ifdef DARWIN_DEBUG
GC_log_printf(
"Adding section __DATA,%s at %p-%p (%lu bytes) from image %s\n",
GC_dyld_sections[i].sect, (void*)start, (void*)end,
(unsigned long)sec->size, name);
# endif
GC_add_roots_inner((ptr_t)start, (ptr_t)end, FALSE);
}
UNLOCK();
}

/* Sections constructed on demand. */
for (j = 0; j < sizeof(GC_dyld_add_sect_fmts) / sizeof(char *); j++) {
const char *fmt = GC_dyld_add_sect_fmts[j];

/* Add our manufactured aligned BSS sections. */
for (i = 0; i <= L2_MAX_OFILE_ALIGNMENT; i++) {
char secnam[16];

(void)snprintf(secnam, sizeof(secnam), fmt, (unsigned)i);
secnam[sizeof(secnam) - 1] = '\0';
sec = GC_GETSECTBYNAME(hdr, SEG_DATA, secnam);
if (sec == NULL || sec->size == 0)
continue;
start = slide + sec->addr;
end = start + sec->size;
# ifdef DARWIN_DEBUG
GC_log_printf("Adding on-demand section __DATA,%s at"
" %p-%p (%lu bytes) from image %s\n",
secnam, (void*)start, (void*)end,
(unsigned long)sec->size, name);
# endif
GC_add_roots((char*)start, (char*)end);
}
}

# if defined(DARWIN_DEBUG) && !defined(NO_DEBUGGING)
LOCK();
GC_print_static_roots();
UNLOCK();
# endif
}

/* This should never be called by a thread holding the lock. */
STATIC void GC_dyld_image_remove(const struct GC_MACH_HEADER *hdr,
intptr_t slide)
{
unsigned long start, end;
unsigned i, j;
const struct GC_MACH_SECTION *sec;
# if defined(DARWIN_DEBUG) && !defined(NO_DEBUGGING)
DCL_LOCK_STATE;
# endif

for (i = 0; i < sizeof(GC_dyld_sections)/sizeof(GC_dyld_sections[0]); i++) {
sec = GC_GETSECTBYNAME(hdr, GC_dyld_sections[i].seg,
GC_dyld_sections[i].sect);
if (sec == NULL || sec->size == 0)
continue;
start = slide + sec->addr;
end = start + sec->size;
# ifdef DARWIN_DEBUG
GC_log_printf(
"Removing section __DATA,%s at %p-%p (%lu bytes) from image %s\n",
GC_dyld_sections[i].sect, (void*)start, (void*)end,
(unsigned long)sec->size, GC_dyld_name_for_hdr(hdr));
# endif
GC_remove_roots((char*)start, (char*)end);
}

/* Remove our on-demand sections. */
for (j = 0; j < sizeof(GC_dyld_add_sect_fmts) / sizeof(char *); j++) {
const char *fmt = GC_dyld_add_sect_fmts[j];

for (i = 0; i <= L2_MAX_OFILE_ALIGNMENT; i++) {
char secnam[16];

(void)snprintf(secnam, sizeof(secnam), fmt, (unsigned)i);
secnam[sizeof(secnam) - 1] = '\0';
sec = GC_GETSECTBYNAME(hdr, SEG_DATA, secnam);
if (sec == NULL || sec->size == 0)
continue;
start = slide + sec->addr;
end = start + sec->size;
# ifdef DARWIN_DEBUG
GC_log_printf("Removing on-demand section __DATA,%s at"
" %p-%p (%lu bytes) from image %s\n", secnam,
(void*)start, (void*)end, (unsigned long)sec->size,
GC_dyld_name_for_hdr(hdr));
# endif
GC_remove_roots((char*)start, (char*)end);
}
}

# if defined(DARWIN_DEBUG) && !defined(NO_DEBUGGING)
LOCK();
GC_print_static_roots();
UNLOCK();
# endif
}

GC_INNER void GC_register_dynamic_libraries(void)
{
/* Currently does nothing. The callbacks are setup by GC_init_dyld()
The dyld library takes it from there. */
}

/* The _dyld_* functions have an internal lock so no _dyld functions
can be called while the world is stopped without the risk of a deadlock.
Because of this we MUST setup callbacks BEFORE we ever stop the world.
This should be called BEFORE any thread is created and WITHOUT the
allocation lock held. */

GC_INNER void GC_init_dyld(void)
{
static GC_bool initialized = FALSE;

if (initialized) return;

# ifdef DARWIN_DEBUG
GC_log_printf("Registering dyld callbacks...\n");
# endif

/* Apple's Documentation:
When you call _dyld_register_func_for_add_image, the dynamic linker
runtime calls the specified callback (func) once for each of the images
that is currently loaded into the program. When a new image is added to
the program, your callback is called again with the mach_header for the
new image, and the virtual memory slide amount of the new image.

This WILL properly register already linked libraries and libraries
linked in the future.
*/
_dyld_register_func_for_add_image(
(void (*)(const struct mach_header*, intptr_t))GC_dyld_image_add);
_dyld_register_func_for_remove_image(
(void (*)(const struct mach_header*, intptr_t))GC_dyld_image_remove);
/* Structure mach_header_64 has the same fields */
/* as mach_header except for the reserved one */
/* at the end, so these casts are OK. */

/* Set this early to avoid reentrancy issues. */
initialized = TRUE;

# ifdef NO_DYLD_BIND_FULLY_IMAGE
/* FIXME: What should we do in this case? */
# else
if (GC_no_dls) return; /* skip main data segment registration */

/* When the environment variable is set, the dynamic linker binds */
/* all undefined symbols the application needs at launch time. */
/* This includes function symbols that are normally bound lazily at */
/* the time of their first invocation. */
if (GETENV("DYLD_BIND_AT_LAUNCH") == 0) {
/* The environment variable is unset, so we should bind manually. */
# ifdef DARWIN_DEBUG
GC_log_printf("Forcing full bind of GC code...\n");
# endif
/* FIXME: '_dyld_bind_fully_image_containing_address' is deprecated. */
if (!_dyld_bind_fully_image_containing_address(
(unsigned long *)GC_malloc))
ABORT("_dyld_bind_fully_image_containing_address failed");
}
# endif
}

#define HAVE_REGISTER_MAIN_STATIC_DATA
GC_INNER GC_bool GC_register_main_static_data(void)
{
/* Already done through dyld callbacks */
return FALSE;
}

#endif /* DARWIN */

#if defined(HAIKU)
# include <kernel/image.h>

GC_INNER void GC_register_dynamic_libraries(void)
{
image_info info;
int32 cookie = 0;

while (get_next_image_info(0, &cookie, &info) == B_OK) {
ptr_t data = (ptr_t)info.data;
GC_add_roots_inner(data, data + info.data_size, TRUE);
}
}
#endif /* HAIKU */

#elif defined(PCR)

# include "il/PCR_IL.h"
# include "th/PCR_ThCtl.h"
# include "mm/PCR_MM.h"

GC_INNER void GC_register_dynamic_libraries(void)
{
/* Add new static data areas of dynamically loaded modules. */
PCR_IL_LoadedFile * p = PCR_IL_GetLastLoadedFile();
PCR_IL_LoadedSegment * q;

/* Skip uncommitted files */
while (p != NIL && !(p -> lf_commitPoint)) {
/* The loading of this file has not yet been committed */
/* Hence its description could be inconsistent. */
/* Furthermore, it hasn't yet been run. Hence its data */
/* segments can't possibly reference heap allocated */
/* objects. */
p = p -> lf_prev;
}
for (; p != NIL; p = p -> lf_prev) {
for (q = p -> lf_ls; q != NIL; q = q -> ls_next) {
if ((q -> ls_flags & PCR_IL_SegFlags_Traced_MASK)
== PCR_IL_SegFlags_Traced_on) {
GC_add_roots_inner((ptr_t)q->ls_addr,
(ptr_t)q->ls_addr + q->ls_bytes, TRUE);
}
}
}
}
#endif /* PCR && !DYNAMIC_LOADING && !MSWIN32 */

#if !defined(HAVE_REGISTER_MAIN_STATIC_DATA) && defined(DYNAMIC_LOADING)
/* Do we need to separately register the main static data segment? */
GC_INNER GC_bool GC_register_main_static_data(void)
{
return TRUE;
}
#endif /* HAVE_REGISTER_MAIN_STATIC_DATA */

/* Register a routine to filter dynamic library registration. */
GC_API void GC_CALL GC_register_has_static_roots_callback(
GC_has_static_roots_func callback)
{
GC_has_static_roots = callback;
}