On Sun, Sep 10, 2017 at 2:11 PM, Ian Lance Taylor <i...@google.com> wrote:
> On Sat, Jul 29, 2017 at 1:42 PM, Denis Khalikov
> <d.khali...@partner.samsung.com> wrote:
>>
>> Hello Ian,
>> thanks for review.
>> I've updated the patch, can you please take a look.
>
> Apologies again for the length of time it took to reply. I've had a
> hard time understanding the patch. It's quite likely that I don't
> understand how it works, but it seems to pass the same file descriptor
> to process_elf_header twice. It seems to look for debug files with
> the buildid in places where they will not be found. It seems to work
> out the file name a second time, even though the file name must
> already be known. I eventually just wrote my own implementation.
>
> Could you try this patch and see if it works for your cases? The
> patch is against current mainline. Thanks.
I have committed this patch as appended. Bootstrapped and tested on
x86_64-pc-linux-gnu.
Ian
2017-09-20 Ian Lance Taylor <i...@golang.org>
Denis Khalikov <d.khali...@partner.samsung.com>
PR sanitizer/77631
Support for external debug info.
* elf.c: Include <errno.h>, <sys/stat.h>, <unistd.h>.
(S_ISLNK): Define if not defined.
(xstrnlen): Define if strnlen is not available.
(b_elf_note): Define type.
(NT_GNU_BUILD_ID): Define macro.
(elf_crc32, elf_crc32_file): New static functions.
(elf_is_symlink, elf_readlink): New static functions.
(elf_open_debugfile_by_buildid): New static function.
(elf_try_debugfile): New static function.
(elf_find_debugfile_by_debuglink): New static function.
(elf_open_debugfile_by_debuglink): New static function.
(elf_add): Add filename and debuginfo parameters. Adjust all
callers. Look for external debug info notes, and try to fetch
debug info from external file.
(struct phdr_data): Add exe_filename field.
(phdr_callback): Pass filename to elf_add.
(backtrace_initialize): Add filename parameter.
* internal.h (backtrace_initialize): Add filename parameter.
* fileline.c (fileline_initialize): Pass filename to
backtrace_initialize.
* pecoff.c (fileline_initialize): Add unused filename parameter.
* unknown.c (fileline_initialize): Likewise.
* xcoff.c (fileline_initialize): Likewise.
* configure.ac: Check for objcopy --add-gnu-debuglink.
* Makefile.am (dtest): New test target.
* configure, Makefile.in: Rebuild.
Index: Makefile.am
===================================================================
--- Makefile.am (revision 253025)
+++ Makefile.am (working copy)
@@ -122,6 +122,16 @@ ttest_LDADD = libbacktrace.la
endif HAVE_PTHREAD
+if HAVE_OBJCOPY_DEBUGLINK
+
+TESTS += dtest
+
+dtest: btest
+ $(OBJCOPY) --only-keep-debug btest btest.debug
+ $(OBJCOPY) --strip-debug --add-gnu-debuglink=btest.debug btest dtest
+
+endif HAVE_OBJCOPY_DEBUGLINK
+
endif NATIVE
# We can't use automake's automatic dependency tracking, because it
Index: configure.ac
===================================================================
--- configure.ac (revision 253025)
+++ configure.ac (working copy)
@@ -404,6 +404,20 @@ AC_SUBST(PTHREAD_CFLAGS)
AM_CONDITIONAL(HAVE_PTHREAD, test "$libgo_cv_lib_pthread" = yes)
+AC_ARG_VAR(OBJCOPY, [location of objcopy])
+AC_CHECK_PROG(OBJCOPY, objcopy, objcopy,)
+AC_CACHE_CHECK([whether objcopy supports debuglink],
+[libbacktrace_cv_objcopy_debuglink],
+[if test -n "${with_target_subdir}"; then
+ libbacktrace_cv_objcopy_debuglink=no
+elif ${OBJCOPY} --add-gnu-debuglink=x /bin/ls /tmp/ls$$; then
+ rm -f /tmp/ls$$
+ libbacktrace_cv_objcopy_debuglink=yes
+else
+ libbacktrace_cv_objcopy_debuglink=no
+fi])
+AM_CONDITIONAL(HAVE_OBJCOPY_DEBUGLINK, test
"$libbacktrace_cv_objcopy_debuglink" = yes)
+
AC_CACHE_CHECK([whether tests can run],
[libbacktrace_cv_sys_native],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([], [return 0;])],
Index: elf.c
===================================================================
--- elf.c (revision 253025)
+++ elf.c (working copy)
@@ -32,9 +32,12 @@ POSSIBILITY OF SUCH DAMAGE. */
#include "config.h"
+#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
#ifdef HAVE_DL_ITERATE_PHDR
#include <link.h>
@@ -43,6 +46,35 @@ POSSIBILITY OF SUCH DAMAGE. */
#include "backtrace.h"
#include "internal.h"
+#ifndef S_ISLNK
+ #ifndef S_IFLNK
+ #define S_IFLNK 0120000
+ #endif
+ #ifndef S_IFMT
+ #define S_IFMT 0170000
+ #endif
+ #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
+#endif
+
+#if !defined(HAVE_DECL_STRNLEN) || !HAVE_DECL_STRNLEN
+
+/* If strnlen is not declared, provide our own version. */
+
+static size_t
+xstrnlen (const char *s, size_t maxlen)
+{
+ size_t i;
+
+ for (i = 0; i < maxlen; ++i)
+ if (s[i] == '\0')
+ break;
+ return i;
+}
+
+#define strnlen xstrnlen
+
+#endif
+
#ifndef HAVE_DL_ITERATE_PHDR
/* Dummy version of dl_iterate_phdr for systems that don't have it. */
@@ -105,6 +137,7 @@ dl_iterate_phdr (int (*callback) (struct
#undef SHT_DYNSYM
#undef STT_OBJECT
#undef STT_FUNC
+#undef NT_GNU_BUILD_ID
/* Basic types. */
@@ -224,6 +257,16 @@ typedef struct
#define STT_OBJECT 1
#define STT_FUNC 2
+typedef struct
+{
+ uint32_t namesz;
+ uint32_t descsz;
+ uint32_t type;
+ char name[1];
+} b_elf_note;
+
+#define NT_GNU_BUILD_ID 3
+
/* An index of ELF sections we care about. */
enum debug_section
@@ -283,6 +326,102 @@ struct elf_syminfo_data
size_t count;
};
+/* Compute the CRC-32 of BUF/LEN. This uses the CRC used for
+ .gnu_debuglink files. */
+
+static uint32_t
+elf_crc32 (uint32_t crc, const unsigned char *buf, size_t len)
+{
+ static const uint32_t crc32_table[256] =
+ {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+ 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+ 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+ 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+ 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+ 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+ 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+ 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+ 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+ 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+ 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+ 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+ 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+ 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+ 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+ 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+ 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+ 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+ 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+ 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+ 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+ 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+ 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+ 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+ 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+ 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+ 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+ 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+ 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+ 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+ 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+ 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+ 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+ 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+ 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+ 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+ 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+ 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+ 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+ 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+ 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+ 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+ 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+ 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+ 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+ 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+ 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+ 0x2d02ef8d
+ };
+ const unsigned char *end;
+
+ crc = ~crc;
+ for (end = buf + len; buf < end; ++ buf)
+ crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+ return ~crc;
+}
+
+/* Return the CRC-32 of the entire file open at DESCRIPTOR. */
+
+static uint32_t
+elf_crc32_file (struct backtrace_state *state, int descriptor,
+ backtrace_error_callback error_callback, void *data)
+{
+ struct stat st;
+ struct backtrace_view file_view;
+ uint32_t ret;
+
+ if (fstat (descriptor, &st) < 0)
+ {
+ error_callback (data, "fstat", errno);
+ return 0;
+ }
+
+ if (!backtrace_get_view (state, descriptor, 0, st.st_size, error_callback,
+ data, &file_view))
+ return 0;
+
+ ret = elf_crc32 (0, (const unsigned char *) file_view.data, st.st_size);
+
+ backtrace_release_view (state, &file_view, error_callback, data);
+
+ return ret;
+}
+
/* A dummy callback function used when we can't find any debug info. */
static int
@@ -510,6 +649,293 @@ elf_syminfo (struct backtrace_state *sta
callback (data, addr, sym->name, sym->address, sym->size);
}
+/* Return whether FILENAME is a symlink. */
+
+static int
+elf_is_symlink (const char *filename)
+{
+ struct stat st;
+
+ if (lstat (filename, &st) < 0)
+ return 0;
+ return S_ISLNK (st.st_mode);
+}
+
+/* Return the results of reading the symlink FILENAME in a buffer
+ allocated by backtrace_alloc. Return the length of the buffer in
+ *LEN. */
+
+static char *
+elf_readlink (struct backtrace_state *state, const char *filename,
+ backtrace_error_callback error_callback, void *data,
+ size_t *plen)
+{
+ size_t len;
+ char *buf;
+
+ len = 128;
+ while (1)
+ {
+ ssize_t rl;
+
+ buf = backtrace_alloc (state, len, error_callback, data);
+ if (buf == NULL)
+ return NULL;
+ rl = readlink (filename, buf, len);
+ if (rl < 0)
+ {
+ backtrace_free (state, buf, len, error_callback, data);
+ return NULL;
+ }
+ if ((size_t) rl < len - 1)
+ {
+ buf[rl] = '\0';
+ *plen = len;
+ return buf;
+ }
+ backtrace_free (state, buf, len, error_callback, data);
+ len *= 2;
+ }
+}
+
+/* Open a separate debug info file, using the build ID to find it.
+ Returns an open file descriptor, or -1.
+
+ The GDB manual says that the only place gdb looks for a debug file
+ when the build ID is known is in /usr/lib/debug/.build-id. */
+
+static int
+elf_open_debugfile_by_buildid (struct backtrace_state *state,
+ const char *buildid_data, size_t buildid_size,
+ backtrace_error_callback error_callback,
+ void *data)
+{
+ const char * const prefix = "/usr/lib/debug/.build-id/";
+ const size_t prefix_len = strlen (prefix);
+ const char * const suffix = ".debug";
+ const size_t suffix_len = strlen (suffix);
+ size_t len;
+ char *bd_filename;
+ char *t;
+ size_t i;
+ int ret;
+ int does_not_exist;
+
+ len = prefix_len + buildid_size * 2 + suffix_len + 2;
+ bd_filename = backtrace_alloc (state, len, error_callback, data);
+ if (bd_filename == NULL)
+ return -1;
+
+ t = bd_filename;
+ memcpy (t, prefix, prefix_len);
+ t += prefix_len;
+ for (i = 0; i < buildid_size; i++)
+ {
+ unsigned char b;
+ unsigned char nib;
+
+ b = (unsigned char) buildid_data[i];
+ nib = (b & 0xf0) >> 4;
+ *t++ = nib < 10 ? '0' + nib : 'a' + nib - 10;
+ nib = b & 0x0f;
+ *t++ = nib < 10 ? '0' + nib : 'a' + nib - 10;
+ if (i == 0)
+ *t++ = '/';
+ }
+ memcpy (t, suffix, suffix_len);
+ t[suffix_len] = '\0';
+
+ ret = backtrace_open (bd_filename, error_callback, data, &does_not_exist);
+
+ backtrace_free (state, bd_filename, len, error_callback, data);
+
+ /* gdb checks that the debuginfo file has the same build ID note.
+ That seems kind of pointless to me--why would it have the right
+ name but not the right build ID?--so skipping the check. */
+
+ return ret;
+}
+
+/* Try to open a file whose name is PREFIX (length PREFIX_LEN)
+ concatenated with PREFIX2 (length PREFIX2_LEN) concatenated with
+ DEBUGLINK_NAME. Returns an open file descriptor, or -1. */
+
+static int
+elf_try_debugfile (struct backtrace_state *state, const char *prefix,
+ size_t prefix_len, const char *prefix2, size_t prefix2_len,
+ const char *debuglink_name,
+ backtrace_error_callback error_callback, void *data)
+{
+ size_t debuglink_len;
+ size_t try_len;
+ char *try;
+ int does_not_exist;
+ int ret;
+
+ debuglink_len = strlen (debuglink_name);
+ try_len = prefix_len + prefix2_len + debuglink_len + 1;
+ try = backtrace_alloc (state, try_len, error_callback, data);
+ if (try == NULL)
+ return -1;
+
+ memcpy (try, prefix, prefix_len);
+ memcpy (try + prefix_len, prefix2, prefix2_len);
+ memcpy (try + prefix_len + prefix2_len, debuglink_name, debuglink_len);
+ try[prefix_len + prefix2_len + debuglink_len] = '\0';
+
+ ret = backtrace_open (try, error_callback, data, &does_not_exist);
+
+ backtrace_free (state, try, try_len, error_callback, data);
+
+ return ret;
+}
+
+/* Find a separate debug info file, using the debuglink section data
+ to find it. Returns an open file descriptor, or -1. */
+
+static int
+elf_find_debugfile_by_debuglink (struct backtrace_state *state,
+ const char *filename,
+ const char *debuglink_name,
+ backtrace_error_callback error_callback,
+ void *data)
+{
+ int ret;
+ char *alc;
+ size_t alc_len;
+ const char *slash;
+ int ddescriptor;
+ const char *prefix;
+ size_t prefix_len;
+
+ /* Resolve symlinks in FILENAME. Since FILENAME is fairly likely to
+ be /proc/self/exe, symlinks are common. We don't try to resolve
+ the whole path name, just the base name. */
+ ret = -1;
+ alc = NULL;
+ alc_len = 0;
+ while (elf_is_symlink (filename))
+ {
+ char *new_buf;
+ size_t new_len;
+
+ new_buf = elf_readlink (state, filename, error_callback, data, &new_len);
+ if (new_buf == NULL)
+ break;
+
+ if (new_buf[0] == '/')
+ filename = new_buf;
+ else
+ {
+ slash = strrchr (filename, '/');
+ if (slash == NULL)
+ filename = new_buf;
+ else
+ {
+ size_t clen;
+ char *c;
+
+ slash++;
+ clen = slash - filename + strlen (new_buf) + 1;
+ c = backtrace_alloc (state, clen, error_callback, data);
+ if (c == NULL)
+ goto done;
+
+ memcpy (c, filename, slash - filename);
+ memcpy (c + (slash - filename), new_buf, strlen (new_buf));
+ c[slash - filename + strlen (new_buf)] = '\0';
+ backtrace_free (state, new_buf, new_len, error_callback, data);
+ filename = c;
+ new_buf = c;
+ new_len = clen;
+ }
+ }
+
+ if (alc != NULL)
+ backtrace_free (state, alc, alc_len, error_callback, data);
+ alc = new_buf;
+ alc_len = new_len;
+ }
+
+ /* Look for DEBUGLINK_NAME in the same directory as FILENAME. */
+
+ slash = strrchr (filename, '/');
+ if (slash == NULL)
+ {
+ prefix = "";
+ prefix_len = 0;
+ }
+ else
+ {
+ slash++;
+ prefix = filename;
+ prefix_len = slash - filename;
+ }
+
+ ddescriptor = elf_try_debugfile (state, prefix, prefix_len, "", 0,
+ debuglink_name, error_callback, data);
+ if (ddescriptor >= 0)
+ {
+ ret = ddescriptor;
+ goto done;
+ }
+
+ /* Look for DEBUGLINK_NAME in a .debug subdirectory of FILENAME. */
+
+ ddescriptor = elf_try_debugfile (state, prefix, prefix_len, ".debug/",
+ strlen (".debug/"), debuglink_name,
+ error_callback, data);
+ if (ddescriptor >= 0)
+ {
+ ret = ddescriptor;
+ goto done;
+ }
+
+ /* Look for DEBUGLINK_NAME in /usr/lib/debug. */
+
+ ddescriptor = elf_try_debugfile (state, "/usr/lib/debug/",
+ strlen ("/usr/lib/debug/"), prefix,
+ prefix_len, debuglink_name,
+ error_callback, data);
+ if (ddescriptor >= 0)
+ ret = ddescriptor;
+
+ done:
+ if (alc != NULL && alc_len > 0)
+ backtrace_free (state, alc, alc_len, error_callback, data);
+ return ret;
+}
+
+/* Open a separate debug info file, using the debuglink section data
+ to find it. Returns an open file descriptor, or -1. */
+
+static int
+elf_open_debugfile_by_debuglink (struct backtrace_state *state,
+ const char *filename,
+ const char *debuglink_name,
+ uint32_t debuglink_crc,
+ backtrace_error_callback error_callback,
+ void *data)
+{
+ int ddescriptor;
+ uint32_t got_crc;
+
+ ddescriptor = elf_find_debugfile_by_debuglink (state, filename,
+ debuglink_name,
+ error_callback, data);
+ if (ddescriptor < 0)
+ return -1;
+
+ got_crc = elf_crc32_file (state, ddescriptor, error_callback, data);
+ if (got_crc != debuglink_crc)
+ {
+ backtrace_close (ddescriptor, error_callback, data);
+ return -1;
+ }
+
+ return ddescriptor;
+}
+
/* Add the backtrace data for one ELF file. Returns 1 on success,
0 on failure (in both cases descriptor is closed) or -1 if exe
is non-zero and the ELF file is ET_DYN, which tells the caller that
@@ -517,9 +943,10 @@ elf_syminfo (struct backtrace_state *sta
base_address is determined. */
static int
-elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
- backtrace_error_callback error_callback, void *data,
- fileline *fileline_fn, int *found_sym, int *found_dwarf, int exe)
+elf_add (struct backtrace_state *state, const char *filename, int descriptor,
+ uintptr_t base_address, backtrace_error_callback error_callback,
+ void *data, fileline *fileline_fn, int *found_sym, int *found_dwarf,
+ int exe, int debuginfo)
{
struct backtrace_view ehdr_view;
b_elf_ehdr ehdr;
@@ -543,6 +970,14 @@ elf_add (struct backtrace_state *state,
int symtab_view_valid;
struct backtrace_view strtab_view;
int strtab_view_valid;
+ struct backtrace_view buildid_view;
+ int buildid_view_valid;
+ const char *buildid_data;
+ uint32_t buildid_size;
+ struct backtrace_view debuglink_view;
+ int debuglink_view_valid;
+ const char *debuglink_name;
+ uint32_t debuglink_crc;
off_t min_offset;
off_t max_offset;
struct backtrace_view debug_view;
@@ -555,6 +990,12 @@ elf_add (struct backtrace_state *state,
names_view_valid = 0;
symtab_view_valid = 0;
strtab_view_valid = 0;
+ buildid_view_valid = 0;
+ buildid_data = NULL;
+ buildid_size = 0;
+ debuglink_view_valid = 0;
+ debuglink_name = NULL;
+ debuglink_crc = 0;
debug_view_valid = 0;
if (!backtrace_get_view (state, descriptor, 0, sizeof ehdr, error_callback,
@@ -707,11 +1148,61 @@ elf_add (struct backtrace_state *state,
break;
}
}
+
+ /* Read the build ID if present. This could check for any
+ SHT_NOTE section with the right note name and type, but gdb
+ looks for a specific section name. */
+ if (!debuginfo
+ && !buildid_view_valid
+ && strcmp (name, ".note.gnu.build-id") == 0)
+ {
+ const b_elf_note *note;
+
+ if (!backtrace_get_view (state, descriptor, shdr->sh_offset,
+ shdr->sh_size, error_callback, data,
+ &buildid_view))
+ goto fail;
+
+ buildid_view_valid = 1;
+ note = (const b_elf_note *) buildid_view.data;
+ if (note->type == NT_GNU_BUILD_ID
+ && note->namesz == 4
+ && strncmp (note->name, "GNU", 4) == 0
+ && shdr->sh_size < 12 + ((note->namesz + 3) & ~ 3) + note->descsz)
+ {
+ buildid_data = ¬e->name[0] + ((note->namesz + 3) & ~ 3);
+ buildid_size = note->descsz;
+ }
+ }
+
+ /* Read the debuglink file if present. */
+ if (!debuginfo
+ && !debuglink_view_valid
+ && strcmp (name, ".gnu_debuglink") == 0)
+ {
+ const char *debuglink_data;
+ size_t crc_offset;
+
+ if (!backtrace_get_view (state, descriptor, shdr->sh_offset,
+ shdr->sh_size, error_callback, data,
+ &debuglink_view))
+ goto fail;
+
+ debuglink_view_valid = 1;
+ debuglink_data = (const char *) debuglink_view.data;
+ crc_offset = strnlen (debuglink_data, shdr->sh_size);
+ crc_offset = (crc_offset + 3) & ~3;
+ if (crc_offset + 4 <= shdr->sh_size)
+ {
+ debuglink_name = debuglink_data;
+ debuglink_crc = *(const uint32_t*)(debuglink_data + crc_offset);
+ }
+ }
}
if (symtab_shndx == 0)
symtab_shndx = dynsym_shndx;
- if (symtab_shndx != 0)
+ if (symtab_shndx != 0 && !debuginfo)
{
const b_elf_shdr *symtab_shdr;
unsigned int strtab_shndx;
@@ -757,6 +1248,7 @@ elf_add (struct backtrace_state *state,
/* We no longer need the symbol table, but we hold on to the
string table permanently. */
backtrace_release_view (state, &symtab_view, error_callback, data);
+ symtab_view_valid = 0;
*found_sym = 1;
@@ -770,6 +1262,53 @@ elf_add (struct backtrace_state *state,
backtrace_release_view (state, &names_view, error_callback, data);
names_view_valid = 0;
+ /* If the debug info is in a separate file, read that one instead. */
+
+ if (buildid_data != NULL)
+ {
+ int d;
+
+ d = elf_open_debugfile_by_buildid (state, buildid_data, buildid_size,
+ error_callback, data);
+ if (d >= 0)
+ {
+ backtrace_release_view (state, &buildid_view, error_callback, data);
+ if (debuglink_view_valid)
+ backtrace_release_view (state, &debuglink_view, error_callback,
+ data);
+ return elf_add (state, NULL, d, base_address, error_callback, data,
+ fileline_fn, found_sym, found_dwarf, 0, 1);
+ }
+ }
+
+ if (buildid_view_valid)
+ {
+ backtrace_release_view (state, &buildid_view, error_callback, data);
+ buildid_view_valid = 0;
+ }
+
+ if (debuglink_name != NULL)
+ {
+ int d;
+
+ d = elf_open_debugfile_by_debuglink (state, filename, debuglink_name,
+ debuglink_crc, error_callback,
+ data);
+ if (d >= 0)
+ {
+ backtrace_release_view (state, &debuglink_view, error_callback,
+ data);
+ return elf_add (state, NULL, d, base_address, error_callback, data,
+ fileline_fn, found_sym, found_dwarf, 0, 1);
+ }
+ }
+
+ if (debuglink_view_valid)
+ {
+ backtrace_release_view (state, &debuglink_view, error_callback, data);
+ debuglink_view_valid = 0;
+ }
+
/* Read all the debug sections in a single view, since they are
probably adjacent in the file. We never release this view. */
@@ -842,6 +1381,10 @@ elf_add (struct backtrace_state *state,
backtrace_release_view (state, &symtab_view, error_callback, data);
if (strtab_view_valid)
backtrace_release_view (state, &strtab_view, error_callback, data);
+ if (debuglink_view_valid)
+ backtrace_release_view (state, &debuglink_view, error_callback, data);
+ if (buildid_view_valid)
+ backtrace_release_view (state, &buildid_view, error_callback, data);
if (debug_view_valid)
backtrace_release_view (state, &debug_view, error_callback, data);
if (descriptor != -1)
@@ -859,6 +1402,7 @@ struct phdr_data
fileline *fileline_fn;
int *found_sym;
int *found_dwarf;
+ const char *exe_filename;
int exe_descriptor;
};
@@ -873,6 +1417,7 @@ phdr_callback (struct dl_phdr_info *info
void *pdata)
{
struct phdr_data *pd = (struct phdr_data *) pdata;
+ const char *filename;
int descriptor;
int does_not_exist;
fileline elf_fileline_fn;
@@ -885,6 +1430,7 @@ phdr_callback (struct dl_phdr_info *info
{
if (pd->exe_descriptor == -1)
return 0;
+ filename = pd->exe_filename;
descriptor = pd->exe_descriptor;
pd->exe_descriptor = -1;
}
@@ -896,14 +1442,16 @@ phdr_callback (struct dl_phdr_info *info
pd->exe_descriptor = -1;
}
+ filename = info->dlpi_name;
descriptor = backtrace_open (info->dlpi_name, pd->error_callback,
pd->data, &does_not_exist);
if (descriptor < 0)
return 0;
}
- if (elf_add (pd->state, descriptor, info->dlpi_addr, pd->error_callback,
- pd->data, &elf_fileline_fn, pd->found_sym, &found_dwarf, 0))
+ if (elf_add (pd->state, filename, descriptor, info->dlpi_addr,
+ pd->error_callback, pd->data, &elf_fileline_fn, pd->found_sym,
+ &found_dwarf, 0, 0))
{
if (found_dwarf)
{
@@ -920,8 +1468,8 @@ phdr_callback (struct dl_phdr_info *info
sections. */
int
-backtrace_initialize (struct backtrace_state *state, int descriptor,
- backtrace_error_callback error_callback,
+backtrace_initialize (struct backtrace_state *state, const char *filename,
+ int descriptor, backtrace_error_callback error_callback,
void *data, fileline *fileline_fn)
{
int ret;
@@ -930,8 +1478,8 @@ backtrace_initialize (struct backtrace_s
fileline elf_fileline_fn = elf_nodebug;
struct phdr_data pd;
- ret = elf_add (state, descriptor, 0, error_callback, data, &elf_fileline_fn,
- &found_sym, &found_dwarf, 1);
+ ret = elf_add (state, filename, descriptor, 0, error_callback, data,
+ &elf_fileline_fn, &found_sym, &found_dwarf, 1, 0);
if (!ret)
return 0;
Index: fileline.c
===================================================================
--- fileline.c (revision 253025)
+++ fileline.c (working copy)
@@ -58,6 +58,7 @@ fileline_initialize (struct backtrace_st
int pass;
int called_error_callback;
int descriptor;
+ const char *filename;
char buf[64];
if (!state->threaded)
@@ -84,7 +85,6 @@ fileline_initialize (struct backtrace_st
called_error_callback = 0;
for (pass = 0; pass < 5; ++pass)
{
- const char *filename;
int does_not_exist;
switch (pass)
@@ -140,8 +140,8 @@ fileline_initialize (struct backtrace_st
if (!failed)
{
- if (!backtrace_initialize (state, descriptor, error_callback, data,
- &fileline_fn))
+ if (!backtrace_initialize (state, filename, descriptor, error_callback,
+ data, &fileline_fn))
failed = 1;
}
Index: internal.h
===================================================================
--- internal.h (revision 253025)
+++ internal.h (working copy)
@@ -268,6 +268,7 @@ extern int backtrace_vector_release (str
appropriate one. */
extern int backtrace_initialize (struct backtrace_state *state,
+ const char *filename,
int descriptor,
backtrace_error_callback error_callback,
void *data,
Index: pecoff.c
===================================================================
--- pecoff.c (revision 253025)
+++ pecoff.c (working copy)
@@ -890,7 +890,8 @@ coff_add (struct backtrace_state *state,
sections. */
int
-backtrace_initialize (struct backtrace_state *state, int descriptor,
+backtrace_initialize (struct backtrace_state *state,
+ const char *filename ATTRIBUTE_UNUSED, int descriptor,
backtrace_error_callback error_callback,
void *data, fileline *fileline_fn)
{
Index: unknown.c
===================================================================
--- unknown.c (revision 253025)
+++ unknown.c (working copy)
@@ -54,6 +54,7 @@ unknown_fileline (struct backtrace_state
int
backtrace_initialize (struct backtrace_state *state ATTRIBUTE_UNUSED,
+ const char *filename ATTRIBUTE_UNUSED,
int descriptor ATTRIBUTE_UNUSED,
backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED, fileline *fileline_fn)
Index: xcoff.c
===================================================================
--- xcoff.c (revision 253025)
+++ xcoff.c (working copy)
@@ -1434,7 +1434,8 @@ xcoff_add_shared_libs (struct backtrace_
Returns 1 on success, 0 on failure. */
int
-backtrace_initialize (struct backtrace_state *state, int descriptor,
+backtrace_initialize (struct backtrace_state *state,
+ const char *filename ATTRIBUTE_UNUSED, int descriptor,
backtrace_error_callback error_callback,
void *data, fileline *fileline_fn)
{
