freebsd-nq/lib/libctf/common/ctf_lib.c
Xin LI 0239dcb737 Update vendor/illumos/dist to 14148:fe28bd725808:
Illumos DTrace issues:
  4005 libctf can't deal with extended sections
2013-08-23 23:34:54 +00:00

505 lines
13 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <ctf_impl.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <dlfcn.h>
#include <gelf.h>
#ifdef _LP64
static const char *_libctf_zlib = "/usr/lib/64/libz.so.1";
#else
static const char *_libctf_zlib = "/usr/lib/libz.so.1";
#endif
static struct {
int (*z_uncompress)(uchar_t *, ulong_t *, const uchar_t *, ulong_t);
const char *(*z_error)(int);
void *z_dlp;
} zlib;
static size_t _PAGESIZE;
static size_t _PAGEMASK;
#pragma init(_libctf_init)
void
_libctf_init(void)
{
const char *p = getenv("LIBCTF_DECOMPRESSOR");
if (p != NULL)
_libctf_zlib = p; /* use alternate decompression library */
_libctf_debug = getenv("LIBCTF_DEBUG") != NULL;
_PAGESIZE = getpagesize();
_PAGEMASK = ~(_PAGESIZE - 1);
}
/*
* Attempt to dlopen the decompression library and locate the symbols of
* interest that we will need to call. This information in cached so
* that multiple calls to ctf_bufopen() do not need to reopen the library.
*/
void *
ctf_zopen(int *errp)
{
ctf_dprintf("decompressing CTF data using %s\n", _libctf_zlib);
if (zlib.z_dlp != NULL)
return (zlib.z_dlp); /* library is already loaded */
if (access(_libctf_zlib, R_OK) == -1)
return (ctf_set_open_errno(errp, ECTF_ZMISSING));
if ((zlib.z_dlp = dlopen(_libctf_zlib, RTLD_LAZY | RTLD_LOCAL)) == NULL)
return (ctf_set_open_errno(errp, ECTF_ZINIT));
zlib.z_uncompress = (int (*)()) dlsym(zlib.z_dlp, "uncompress");
zlib.z_error = (const char *(*)()) dlsym(zlib.z_dlp, "zError");
if (zlib.z_uncompress == NULL || zlib.z_error == NULL) {
(void) dlclose(zlib.z_dlp);
bzero(&zlib, sizeof (zlib));
return (ctf_set_open_errno(errp, ECTF_ZINIT));
}
return (zlib.z_dlp);
}
/*
* The ctf_bufopen() routine calls these subroutines, defined by <sys/zmod.h>,
* which we then patch through to the functions in the decompression library.
*/
int
z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
return (zlib.z_uncompress(dst, (ulong_t *)dstlen, src, srclen));
}
const char *
z_strerror(int err)
{
return (zlib.z_error(err));
}
/*
* Convert a 32-bit ELF file header into GElf.
*/
static void
ehdr_to_gelf(const Elf32_Ehdr *src, GElf_Ehdr *dst)
{
bcopy(src->e_ident, dst->e_ident, EI_NIDENT);
dst->e_type = src->e_type;
dst->e_machine = src->e_machine;
dst->e_version = src->e_version;
dst->e_entry = (Elf64_Addr)src->e_entry;
dst->e_phoff = (Elf64_Off)src->e_phoff;
dst->e_shoff = (Elf64_Off)src->e_shoff;
dst->e_flags = src->e_flags;
dst->e_ehsize = src->e_ehsize;
dst->e_phentsize = src->e_phentsize;
dst->e_phnum = src->e_phnum;
dst->e_shentsize = src->e_shentsize;
dst->e_shnum = src->e_shnum;
dst->e_shstrndx = src->e_shstrndx;
}
/*
* Convert a 32-bit ELF section header into GElf.
*/
static void
shdr_to_gelf(const Elf32_Shdr *src, GElf_Shdr *dst)
{
dst->sh_name = src->sh_name;
dst->sh_type = src->sh_type;
dst->sh_flags = src->sh_flags;
dst->sh_addr = src->sh_addr;
dst->sh_offset = src->sh_offset;
dst->sh_size = src->sh_size;
dst->sh_link = src->sh_link;
dst->sh_info = src->sh_info;
dst->sh_addralign = src->sh_addralign;
dst->sh_entsize = src->sh_entsize;
}
/*
* In order to mmap a section from the ELF file, we must round down sh_offset
* to the previous page boundary, and mmap the surrounding page. We store
* the pointer to the start of the actual section data back into sp->cts_data.
*/
const void *
ctf_sect_mmap(ctf_sect_t *sp, int fd)
{
size_t pageoff = sp->cts_offset & ~_PAGEMASK;
caddr_t base = mmap64(NULL, sp->cts_size + pageoff, PROT_READ,
MAP_PRIVATE, fd, sp->cts_offset & _PAGEMASK);
if (base != MAP_FAILED)
sp->cts_data = base + pageoff;
return (base);
}
/*
* Since sp->cts_data has the adjusted offset, we have to again round down
* to get the actual mmap address and round up to get the size.
*/
void
ctf_sect_munmap(const ctf_sect_t *sp)
{
uintptr_t addr = (uintptr_t)sp->cts_data;
uintptr_t pageoff = addr & ~_PAGEMASK;
(void) munmap((void *)(addr - pageoff), sp->cts_size + pageoff);
}
/*
* Open the specified file descriptor and return a pointer to a CTF container.
* The file can be either an ELF file or raw CTF file. The caller is
* responsible for closing the file descriptor when it is no longer needed.
*/
ctf_file_t *
ctf_fdopen(int fd, int *errp)
{
ctf_sect_t ctfsect, symsect, strsect;
ctf_file_t *fp = NULL;
size_t shstrndx, shnum;
struct stat64 st;
ssize_t nbytes;
union {
ctf_preamble_t ctf;
Elf32_Ehdr e32;
GElf_Ehdr e64;
} hdr;
bzero(&ctfsect, sizeof (ctf_sect_t));
bzero(&symsect, sizeof (ctf_sect_t));
bzero(&strsect, sizeof (ctf_sect_t));
bzero(&hdr.ctf, sizeof (hdr));
if (fstat64(fd, &st) == -1)
return (ctf_set_open_errno(errp, errno));
if ((nbytes = pread64(fd, &hdr.ctf, sizeof (hdr), 0)) <= 0)
return (ctf_set_open_errno(errp, nbytes < 0? errno : ECTF_FMT));
/*
* If we have read enough bytes to form a CTF header and the magic
* string matches, attempt to interpret the file as raw CTF.
*/
if (nbytes >= sizeof (ctf_preamble_t) &&
hdr.ctf.ctp_magic == CTF_MAGIC) {
if (hdr.ctf.ctp_version > CTF_VERSION)
return (ctf_set_open_errno(errp, ECTF_CTFVERS));
ctfsect.cts_data = mmap64(NULL, st.st_size, PROT_READ,
MAP_PRIVATE, fd, 0);
if (ctfsect.cts_data == MAP_FAILED)
return (ctf_set_open_errno(errp, errno));
ctfsect.cts_name = _CTF_SECTION;
ctfsect.cts_type = SHT_PROGBITS;
ctfsect.cts_flags = SHF_ALLOC;
ctfsect.cts_size = (size_t)st.st_size;
ctfsect.cts_entsize = 1;
ctfsect.cts_offset = 0;
if ((fp = ctf_bufopen(&ctfsect, NULL, NULL, errp)) == NULL)
ctf_sect_munmap(&ctfsect);
return (fp);
}
/*
* If we have read enough bytes to form an ELF header and the magic
* string matches, attempt to interpret the file as an ELF file. We
* do our own largefile ELF processing, and convert everything to
* GElf structures so that clients can operate on any data model.
*/
if (nbytes >= sizeof (Elf32_Ehdr) &&
bcmp(&hdr.e32.e_ident[EI_MAG0], ELFMAG, SELFMAG) == 0) {
#ifdef _BIG_ENDIAN
uchar_t order = ELFDATA2MSB;
#else
uchar_t order = ELFDATA2LSB;
#endif
GElf_Shdr *sp;
void *strs_map;
size_t strs_mapsz, i;
const char *strs;
if (hdr.e32.e_ident[EI_DATA] != order)
return (ctf_set_open_errno(errp, ECTF_ENDIAN));
if (hdr.e32.e_version != EV_CURRENT)
return (ctf_set_open_errno(errp, ECTF_ELFVERS));
if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS64) {
if (nbytes < sizeof (GElf_Ehdr))
return (ctf_set_open_errno(errp, ECTF_FMT));
} else {
Elf32_Ehdr e32 = hdr.e32;
ehdr_to_gelf(&e32, &hdr.e64);
}
shnum = hdr.e64.e_shnum;
shstrndx = hdr.e64.e_shstrndx;
/* Extended ELF sections */
if ((shstrndx == SHN_XINDEX) || (shnum == 0)) {
if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
Elf32_Shdr x32;
if (pread64(fd, &x32, sizeof (x32),
hdr.e64.e_shoff) != sizeof (x32))
return (ctf_set_open_errno(errp,
errno));
shnum = x32.sh_size;
shstrndx = x32.sh_link;
} else {
Elf64_Shdr x64;
if (pread64(fd, &x64, sizeof (x64),
hdr.e64.e_shoff) != sizeof (x64))
return (ctf_set_open_errno(errp,
errno));
shnum = x64.sh_size;
shstrndx = x64.sh_link;
}
}
if (shstrndx >= shnum)
return (ctf_set_open_errno(errp, ECTF_CORRUPT));
nbytes = sizeof (GElf_Shdr) * shnum;
if ((sp = malloc(nbytes)) == NULL)
return (ctf_set_open_errno(errp, errno));
/*
* Read in and convert to GElf the array of Shdr structures
* from e_shoff so we can locate sections of interest.
*/
if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
Elf32_Shdr *sp32;
nbytes = sizeof (Elf32_Shdr) * shnum;
if ((sp32 = malloc(nbytes)) == NULL || pread64(fd,
sp32, nbytes, hdr.e64.e_shoff) != nbytes) {
free(sp);
return (ctf_set_open_errno(errp, errno));
}
for (i = 0; i < shnum; i++)
shdr_to_gelf(&sp32[i], &sp[i]);
free(sp32);
} else if (pread64(fd, sp, nbytes, hdr.e64.e_shoff) != nbytes) {
free(sp);
return (ctf_set_open_errno(errp, errno));
}
/*
* Now mmap the section header strings section so that we can
* perform string comparison on the section names.
*/
strs_mapsz = sp[shstrndx].sh_size +
(sp[shstrndx].sh_offset & ~_PAGEMASK);
strs_map = mmap64(NULL, strs_mapsz, PROT_READ, MAP_PRIVATE,
fd, sp[shstrndx].sh_offset & _PAGEMASK);
strs = (const char *)strs_map +
(sp[shstrndx].sh_offset & ~_PAGEMASK);
if (strs_map == MAP_FAILED) {
free(sp);
return (ctf_set_open_errno(errp, ECTF_MMAP));
}
/*
* Iterate over the section header array looking for the CTF
* section and symbol table. The strtab is linked to symtab.
*/
for (i = 0; i < shnum; i++) {
const GElf_Shdr *shp = &sp[i];
const GElf_Shdr *lhp = &sp[shp->sh_link];
if (shp->sh_link >= shnum)
continue; /* corrupt sh_link field */
if (shp->sh_name >= sp[shstrndx].sh_size ||
lhp->sh_name >= sp[shstrndx].sh_size)
continue; /* corrupt sh_name field */
if (shp->sh_type == SHT_PROGBITS &&
strcmp(strs + shp->sh_name, _CTF_SECTION) == 0) {
ctfsect.cts_name = strs + shp->sh_name;
ctfsect.cts_type = shp->sh_type;
ctfsect.cts_flags = shp->sh_flags;
ctfsect.cts_size = shp->sh_size;
ctfsect.cts_entsize = shp->sh_entsize;
ctfsect.cts_offset = (off64_t)shp->sh_offset;
} else if (shp->sh_type == SHT_SYMTAB) {
symsect.cts_name = strs + shp->sh_name;
symsect.cts_type = shp->sh_type;
symsect.cts_flags = shp->sh_flags;
symsect.cts_size = shp->sh_size;
symsect.cts_entsize = shp->sh_entsize;
symsect.cts_offset = (off64_t)shp->sh_offset;
strsect.cts_name = strs + lhp->sh_name;
strsect.cts_type = lhp->sh_type;
strsect.cts_flags = lhp->sh_flags;
strsect.cts_size = lhp->sh_size;
strsect.cts_entsize = lhp->sh_entsize;
strsect.cts_offset = (off64_t)lhp->sh_offset;
}
}
free(sp); /* free section header array */
if (ctfsect.cts_type == SHT_NULL) {
(void) munmap(strs_map, strs_mapsz);
return (ctf_set_open_errno(errp, ECTF_NOCTFDATA));
}
/*
* Now mmap the CTF data, symtab, and strtab sections and
* call ctf_bufopen() to do the rest of the work.
*/
if (ctf_sect_mmap(&ctfsect, fd) == MAP_FAILED) {
(void) munmap(strs_map, strs_mapsz);
return (ctf_set_open_errno(errp, ECTF_MMAP));
}
if (symsect.cts_type != SHT_NULL &&
strsect.cts_type != SHT_NULL) {
if (ctf_sect_mmap(&symsect, fd) == MAP_FAILED ||
ctf_sect_mmap(&strsect, fd) == MAP_FAILED) {
(void) ctf_set_open_errno(errp, ECTF_MMAP);
goto bad; /* unmap all and abort */
}
fp = ctf_bufopen(&ctfsect, &symsect, &strsect, errp);
} else
fp = ctf_bufopen(&ctfsect, NULL, NULL, errp);
bad:
if (fp == NULL) {
ctf_sect_munmap(&ctfsect);
ctf_sect_munmap(&symsect);
ctf_sect_munmap(&strsect);
} else
fp->ctf_flags |= LCTF_MMAP;
(void) munmap(strs_map, strs_mapsz);
return (fp);
}
return (ctf_set_open_errno(errp, ECTF_FMT));
}
/*
* Open the specified file and return a pointer to a CTF container. The file
* can be either an ELF file or raw CTF file. This is just a convenient
* wrapper around ctf_fdopen() for callers.
*/
ctf_file_t *
ctf_open(const char *filename, int *errp)
{
ctf_file_t *fp;
int fd;
if ((fd = open64(filename, O_RDONLY)) == -1) {
if (errp != NULL)
*errp = errno;
return (NULL);
}
fp = ctf_fdopen(fd, errp);
(void) close(fd);
return (fp);
}
/*
* Write the uncompressed CTF data stream to the specified file descriptor.
* This is useful for saving the results of dynamic CTF containers.
*/
int
ctf_write(ctf_file_t *fp, int fd)
{
const uchar_t *buf = fp->ctf_base;
ssize_t resid = fp->ctf_size;
ssize_t len;
while (resid != 0) {
if ((len = write(fd, buf, resid)) <= 0)
return (ctf_set_errno(fp, errno));
resid -= len;
buf += len;
}
return (0);
}
/*
* Set the CTF library client version to the specified version. If version is
* zero, we just return the default library version number.
*/
int
ctf_version(int version)
{
if (version < 0) {
errno = EINVAL;
return (-1);
}
if (version > 0) {
if (version > CTF_VERSION) {
errno = ENOTSUP;
return (-1);
}
ctf_dprintf("ctf_version: client using version %d\n", version);
_libctf_version = version;
}
return (_libctf_version);
}