/* $NetBSD: kern_ctf.c,v 1.9 2025/05/08 08:30:15 hannken Exp $ */
/*-
* Copyright (c) 2008 John Birrell <
[email protected]>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/sys/kern/kern_ctf.c,v 1.1.4.1 2009/08/03 08:13:06 kensmith Exp $
*/
#define ELFSIZE ARCH_ELFSIZE
#include <sys/proc.h>
#include <sys/module.h>
#include <sys/exec.h>
#include <sys/exec_elf.h>
#include <sys/kmem.h>
#include <sys/malloc.h>
#include <sys/kobj_impl.h>
#include <sys/kobj.h>
#include <sys/kern_ctf.h>
#define _KSYMS_PRIVATE
#include <sys/ksyms.h>
#include <net/zlib.h>
/*
* Note this file is included by both link_elf.c and link_elf_obj.c.
*
* The CTF header structure definition can't be used here because it's
* (annoyingly) covered by the CDDL. We will just use a few bytes from
* it as an integer array where we 'know' what they mean.
*/
#define CTF_HDR_SIZE 36
#define CTF_HDR_STRTAB_U32 7
#define CTF_HDR_STRLEN_U32 8
static void *
z_alloc(void *nil, u_int items, u_int size)
{
void *ptr;
ptr = malloc(items * size, M_TEMP, M_NOWAIT);
return ptr;
}
static void
z_free(void *nil, void *ptr)
{
free(ptr, M_TEMP);
}
int
mod_ctf_get(struct module *mod, mod_ctf_t **mcp)
{
mod_ctf_t *mc;
struct ksyms_symtab *st;
void * ctftab = NULL;
size_t sz;
int error = 0;
int compressed = 0;
void *ctfbuf = NULL;
uint8_t *ctfaddr;
uint16_t ctfmagic;
size_t ctfsize;
/*
* Return the cached mc if there is one already.
*/
extern specificdata_key_t fbt_module_key;
mc = module_getspecific(mod, fbt_module_key);
if (mc != NULL) {
*mcp = mc;
return (0);
}
/*
* Allocate and initialize a new mc.
*/
mc = kmem_zalloc(sizeof(mod_ctf_t), KM_SLEEP);
st = ksyms_get_mod(module_name(mod));
if (st != NULL) {
mc->nmap = st->sd_nmap;
mc->nmapsize = st->sd_nmapsize;
}
if (mod->mod_kobj == NULL) {
/* no kobj entry, try building from ksyms list */
if (st == NULL) {
error = ENOENT;
goto out;
}
ctfaddr = st->sd_ctfstart;
ctfsize = st->sd_ctfsize;
mc->symtab = st->sd_symstart;
mc->strtab = st->sd_strstart;
mc->strcnt = 0; /* XXX TBD */
mc->nsym = st->sd_symsize / sizeof(Elf_Sym);
} else {
if (kobj_find_section(mod->mod_kobj, ".SUNW_ctf", (void **)&ctfaddr, &ctfsize)) {
error = ENOENT;
goto out;
}
mc->symtab = mod->mod_kobj->ko_symtab;
mc->strtab = mod->mod_kobj->ko_strtab;
mc->strcnt = 0; /* XXX TBD */
mc->nsym = mod->mod_kobj->ko_symcnt;
}
if (ctfaddr == NULL) {
error = ENOENT;
goto out;
}
/* Check the CTF magic number. */
memcpy(&ctfmagic, ctfaddr, sizeof ctfmagic);
if (ctfmagic != CTF_MAGIC) {
error = EINVAL;
goto out;
}
/* Check if version 2 or 3. */
if (ctfaddr[2] != 2 && ctfaddr[2] != 3) {
error = EINVAL;
goto out;
}
/* Check if the data is compressed. */
if ((ctfaddr[3] & 0x1) != 0) {
uint32_t *u32 = (uint32_t *) ctfaddr;
/*
* The last two fields in the CTF header are the offset
* from the end of the header to the start of the string
* data and the length of that string data. se this
* information to determine the decompressed CTF data
* buffer required.
*/
sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
CTF_HDR_SIZE;
compressed = 1;
} else {
/*
* The CTF data is not compressed, so the ELF section
* size is the same as the buffer size required.
*/
sz = ctfsize;
}
/*
* Allocate memory to buffer the CTF data in its decompressed
* form.
*/
if (compressed) {
if ((ctfbuf = malloc(sz, M_TEMP, M_WAITOK)) == NULL) {
error = ENOMEM;
goto out;
}
ctftab = ctfbuf;
mc->ctfalloc = 1;
} else {
ctftab = (void *)ctfaddr;
}
/* Check if decompression is required. */
if (compressed) {
z_stream zs;
int ret;
/*
* The header isn't compressed, so copy that into the
* CTF buffer first.
*/
memcpy(ctftab, ctfaddr, CTF_HDR_SIZE);
/* Initialise the zlib structure. */
memset(&zs, 0, sizeof(zs));
zs.zalloc = z_alloc;
zs.zfree = z_free;
if (inflateInit2(&zs, MAX_WBITS) != Z_OK) {
error = EIO;
goto out;
}
zs.avail_in = ctfsize - CTF_HDR_SIZE;
zs.next_in = ctfaddr + CTF_HDR_SIZE;
zs.avail_out = sz - CTF_HDR_SIZE;
zs.next_out = ((uint8_t *) ctftab) + CTF_HDR_SIZE;
inflateReset(&zs);
if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
error = EIO;
goto out;
}
}
/* Got the CTF data! */
mc->ctfcnt = ctfsize;
mc->ctftab = ctftab;
ctfbuf = NULL;
module_setspecific(mod, fbt_module_key, mc);
*mcp = mc;
mc = NULL;
out:
if (ctfbuf != NULL)
free(ctfbuf, M_TEMP);
if (mc != NULL)
kmem_free(mc, sizeof(*mc));
return (error);
}
