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[PATCH][PR sanitizer/77631] Support separate debug info in libbacktrace
- From: Denis Khalikov <d dot khalikov at partner dot samsung dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 16 Jun 2017 18:39:40 +0300
- Subject: [PATCH][PR sanitizer/77631] Support separate debug info in libbacktrace
- Authentication-results: sourceware.org; auth=none
- Cms-type: 201P
- References: <CGME20170616153942eucas1p1945271f893265484bbb3991a368bcd92@eucas1p1.samsung.com>
Hello everyone,
This is a patch for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77631
Can some one please review attached patch.
Thanks.
From ae74cf3d632b06a91a986e32e3a6c16223767b24 Mon Sep 17 00:00:00 2001
From: Denis Khalikov <d.khalikov@partner.samsung.com>
Date: Fri, 16 Jun 2017 12:13:13 +0300
Subject: [PATCH] PR sanitizer/77631
* Makefile.in: Regenerated.
* configure.ac: Add searching for limits.h, sys/param.h
* config.h.in: Regenerated.
* configure: Regenerated.
* elf.c (enum type_of_file): New enum.
(enum type_of_elf): New enum.
(enum debug_path): New enum.
(getl32): New function.
(gnu_debuglink_crc32): New function. Generate crc32 sum.
(get_crc32): New function.
(pathlen): New function.
(check_sum): New function. Verify sum.
(process_elf_header): New function. Verify elf header.
(elf_get_section_by_name): New function. Get section by name.
(backtrace_readlink): New function. Get type of file from filename.
(resolve_realname): New function. Resolve real name if file is link.
(backtrace_resolve_realname): New function. Resolve real name for any
file type.
(search_for_debugfile): New function. Search for debug file in known
paths.
(open_debugfile_by_gnulink): New function. Open debug file with
gnulink.
(hex): New function. Convert to hex.
(get_build_id_name): New function. Generate build-id name.
(open_debugfile_by_build_id): New function. Open debug file with
build-id.
(backtrace_open_debugfile): New function. Open debug file.
(elf_add): Move code which reads elf header to elf_header_is_valid.
(phdr_callback): Call backtrace_open_debugfile function for shared
library.
* fileline.c (fileline_initialize): Call backtrace_open_debugfile for
executable.
* internal.h: Updated.
---
libbacktrace/ChangeLog | 37 ++
libbacktrace/Makefile.in | 2 +-
libbacktrace/config.h.in | 6 +
libbacktrace/configure | 26 ++
libbacktrace/configure.ac | 4 +
libbacktrace/elf.c | 949 +++++++++++++++++++++++++++++++++++++++++-----
libbacktrace/fileline.c | 13 +-
libbacktrace/internal.h | 8 +
8 files changed, 958 insertions(+), 87 deletions(-)
diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index 096ceb6..4bd97f3 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,40 @@
+2017-06-16 Denis Khalikov <d.khalikov@partner.samsung.com>
+
+ PR sanitizer/77631
+ * Makefile.in: Regenerated.
+ * configure.ac: Add searching for limits.h, sys/param.h
+ * config.h.in: Regenerated.
+ * configure: Regenerated.
+ * elf.c (enum type_of_file): New enum.
+ (enum type_of_elf): New enum.
+ (enum debug_path): New enum.
+ (getl32): New function.
+ (gnu_debuglink_crc32): New function. Generate crc32 sum.
+ (get_crc32): New function.
+ (pathlen): New function.
+ (check_sum): New function. Verify sum.
+ (process_elf_header): New function. Verify elf header.
+ (elf_get_section_by_name): New function. Get section by name.
+ (backtrace_readlink): New function. Get type of file from filename.
+ (resolve_realname): New function. Resolve real name if file is link.
+ (backtrace_resolve_realname): New function. Resolve real name for any
+ file type.
+ (search_for_debugfile): New function. Search for debug file in known
+ paths.
+ (open_debugfile_by_gnulink): New function. Open debug file with
+ gnulink.
+ (hex): New function. Convert to hex.
+ (get_build_id_name): New function. Generate build-id name.
+ (open_debugfile_by_build_id): New function. Open debug file with
+ build-id.
+ (backtrace_open_debugfile): New function. Open debug file.
+ (elf_add): Move code which reads elf header to elf_header_is_valid.
+ (phdr_callback): Call backtrace_open_debugfile function for shared
+ library.
+ * fileline.c (fileline_initialize): Call backtrace_open_debugfile for
+ executable.
+ * internal.h: Updated.
+
2017-05-02 Release Manager
* GCC 7.1.0 released.
diff --git a/libbacktrace/Makefile.in b/libbacktrace/Makefile.in
index de74b5d..e604b6c 100644
--- a/libbacktrace/Makefile.in
+++ b/libbacktrace/Makefile.in
@@ -16,7 +16,7 @@
@SET_MAKE@
# Makefile.am -- Backtrace Makefile.
-# Copyright (C) 2012-2016 Free Software Foundation, Inc.
+# Copyright (C) 2012-2017 Free Software Foundation, Inc.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
diff --git a/libbacktrace/config.h.in b/libbacktrace/config.h.in
index 87cb805..edbd9af 100644
--- a/libbacktrace/config.h.in
+++ b/libbacktrace/config.h.in
@@ -28,6 +28,9 @@
/* Define to 1 if you have the <inttypes.h> header file. */
#undef HAVE_INTTYPES_H
+/* Define 1 if <limits.h> is available. */
+#undef HAVE_LIMITS_H
+
/* Define to 1 if you have the <link.h> header file. */
#undef HAVE_LINK_H
@@ -52,6 +55,9 @@
/* Define to 1 if you have the <sys/mman.h> header file. */
#undef HAVE_SYS_MMAN_H
+/* Define 1 if <sys/param.h> is available. */
+#undef HAVE_SYS_PARAM_H
+
/* Define to 1 if you have the <sys/stat.h> header file. */
#undef HAVE_SYS_STAT_H
diff --git a/libbacktrace/configure b/libbacktrace/configure
index ee90bc6..edd50b0 100755
--- a/libbacktrace/configure
+++ b/libbacktrace/configure
@@ -12350,6 +12350,32 @@ if test "$ALLOC_FILE" = "alloc.lo"; then
fi
+for ac_header in limits.h
+do :
+ ac_fn_c_check_header_mongrel "$LINENO" "limits.h" "ac_cv_header_limits_h" "$ac_includes_default"
+if test "x$ac_cv_header_limits_h" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_LIMITS_H 1
+_ACEOF
+
+fi
+
+done
+
+
+for ac_header in sys/param.h
+do :
+ ac_fn_c_check_header_mongrel "$LINENO" "sys/param.h" "ac_cv_header_sys_param_h" "$ac_includes_default"
+if test "x$ac_cv_header_sys_param_h" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_SYS_PARAM_H 1
+_ACEOF
+
+fi
+
+done
+
+
# Check for dl_iterate_phdr.
for ac_header in link.h
do :
diff --git a/libbacktrace/configure.ac b/libbacktrace/configure.ac
index f9cad21..01ac2a1 100644
--- a/libbacktrace/configure.ac
+++ b/libbacktrace/configure.ac
@@ -301,6 +301,10 @@ if test "$ALLOC_FILE" = "alloc.lo"; then
fi
AC_SUBST(BACKTRACE_USES_MALLOC)
+AC_CHECK_HEADERS(limits.h)
+
+AC_CHECK_HEADERS(sys/param.h)
+
# Check for dl_iterate_phdr.
AC_CHECK_HEADERS(link.h)
if test "$ac_cv_header_link_h" = "no"; then
diff --git a/libbacktrace/elf.c b/libbacktrace/elf.c
index 89ed42b..32f6871 100644
--- a/libbacktrace/elf.c
+++ b/libbacktrace/elf.c
@@ -35,6 +35,9 @@ POSSIBILITY OF SUCH DAMAGE. */
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
#ifdef HAVE_DL_ITERATE_PHDR
#include <link.h>
@@ -42,6 +45,32 @@ POSSIBILITY OF SUCH DAMAGE. */
#include "backtrace.h"
#include "internal.h"
+#include "filenames.h"
+
+/* The following is from pathmax.h. */
+/* Non-POSIX BSD systems might have gcc's limits.h, which doesn't define
+ PATH_MAX but might cause redefinition warnings when sys/param.h is
+ later included (as on MORE/BSD 4.3). */
+#if defined _POSIX_VERSION || (defined HAVE_LIMITS_H && !defined __GNUC__)
+# include <limits.h>
+#endif
+
+#ifndef _POSIX_PATH_MAX
+# define _POSIX_PATH_MAX 255
+#endif
+
+/* Don't include sys/param.h if it already has been. */
+#if defined HAVE_SYS_PARAM_H && !defined PATH_MAX && !defined MAXPATHLEN
+# include <sys/param.h>
+#endif
+
+#if !defined PATH_MAX && defined MAXPATHLEN
+# define PATH_MAX MAXPATHLEN
+#endif
+
+#ifndef PATH_MAX
+# define PATH_MAX _POSIX_PATH_MAX
+#endif
#ifndef HAVE_DL_ITERATE_PHDR
@@ -283,6 +312,821 @@ struct elf_syminfo_data
size_t count;
};
+/* Information to read ELF note section. */
+
+typedef struct
+{
+ unsigned char namesz[4];
+ unsigned char descsz[4];
+ unsigned char type[4];
+ unsigned char name[1];
+} Elf_External_Note;
+
+/* Information about type of the file. */
+
+enum type_of_file
+{
+ LINK = 1,
+ REGULAR = 2
+};
+
+/* Information about debug paths. */
+
+enum debug_path
+{
+ CURRENT,
+ CURRENT_DEBUG,
+ USR_LIB_DEBUG,
+ USR_LIB_DEBUG_PATH_TO_EXE,
+ DEBUG_PATH_MAX
+};
+
+/* Type of the ELF file. */
+
+enum type_of_elf
+{
+ DYN = -1,
+ INVALID = 0,
+ EXEC = 1
+};
+
+/* Paths to debug file. */
+
+static const char *const debug_file_path[DEBUG_PATH_MAX]
+ = {"", ".debug/", "/usr/lib/debug/", "/usr/lib/debug"};
+
+/* Cast from void pointer to uint32_t. */
+
+static uint32_t
+getl32 (void *p)
+{
+ char *addr = (char *) p;
+ uint32_t v = 0;
+ v = *((uint32_t *) addr);
+ return v;
+}
+
+/* Function that produce a crc32 value for input buffer. */
+
+static unsigned long
+gnu_debuglink_crc32 (unsigned long crc, const unsigned char *buf, size_t len)
+{
+ static const unsigned long 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 & 0xffffffff;
+ for (end = buf + len; buf < end; ++buf)
+ crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+ return ~crc & 0xffffffff;
+}
+
+/* Generate crc32 sum from the file. */
+
+static unsigned long
+get_crc32 (int descriptor)
+{
+ unsigned char buffer[8 * 1024];
+ memset (buffer, 0, 8 * 1024);
+ unsigned long file_crc = 0;
+ ssize_t count;
+
+ while ((count = read (descriptor, buffer, sizeof (buffer))) > 0)
+ file_crc = gnu_debuglink_crc32 (file_crc, buffer, count);
+
+ return file_crc;
+}
+
+/* Get length of the path. */
+
+static int
+pathlen (const char *buffer)
+{
+ int len;
+
+ len = strlen (buffer);
+ while (len > 1 && !IS_DIR_SEPARATOR (buffer[len - 1]))
+ --len;
+ return len > 1 ? len : -1;
+}
+
+/* Verify crc32 sum. */
+
+static int
+check_sum (int descriptor, char *debug_link, int offset, int section_size)
+{
+ unsigned long crc32_debug_link;
+ unsigned long crc32_debug_file;
+ offset += 1;
+ offset = (offset + 3) & ~3;
+ if (offset >= section_size)
+ return 0;
+ crc32_debug_link = getl32 (debug_link + offset);
+ crc32_debug_file = get_crc32 (descriptor);
+ return crc32_debug_link == crc32_debug_file;
+}
+
+/* Process elf header. Verify magic number, version, etc, of the ELF
+ header. Return 1 if the file type is EXE, -1 if type of the file
+ is DYN and 0 on the fail. */
+
+static int
+process_elf_header (struct backtrace_state *state, int descriptor,
+ backtrace_error_callback error_callback, void *data,
+ int exe, off_t *shoff_out, unsigned int *shnum_out,
+ unsigned int *shstrndx_out, b_elf_ehdr *ehdr_out)
+{
+ struct backtrace_view ehdr_view;
+
+ if (!backtrace_get_view (state, descriptor, 0, sizeof *ehdr_out,
+ error_callback, data, &ehdr_view))
+ goto fail;
+
+ memcpy (ehdr_out, ehdr_view.data, sizeof *ehdr_out);
+
+ backtrace_release_view (state, &ehdr_view, error_callback, data);
+
+ if (ehdr_out->e_ident[EI_MAG0] != ELFMAG0
+ || ehdr_out->e_ident[EI_MAG1] != ELFMAG1
+ || ehdr_out->e_ident[EI_MAG2] != ELFMAG2
+ || ehdr_out->e_ident[EI_MAG3] != ELFMAG3)
+ {
+ error_callback (data, "executable file is not ELF", 0);
+ goto fail;
+ }
+ if (ehdr_out->e_ident[EI_VERSION] != EV_CURRENT)
+ {
+ error_callback (data, "executable file is unrecognized ELF version", 0);
+ goto fail;
+ }
+
+#if BACKTRACE_ELF_SIZE == 32
+#define BACKTRACE_ELFCLASS ELFCLASS32
+#else
+#define BACKTRACE_ELFCLASS ELFCLASS64
+#endif
+
+ if (ehdr_out->e_ident[EI_CLASS] != BACKTRACE_ELFCLASS)
+ {
+ error_callback (data, "executable file is unexpected ELF class", 0);
+ goto fail;
+ }
+
+ if (ehdr_out->e_ident[EI_DATA] != ELFDATA2LSB
+ && ehdr_out->e_ident[EI_DATA] != ELFDATA2MSB)
+ {
+ error_callback (data, "executable file has unknown endianness", 0);
+ goto fail;
+ }
+
+ /* If the executable is ET_DYN, it is either a PIE, or we are running
+ directly a shared library with .interp. We need to wait for
+ dl_iterate_phdr in that case to determine the actual base_address. */
+ if (exe && ehdr_out->e_type == ET_DYN)
+ return -1;
+
+ *shoff_out = ehdr_out->e_shoff;
+ *shnum_out = ehdr_out->e_shnum;
+ *shstrndx_out = ehdr_out->e_shstrndx;
+
+ if ((*shnum_out == 0 || *shstrndx_out == SHN_XINDEX) && *shoff_out != 0)
+ {
+ struct backtrace_view shdr_view;
+ const b_elf_shdr *shdr;
+
+ if (!backtrace_get_view(state, descriptor, *shoff_out,
+ sizeof (b_elf_shdr), error_callback,
+ data, &shdr_view))
+ goto fail;
+
+ shdr = (const b_elf_shdr *) shdr_view.data;
+
+ if (*shnum_out == 0)
+ *shnum_out = shdr->sh_size;
+
+ if (*shstrndx_out == SHN_XINDEX)
+ {
+ *shstrndx_out = shdr->sh_link;
+
+ /* Versions of the GNU binutils between 2.12 and 2.18 did
+ not handle objects with more than SHN_LORESERVE sections
+ correctly. All large section indexes were offset by
+ 0x100. There is more information at
+ http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
+ Fortunately these object files are easy to detect, as the
+ GNU binutils always put the section header string table
+ near the end of the list of sections. Thus if the
+ section header string table index is larger than the
+ number of sections, then we know we have to subtract
+ 0x100 to get the real section index. */
+ if (*shstrndx_out >= *shnum_out
+ && *shstrndx_out >= SHN_LORESERVE + 0x100)
+ *shstrndx_out -= 0x100;
+ }
+ backtrace_release_view (state, &shdr_view, error_callback, data);
+ }
+ return 1;
+ fail:
+ return 0;
+}
+
+
+/* Get content of the specifying section. */
+
+static unsigned char *
+elf_get_section_by_name (struct backtrace_state *state, int descriptor,
+ backtrace_error_callback error_callback, void *data,
+ int *section_data_len_out, const char *section_name)
+{
+ b_elf_ehdr ehdr;
+ off_t shoff;
+ unsigned int shnum;
+ unsigned int shstrndx;
+ struct backtrace_view shdrs_view;
+ int shdrs_view_valid;
+ const b_elf_shdr *shdrs;
+ const b_elf_shdr *shstrhdr;
+ size_t shstr_size;
+ off_t shstr_off;
+ struct backtrace_view names_view;
+ struct backtrace_view section_view;
+ int names_view_valid;
+ const char *names;
+ unsigned int i;
+ int section_view_valid;
+ unsigned char *section_data;
+
+ section_view_valid = 0;
+ shdrs_view_valid = 0;
+ names_view_valid = 0;
+ section_data = NULL;
+
+ if (!process_elf_header (state, descriptor, error_callback, data, 0,
+ &shoff, &shnum, &shstrndx, &ehdr))
+ goto exit;
+
+ if (!backtrace_get_view (state, descriptor, shoff + sizeof (b_elf_shdr),
+ (shnum - 1) * sizeof (b_elf_shdr), error_callback,
+ data, &shdrs_view))
+ goto exit;
+
+ shdrs_view_valid = 1;
+ shdrs = (const b_elf_shdr *) shdrs_view.data;
+
+ /* Read the section names. */
+
+ shstrhdr = &shdrs[shstrndx - 1];
+ shstr_size = shstrhdr->sh_size;
+ shstr_off = shstrhdr->sh_offset;
+
+ if (!backtrace_get_view (state, descriptor, shstr_off, shstr_size,
+ error_callback, data, &names_view))
+ goto exit;
+
+ names_view_valid = 1;
+ names = (const char *) names_view.data;
+
+ for (i = 1; i < shnum; ++i)
+ {
+ const b_elf_shdr *shdr;
+ unsigned int sh_name;
+ const char *name;
+ shdr = &shdrs[i - 1];
+ sh_name = shdr->sh_name;
+ if (sh_name >= shstr_size)
+ {
+ error_callback (data, "ELF section name out of range", 0);
+ goto exit;
+ }
+
+ name = names + sh_name;
+
+ if (strcmp (name, section_name) == 0)
+ {
+ if (backtrace_get_view (state, descriptor, shdr->sh_offset,
+ shdr->sh_size, error_callback, data,
+ §ion_view))
+ {
+ section_view_valid = 1;
+ section_data
+ = backtrace_alloc (state, shdr->sh_size, error_callback, data);
+ if (section_data == NULL)
+ goto exit;
+ memcpy (section_data, section_view.data, shdr->sh_size);
+ *section_data_len_out = shdr->sh_size;
+ }
+ break;
+ }
+ }
+
+ exit:
+ if (shdrs_view_valid)
+ backtrace_release_view (state, &shdrs_view, error_callback, data);
+ if (names_view_valid)
+ backtrace_release_view (state, &names_view, error_callback, data);
+ if (section_view_valid)
+ backtrace_release_view (state, §ion_view, error_callback, data);
+ return section_data;
+}
+
+
+/* Verify type of the file. */
+
+static int
+backtrace_readlink (const char *filename,
+ backtrace_error_callback error_callback, void *data)
+{
+ struct stat link_stat;
+ int file_type;
+ mode_t mode;
+
+ memset (&link_stat, 0, sizeof (struct stat));
+
+ if (lstat (filename, &link_stat) == -1)
+ {
+ if (errno != ENOENT)
+ error_callback (data, filename, errno);
+ file_type = -1;
+ }
+
+ mode = link_stat.st_mode & S_IFMT;
+
+ switch (mode)
+ {
+ case S_IFLNK:
+ file_type = LINK;
+ break;
+ case S_IFREG:
+ file_type = REGULAR;
+ break;
+ default:
+ file_type = -1;
+ }
+ return file_type;
+}
+
+/* Resolve full name of the link. In this case we can't use realpath function
+ because it could be undefined on some platfroms, also it allocates memory
+ by malloc, which we can't use. */
+
+static int
+resolve_realname (const char *filename, char *buffer,
+ struct backtrace_state *state,
+ backtrace_error_callback error_callback, void *data)
+{
+ char *temp_buffer;
+ int file_type;
+ int filename_len;
+ int temp_filename_len;
+ int valid_temp_buffer;
+ int path_len;
+
+ valid_temp_buffer = 0;
+ filename_len = -1;
+ file_type = LINK;
+
+ /* Allocate memory for sizeof(PATH_MAX) + 1 bytes because at this time
+ we don't know how long path could be. */
+ temp_buffer = backtrace_alloc (state, PATH_MAX + 1, error_callback, data);
+ if (temp_buffer == NULL)
+ return -1;
+
+ valid_temp_buffer = 1;
+
+ memset (temp_buffer, 0, PATH_MAX + 1);
+ memcpy (temp_buffer, filename, strlen (filename));
+
+ while (file_type == LINK)
+ {
+ filename_len = readlink (temp_buffer, buffer, PATH_MAX);
+ if (filename_len < 1)
+ goto exit;
+
+ temp_filename_len = strlen (buffer);
+
+ /* Full path. */
+ if (buffer[0] == '/')
+ {
+ memset (temp_buffer, 0, PATH_MAX);
+ memcpy (temp_buffer, buffer, temp_filename_len);
+ }
+ else
+ {
+ /* Relative path. */
+ path_len = pathlen (temp_buffer);
+ if (path_len < 1)
+ goto exit;
+
+ memcpy (temp_buffer + path_len, buffer, filename_len);
+ temp_buffer[path_len + filename_len] = '\0';
+ }
+
+ file_type = backtrace_readlink (temp_buffer, error_callback, data);
+ memset (buffer, 0, filename_len);
+ }
+
+ if (file_type != REGULAR)
+ {
+ filename_len = -1;
+ goto exit;
+ }
+
+ filename_len = strlen (temp_buffer);
+ memcpy (buffer, temp_buffer, filename_len);
+
+ exit:
+ if (valid_temp_buffer)
+ backtrace_free (state, temp_buffer, PATH_MAX + 1, error_callback, data);
+ return filename_len;
+}
+
+/* Resolve realname of the filename. This function verifies filename.
+ If filename is name of the file it populates realname buffer.
+ If filename is link, it calls resolve_realname function. */
+
+static char *
+backtrace_resolve_realname (const char *filename, int *filename_len,
+ struct backtrace_state *state,
+ backtrace_error_callback error_callback, void *data)
+{
+ int file_type;
+ char *realname;
+
+ *filename_len = -1;
+
+ realname = backtrace_alloc (state, PATH_MAX + 1, error_callback, data);
+ if (realname == NULL)
+ goto exit;
+
+ file_type = backtrace_readlink (filename, error_callback, data);
+
+ if (file_type == LINK)
+ {
+ /* Read the actual filename. */
+ *filename_len
+ = resolve_realname (filename, realname, state, error_callback, data);
+ if (*filename_len < 0)
+ goto exit;
+ }
+ else if (file_type == REGULAR)
+ {
+ *filename_len = strlen (filename);
+ if (*filename_len > PATH_MAX)
+ goto exit;
+
+ memcpy (realname, filename, *filename_len);
+ }
+
+ exit:
+ return realname;
+}
+
+/* Search for debug file into specifying directorires. */
+
+static int
+search_for_debugfile (char *realname, char *debug_filename,
+ backtrace_error_callback error_callback, void *data,
+ struct backtrace_state *state)
+{
+ int debug_filename_len;
+ int pass;
+ int debug_path_len;
+ int debug_does_not_exist;
+ int debug_descriptor;
+ int path_len;
+ char *buffer;
+ int buffer_len;
+ int valid_buffer;
+
+ debug_descriptor = -1;
+ valid_buffer = 0;
+
+ path_len = pathlen (realname);
+ debug_filename_len = strlen ((const char *) debug_filename);
+
+ if (debug_filename_len < 1)
+ goto exit;
+
+ buffer_len = path_len + strlen (debug_file_path[USR_LIB_DEBUG])
+ + debug_filename_len + 1;
+
+ buffer = backtrace_alloc (state, buffer_len, error_callback, data);
+
+ if (buffer == NULL)
+ goto exit;
+ memset (buffer, 0, buffer_len);
+ memcpy (buffer, realname, path_len);
+
+ valid_buffer = 1;
+ for (pass = 0; pass < DEBUG_PATH_MAX; ++pass)
+ {
+ switch (pass)
+ {
+ case CURRENT:
+ {
+ memcpy (buffer + path_len, debug_filename, debug_filename_len);
+ break;
+ }
+ case CURRENT_DEBUG:
+ {
+ debug_path_len = strlen (debug_file_path[CURRENT_DEBUG]);
+ memcpy (buffer + path_len, debug_file_path[CURRENT_DEBUG],
+ debug_path_len);
+ memcpy (buffer + path_len + debug_path_len, debug_filename,
+ debug_filename_len);
+ break;
+ }
+ case USR_LIB_DEBUG:
+ {
+ debug_path_len = strlen (debug_file_path[USR_LIB_DEBUG]);
+ memset (buffer, 0, buffer_len);
+ memcpy (buffer, debug_file_path[USR_LIB_DEBUG], debug_path_len);
+ memcpy (buffer + debug_path_len, debug_filename,
+ debug_filename_len);
+ break;
+ }
+ case USR_LIB_DEBUG_PATH_TO_EXE:
+ {
+ debug_path_len
+ = strlen (debug_file_path[USR_LIB_DEBUG_PATH_TO_EXE]);
+ memset (buffer, 0, buffer_len);
+ memcpy (buffer, debug_file_path[USR_LIB_DEBUG_PATH_TO_EXE],
+ debug_path_len);
+ memcpy (buffer + debug_path_len, realname, path_len);
+ memcpy (buffer + debug_path_len + path_len, debug_filename,
+ debug_filename_len);
+ break;
+ }
+ default:
+ goto exit;
+ }
+
+ debug_descriptor
+ = backtrace_open (buffer, error_callback, data, &debug_does_not_exist);
+
+ if (debug_descriptor > 0)
+ break;
+ }
+ exit:
+ if (valid_buffer)
+ backtrace_free (state, buffer, buffer_len, error_callback, data);
+ return debug_descriptor;
+}
+
+/* Open debug file by gnulink. */
+
+static int
+open_debugfile_by_gnulink (char *realname, unsigned char *section_data,
+ int section_data_len, struct backtrace_state *state,
+ backtrace_error_callback error_callback, void *data)
+{
+ int debug_descriptor;
+
+ debug_descriptor = search_for_debugfile (realname, (char *) section_data,
+ error_callback, data, state);
+ if (debug_descriptor < 0)
+ goto exit;
+
+ /* Check the crc32 checksum if it not the same return -1. */
+
+ if (!check_sum (debug_descriptor, (char *) section_data,
+ strlen ((char *) section_data), section_data_len))
+ debug_descriptor = -1;
+
+ exit:
+ return debug_descriptor;
+}
+
+/* Convert char to hex */
+
+static char
+hex (char ch)
+{
+ return ch > 9 ? ('a' + (ch - 10)) : ('0' + ch);
+}
+
+/* Get build-id name. */
+
+static char *
+get_build_id_name (unsigned char *section_data, int *len,
+ struct backtrace_state *state,
+ backtrace_error_callback error_callback, void *data)
+{
+ Elf_External_Note *build_id_section;
+ char *build_id_name;
+ char *temp;
+ const char *debug_postfix;
+ const char *debug_prefix;
+ size_t debug_postfix_len;
+ size_t debug_prefix_len;
+ size_t name_size;
+ int offset;
+ unsigned char *hash_start;
+ unsigned long hash_size;
+ unsigned long identifier;
+
+ debug_postfix_len = 6;
+ debug_prefix_len = 10;
+ debug_postfix = ".debug";
+ debug_prefix = ".build-id/";
+ *len = 0;
+
+ build_id_section = (Elf_External_Note *) section_data;
+ hash_size = getl32 (build_id_section->descsz);
+ identifier = getl32 (build_id_section->type);
+ name_size = getl32 (build_id_section->namesz);
+
+ if (identifier != NT_GNU_BUILD_ID || hash_size == 0 || name_size != 4
+ || strncmp ((char *) build_id_section->name, "GNU", 3) != 0)
+ return NULL;
+
+ offset = 16;
+ hash_start = section_data + offset;
+ *len = hash_size * 2 + debug_postfix_len + debug_prefix_len + 1;
+ build_id_name = backtrace_alloc (state, *len, error_callback, data);
+
+ memset (build_id_name, 0, *len);
+ memcpy (build_id_name, debug_prefix, debug_prefix_len);
+ temp = build_id_name + debug_prefix_len;
+
+ *temp++ = hex ((*hash_start & 0xF0) >> 4);
+ *temp++ = hex (*hash_start & 0x0F);
+ ++hash_start;
+ --hash_size;
+
+ memcpy (temp, "/", 1);
+ ++temp;
+
+ while (hash_size--)
+ {
+ *temp++ = hex ((*hash_start & 0xF0) >> 4);
+ *temp++ = hex (*hash_start & 0x0F);
+ ++hash_start;
+ }
+
+ memcpy (temp, debug_postfix, debug_postfix_len);
+ return build_id_name;
+}
+
+/* Open file by build-id. */
+
+static int
+open_debugfile_by_build_id (char *realname, unsigned char *section_data,
+ struct backtrace_state *state,
+ backtrace_error_callback error_callback, void *data)
+
+{
+ char *build_id_name;
+ int debug_descriptor;
+ int build_id_name_len;
+ int valid_build_id_name;
+
+ debug_descriptor = -1;
+ valid_build_id_name = 0;
+
+ build_id_name = get_build_id_name (section_data, &build_id_name_len, state,
+ error_callback, data);
+
+ if (build_id_name == NULL || build_id_name_len <= 0)
+ goto exit;
+
+ valid_build_id_name = 1;
+
+ debug_descriptor = search_for_debugfile (realname, build_id_name,
+ error_callback, data, state);
+
+ exit:
+ if (valid_build_id_name)
+ backtrace_free (state, build_id_name, build_id_name_len, error_callback,
+ data);
+ return debug_descriptor;
+}
+
+/* Open debug file. */
+
+int
+backtrace_open_debugfile (int descriptor, const char *filename,
+ backtrace_error_callback error_callback, void *data,
+ struct backtrace_state *state)
+{
+ int debug_descriptor;
+ unsigned char *gnulink_section_data;
+ unsigned char *build_id_section_data;
+ size_t valid_descriptor;
+ size_t valid_gnulink_section_data;
+ size_t valid_build_id_section_data;
+ size_t valid_realname;
+ int build_id_section_data_len;
+ int gnu_link_section_data_len;
+ char *realname;
+ int filename_len;
+
+ valid_realname = 0;
+ valid_descriptor = 0;
+ valid_gnulink_section_data = 0;
+ valid_build_id_section_data = 0;
+ build_id_section_data_len = 0;
+ gnu_link_section_data_len = 0;
+ debug_descriptor = -1;
+
+ realname = backtrace_resolve_realname (filename, &filename_len, state,
+ error_callback, data);
+
+ if (realname == NULL || filename_len < 0)
+ goto exit;
+
+ valid_realname = 1;
+
+ /* Check if build-id section does exist. */
+ build_id_section_data
+ = elf_get_section_by_name (state, descriptor, error_callback, data,
+ &build_id_section_data_len,
+ ".note.gnu.build-id");
+
+ if (build_id_section_data != NULL && build_id_section_data_len > 0)
+ {
+ valid_build_id_section_data = 1;
+ debug_descriptor
+ = open_debugfile_by_build_id (realname, build_id_section_data, state,
+ error_callback, data);
+ }
+
+ if (debug_descriptor < 0)
+ {
+ gnulink_section_data
+ = elf_get_section_by_name (state, descriptor, error_callback, data,
+ &gnu_link_section_data_len,
+ ".gnu_debuglink");
+
+ if (gnulink_section_data != NULL && gnu_link_section_data_len > 0)
+ {
+ valid_gnulink_section_data = 1;
+ debug_descriptor
+ = open_debugfile_by_gnulink (realname, gnulink_section_data,
+ gnu_link_section_data_len, state,
+ error_callback, data);
+ }
+ }
+
+ if (debug_descriptor >= 0)
+ valid_descriptor = 1;
+
+ exit:
+ if (valid_descriptor)
+ backtrace_close (descriptor, error_callback, data);
+ if (valid_gnulink_section_data)
+ backtrace_free (state, gnulink_section_data, gnu_link_section_data_len,
+ error_callback, data);
+ if (valid_build_id_section_data)
+ backtrace_free (state, build_id_section_data, build_id_section_data_len,
+ error_callback, data);
+ if (valid_realname)
+ backtrace_free (state, realname, PATH_MAX + 1, error_callback, data);
+ return debug_descriptor;
+}
+
/* A dummy callback function used when we can't find any debug info. */
static int
@@ -521,7 +1365,6 @@ 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)
{
- struct backtrace_view ehdr_view;
b_elf_ehdr ehdr;
off_t shoff;
unsigned int shnum;
@@ -547,6 +1390,7 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
off_t max_offset;
struct backtrace_view debug_view;
int debug_view_valid;
+ enum type_of_elf elf_type;
*found_sym = 0;
*found_dwarf = 0;
@@ -557,94 +1401,20 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
strtab_view_valid = 0;
debug_view_valid = 0;
- if (!backtrace_get_view (state, descriptor, 0, sizeof ehdr, error_callback,
- data, &ehdr_view))
- goto fail;
-
- memcpy (&ehdr, ehdr_view.data, sizeof ehdr);
-
- backtrace_release_view (state, &ehdr_view, error_callback, data);
-
- if (ehdr.e_ident[EI_MAG0] != ELFMAG0
- || ehdr.e_ident[EI_MAG1] != ELFMAG1
- || ehdr.e_ident[EI_MAG2] != ELFMAG2
- || ehdr.e_ident[EI_MAG3] != ELFMAG3)
- {
- error_callback (data, "executable file is not ELF", 0);
- goto fail;
- }
- if (ehdr.e_ident[EI_VERSION] != EV_CURRENT)
+ elf_type = process_elf_header (state, descriptor, error_callback, data, exe,
+ &shoff, &shnum, &shstrndx, &ehdr);
+ switch (elf_type)
{
- error_callback (data, "executable file is unrecognized ELF version", 0);
+ /* Binary compiled with PIE option. */
+ case DYN:
+ return -1;
+ case EXEC:
+ break;
+ /* Header is invalid. */
+ case INVALID:
goto fail;
}
-#if BACKTRACE_ELF_SIZE == 32
-#define BACKTRACE_ELFCLASS ELFCLASS32
-#else
-#define BACKTRACE_ELFCLASS ELFCLASS64
-#endif
-
- if (ehdr.e_ident[EI_CLASS] != BACKTRACE_ELFCLASS)
- {
- error_callback (data, "executable file is unexpected ELF class", 0);
- goto fail;
- }
-
- if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB
- && ehdr.e_ident[EI_DATA] != ELFDATA2MSB)
- {
- error_callback (data, "executable file has unknown endianness", 0);
- goto fail;
- }
-
- /* If the executable is ET_DYN, it is either a PIE, or we are running
- directly a shared library with .interp. We need to wait for
- dl_iterate_phdr in that case to determine the actual base_address. */
- if (exe && ehdr.e_type == ET_DYN)
- return -1;
-
- shoff = ehdr.e_shoff;
- shnum = ehdr.e_shnum;
- shstrndx = ehdr.e_shstrndx;
-
- if ((shnum == 0 || shstrndx == SHN_XINDEX)
- && shoff != 0)
- {
- struct backtrace_view shdr_view;
- const b_elf_shdr *shdr;
-
- if (!backtrace_get_view (state, descriptor, shoff, sizeof shdr,
- error_callback, data, &shdr_view))
- goto fail;
-
- shdr = (const b_elf_shdr *) shdr_view.data;
-
- if (shnum == 0)
- shnum = shdr->sh_size;
-
- if (shstrndx == SHN_XINDEX)
- {
- shstrndx = shdr->sh_link;
-
- /* Versions of the GNU binutils between 2.12 and 2.18 did
- not handle objects with more than SHN_LORESERVE sections
- correctly. All large section indexes were offset by
- 0x100. There is more information at
- http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
- Fortunately these object files are easy to detect, as the
- GNU binutils always put the section header string table
- near the end of the list of sections. Thus if the
- section header string table index is larger than the
- number of sections, then we know we have to subtract
- 0x100 to get the real section index. */
- if (shstrndx >= shnum && shstrndx >= SHN_LORESERVE + 0x100)
- shstrndx -= 0x100;
- }
-
- backtrace_release_view (state, &shdr_view, error_callback, data);
- }
-
/* To translate PC to file/line when using DWARF, we need to find
the .debug_info and .debug_line sections. */
@@ -877,6 +1647,7 @@ phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
int does_not_exist;
fileline elf_fileline_fn;
int found_dwarf;
+ int debug_descriptor;
/* There is not much we can do if we don't have the module name,
unless executable is ET_DYN, where we expect the very first
@@ -895,11 +1666,19 @@ phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
backtrace_close (pd->exe_descriptor, pd->error_callback, pd->data);
pd->exe_descriptor = -1;
}
+ debug_descriptor = -1;
descriptor = backtrace_open (info->dlpi_name, pd->error_callback,
pd->data, &does_not_exist);
+
if (descriptor < 0)
return 0;
+
+ debug_descriptor
+ = backtrace_open_debugfile (descriptor, info->dlpi_name,
+ pd->error_callback, pd->data, pd->state);
+ if (debug_descriptor >= 0)
+ descriptor = debug_descriptor;
}
if (elf_add (pd->state, descriptor, info->dlpi_addr, pd->error_callback,
diff --git a/libbacktrace/fileline.c b/libbacktrace/fileline.c
index 0fd350a..1a5cfda 100644
--- a/libbacktrace/fileline.c
+++ b/libbacktrace/fileline.c
@@ -57,6 +57,7 @@ fileline_initialize (struct backtrace_state *state,
int pass;
int called_error_callback;
int descriptor;
+ int debug_descriptor;
if (!state->threaded)
failed = state->fileline_initialization_failed;
@@ -79,6 +80,7 @@ fileline_initialize (struct backtrace_state *state,
/* We have not initialized the information. Do it now. */
descriptor = -1;
+ debug_descriptor = -1;
called_error_callback = 0;
for (pass = 0; pass < 4; ++pass)
{
@@ -108,13 +110,22 @@ fileline_initialize (struct backtrace_state *state,
descriptor = backtrace_open (filename, error_callback, data,
&does_not_exist);
+
if (descriptor < 0 && !does_not_exist)
{
called_error_callback = 1;
break;
}
+
if (descriptor >= 0)
- break;
+ {
+ debug_descriptor
+ = backtrace_open_debugfile (descriptor, filename, error_callback,
+ data, state);
+ if (debug_descriptor >= 0)
+ descriptor = debug_descriptor;
+ break;
+ }
}
if (descriptor < 0)
diff --git a/libbacktrace/internal.h b/libbacktrace/internal.h
index 89b7bf7..dc4b5f8 100644
--- a/libbacktrace/internal.h
+++ b/libbacktrace/internal.h
@@ -176,6 +176,14 @@ struct backtrace_view
size_t len;
};
+/* Open debug file whose name is placed in gnu_debuglink section.
+ Check the crc32 sum and search file with debug data. On success returns
+ descriptor of that file on fail -1. */
+
+extern int backtrace_open_debugfile (int descriptor, const char *filename,
+ backtrace_error_callback, void *data,
+ struct backtrace_state *state);
+
/* Create a view of SIZE bytes from DESCRIPTOR at OFFSET. Store the
result in *VIEW. Returns 1 on success, 0 on error. */
extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
--
1.9.1