diff options
author | max42 <max42@yandex-team.com> | 2023-06-30 03:37:03 +0300 |
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committer | max42 <max42@yandex-team.com> | 2023-06-30 03:37:03 +0300 |
commit | fac2bd72b4b31ec3238292caf8fb2a8aaa6d6c4a (patch) | |
tree | b8cbc1deb00309c7f1a7ab6df520a76cf0b5c6d7 /contrib/libs/backtrace/elf.c | |
parent | 7bf166b1a7ed0af927f230022b245af618e998c1 (diff) | |
download | ydb-fac2bd72b4b31ec3238292caf8fb2a8aaa6d6c4a.tar.gz |
YT-19324: move YT provider to ydb/library/yql
This commit is formed by the following script: https://paste.yandex-team.ru/6f92e4b8-efc5-4d34-948b-15ee2accd7e7/text.
This commit has zero effect on all projects that depend on YQL.
The summary of changes:
- `yql/providers/yt -> ydb/library/yql/providers/yt `- the whole implementation of YT provider is moved into YDB code base for further export as a part of YT YQL plugin shared library;
- `yql/providers/stat/{expr_nodes,uploader} -> ydb/library/yql/providers/stat/{expr_nodes,uploader}` - a small interface without implementation and the description of stat expr nodes;
- `yql/core/extract_predicate/ut -> ydb/library/yql/core/extract_predicate/ut`;
- `yql/core/{ut,ut_common} -> ydb/library/yql/core/{ut,ut_common}`;
- `yql/core` is gone;
- `yql/library/url_preprocessing -> ydb/library/yql/core/url_preprocessing`.
**NB**: all new targets inside `ydb/` are under `IF (NOT CMAKE_EXPORT)` clause which disables them from open-source cmake generation and ya make build. They will be enabled in the subsequent commits.
Diffstat (limited to 'contrib/libs/backtrace/elf.c')
-rw-r--r-- | contrib/libs/backtrace/elf.c | 4924 |
1 files changed, 4924 insertions, 0 deletions
diff --git a/contrib/libs/backtrace/elf.c b/contrib/libs/backtrace/elf.c new file mode 100644 index 0000000000..77a1a728fd --- /dev/null +++ b/contrib/libs/backtrace/elf.c @@ -0,0 +1,4924 @@ +/* elf.c -- Get debug data from an ELF file for backtraces. + Copyright (C) 2012-2021 Free Software Foundation, Inc. + Written by Ian Lance Taylor, Google. + +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. + + (3) The name of the author may not be used to + endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. */ + +#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 + #ifdef HAVE_LINK_H + #include <link.h> + #endif + #ifdef HAVE_SYS_LINK_H + #error #include <sys/link.h> + #endif +#endif + +#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 + +#ifndef __GNUC__ +#define __builtin_prefetch(p, r, l) +#define unlikely(x) (x) +#else +#define unlikely(x) __builtin_expect(!!(x), 0) +#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_LSTAT + +/* Dummy version of lstat for systems that don't have it. */ + +static int +xlstat (const char *path ATTRIBUTE_UNUSED, struct stat *st ATTRIBUTE_UNUSED) +{ + return -1; +} + +#define lstat xlstat + +#endif + +#ifndef HAVE_READLINK + +/* Dummy version of readlink for systems that don't have it. */ + +static ssize_t +xreadlink (const char *path ATTRIBUTE_UNUSED, char *buf ATTRIBUTE_UNUSED, + size_t bufsz ATTRIBUTE_UNUSED) +{ + return -1; +} + +#define readlink xreadlink + +#endif + +#ifndef HAVE_DL_ITERATE_PHDR + +/* Dummy version of dl_iterate_phdr for systems that don't have it. */ + +#define dl_phdr_info x_dl_phdr_info +#define dl_iterate_phdr x_dl_iterate_phdr + +struct dl_phdr_info +{ + uintptr_t dlpi_addr; + const char *dlpi_name; +}; + +static int +dl_iterate_phdr (int (*callback) (struct dl_phdr_info *, + size_t, void *) ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + return 0; +} + +#endif /* ! defined (HAVE_DL_ITERATE_PHDR) */ + +/* The configure script must tell us whether we are 32-bit or 64-bit + ELF. We could make this code test and support either possibility, + but there is no point. This code only works for the currently + running executable, which means that we know the ELF mode at + configure time. */ + +#if BACKTRACE_ELF_SIZE != 32 && BACKTRACE_ELF_SIZE != 64 +#error "Unknown BACKTRACE_ELF_SIZE" +#endif + +/* <link.h> might #include <elf.h> which might define our constants + with slightly different values. Undefine them to be safe. */ + +#undef EI_NIDENT +#undef EI_MAG0 +#undef EI_MAG1 +#undef EI_MAG2 +#undef EI_MAG3 +#undef EI_CLASS +#undef EI_DATA +#undef EI_VERSION +#undef ELF_MAG0 +#undef ELF_MAG1 +#undef ELF_MAG2 +#undef ELF_MAG3 +#undef ELFCLASS32 +#undef ELFCLASS64 +#undef ELFDATA2LSB +#undef ELFDATA2MSB +#undef EV_CURRENT +#undef ET_DYN +#undef EM_PPC64 +#undef EF_PPC64_ABI +#undef SHN_LORESERVE +#undef SHN_XINDEX +#undef SHN_UNDEF +#undef SHT_PROGBITS +#undef SHT_SYMTAB +#undef SHT_STRTAB +#undef SHT_DYNSYM +#undef SHF_COMPRESSED +#undef STT_OBJECT +#undef STT_FUNC +#undef NT_GNU_BUILD_ID +#undef ELFCOMPRESS_ZLIB + +/* Basic types. */ + +typedef uint16_t b_elf_half; /* Elf_Half. */ +typedef uint32_t b_elf_word; /* Elf_Word. */ +typedef int32_t b_elf_sword; /* Elf_Sword. */ + +#if BACKTRACE_ELF_SIZE == 32 + +typedef uint32_t b_elf_addr; /* Elf_Addr. */ +typedef uint32_t b_elf_off; /* Elf_Off. */ + +typedef uint32_t b_elf_wxword; /* 32-bit Elf_Word, 64-bit ELF_Xword. */ + +#else + +typedef uint64_t b_elf_addr; /* Elf_Addr. */ +typedef uint64_t b_elf_off; /* Elf_Off. */ +typedef uint64_t b_elf_xword; /* Elf_Xword. */ +typedef int64_t b_elf_sxword; /* Elf_Sxword. */ + +typedef uint64_t b_elf_wxword; /* 32-bit Elf_Word, 64-bit ELF_Xword. */ + +#endif + +/* Data structures and associated constants. */ + +#define EI_NIDENT 16 + +typedef struct { + unsigned char e_ident[EI_NIDENT]; /* ELF "magic number" */ + b_elf_half e_type; /* Identifies object file type */ + b_elf_half e_machine; /* Specifies required architecture */ + b_elf_word e_version; /* Identifies object file version */ + b_elf_addr e_entry; /* Entry point virtual address */ + b_elf_off e_phoff; /* Program header table file offset */ + b_elf_off e_shoff; /* Section header table file offset */ + b_elf_word e_flags; /* Processor-specific flags */ + b_elf_half e_ehsize; /* ELF header size in bytes */ + b_elf_half e_phentsize; /* Program header table entry size */ + b_elf_half e_phnum; /* Program header table entry count */ + b_elf_half e_shentsize; /* Section header table entry size */ + b_elf_half e_shnum; /* Section header table entry count */ + b_elf_half e_shstrndx; /* Section header string table index */ +} b_elf_ehdr; /* Elf_Ehdr. */ + +#define EI_MAG0 0 +#define EI_MAG1 1 +#define EI_MAG2 2 +#define EI_MAG3 3 +#define EI_CLASS 4 +#define EI_DATA 5 +#define EI_VERSION 6 + +#define ELFMAG0 0x7f +#define ELFMAG1 'E' +#define ELFMAG2 'L' +#define ELFMAG3 'F' + +#define ELFCLASS32 1 +#define ELFCLASS64 2 + +#define ELFDATA2LSB 1 +#define ELFDATA2MSB 2 + +#define EV_CURRENT 1 + +#define ET_DYN 3 + +#define EM_PPC64 21 +#define EF_PPC64_ABI 3 + +typedef struct { + b_elf_word sh_name; /* Section name, index in string tbl */ + b_elf_word sh_type; /* Type of section */ + b_elf_wxword sh_flags; /* Miscellaneous section attributes */ + b_elf_addr sh_addr; /* Section virtual addr at execution */ + b_elf_off sh_offset; /* Section file offset */ + b_elf_wxword sh_size; /* Size of section in bytes */ + b_elf_word sh_link; /* Index of another section */ + b_elf_word sh_info; /* Additional section information */ + b_elf_wxword sh_addralign; /* Section alignment */ + b_elf_wxword sh_entsize; /* Entry size if section holds table */ +} b_elf_shdr; /* Elf_Shdr. */ + +#define SHN_UNDEF 0x0000 /* Undefined section */ +#define SHN_LORESERVE 0xFF00 /* Begin range of reserved indices */ +#define SHN_XINDEX 0xFFFF /* Section index is held elsewhere */ + +#define SHT_PROGBITS 1 +#define SHT_SYMTAB 2 +#define SHT_STRTAB 3 +#define SHT_DYNSYM 11 + +#define SHF_COMPRESSED 0x800 + +#if BACKTRACE_ELF_SIZE == 32 + +typedef struct +{ + b_elf_word st_name; /* Symbol name, index in string tbl */ + b_elf_addr st_value; /* Symbol value */ + b_elf_word st_size; /* Symbol size */ + unsigned char st_info; /* Symbol binding and type */ + unsigned char st_other; /* Visibility and other data */ + b_elf_half st_shndx; /* Symbol section index */ +} b_elf_sym; /* Elf_Sym. */ + +#else /* BACKTRACE_ELF_SIZE != 32 */ + +typedef struct +{ + b_elf_word st_name; /* Symbol name, index in string tbl */ + unsigned char st_info; /* Symbol binding and type */ + unsigned char st_other; /* Visibility and other data */ + b_elf_half st_shndx; /* Symbol section index */ + b_elf_addr st_value; /* Symbol value */ + b_elf_xword st_size; /* Symbol size */ +} b_elf_sym; /* Elf_Sym. */ + +#endif /* BACKTRACE_ELF_SIZE != 32 */ + +#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 + +#if BACKTRACE_ELF_SIZE == 32 + +typedef struct +{ + b_elf_word ch_type; /* Compresstion algorithm */ + b_elf_word ch_size; /* Uncompressed size */ + b_elf_word ch_addralign; /* Alignment for uncompressed data */ +} b_elf_chdr; /* Elf_Chdr */ + +#else /* BACKTRACE_ELF_SIZE != 32 */ + +typedef struct +{ + b_elf_word ch_type; /* Compression algorithm */ + b_elf_word ch_reserved; /* Reserved */ + b_elf_xword ch_size; /* Uncompressed size */ + b_elf_xword ch_addralign; /* Alignment for uncompressed data */ +} b_elf_chdr; /* Elf_Chdr */ + +#endif /* BACKTRACE_ELF_SIZE != 32 */ + +#define ELFCOMPRESS_ZLIB 1 + +/* Names of sections, indexed by enum dwarf_section in internal.h. */ + +static const char * const dwarf_section_names[DEBUG_MAX] = +{ + ".debug_info", + ".debug_line", + ".debug_abbrev", + ".debug_ranges", + ".debug_str", + ".debug_addr", + ".debug_str_offsets", + ".debug_line_str", + ".debug_rnglists" +}; + +/* Information we gather for the sections we care about. */ + +struct debug_section_info +{ + /* Section file offset. */ + off_t offset; + /* Section size. */ + size_t size; + /* Section contents, after read from file. */ + const unsigned char *data; + /* Whether the SHF_COMPRESSED flag is set for the section. */ + int compressed; +}; + +/* Information we keep for an ELF symbol. */ + +struct elf_symbol +{ + /* The name of the symbol. */ + const char *name; + /* The address of the symbol. */ + uintptr_t address; + /* The size of the symbol. */ + size_t size; +}; + +/* Information to pass to elf_syminfo. */ + +struct elf_syminfo_data +{ + /* Symbols for the next module. */ + struct elf_syminfo_data *next; + /* The ELF symbols, sorted by address. */ + struct elf_symbol *symbols; + /* The number of symbols. */ + size_t count; +}; + +/* A view that works for either a file or memory. */ + +struct elf_view +{ + struct backtrace_view view; + int release; /* If non-zero, must call backtrace_release_view. */ +}; + +/* Information about PowerPC64 ELFv1 .opd section. */ + +struct elf_ppc64_opd_data +{ + /* Address of the .opd section. */ + b_elf_addr addr; + /* Section data. */ + const char *data; + /* Size of the .opd section. */ + size_t size; + /* Corresponding section view. */ + struct elf_view view; +}; + +/* Create a view of SIZE bytes from DESCRIPTOR/MEMORY at OFFSET. */ + +static int +elf_get_view (struct backtrace_state *state, int descriptor, + const unsigned char *memory, size_t memory_size, off_t offset, + uint64_t size, backtrace_error_callback error_callback, + void *data, struct elf_view *view) +{ + if (memory == NULL) + { + view->release = 1; + return backtrace_get_view (state, descriptor, offset, size, + error_callback, data, &view->view); + } + else + { + if ((uint64_t) offset + size > (uint64_t) memory_size) + { + error_callback (data, "out of range for in-memory file", 0); + return 0; + } + view->view.data = (const void *) (memory + offset); + view->view.base = NULL; + view->view.len = size; + view->release = 0; + return 1; + } +} + +/* Release a view read by elf_get_view. */ + +static void +elf_release_view (struct backtrace_state *state, struct elf_view *view, + backtrace_error_callback error_callback, void *data) +{ + if (view->release) + backtrace_release_view (state, &view->view, error_callback, data); +} + +/* 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 a symbol + table. */ + +static void +elf_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED, + uintptr_t addr ATTRIBUTE_UNUSED, + backtrace_syminfo_callback callback ATTRIBUTE_UNUSED, + backtrace_error_callback error_callback, void *data) +{ + error_callback (data, "no symbol table in ELF executable", -1); +} + +/* A callback function used when we can't find any debug info. */ + +static int +elf_nodebug (struct backtrace_state *state, uintptr_t pc, + backtrace_full_callback callback, + backtrace_error_callback error_callback, void *data) +{ + if (state->syminfo_fn != NULL && state->syminfo_fn != elf_nosyms) + { + struct backtrace_call_full bdata; + + /* Fetch symbol information so that we can least get the + function name. */ + + bdata.full_callback = callback; + bdata.full_error_callback = error_callback; + bdata.full_data = data; + bdata.ret = 0; + state->syminfo_fn (state, pc, backtrace_syminfo_to_full_callback, + backtrace_syminfo_to_full_error_callback, &bdata); + return bdata.ret; + } + + error_callback (data, "no debug info in ELF executable", -1); + return 0; +} + +/* Compare struct elf_symbol for qsort. */ + +static int +elf_symbol_compare (const void *v1, const void *v2) +{ + const struct elf_symbol *e1 = (const struct elf_symbol *) v1; + const struct elf_symbol *e2 = (const struct elf_symbol *) v2; + + if (e1->address < e2->address) + return -1; + else if (e1->address > e2->address) + return 1; + else + return 0; +} + +/* Compare an ADDR against an elf_symbol for bsearch. We allocate one + extra entry in the array so that this can look safely at the next + entry. */ + +static int +elf_symbol_search (const void *vkey, const void *ventry) +{ + const uintptr_t *key = (const uintptr_t *) vkey; + const struct elf_symbol *entry = (const struct elf_symbol *) ventry; + uintptr_t addr; + + addr = *key; + if (addr < entry->address) + return -1; + else if (addr >= entry->address + entry->size) + return 1; + else + return 0; +} + +/* Initialize the symbol table info for elf_syminfo. */ + +static int +elf_initialize_syminfo (struct backtrace_state *state, + uintptr_t base_address, + const unsigned char *symtab_data, size_t symtab_size, + const unsigned char *strtab, size_t strtab_size, + backtrace_error_callback error_callback, + void *data, struct elf_syminfo_data *sdata, + struct elf_ppc64_opd_data *opd) +{ + size_t sym_count; + const b_elf_sym *sym; + size_t elf_symbol_count; + size_t elf_symbol_size; + struct elf_symbol *elf_symbols; + size_t i; + unsigned int j; + + sym_count = symtab_size / sizeof (b_elf_sym); + + /* We only care about function symbols. Count them. */ + sym = (const b_elf_sym *) symtab_data; + elf_symbol_count = 0; + for (i = 0; i < sym_count; ++i, ++sym) + { + int info; + + info = sym->st_info & 0xf; + if ((info == STT_FUNC || info == STT_OBJECT) + && sym->st_shndx != SHN_UNDEF) + ++elf_symbol_count; + } + + elf_symbol_size = elf_symbol_count * sizeof (struct elf_symbol); + elf_symbols = ((struct elf_symbol *) + backtrace_alloc (state, elf_symbol_size, error_callback, + data)); + if (elf_symbols == NULL) + return 0; + + sym = (const b_elf_sym *) symtab_data; + j = 0; + for (i = 0; i < sym_count; ++i, ++sym) + { + int info; + + info = sym->st_info & 0xf; + if (info != STT_FUNC && info != STT_OBJECT) + continue; + if (sym->st_shndx == SHN_UNDEF) + continue; + if (sym->st_name >= strtab_size) + { + error_callback (data, "symbol string index out of range", 0); + backtrace_free (state, elf_symbols, elf_symbol_size, error_callback, + data); + return 0; + } + elf_symbols[j].name = (const char *) strtab + sym->st_name; + /* Special case PowerPC64 ELFv1 symbols in .opd section, if the symbol + is a function descriptor, read the actual code address from the + descriptor. */ + if (opd + && sym->st_value >= opd->addr + && sym->st_value < opd->addr + opd->size) + elf_symbols[j].address + = *(const b_elf_addr *) (opd->data + (sym->st_value - opd->addr)); + else + elf_symbols[j].address = sym->st_value; + elf_symbols[j].address += base_address; + elf_symbols[j].size = sym->st_size; + ++j; + } + + backtrace_qsort (elf_symbols, elf_symbol_count, sizeof (struct elf_symbol), + elf_symbol_compare); + + sdata->next = NULL; + sdata->symbols = elf_symbols; + sdata->count = elf_symbol_count; + + return 1; +} + +/* Add EDATA to the list in STATE. */ + +static void +elf_add_syminfo_data (struct backtrace_state *state, + struct elf_syminfo_data *edata) +{ + if (!state->threaded) + { + struct elf_syminfo_data **pp; + + for (pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data; + *pp != NULL; + pp = &(*pp)->next) + ; + *pp = edata; + } + else + { + while (1) + { + struct elf_syminfo_data **pp; + + pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data; + + while (1) + { + struct elf_syminfo_data *p; + + p = backtrace_atomic_load_pointer (pp); + + if (p == NULL) + break; + + pp = &p->next; + } + + if (__sync_bool_compare_and_swap (pp, NULL, edata)) + break; + } + } +} + +/* Return the symbol name and value for an ADDR. */ + +static void +elf_syminfo (struct backtrace_state *state, uintptr_t addr, + backtrace_syminfo_callback callback, + backtrace_error_callback error_callback ATTRIBUTE_UNUSED, + void *data) +{ + struct elf_syminfo_data *edata; + struct elf_symbol *sym = NULL; + + if (!state->threaded) + { + for (edata = (struct elf_syminfo_data *) state->syminfo_data; + edata != NULL; + edata = edata->next) + { + sym = ((struct elf_symbol *) + bsearch (&addr, edata->symbols, edata->count, + sizeof (struct elf_symbol), elf_symbol_search)); + if (sym != NULL) + break; + } + } + else + { + struct elf_syminfo_data **pp; + + pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data; + while (1) + { + edata = backtrace_atomic_load_pointer (pp); + if (edata == NULL) + break; + + sym = ((struct elf_symbol *) + bsearch (&addr, edata->symbols, edata->count, + sizeof (struct elf_symbol), elf_symbol_search)); + if (sym != NULL) + break; + + pp = &edata->next; + } + } + + if (sym == NULL) + callback (data, addr, NULL, 0, 0); + else + 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; + } +} + +#define SYSTEM_BUILD_ID_DIR "/usr/lib/debug/.build-id/" + +/* 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 = SYSTEM_BUILD_ID_DIR; + 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; + + ddescriptor = elf_find_debugfile_by_debuglink (state, filename, + debuglink_name, + error_callback, data); + if (ddescriptor < 0) + return -1; + + if (debuglink_crc != 0) + { + uint32_t got_crc; + + 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; +} + +/* A function useful for setting a breakpoint for an inflation failure + when this code is compiled with -g. */ + +static void +elf_uncompress_failed(void) +{ +} + +/* *PVAL is the current value being read from the stream, and *PBITS + is the number of valid bits. Ensure that *PVAL holds at least 15 + bits by reading additional bits from *PPIN, up to PINEND, as + needed. Updates *PPIN, *PVAL and *PBITS. Returns 1 on success, 0 + on error. */ + +static int +elf_zlib_fetch (const unsigned char **ppin, const unsigned char *pinend, + uint64_t *pval, unsigned int *pbits) +{ + unsigned int bits; + const unsigned char *pin; + uint64_t val; + uint32_t next; + + bits = *pbits; + if (bits >= 15) + return 1; + pin = *ppin; + val = *pval; + + if (unlikely (pinend - pin < 4)) + { + elf_uncompress_failed (); + return 0; + } + +#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) \ + && defined(__ORDER_BIG_ENDIAN__) \ + && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ \ + || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) + /* We've ensured that PIN is aligned. */ + next = *(const uint32_t *)pin; + +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + next = __builtin_bswap32 (next); +#endif +#else + next = pin[0] | (pin[1] << 8) | (pin[2] << 16) | (pin[3] << 24); +#endif + + val |= (uint64_t)next << bits; + bits += 32; + pin += 4; + + /* We will need the next four bytes soon. */ + __builtin_prefetch (pin, 0, 0); + + *ppin = pin; + *pval = val; + *pbits = bits; + return 1; +} + +/* Huffman code tables, like the rest of the zlib format, are defined + by RFC 1951. We store a Huffman code table as a series of tables + stored sequentially in memory. Each entry in a table is 16 bits. + The first, main, table has 256 entries. It is followed by a set of + secondary tables of length 2 to 128 entries. The maximum length of + a code sequence in the deflate format is 15 bits, so that is all we + need. Each secondary table has an index, which is the offset of + the table in the overall memory storage. + + The deflate format says that all codes of a given bit length are + lexicographically consecutive. Perhaps we could have 130 values + that require a 15-bit code, perhaps requiring three secondary + tables of size 128. I don't know if this is actually possible, but + it suggests that the maximum size required for secondary tables is + 3 * 128 + 3 * 64 ... == 768. The zlib enough program reports 660 + as the maximum. We permit 768, since in addition to the 256 for + the primary table, with two bytes per entry, and with the two + tables we need, that gives us a page. + + A single table entry needs to store a value or (for the main table + only) the index and size of a secondary table. Values range from 0 + to 285, inclusive. Secondary table indexes, per above, range from + 0 to 510. For a value we need to store the number of bits we need + to determine that value (one value may appear multiple times in the + table), which is 1 to 8. For a secondary table we need to store + the number of bits used to index into the table, which is 1 to 7. + And of course we need 1 bit to decide whether we have a value or a + secondary table index. So each entry needs 9 bits for value/table + index, 3 bits for size, 1 bit what it is. For simplicity we use 16 + bits per entry. */ + +/* Number of entries we allocate to for one code table. We get a page + for the two code tables we need. */ + +#define HUFFMAN_TABLE_SIZE (1024) + +/* Bit masks and shifts for the values in the table. */ + +#define HUFFMAN_VALUE_MASK 0x01ff +#define HUFFMAN_BITS_SHIFT 9 +#define HUFFMAN_BITS_MASK 0x7 +#define HUFFMAN_SECONDARY_SHIFT 12 + +/* For working memory while inflating we need two code tables, we need + an array of code lengths (max value 15, so we use unsigned char), + and an array of unsigned shorts used while building a table. The + latter two arrays must be large enough to hold the maximum number + of code lengths, which RFC 1951 defines as 286 + 30. */ + +#define ZDEBUG_TABLE_SIZE \ + (2 * HUFFMAN_TABLE_SIZE * sizeof (uint16_t) \ + + (286 + 30) * sizeof (uint16_t) \ + + (286 + 30) * sizeof (unsigned char)) + +#define ZDEBUG_TABLE_CODELEN_OFFSET \ + (2 * HUFFMAN_TABLE_SIZE * sizeof (uint16_t) \ + + (286 + 30) * sizeof (uint16_t)) + +#define ZDEBUG_TABLE_WORK_OFFSET \ + (2 * HUFFMAN_TABLE_SIZE * sizeof (uint16_t)) + +#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE + +/* Used by the main function that generates the fixed table to learn + the table size. */ +static size_t final_next_secondary; + +#endif + +/* Build a Huffman code table from an array of lengths in CODES of + length CODES_LEN. The table is stored into *TABLE. ZDEBUG_TABLE + is the same as for elf_zlib_inflate, used to find some work space. + Returns 1 on success, 0 on error. */ + +static int +elf_zlib_inflate_table (unsigned char *codes, size_t codes_len, + uint16_t *zdebug_table, uint16_t *table) +{ + uint16_t count[16]; + uint16_t start[16]; + uint16_t prev[16]; + uint16_t firstcode[7]; + uint16_t *next; + size_t i; + size_t j; + unsigned int code; + size_t next_secondary; + + /* Count the number of code of each length. Set NEXT[val] to be the + next value after VAL with the same bit length. */ + + next = (uint16_t *) (((unsigned char *) zdebug_table) + + ZDEBUG_TABLE_WORK_OFFSET); + + memset (&count[0], 0, 16 * sizeof (uint16_t)); + for (i = 0; i < codes_len; ++i) + { + if (unlikely (codes[i] >= 16)) + { + elf_uncompress_failed (); + return 0; + } + + if (count[codes[i]] == 0) + { + start[codes[i]] = i; + prev[codes[i]] = i; + } + else + { + next[prev[codes[i]]] = i; + prev[codes[i]] = i; + } + + ++count[codes[i]]; + } + + /* For each length, fill in the table for the codes of that + length. */ + + memset (table, 0, HUFFMAN_TABLE_SIZE * sizeof (uint16_t)); + + /* Handle the values that do not require a secondary table. */ + + code = 0; + for (j = 1; j <= 8; ++j) + { + unsigned int jcnt; + unsigned int val; + + jcnt = count[j]; + if (jcnt == 0) + continue; + + if (unlikely (jcnt > (1U << j))) + { + elf_uncompress_failed (); + return 0; + } + + /* There are JCNT values that have this length, the values + starting from START[j] continuing through NEXT[VAL]. Those + values are assigned consecutive values starting at CODE. */ + + val = start[j]; + for (i = 0; i < jcnt; ++i) + { + uint16_t tval; + size_t ind; + unsigned int incr; + + /* In the compressed bit stream, the value VAL is encoded as + J bits with the value C. */ + + if (unlikely ((val & ~HUFFMAN_VALUE_MASK) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + tval = val | ((j - 1) << HUFFMAN_BITS_SHIFT); + + /* The table lookup uses 8 bits. If J is less than 8, we + don't know what the other bits will be. We need to fill + in all possibilities in the table. Since the Huffman + code is unambiguous, those entries can't be used for any + other code. */ + + for (ind = code; ind < 0x100; ind += 1 << j) + { + if (unlikely (table[ind] != 0)) + { + elf_uncompress_failed (); + return 0; + } + table[ind] = tval; + } + + /* Advance to the next value with this length. */ + if (i + 1 < jcnt) + val = next[val]; + + /* The Huffman codes are stored in the bitstream with the + most significant bit first, as is required to make them + unambiguous. The effect is that when we read them from + the bitstream we see the bit sequence in reverse order: + the most significant bit of the Huffman code is the least + significant bit of the value we read from the bitstream. + That means that to make our table lookups work, we need + to reverse the bits of CODE. Since reversing bits is + tedious and in general requires using a table, we instead + increment CODE in reverse order. That is, if the number + of bits we are currently using, here named J, is 3, we + count as 000, 100, 010, 110, 001, 101, 011, 111, which is + to say the numbers from 0 to 7 but with the bits + reversed. Going to more bits, aka incrementing J, + effectively just adds more zero bits as the beginning, + and as such does not change the numeric value of CODE. + + To increment CODE of length J in reverse order, find the + most significant zero bit and set it to one while + clearing all higher bits. In other words, add 1 modulo + 2^J, only reversed. */ + + incr = 1U << (j - 1); + while ((code & incr) != 0) + incr >>= 1; + if (incr == 0) + code = 0; + else + { + code &= incr - 1; + code += incr; + } + } + } + + /* Handle the values that require a secondary table. */ + + /* Set FIRSTCODE, the number at which the codes start, for each + length. */ + + for (j = 9; j < 16; j++) + { + unsigned int jcnt; + unsigned int k; + + jcnt = count[j]; + if (jcnt == 0) + continue; + + /* There are JCNT values that have this length, the values + starting from START[j]. Those values are assigned + consecutive values starting at CODE. */ + + firstcode[j - 9] = code; + + /* Reverse add JCNT to CODE modulo 2^J. */ + for (k = 0; k < j; ++k) + { + if ((jcnt & (1U << k)) != 0) + { + unsigned int m; + unsigned int bit; + + bit = 1U << (j - k - 1); + for (m = 0; m < j - k; ++m, bit >>= 1) + { + if ((code & bit) == 0) + { + code += bit; + break; + } + code &= ~bit; + } + jcnt &= ~(1U << k); + } + } + if (unlikely (jcnt != 0)) + { + elf_uncompress_failed (); + return 0; + } + } + + /* For J from 9 to 15, inclusive, we store COUNT[J] consecutive + values starting at START[J] with consecutive codes starting at + FIRSTCODE[J - 9]. In the primary table we need to point to the + secondary table, and the secondary table will be indexed by J - 9 + bits. We count down from 15 so that we install the larger + secondary tables first, as the smaller ones may be embedded in + the larger ones. */ + + next_secondary = 0; /* Index of next secondary table (after primary). */ + for (j = 15; j >= 9; j--) + { + unsigned int jcnt; + unsigned int val; + size_t primary; /* Current primary index. */ + size_t secondary; /* Offset to current secondary table. */ + size_t secondary_bits; /* Bit size of current secondary table. */ + + jcnt = count[j]; + if (jcnt == 0) + continue; + + val = start[j]; + code = firstcode[j - 9]; + primary = 0x100; + secondary = 0; + secondary_bits = 0; + for (i = 0; i < jcnt; ++i) + { + uint16_t tval; + size_t ind; + unsigned int incr; + + if ((code & 0xff) != primary) + { + uint16_t tprimary; + + /* Fill in a new primary table entry. */ + + primary = code & 0xff; + + tprimary = table[primary]; + if (tprimary == 0) + { + /* Start a new secondary table. */ + + if (unlikely ((next_secondary & HUFFMAN_VALUE_MASK) + != next_secondary)) + { + elf_uncompress_failed (); + return 0; + } + + secondary = next_secondary; + secondary_bits = j - 8; + next_secondary += 1 << secondary_bits; + table[primary] = (secondary + + ((j - 8) << HUFFMAN_BITS_SHIFT) + + (1U << HUFFMAN_SECONDARY_SHIFT)); + } + else + { + /* There is an existing entry. It had better be a + secondary table with enough bits. */ + if (unlikely ((tprimary & (1U << HUFFMAN_SECONDARY_SHIFT)) + == 0)) + { + elf_uncompress_failed (); + return 0; + } + secondary = tprimary & HUFFMAN_VALUE_MASK; + secondary_bits = ((tprimary >> HUFFMAN_BITS_SHIFT) + & HUFFMAN_BITS_MASK); + if (unlikely (secondary_bits < j - 8)) + { + elf_uncompress_failed (); + return 0; + } + } + } + + /* Fill in secondary table entries. */ + + tval = val | ((j - 8) << HUFFMAN_BITS_SHIFT); + + for (ind = code >> 8; + ind < (1U << secondary_bits); + ind += 1U << (j - 8)) + { + if (unlikely (table[secondary + 0x100 + ind] != 0)) + { + elf_uncompress_failed (); + return 0; + } + table[secondary + 0x100 + ind] = tval; + } + + if (i + 1 < jcnt) + val = next[val]; + + incr = 1U << (j - 1); + while ((code & incr) != 0) + incr >>= 1; + if (incr == 0) + code = 0; + else + { + code &= incr - 1; + code += incr; + } + } + } + +#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE + final_next_secondary = next_secondary; +#endif + + return 1; +} + +#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE + +/* Used to generate the fixed Huffman table for block type 1. */ + +#include <stdio.h> + +static uint16_t table[ZDEBUG_TABLE_SIZE]; +static unsigned char codes[288]; + +int +main () +{ + size_t i; + + for (i = 0; i <= 143; ++i) + codes[i] = 8; + for (i = 144; i <= 255; ++i) + codes[i] = 9; + for (i = 256; i <= 279; ++i) + codes[i] = 7; + for (i = 280; i <= 287; ++i) + codes[i] = 8; + if (!elf_zlib_inflate_table (&codes[0], 288, &table[0], &table[0])) + { + fprintf (stderr, "elf_zlib_inflate_table failed\n"); + exit (EXIT_FAILURE); + } + + printf ("static const uint16_t elf_zlib_default_table[%#zx] =\n", + final_next_secondary + 0x100); + printf ("{\n"); + for (i = 0; i < final_next_secondary + 0x100; i += 8) + { + size_t j; + + printf (" "); + for (j = i; j < final_next_secondary + 0x100 && j < i + 8; ++j) + printf (" %#x,", table[j]); + printf ("\n"); + } + printf ("};\n"); + printf ("\n"); + + for (i = 0; i < 32; ++i) + codes[i] = 5; + if (!elf_zlib_inflate_table (&codes[0], 32, &table[0], &table[0])) + { + fprintf (stderr, "elf_zlib_inflate_table failed\n"); + exit (EXIT_FAILURE); + } + + printf ("static const uint16_t elf_zlib_default_dist_table[%#zx] =\n", + final_next_secondary + 0x100); + printf ("{\n"); + for (i = 0; i < final_next_secondary + 0x100; i += 8) + { + size_t j; + + printf (" "); + for (j = i; j < final_next_secondary + 0x100 && j < i + 8; ++j) + printf (" %#x,", table[j]); + printf ("\n"); + } + printf ("};\n"); + + return 0; +} + +#endif + +/* The fixed tables generated by the #ifdef'ed out main function + above. */ + +static const uint16_t elf_zlib_default_table[0x170] = +{ + 0xd00, 0xe50, 0xe10, 0xf18, 0xd10, 0xe70, 0xe30, 0x1230, + 0xd08, 0xe60, 0xe20, 0x1210, 0xe00, 0xe80, 0xe40, 0x1250, + 0xd04, 0xe58, 0xe18, 0x1200, 0xd14, 0xe78, 0xe38, 0x1240, + 0xd0c, 0xe68, 0xe28, 0x1220, 0xe08, 0xe88, 0xe48, 0x1260, + 0xd02, 0xe54, 0xe14, 0xf1c, 0xd12, 0xe74, 0xe34, 0x1238, + 0xd0a, 0xe64, 0xe24, 0x1218, 0xe04, 0xe84, 0xe44, 0x1258, + 0xd06, 0xe5c, 0xe1c, 0x1208, 0xd16, 0xe7c, 0xe3c, 0x1248, + 0xd0e, 0xe6c, 0xe2c, 0x1228, 0xe0c, 0xe8c, 0xe4c, 0x1268, + 0xd01, 0xe52, 0xe12, 0xf1a, 0xd11, 0xe72, 0xe32, 0x1234, + 0xd09, 0xe62, 0xe22, 0x1214, 0xe02, 0xe82, 0xe42, 0x1254, + 0xd05, 0xe5a, 0xe1a, 0x1204, 0xd15, 0xe7a, 0xe3a, 0x1244, + 0xd0d, 0xe6a, 0xe2a, 0x1224, 0xe0a, 0xe8a, 0xe4a, 0x1264, + 0xd03, 0xe56, 0xe16, 0xf1e, 0xd13, 0xe76, 0xe36, 0x123c, + 0xd0b, 0xe66, 0xe26, 0x121c, 0xe06, 0xe86, 0xe46, 0x125c, + 0xd07, 0xe5e, 0xe1e, 0x120c, 0xd17, 0xe7e, 0xe3e, 0x124c, + 0xd0f, 0xe6e, 0xe2e, 0x122c, 0xe0e, 0xe8e, 0xe4e, 0x126c, + 0xd00, 0xe51, 0xe11, 0xf19, 0xd10, 0xe71, 0xe31, 0x1232, + 0xd08, 0xe61, 0xe21, 0x1212, 0xe01, 0xe81, 0xe41, 0x1252, + 0xd04, 0xe59, 0xe19, 0x1202, 0xd14, 0xe79, 0xe39, 0x1242, + 0xd0c, 0xe69, 0xe29, 0x1222, 0xe09, 0xe89, 0xe49, 0x1262, + 0xd02, 0xe55, 0xe15, 0xf1d, 0xd12, 0xe75, 0xe35, 0x123a, + 0xd0a, 0xe65, 0xe25, 0x121a, 0xe05, 0xe85, 0xe45, 0x125a, + 0xd06, 0xe5d, 0xe1d, 0x120a, 0xd16, 0xe7d, 0xe3d, 0x124a, + 0xd0e, 0xe6d, 0xe2d, 0x122a, 0xe0d, 0xe8d, 0xe4d, 0x126a, + 0xd01, 0xe53, 0xe13, 0xf1b, 0xd11, 0xe73, 0xe33, 0x1236, + 0xd09, 0xe63, 0xe23, 0x1216, 0xe03, 0xe83, 0xe43, 0x1256, + 0xd05, 0xe5b, 0xe1b, 0x1206, 0xd15, 0xe7b, 0xe3b, 0x1246, + 0xd0d, 0xe6b, 0xe2b, 0x1226, 0xe0b, 0xe8b, 0xe4b, 0x1266, + 0xd03, 0xe57, 0xe17, 0xf1f, 0xd13, 0xe77, 0xe37, 0x123e, + 0xd0b, 0xe67, 0xe27, 0x121e, 0xe07, 0xe87, 0xe47, 0x125e, + 0xd07, 0xe5f, 0xe1f, 0x120e, 0xd17, 0xe7f, 0xe3f, 0x124e, + 0xd0f, 0xe6f, 0xe2f, 0x122e, 0xe0f, 0xe8f, 0xe4f, 0x126e, + 0x290, 0x291, 0x292, 0x293, 0x294, 0x295, 0x296, 0x297, + 0x298, 0x299, 0x29a, 0x29b, 0x29c, 0x29d, 0x29e, 0x29f, + 0x2a0, 0x2a1, 0x2a2, 0x2a3, 0x2a4, 0x2a5, 0x2a6, 0x2a7, + 0x2a8, 0x2a9, 0x2aa, 0x2ab, 0x2ac, 0x2ad, 0x2ae, 0x2af, + 0x2b0, 0x2b1, 0x2b2, 0x2b3, 0x2b4, 0x2b5, 0x2b6, 0x2b7, + 0x2b8, 0x2b9, 0x2ba, 0x2bb, 0x2bc, 0x2bd, 0x2be, 0x2bf, + 0x2c0, 0x2c1, 0x2c2, 0x2c3, 0x2c4, 0x2c5, 0x2c6, 0x2c7, + 0x2c8, 0x2c9, 0x2ca, 0x2cb, 0x2cc, 0x2cd, 0x2ce, 0x2cf, + 0x2d0, 0x2d1, 0x2d2, 0x2d3, 0x2d4, 0x2d5, 0x2d6, 0x2d7, + 0x2d8, 0x2d9, 0x2da, 0x2db, 0x2dc, 0x2dd, 0x2de, 0x2df, + 0x2e0, 0x2e1, 0x2e2, 0x2e3, 0x2e4, 0x2e5, 0x2e6, 0x2e7, + 0x2e8, 0x2e9, 0x2ea, 0x2eb, 0x2ec, 0x2ed, 0x2ee, 0x2ef, + 0x2f0, 0x2f1, 0x2f2, 0x2f3, 0x2f4, 0x2f5, 0x2f6, 0x2f7, + 0x2f8, 0x2f9, 0x2fa, 0x2fb, 0x2fc, 0x2fd, 0x2fe, 0x2ff, +}; + +static const uint16_t elf_zlib_default_dist_table[0x100] = +{ + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, + 0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c, + 0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e, + 0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d, + 0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f, +}; + +/* Inflate a zlib stream from PIN/SIN to POUT/SOUT. Return 1 on + success, 0 on some error parsing the stream. */ + +static int +elf_zlib_inflate (const unsigned char *pin, size_t sin, uint16_t *zdebug_table, + unsigned char *pout, size_t sout) +{ + unsigned char *porigout; + const unsigned char *pinend; + unsigned char *poutend; + + /* We can apparently see multiple zlib streams concatenated + together, so keep going as long as there is something to read. + The last 4 bytes are the checksum. */ + porigout = pout; + pinend = pin + sin; + poutend = pout + sout; + while ((pinend - pin) > 4) + { + uint64_t val; + unsigned int bits; + int last; + + /* Read the two byte zlib header. */ + + if (unlikely ((pin[0] & 0xf) != 8)) /* 8 is zlib encoding. */ + { + /* Unknown compression method. */ + elf_uncompress_failed (); + return 0; + } + if (unlikely ((pin[0] >> 4) > 7)) + { + /* Window size too large. Other than this check, we don't + care about the window size. */ + elf_uncompress_failed (); + return 0; + } + if (unlikely ((pin[1] & 0x20) != 0)) + { + /* Stream expects a predefined dictionary, but we have no + dictionary. */ + elf_uncompress_failed (); + return 0; + } + val = (pin[0] << 8) | pin[1]; + if (unlikely (val % 31 != 0)) + { + /* Header check failure. */ + elf_uncompress_failed (); + return 0; + } + pin += 2; + + /* Align PIN to a 32-bit boundary. */ + + val = 0; + bits = 0; + while ((((uintptr_t) pin) & 3) != 0) + { + val |= (uint64_t)*pin << bits; + bits += 8; + ++pin; + } + + /* Read blocks until one is marked last. */ + + last = 0; + + while (!last) + { + unsigned int type; + const uint16_t *tlit; + const uint16_t *tdist; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + last = val & 1; + type = (val >> 1) & 3; + val >>= 3; + bits -= 3; + + if (unlikely (type == 3)) + { + /* Invalid block type. */ + elf_uncompress_failed (); + return 0; + } + + if (type == 0) + { + uint16_t len; + uint16_t lenc; + + /* An uncompressed block. */ + + /* If we've read ahead more than a byte, back up. */ + while (bits >= 8) + { + --pin; + bits -= 8; + } + + val = 0; + bits = 0; + if (unlikely ((pinend - pin) < 4)) + { + /* Missing length. */ + elf_uncompress_failed (); + return 0; + } + len = pin[0] | (pin[1] << 8); + lenc = pin[2] | (pin[3] << 8); + pin += 4; + lenc = ~lenc; + if (unlikely (len != lenc)) + { + /* Corrupt data. */ + elf_uncompress_failed (); + return 0; + } + if (unlikely (len > (unsigned int) (pinend - pin) + || len > (unsigned int) (poutend - pout))) + { + /* Not enough space in buffers. */ + elf_uncompress_failed (); + return 0; + } + memcpy (pout, pin, len); + pout += len; + pin += len; + + /* Align PIN. */ + while ((((uintptr_t) pin) & 3) != 0) + { + val |= (uint64_t)*pin << bits; + bits += 8; + ++pin; + } + + /* Go around to read the next block. */ + continue; + } + + if (type == 1) + { + tlit = elf_zlib_default_table; + tdist = elf_zlib_default_dist_table; + } + else + { + unsigned int nlit; + unsigned int ndist; + unsigned int nclen; + unsigned char codebits[19]; + unsigned char *plenbase; + unsigned char *plen; + unsigned char *plenend; + + /* Read a Huffman encoding table. The various magic + numbers here are from RFC 1951. */ + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + nlit = (val & 0x1f) + 257; + val >>= 5; + ndist = (val & 0x1f) + 1; + val >>= 5; + nclen = (val & 0xf) + 4; + val >>= 4; + bits -= 14; + if (unlikely (nlit > 286 || ndist > 30)) + { + /* Values out of range. */ + elf_uncompress_failed (); + return 0; + } + + /* Read and build the table used to compress the + literal, length, and distance codes. */ + + memset(&codebits[0], 0, 19); + + /* There are always at least 4 elements in the + table. */ + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + codebits[16] = val & 7; + codebits[17] = (val >> 3) & 7; + codebits[18] = (val >> 6) & 7; + codebits[0] = (val >> 9) & 7; + val >>= 12; + bits -= 12; + + if (nclen == 4) + goto codebitsdone; + + codebits[8] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 5) + goto codebitsdone; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + codebits[7] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 6) + goto codebitsdone; + + codebits[9] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 7) + goto codebitsdone; + + codebits[6] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 8) + goto codebitsdone; + + codebits[10] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 9) + goto codebitsdone; + + codebits[5] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 10) + goto codebitsdone; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + codebits[11] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 11) + goto codebitsdone; + + codebits[4] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 12) + goto codebitsdone; + + codebits[12] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 13) + goto codebitsdone; + + codebits[3] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 14) + goto codebitsdone; + + codebits[13] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 15) + goto codebitsdone; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + codebits[2] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 16) + goto codebitsdone; + + codebits[14] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 17) + goto codebitsdone; + + codebits[1] = val & 7; + val >>= 3; + bits -= 3; + + if (nclen == 18) + goto codebitsdone; + + codebits[15] = val & 7; + val >>= 3; + bits -= 3; + + codebitsdone: + + if (!elf_zlib_inflate_table (codebits, 19, zdebug_table, + zdebug_table)) + return 0; + + /* Read the compressed bit lengths of the literal, + length, and distance codes. We have allocated space + at the end of zdebug_table to hold them. */ + + plenbase = (((unsigned char *) zdebug_table) + + ZDEBUG_TABLE_CODELEN_OFFSET); + plen = plenbase; + plenend = plen + nlit + ndist; + while (plen < plenend) + { + uint16_t t; + unsigned int b; + uint16_t v; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + t = zdebug_table[val & 0xff]; + + /* The compression here uses bit lengths up to 7, so + a secondary table is never necessary. */ + if (unlikely ((t & (1U << HUFFMAN_SECONDARY_SHIFT)) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + b = (t >> HUFFMAN_BITS_SHIFT) & HUFFMAN_BITS_MASK; + val >>= b + 1; + bits -= b + 1; + + v = t & HUFFMAN_VALUE_MASK; + if (v < 16) + *plen++ = v; + else if (v == 16) + { + unsigned int c; + unsigned int prev; + + /* Copy previous entry 3 to 6 times. */ + + if (unlikely (plen == plenbase)) + { + elf_uncompress_failed (); + return 0; + } + + /* We used up to 7 bits since the last + elf_zlib_fetch, so we have at least 8 bits + available here. */ + + c = 3 + (val & 0x3); + val >>= 2; + bits -= 2; + if (unlikely ((unsigned int) (plenend - plen) < c)) + { + elf_uncompress_failed (); + return 0; + } + + prev = plen[-1]; + switch (c) + { + case 6: + *plen++ = prev; + ATTRIBUTE_FALLTHROUGH; + case 5: + *plen++ = prev; + ATTRIBUTE_FALLTHROUGH; + case 4: + *plen++ = prev; + } + *plen++ = prev; + *plen++ = prev; + *plen++ = prev; + } + else if (v == 17) + { + unsigned int c; + + /* Store zero 3 to 10 times. */ + + /* We used up to 7 bits since the last + elf_zlib_fetch, so we have at least 8 bits + available here. */ + + c = 3 + (val & 0x7); + val >>= 3; + bits -= 3; + if (unlikely ((unsigned int) (plenend - plen) < c)) + { + elf_uncompress_failed (); + return 0; + } + + switch (c) + { + case 10: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 9: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 8: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 7: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 6: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 5: + *plen++ = 0; + ATTRIBUTE_FALLTHROUGH; + case 4: + *plen++ = 0; + } + *plen++ = 0; + *plen++ = 0; + *plen++ = 0; + } + else if (v == 18) + { + unsigned int c; + + /* Store zero 11 to 138 times. */ + + /* We used up to 7 bits since the last + elf_zlib_fetch, so we have at least 8 bits + available here. */ + + c = 11 + (val & 0x7f); + val >>= 7; + bits -= 7; + if (unlikely ((unsigned int) (plenend - plen) < c)) + { + elf_uncompress_failed (); + return 0; + } + + memset (plen, 0, c); + plen += c; + } + else + { + elf_uncompress_failed (); + return 0; + } + } + + /* Make sure that the stop code can appear. */ + + plen = plenbase; + if (unlikely (plen[256] == 0)) + { + elf_uncompress_failed (); + return 0; + } + + /* Build the decompression tables. */ + + if (!elf_zlib_inflate_table (plen, nlit, zdebug_table, + zdebug_table)) + return 0; + if (!elf_zlib_inflate_table (plen + nlit, ndist, zdebug_table, + zdebug_table + HUFFMAN_TABLE_SIZE)) + return 0; + tlit = zdebug_table; + tdist = zdebug_table + HUFFMAN_TABLE_SIZE; + } + + /* Inflate values until the end of the block. This is the + main loop of the inflation code. */ + + while (1) + { + uint16_t t; + unsigned int b; + uint16_t v; + unsigned int lit; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + t = tlit[val & 0xff]; + b = (t >> HUFFMAN_BITS_SHIFT) & HUFFMAN_BITS_MASK; + v = t & HUFFMAN_VALUE_MASK; + + if ((t & (1U << HUFFMAN_SECONDARY_SHIFT)) == 0) + { + lit = v; + val >>= b + 1; + bits -= b + 1; + } + else + { + t = tlit[v + 0x100 + ((val >> 8) & ((1U << b) - 1))]; + b = (t >> HUFFMAN_BITS_SHIFT) & HUFFMAN_BITS_MASK; + lit = t & HUFFMAN_VALUE_MASK; + val >>= b + 8; + bits -= b + 8; + } + + if (lit < 256) + { + if (unlikely (pout == poutend)) + { + elf_uncompress_failed (); + return 0; + } + + *pout++ = lit; + + /* We will need to write the next byte soon. We ask + for high temporal locality because we will write + to the whole cache line soon. */ + __builtin_prefetch (pout, 1, 3); + } + else if (lit == 256) + { + /* The end of the block. */ + break; + } + else + { + unsigned int dist; + unsigned int len; + + /* Convert lit into a length. */ + + if (lit < 265) + len = lit - 257 + 3; + else if (lit == 285) + len = 258; + else if (unlikely (lit > 285)) + { + elf_uncompress_failed (); + return 0; + } + else + { + unsigned int extra; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + /* This is an expression for the table of length + codes in RFC 1951 3.2.5. */ + lit -= 265; + extra = (lit >> 2) + 1; + len = (lit & 3) << extra; + len += 11; + len += ((1U << (extra - 1)) - 1) << 3; + len += val & ((1U << extra) - 1); + val >>= extra; + bits -= extra; + } + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + t = tdist[val & 0xff]; + b = (t >> HUFFMAN_BITS_SHIFT) & HUFFMAN_BITS_MASK; + v = t & HUFFMAN_VALUE_MASK; + + if ((t & (1U << HUFFMAN_SECONDARY_SHIFT)) == 0) + { + dist = v; + val >>= b + 1; + bits -= b + 1; + } + else + { + t = tdist[v + 0x100 + ((val >> 8) & ((1U << b) - 1))]; + b = (t >> HUFFMAN_BITS_SHIFT) & HUFFMAN_BITS_MASK; + dist = t & HUFFMAN_VALUE_MASK; + val >>= b + 8; + bits -= b + 8; + } + + /* Convert dist to a distance. */ + + if (dist == 0) + { + /* A distance of 1. A common case, meaning + repeat the last character LEN times. */ + + if (unlikely (pout == porigout)) + { + elf_uncompress_failed (); + return 0; + } + + if (unlikely ((unsigned int) (poutend - pout) < len)) + { + elf_uncompress_failed (); + return 0; + } + + memset (pout, pout[-1], len); + pout += len; + } + else if (unlikely (dist > 29)) + { + elf_uncompress_failed (); + return 0; + } + else + { + if (dist < 4) + dist = dist + 1; + else + { + unsigned int extra; + + if (!elf_zlib_fetch (&pin, pinend, &val, &bits)) + return 0; + + /* This is an expression for the table of + distance codes in RFC 1951 3.2.5. */ + dist -= 4; + extra = (dist >> 1) + 1; + dist = (dist & 1) << extra; + dist += 5; + dist += ((1U << (extra - 1)) - 1) << 2; + dist += val & ((1U << extra) - 1); + val >>= extra; + bits -= extra; + } + + /* Go back dist bytes, and copy len bytes from + there. */ + + if (unlikely ((unsigned int) (pout - porigout) < dist)) + { + elf_uncompress_failed (); + return 0; + } + + if (unlikely ((unsigned int) (poutend - pout) < len)) + { + elf_uncompress_failed (); + return 0; + } + + if (dist >= len) + { + memcpy (pout, pout - dist, len); + pout += len; + } + else + { + while (len > 0) + { + unsigned int copy; + + copy = len < dist ? len : dist; + memcpy (pout, pout - dist, copy); + len -= copy; + pout += copy; + } + } + } + } + } + } + } + + /* We should have filled the output buffer. */ + if (unlikely (pout != poutend)) + { + elf_uncompress_failed (); + return 0; + } + + return 1; +} + +/* Verify the zlib checksum. The checksum is in the 4 bytes at + CHECKBYTES, and the uncompressed data is at UNCOMPRESSED / + UNCOMPRESSED_SIZE. Returns 1 on success, 0 on failure. */ + +static int +elf_zlib_verify_checksum (const unsigned char *checkbytes, + const unsigned char *uncompressed, + size_t uncompressed_size) +{ + unsigned int i; + unsigned int cksum; + const unsigned char *p; + uint32_t s1; + uint32_t s2; + size_t hsz; + + cksum = 0; + for (i = 0; i < 4; i++) + cksum = (cksum << 8) | checkbytes[i]; + + s1 = 1; + s2 = 0; + + /* Minimize modulo operations. */ + + p = uncompressed; + hsz = uncompressed_size; + while (hsz >= 5552) + { + for (i = 0; i < 5552; i += 16) + { + /* Manually unroll loop 16 times. */ + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + } + hsz -= 5552; + s1 %= 65521; + s2 %= 65521; + } + + while (hsz >= 16) + { + /* Manually unroll loop 16 times. */ + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + s1 = s1 + *p++; + s2 = s2 + s1; + + hsz -= 16; + } + + for (i = 0; i < hsz; ++i) + { + s1 = s1 + *p++; + s2 = s2 + s1; + } + + s1 %= 65521; + s2 %= 65521; + + if (unlikely ((s2 << 16) + s1 != cksum)) + { + elf_uncompress_failed (); + return 0; + } + + return 1; +} + +/* Inflate a zlib stream from PIN/SIN to POUT/SOUT, and verify the + checksum. Return 1 on success, 0 on error. */ + +static int +elf_zlib_inflate_and_verify (const unsigned char *pin, size_t sin, + uint16_t *zdebug_table, unsigned char *pout, + size_t sout) +{ + if (!elf_zlib_inflate (pin, sin, zdebug_table, pout, sout)) + return 0; + if (!elf_zlib_verify_checksum (pin + sin - 4, pout, sout)) + return 0; + return 1; +} + +/* Uncompress the old compressed debug format, the one emitted by + --compress-debug-sections=zlib-gnu. The compressed data is in + COMPRESSED / COMPRESSED_SIZE, and the function writes to + *UNCOMPRESSED / *UNCOMPRESSED_SIZE. ZDEBUG_TABLE is work space to + hold Huffman tables. Returns 0 on error, 1 on successful + decompression or if something goes wrong. In general we try to + carry on, by returning 1, even if we can't decompress. */ + +static int +elf_uncompress_zdebug (struct backtrace_state *state, + const unsigned char *compressed, size_t compressed_size, + uint16_t *zdebug_table, + backtrace_error_callback error_callback, void *data, + unsigned char **uncompressed, size_t *uncompressed_size) +{ + size_t sz; + size_t i; + unsigned char *po; + + *uncompressed = NULL; + *uncompressed_size = 0; + + /* The format starts with the four bytes ZLIB, followed by the 8 + byte length of the uncompressed data in big-endian order, + followed by a zlib stream. */ + + if (compressed_size < 12 || memcmp (compressed, "ZLIB", 4) != 0) + return 1; + + sz = 0; + for (i = 0; i < 8; i++) + sz = (sz << 8) | compressed[i + 4]; + + if (*uncompressed != NULL && *uncompressed_size >= sz) + po = *uncompressed; + else + { + po = (unsigned char *) backtrace_alloc (state, sz, error_callback, data); + if (po == NULL) + return 0; + } + + if (!elf_zlib_inflate_and_verify (compressed + 12, compressed_size - 12, + zdebug_table, po, sz)) + return 1; + + *uncompressed = po; + *uncompressed_size = sz; + + return 1; +} + +/* Uncompress the new compressed debug format, the official standard + ELF approach emitted by --compress-debug-sections=zlib-gabi. The + compressed data is in COMPRESSED / COMPRESSED_SIZE, and the + function writes to *UNCOMPRESSED / *UNCOMPRESSED_SIZE. + ZDEBUG_TABLE is work space as for elf_uncompress_zdebug. Returns 0 + on error, 1 on successful decompression or if something goes wrong. + In general we try to carry on, by returning 1, even if we can't + decompress. */ + +static int +elf_uncompress_chdr (struct backtrace_state *state, + const unsigned char *compressed, size_t compressed_size, + uint16_t *zdebug_table, + backtrace_error_callback error_callback, void *data, + unsigned char **uncompressed, size_t *uncompressed_size) +{ + const b_elf_chdr *chdr; + unsigned char *po; + + *uncompressed = NULL; + *uncompressed_size = 0; + + /* The format starts with an ELF compression header. */ + if (compressed_size < sizeof (b_elf_chdr)) + return 1; + + chdr = (const b_elf_chdr *) compressed; + + if (chdr->ch_type != ELFCOMPRESS_ZLIB) + { + /* Unsupported compression algorithm. */ + return 1; + } + + if (*uncompressed != NULL && *uncompressed_size >= chdr->ch_size) + po = *uncompressed; + else + { + po = (unsigned char *) backtrace_alloc (state, chdr->ch_size, + error_callback, data); + if (po == NULL) + return 0; + } + + if (!elf_zlib_inflate_and_verify (compressed + sizeof (b_elf_chdr), + compressed_size - sizeof (b_elf_chdr), + zdebug_table, po, chdr->ch_size)) + return 1; + + *uncompressed = po; + *uncompressed_size = chdr->ch_size; + + return 1; +} + +/* This function is a hook for testing the zlib support. It is only + used by tests. */ + +int +backtrace_uncompress_zdebug (struct backtrace_state *state, + const unsigned char *compressed, + size_t compressed_size, + backtrace_error_callback error_callback, + void *data, unsigned char **uncompressed, + size_t *uncompressed_size) +{ + uint16_t *zdebug_table; + int ret; + + zdebug_table = ((uint16_t *) backtrace_alloc (state, ZDEBUG_TABLE_SIZE, + error_callback, data)); + if (zdebug_table == NULL) + return 0; + ret = elf_uncompress_zdebug (state, compressed, compressed_size, + zdebug_table, error_callback, data, + uncompressed, uncompressed_size); + backtrace_free (state, zdebug_table, ZDEBUG_TABLE_SIZE, + error_callback, data); + return ret; +} + +/* Number of LZMA states. */ +#define LZMA_STATES (12) + +/* Number of LZMA position states. The pb value of the property byte + is the number of bits to include in these states, and the maximum + value of pb is 4. */ +#define LZMA_POS_STATES (16) + +/* Number of LZMA distance states. These are used match distances + with a short match length: up to 4 bytes. */ +#define LZMA_DIST_STATES (4) + +/* Number of LZMA distance slots. LZMA uses six bits to encode larger + match lengths, so 1 << 6 possible probabilities. */ +#define LZMA_DIST_SLOTS (64) + +/* LZMA distances 0 to 3 are encoded directly, larger values use a + probability model. */ +#define LZMA_DIST_MODEL_START (4) + +/* The LZMA probability model ends at 14. */ +#define LZMA_DIST_MODEL_END (14) + +/* LZMA distance slots for distances less than 127. */ +#define LZMA_FULL_DISTANCES (128) + +/* LZMA uses four alignment bits. */ +#define LZMA_ALIGN_SIZE (16) + +/* LZMA match length is encoded with 4, 5, or 10 bits, some of which + are already known. */ +#define LZMA_LEN_LOW_SYMBOLS (8) +#define LZMA_LEN_MID_SYMBOLS (8) +#define LZMA_LEN_HIGH_SYMBOLS (256) + +/* LZMA literal encoding. */ +#define LZMA_LITERAL_CODERS_MAX (16) +#define LZMA_LITERAL_CODER_SIZE (0x300) + +/* LZMA is based on a large set of probabilities, each managed + independently. Each probability is an 11 bit number that we store + in a uint16_t. We use a single large array of probabilities. */ + +/* Lengths of entries in the LZMA probabilities array. The names used + here are copied from the Linux kernel implementation. */ + +#define LZMA_PROB_IS_MATCH_LEN (LZMA_STATES * LZMA_POS_STATES) +#define LZMA_PROB_IS_REP_LEN LZMA_STATES +#define LZMA_PROB_IS_REP0_LEN LZMA_STATES +#define LZMA_PROB_IS_REP1_LEN LZMA_STATES +#define LZMA_PROB_IS_REP2_LEN LZMA_STATES +#define LZMA_PROB_IS_REP0_LONG_LEN (LZMA_STATES * LZMA_POS_STATES) +#define LZMA_PROB_DIST_SLOT_LEN (LZMA_DIST_STATES * LZMA_DIST_SLOTS) +#define LZMA_PROB_DIST_SPECIAL_LEN (LZMA_FULL_DISTANCES - LZMA_DIST_MODEL_END) +#define LZMA_PROB_DIST_ALIGN_LEN LZMA_ALIGN_SIZE +#define LZMA_PROB_MATCH_LEN_CHOICE_LEN 1 +#define LZMA_PROB_MATCH_LEN_CHOICE2_LEN 1 +#define LZMA_PROB_MATCH_LEN_LOW_LEN (LZMA_POS_STATES * LZMA_LEN_LOW_SYMBOLS) +#define LZMA_PROB_MATCH_LEN_MID_LEN (LZMA_POS_STATES * LZMA_LEN_MID_SYMBOLS) +#define LZMA_PROB_MATCH_LEN_HIGH_LEN LZMA_LEN_HIGH_SYMBOLS +#define LZMA_PROB_REP_LEN_CHOICE_LEN 1 +#define LZMA_PROB_REP_LEN_CHOICE2_LEN 1 +#define LZMA_PROB_REP_LEN_LOW_LEN (LZMA_POS_STATES * LZMA_LEN_LOW_SYMBOLS) +#define LZMA_PROB_REP_LEN_MID_LEN (LZMA_POS_STATES * LZMA_LEN_MID_SYMBOLS) +#define LZMA_PROB_REP_LEN_HIGH_LEN LZMA_LEN_HIGH_SYMBOLS +#define LZMA_PROB_LITERAL_LEN \ + (LZMA_LITERAL_CODERS_MAX * LZMA_LITERAL_CODER_SIZE) + +/* Offsets into the LZMA probabilities array. This is mechanically + generated from the above lengths. */ + +#define LZMA_PROB_IS_MATCH_OFFSET 0 +#define LZMA_PROB_IS_REP_OFFSET \ + (LZMA_PROB_IS_MATCH_OFFSET + LZMA_PROB_IS_MATCH_LEN) +#define LZMA_PROB_IS_REP0_OFFSET \ + (LZMA_PROB_IS_REP_OFFSET + LZMA_PROB_IS_REP_LEN) +#define LZMA_PROB_IS_REP1_OFFSET \ + (LZMA_PROB_IS_REP0_OFFSET + LZMA_PROB_IS_REP0_LEN) +#define LZMA_PROB_IS_REP2_OFFSET \ + (LZMA_PROB_IS_REP1_OFFSET + LZMA_PROB_IS_REP1_LEN) +#define LZMA_PROB_IS_REP0_LONG_OFFSET \ + (LZMA_PROB_IS_REP2_OFFSET + LZMA_PROB_IS_REP2_LEN) +#define LZMA_PROB_DIST_SLOT_OFFSET \ + (LZMA_PROB_IS_REP0_LONG_OFFSET + LZMA_PROB_IS_REP0_LONG_LEN) +#define LZMA_PROB_DIST_SPECIAL_OFFSET \ + (LZMA_PROB_DIST_SLOT_OFFSET + LZMA_PROB_DIST_SLOT_LEN) +#define LZMA_PROB_DIST_ALIGN_OFFSET \ + (LZMA_PROB_DIST_SPECIAL_OFFSET + LZMA_PROB_DIST_SPECIAL_LEN) +#define LZMA_PROB_MATCH_LEN_CHOICE_OFFSET \ + (LZMA_PROB_DIST_ALIGN_OFFSET + LZMA_PROB_DIST_ALIGN_LEN) +#define LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET \ + (LZMA_PROB_MATCH_LEN_CHOICE_OFFSET + LZMA_PROB_MATCH_LEN_CHOICE_LEN) +#define LZMA_PROB_MATCH_LEN_LOW_OFFSET \ + (LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET + LZMA_PROB_MATCH_LEN_CHOICE2_LEN) +#define LZMA_PROB_MATCH_LEN_MID_OFFSET \ + (LZMA_PROB_MATCH_LEN_LOW_OFFSET + LZMA_PROB_MATCH_LEN_LOW_LEN) +#define LZMA_PROB_MATCH_LEN_HIGH_OFFSET \ + (LZMA_PROB_MATCH_LEN_MID_OFFSET + LZMA_PROB_MATCH_LEN_MID_LEN) +#define LZMA_PROB_REP_LEN_CHOICE_OFFSET \ + (LZMA_PROB_MATCH_LEN_HIGH_OFFSET + LZMA_PROB_MATCH_LEN_HIGH_LEN) +#define LZMA_PROB_REP_LEN_CHOICE2_OFFSET \ + (LZMA_PROB_REP_LEN_CHOICE_OFFSET + LZMA_PROB_REP_LEN_CHOICE_LEN) +#define LZMA_PROB_REP_LEN_LOW_OFFSET \ + (LZMA_PROB_REP_LEN_CHOICE2_OFFSET + LZMA_PROB_REP_LEN_CHOICE2_LEN) +#define LZMA_PROB_REP_LEN_MID_OFFSET \ + (LZMA_PROB_REP_LEN_LOW_OFFSET + LZMA_PROB_REP_LEN_LOW_LEN) +#define LZMA_PROB_REP_LEN_HIGH_OFFSET \ + (LZMA_PROB_REP_LEN_MID_OFFSET + LZMA_PROB_REP_LEN_MID_LEN) +#define LZMA_PROB_LITERAL_OFFSET \ + (LZMA_PROB_REP_LEN_HIGH_OFFSET + LZMA_PROB_REP_LEN_HIGH_LEN) + +#define LZMA_PROB_TOTAL_COUNT \ + (LZMA_PROB_LITERAL_OFFSET + LZMA_PROB_LITERAL_LEN) + +/* Check that the number of LZMA probabilities is the same as the + Linux kernel implementation. */ + +#if LZMA_PROB_TOTAL_COUNT != 1846 + (1 << 4) * 0x300 + #error Wrong number of LZMA probabilities +#endif + +/* Expressions for the offset in the LZMA probabilities array of a + specific probability. */ + +#define LZMA_IS_MATCH(state, pos) \ + (LZMA_PROB_IS_MATCH_OFFSET + (state) * LZMA_POS_STATES + (pos)) +#define LZMA_IS_REP(state) \ + (LZMA_PROB_IS_REP_OFFSET + (state)) +#define LZMA_IS_REP0(state) \ + (LZMA_PROB_IS_REP0_OFFSET + (state)) +#define LZMA_IS_REP1(state) \ + (LZMA_PROB_IS_REP1_OFFSET + (state)) +#define LZMA_IS_REP2(state) \ + (LZMA_PROB_IS_REP2_OFFSET + (state)) +#define LZMA_IS_REP0_LONG(state, pos) \ + (LZMA_PROB_IS_REP0_LONG_OFFSET + (state) * LZMA_POS_STATES + (pos)) +#define LZMA_DIST_SLOT(dist, slot) \ + (LZMA_PROB_DIST_SLOT_OFFSET + (dist) * LZMA_DIST_SLOTS + (slot)) +#define LZMA_DIST_SPECIAL(dist) \ + (LZMA_PROB_DIST_SPECIAL_OFFSET + (dist)) +#define LZMA_DIST_ALIGN(dist) \ + (LZMA_PROB_DIST_ALIGN_OFFSET + (dist)) +#define LZMA_MATCH_LEN_CHOICE \ + LZMA_PROB_MATCH_LEN_CHOICE_OFFSET +#define LZMA_MATCH_LEN_CHOICE2 \ + LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET +#define LZMA_MATCH_LEN_LOW(pos, sym) \ + (LZMA_PROB_MATCH_LEN_LOW_OFFSET + (pos) * LZMA_LEN_LOW_SYMBOLS + (sym)) +#define LZMA_MATCH_LEN_MID(pos, sym) \ + (LZMA_PROB_MATCH_LEN_MID_OFFSET + (pos) * LZMA_LEN_MID_SYMBOLS + (sym)) +#define LZMA_MATCH_LEN_HIGH(sym) \ + (LZMA_PROB_MATCH_LEN_HIGH_OFFSET + (sym)) +#define LZMA_REP_LEN_CHOICE \ + LZMA_PROB_REP_LEN_CHOICE_OFFSET +#define LZMA_REP_LEN_CHOICE2 \ + LZMA_PROB_REP_LEN_CHOICE2_OFFSET +#define LZMA_REP_LEN_LOW(pos, sym) \ + (LZMA_PROB_REP_LEN_LOW_OFFSET + (pos) * LZMA_LEN_LOW_SYMBOLS + (sym)) +#define LZMA_REP_LEN_MID(pos, sym) \ + (LZMA_PROB_REP_LEN_MID_OFFSET + (pos) * LZMA_LEN_MID_SYMBOLS + (sym)) +#define LZMA_REP_LEN_HIGH(sym) \ + (LZMA_PROB_REP_LEN_HIGH_OFFSET + (sym)) +#define LZMA_LITERAL(code, size) \ + (LZMA_PROB_LITERAL_OFFSET + (code) * LZMA_LITERAL_CODER_SIZE + (size)) + +/* Read an LZMA varint from BUF, reading and updating *POFFSET, + setting *VAL. Returns 0 on error, 1 on success. */ + +static int +elf_lzma_varint (const unsigned char *compressed, size_t compressed_size, + size_t *poffset, uint64_t *val) +{ + size_t off; + int i; + uint64_t v; + unsigned char b; + + off = *poffset; + i = 0; + v = 0; + while (1) + { + if (unlikely (off >= compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + b = compressed[off]; + v |= (b & 0x7f) << (i * 7); + ++off; + if ((b & 0x80) == 0) + { + *poffset = off; + *val = v; + return 1; + } + ++i; + if (unlikely (i >= 9)) + { + elf_uncompress_failed (); + return 0; + } + } +} + +/* Normalize the LZMA range decoder, pulling in an extra input byte if + needed. */ + +static void +elf_lzma_range_normalize (const unsigned char *compressed, + size_t compressed_size, size_t *poffset, + uint32_t *prange, uint32_t *pcode) +{ + if (*prange < (1U << 24)) + { + if (unlikely (*poffset >= compressed_size)) + { + /* We assume this will be caught elsewhere. */ + elf_uncompress_failed (); + return; + } + *prange <<= 8; + *pcode <<= 8; + *pcode += compressed[*poffset]; + ++*poffset; + } +} + +/* Read and return a single bit from the LZMA stream, reading and + updating *PROB. Each bit comes from the range coder. */ + +static int +elf_lzma_bit (const unsigned char *compressed, size_t compressed_size, + uint16_t *prob, size_t *poffset, uint32_t *prange, + uint32_t *pcode) +{ + uint32_t bound; + + elf_lzma_range_normalize (compressed, compressed_size, poffset, + prange, pcode); + bound = (*prange >> 11) * (uint32_t) *prob; + if (*pcode < bound) + { + *prange = bound; + *prob += ((1U << 11) - *prob) >> 5; + return 0; + } + else + { + *prange -= bound; + *pcode -= bound; + *prob -= *prob >> 5; + return 1; + } +} + +/* Read an integer of size BITS from the LZMA stream, most significant + bit first. The bits are predicted using PROBS. */ + +static uint32_t +elf_lzma_integer (const unsigned char *compressed, size_t compressed_size, + uint16_t *probs, uint32_t bits, size_t *poffset, + uint32_t *prange, uint32_t *pcode) +{ + uint32_t sym; + uint32_t i; + + sym = 1; + for (i = 0; i < bits; i++) + { + int bit; + + bit = elf_lzma_bit (compressed, compressed_size, probs + sym, poffset, + prange, pcode); + sym <<= 1; + sym += bit; + } + return sym - (1 << bits); +} + +/* Read an integer of size BITS from the LZMA stream, least + significant bit first. The bits are predicted using PROBS. */ + +static uint32_t +elf_lzma_reverse_integer (const unsigned char *compressed, + size_t compressed_size, uint16_t *probs, + uint32_t bits, size_t *poffset, uint32_t *prange, + uint32_t *pcode) +{ + uint32_t sym; + uint32_t val; + uint32_t i; + + sym = 1; + val = 0; + for (i = 0; i < bits; i++) + { + int bit; + + bit = elf_lzma_bit (compressed, compressed_size, probs + sym, poffset, + prange, pcode); + sym <<= 1; + sym += bit; + val += bit << i; + } + return val; +} + +/* Read a length from the LZMA stream. IS_REP picks either LZMA_MATCH + or LZMA_REP probabilities. */ + +static uint32_t +elf_lzma_len (const unsigned char *compressed, size_t compressed_size, + uint16_t *probs, int is_rep, unsigned int pos_state, + size_t *poffset, uint32_t *prange, uint32_t *pcode) +{ + uint16_t *probs_choice; + uint16_t *probs_sym; + uint32_t bits; + uint32_t len; + + probs_choice = probs + (is_rep + ? LZMA_REP_LEN_CHOICE + : LZMA_MATCH_LEN_CHOICE); + if (elf_lzma_bit (compressed, compressed_size, probs_choice, poffset, + prange, pcode)) + { + probs_choice = probs + (is_rep + ? LZMA_REP_LEN_CHOICE2 + : LZMA_MATCH_LEN_CHOICE2); + if (elf_lzma_bit (compressed, compressed_size, probs_choice, + poffset, prange, pcode)) + { + probs_sym = probs + (is_rep + ? LZMA_REP_LEN_HIGH (0) + : LZMA_MATCH_LEN_HIGH (0)); + bits = 8; + len = 2 + 8 + 8; + } + else + { + probs_sym = probs + (is_rep + ? LZMA_REP_LEN_MID (pos_state, 0) + : LZMA_MATCH_LEN_MID (pos_state, 0)); + bits = 3; + len = 2 + 8; + } + } + else + { + probs_sym = probs + (is_rep + ? LZMA_REP_LEN_LOW (pos_state, 0) + : LZMA_MATCH_LEN_LOW (pos_state, 0)); + bits = 3; + len = 2; + } + + len += elf_lzma_integer (compressed, compressed_size, probs_sym, bits, + poffset, prange, pcode); + return len; +} + +/* Uncompress one LZMA block from a minidebug file. The compressed + data is at COMPRESSED + *POFFSET. Update *POFFSET. Store the data + into the memory at UNCOMPRESSED, size UNCOMPRESSED_SIZE. CHECK is + the stream flag from the xz header. Return 1 on successful + decompression. */ + +static int +elf_uncompress_lzma_block (const unsigned char *compressed, + size_t compressed_size, unsigned char check, + uint16_t *probs, unsigned char *uncompressed, + size_t uncompressed_size, size_t *poffset) +{ + size_t off; + size_t block_header_offset; + size_t block_header_size; + unsigned char block_flags; + uint64_t header_compressed_size; + uint64_t header_uncompressed_size; + unsigned char lzma2_properties; + uint32_t computed_crc; + uint32_t stream_crc; + size_t uncompressed_offset; + size_t dict_start_offset; + unsigned int lc; + unsigned int lp; + unsigned int pb; + uint32_t range; + uint32_t code; + uint32_t lstate; + uint32_t dist[4]; + + off = *poffset; + block_header_offset = off; + + /* Block header size is a single byte. */ + if (unlikely (off >= compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + block_header_size = (compressed[off] + 1) * 4; + if (unlikely (off + block_header_size > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + /* Block flags. */ + block_flags = compressed[off + 1]; + if (unlikely ((block_flags & 0x3c) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + off += 2; + + /* Optional compressed size. */ + header_compressed_size = 0; + if ((block_flags & 0x40) != 0) + { + *poffset = off; + if (!elf_lzma_varint (compressed, compressed_size, poffset, + &header_compressed_size)) + return 0; + off = *poffset; + } + + /* Optional uncompressed size. */ + header_uncompressed_size = 0; + if ((block_flags & 0x80) != 0) + { + *poffset = off; + if (!elf_lzma_varint (compressed, compressed_size, poffset, + &header_uncompressed_size)) + return 0; + off = *poffset; + } + + /* The recipe for creating a minidebug file is to run the xz program + with no arguments, so we expect exactly one filter: lzma2. */ + + if (unlikely ((block_flags & 0x3) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + if (unlikely (off + 2 >= block_header_offset + block_header_size)) + { + elf_uncompress_failed (); + return 0; + } + + /* The filter ID for LZMA2 is 0x21. */ + if (unlikely (compressed[off] != 0x21)) + { + elf_uncompress_failed (); + return 0; + } + ++off; + + /* The size of the filter properties for LZMA2 is 1. */ + if (unlikely (compressed[off] != 1)) + { + elf_uncompress_failed (); + return 0; + } + ++off; + + lzma2_properties = compressed[off]; + ++off; + + if (unlikely (lzma2_properties > 40)) + { + elf_uncompress_failed (); + return 0; + } + + /* The properties describe the dictionary size, but we don't care + what that is. */ + + /* Block header padding. */ + if (unlikely (off + 4 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + off = (off + 3) &~ (size_t) 3; + + if (unlikely (off + 4 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + /* Block header CRC. */ + computed_crc = elf_crc32 (0, compressed + block_header_offset, + block_header_size - 4); + stream_crc = (compressed[off] + | (compressed[off + 1] << 8) + | (compressed[off + 2] << 16) + | (compressed[off + 3] << 24)); + if (unlikely (computed_crc != stream_crc)) + { + elf_uncompress_failed (); + return 0; + } + off += 4; + + /* Read a sequence of LZMA2 packets. */ + + uncompressed_offset = 0; + dict_start_offset = 0; + lc = 0; + lp = 0; + pb = 0; + lstate = 0; + while (off < compressed_size) + { + unsigned char control; + + range = 0xffffffff; + code = 0; + + control = compressed[off]; + ++off; + if (unlikely (control == 0)) + { + /* End of packets. */ + break; + } + + if (control == 1 || control >= 0xe0) + { + /* Reset dictionary to empty. */ + dict_start_offset = uncompressed_offset; + } + + if (control < 0x80) + { + size_t chunk_size; + + /* The only valid values here are 1 or 2. A 1 means to + reset the dictionary (done above). Then we see an + uncompressed chunk. */ + + if (unlikely (control > 2)) + { + elf_uncompress_failed (); + return 0; + } + + /* An uncompressed chunk is a two byte size followed by + data. */ + + if (unlikely (off + 2 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + chunk_size = compressed[off] << 8; + chunk_size += compressed[off + 1]; + ++chunk_size; + + off += 2; + + if (unlikely (off + chunk_size > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + if (unlikely (uncompressed_offset + chunk_size > uncompressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + memcpy (uncompressed + uncompressed_offset, compressed + off, + chunk_size); + uncompressed_offset += chunk_size; + off += chunk_size; + } + else + { + size_t uncompressed_chunk_start; + size_t uncompressed_chunk_size; + size_t compressed_chunk_size; + size_t limit; + + /* An LZMA chunk. This starts with an uncompressed size and + a compressed size. */ + + if (unlikely (off + 4 >= compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + uncompressed_chunk_start = uncompressed_offset; + + uncompressed_chunk_size = (control & 0x1f) << 16; + uncompressed_chunk_size += compressed[off] << 8; + uncompressed_chunk_size += compressed[off + 1]; + ++uncompressed_chunk_size; + + compressed_chunk_size = compressed[off + 2] << 8; + compressed_chunk_size += compressed[off + 3]; + ++compressed_chunk_size; + + off += 4; + + /* Bit 7 (0x80) is set. + Bits 6 and 5 (0x40 and 0x20) are as follows: + 0: don't reset anything + 1: reset state + 2: reset state, read properties + 3: reset state, read properties, reset dictionary (done above) */ + + if (control >= 0xc0) + { + unsigned char props; + + /* Bit 6 is set, read properties. */ + + if (unlikely (off >= compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + props = compressed[off]; + ++off; + if (unlikely (props > (4 * 5 + 4) * 9 + 8)) + { + elf_uncompress_failed (); + return 0; + } + pb = 0; + while (props >= 9 * 5) + { + props -= 9 * 5; + ++pb; + } + lp = 0; + while (props > 9) + { + props -= 9; + ++lp; + } + lc = props; + if (unlikely (lc + lp > 4)) + { + elf_uncompress_failed (); + return 0; + } + } + + if (control >= 0xa0) + { + size_t i; + + /* Bit 5 or 6 is set, reset LZMA state. */ + + lstate = 0; + memset (&dist, 0, sizeof dist); + for (i = 0; i < LZMA_PROB_TOTAL_COUNT; i++) + probs[i] = 1 << 10; + range = 0xffffffff; + code = 0; + } + + /* Read the range code. */ + + if (unlikely (off + 5 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + /* The byte at compressed[off] is ignored for some + reason. */ + + code = ((compressed[off + 1] << 24) + + (compressed[off + 2] << 16) + + (compressed[off + 3] << 8) + + compressed[off + 4]); + off += 5; + + /* This is the main LZMA decode loop. */ + + limit = off + compressed_chunk_size; + *poffset = off; + while (*poffset < limit) + { + unsigned int pos_state; + + if (unlikely (uncompressed_offset + == (uncompressed_chunk_start + + uncompressed_chunk_size))) + { + /* We've decompressed all the expected bytes. */ + break; + } + + pos_state = ((uncompressed_offset - dict_start_offset) + & ((1 << pb) - 1)); + + if (elf_lzma_bit (compressed, compressed_size, + probs + LZMA_IS_MATCH (lstate, pos_state), + poffset, &range, &code)) + { + uint32_t len; + + if (elf_lzma_bit (compressed, compressed_size, + probs + LZMA_IS_REP (lstate), + poffset, &range, &code)) + { + int short_rep; + uint32_t next_dist; + + /* Repeated match. */ + + short_rep = 0; + if (elf_lzma_bit (compressed, compressed_size, + probs + LZMA_IS_REP0 (lstate), + poffset, &range, &code)) + { + if (elf_lzma_bit (compressed, compressed_size, + probs + LZMA_IS_REP1 (lstate), + poffset, &range, &code)) + { + if (elf_lzma_bit (compressed, compressed_size, + probs + LZMA_IS_REP2 (lstate), + poffset, &range, &code)) + { + next_dist = dist[3]; + dist[3] = dist[2]; + } + else + { + next_dist = dist[2]; + } + dist[2] = dist[1]; + } + else + { + next_dist = dist[1]; + } + + dist[1] = dist[0]; + dist[0] = next_dist; + } + else + { + if (!elf_lzma_bit (compressed, compressed_size, + (probs + + LZMA_IS_REP0_LONG (lstate, + pos_state)), + poffset, &range, &code)) + short_rep = 1; + } + + if (lstate < 7) + lstate = short_rep ? 9 : 8; + else + lstate = 11; + + if (short_rep) + len = 1; + else + len = elf_lzma_len (compressed, compressed_size, + probs, 1, pos_state, poffset, + &range, &code); + } + else + { + uint32_t dist_state; + uint32_t dist_slot; + uint16_t *probs_dist; + + /* Match. */ + + if (lstate < 7) + lstate = 7; + else + lstate = 10; + dist[3] = dist[2]; + dist[2] = dist[1]; + dist[1] = dist[0]; + len = elf_lzma_len (compressed, compressed_size, + probs, 0, pos_state, poffset, + &range, &code); + + if (len < 4 + 2) + dist_state = len - 2; + else + dist_state = 3; + probs_dist = probs + LZMA_DIST_SLOT (dist_state, 0); + dist_slot = elf_lzma_integer (compressed, + compressed_size, + probs_dist, 6, + poffset, &range, + &code); + if (dist_slot < LZMA_DIST_MODEL_START) + dist[0] = dist_slot; + else + { + uint32_t limit; + + limit = (dist_slot >> 1) - 1; + dist[0] = 2 + (dist_slot & 1); + if (dist_slot < LZMA_DIST_MODEL_END) + { + dist[0] <<= limit; + probs_dist = (probs + + LZMA_DIST_SPECIAL(dist[0] + - dist_slot + - 1)); + dist[0] += + elf_lzma_reverse_integer (compressed, + compressed_size, + probs_dist, + limit, poffset, + &range, &code); + } + else + { + uint32_t dist0; + uint32_t i; + + dist0 = dist[0]; + for (i = 0; i < limit - 4; i++) + { + uint32_t mask; + + elf_lzma_range_normalize (compressed, + compressed_size, + poffset, + &range, &code); + range >>= 1; + code -= range; + mask = -(code >> 31); + code += range & mask; + dist0 <<= 1; + dist0 += mask + 1; + } + dist0 <<= 4; + probs_dist = probs + LZMA_DIST_ALIGN (0); + dist0 += + elf_lzma_reverse_integer (compressed, + compressed_size, + probs_dist, 4, + poffset, + &range, &code); + dist[0] = dist0; + } + } + } + + if (unlikely (uncompressed_offset + - dict_start_offset < dist[0] + 1)) + { + elf_uncompress_failed (); + return 0; + } + if (unlikely (uncompressed_offset + len > uncompressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + if (dist[0] == 0) + { + /* A common case, meaning repeat the last + character LEN times. */ + memset (uncompressed + uncompressed_offset, + uncompressed[uncompressed_offset - 1], + len); + uncompressed_offset += len; + } + else if (dist[0] + 1 >= len) + { + memcpy (uncompressed + uncompressed_offset, + uncompressed + uncompressed_offset - dist[0] - 1, + len); + uncompressed_offset += len; + } + else + { + while (len > 0) + { + uint32_t copy; + + copy = len < dist[0] + 1 ? len : dist[0] + 1; + memcpy (uncompressed + uncompressed_offset, + (uncompressed + uncompressed_offset + - dist[0] - 1), + copy); + len -= copy; + uncompressed_offset += copy; + } + } + } + else + { + unsigned char prev; + unsigned char low; + size_t high; + uint16_t *lit_probs; + unsigned int sym; + + /* Literal value. */ + + if (uncompressed_offset > 0) + prev = uncompressed[uncompressed_offset - 1]; + else + prev = 0; + low = prev >> (8 - lc); + high = (((uncompressed_offset - dict_start_offset) + & ((1 << lp) - 1)) + << lc); + lit_probs = probs + LZMA_LITERAL (low + high, 0); + if (lstate < 7) + sym = elf_lzma_integer (compressed, compressed_size, + lit_probs, 8, poffset, &range, + &code); + else + { + unsigned int match; + unsigned int bit; + unsigned int match_bit; + unsigned int idx; + + sym = 1; + if (uncompressed_offset >= dist[0] + 1) + match = uncompressed[uncompressed_offset - dist[0] - 1]; + else + match = 0; + match <<= 1; + bit = 0x100; + do + { + match_bit = match & bit; + match <<= 1; + idx = bit + match_bit + sym; + sym <<= 1; + if (elf_lzma_bit (compressed, compressed_size, + lit_probs + idx, poffset, + &range, &code)) + { + ++sym; + bit &= match_bit; + } + else + { + bit &= ~ match_bit; + } + } + while (sym < 0x100); + } + + if (unlikely (uncompressed_offset >= uncompressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + uncompressed[uncompressed_offset] = (unsigned char) sym; + ++uncompressed_offset; + if (lstate <= 3) + lstate = 0; + else if (lstate <= 9) + lstate -= 3; + else + lstate -= 6; + } + } + + elf_lzma_range_normalize (compressed, compressed_size, poffset, + &range, &code); + + off = *poffset; + } + } + + /* We have reached the end of the block. Pad to four byte + boundary. */ + off = (off + 3) &~ (size_t) 3; + if (unlikely (off > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + + switch (check) + { + case 0: + /* No check. */ + break; + + case 1: + /* CRC32 */ + if (unlikely (off + 4 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + computed_crc = elf_crc32 (0, uncompressed, uncompressed_offset); + stream_crc = (compressed[off] + | (compressed[off + 1] << 8) + | (compressed[off + 2] << 16) + | (compressed[off + 3] << 24)); + if (computed_crc != stream_crc) + { + elf_uncompress_failed (); + return 0; + } + off += 4; + break; + + case 4: + /* CRC64. We don't bother computing a CRC64 checksum. */ + if (unlikely (off + 8 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + off += 8; + break; + + case 10: + /* SHA. We don't bother computing a SHA checksum. */ + if (unlikely (off + 32 > compressed_size)) + { + elf_uncompress_failed (); + return 0; + } + off += 32; + break; + + default: + elf_uncompress_failed (); + return 0; + } + + *poffset = off; + + return 1; +} + +/* Uncompress LZMA data found in a minidebug file. The minidebug + format is described at + https://sourceware.org/gdb/current/onlinedocs/gdb/MiniDebugInfo.html. + Returns 0 on error, 1 on successful decompression. For this + function we return 0 on failure to decompress, as the calling code + will carry on in that case. */ + +static int +elf_uncompress_lzma (struct backtrace_state *state, + const unsigned char *compressed, size_t compressed_size, + backtrace_error_callback error_callback, void *data, + unsigned char **uncompressed, size_t *uncompressed_size) +{ + size_t header_size; + size_t footer_size; + unsigned char check; + uint32_t computed_crc; + uint32_t stream_crc; + size_t offset; + size_t index_size; + size_t footer_offset; + size_t index_offset; + uint64_t index_compressed_size; + uint64_t index_uncompressed_size; + unsigned char *mem; + uint16_t *probs; + size_t compressed_block_size; + + /* The format starts with a stream header and ends with a stream + footer. */ + header_size = 12; + footer_size = 12; + if (unlikely (compressed_size < header_size + footer_size)) + { + elf_uncompress_failed (); + return 0; + } + + /* The stream header starts with a magic string. */ + if (unlikely (memcmp (compressed, "\375" "7zXZ\0", 6) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + /* Next come stream flags. The first byte is zero, the second byte + is the check. */ + if (unlikely (compressed[6] != 0)) + { + elf_uncompress_failed (); + return 0; + } + check = compressed[7]; + if (unlikely ((check & 0xf8) != 0)) + { + elf_uncompress_failed (); + return 0; + } + + /* Next comes a CRC of the stream flags. */ + computed_crc = elf_crc32 (0, compressed + 6, 2); + stream_crc = (compressed[8] + | (compressed[9] << 8) + | (compressed[10] << 16) + | (compressed[11] << 24)); + if (unlikely (computed_crc != stream_crc)) + { + elf_uncompress_failed (); + return 0; + } + + /* Now that we've parsed the header, parse the footer, so that we + can get the uncompressed size. */ + + /* The footer ends with two magic bytes. */ + + offset = compressed_size; + if (unlikely (memcmp (compressed + offset - 2, "YZ", 2) != 0)) + { + elf_uncompress_failed (); + return 0; + } + offset -= 2; + + /* Before that are the stream flags, which should be the same as the + flags in the header. */ + if (unlikely (compressed[offset - 2] != 0 + || compressed[offset - 1] != check)) + { + elf_uncompress_failed (); + return 0; + } + offset -= 2; + + /* Before that is the size of the index field, which precedes the + footer. */ + index_size = (compressed[offset - 4] + | (compressed[offset - 3] << 8) + | (compressed[offset - 2] << 16) + | (compressed[offset - 1] << 24)); + index_size = (index_size + 1) * 4; + offset -= 4; + + /* Before that is a footer CRC. */ + computed_crc = elf_crc32 (0, compressed + offset, 6); + stream_crc = (compressed[offset - 4] + | (compressed[offset - 3] << 8) + | (compressed[offset - 2] << 16) + | (compressed[offset - 1] << 24)); + if (unlikely (computed_crc != stream_crc)) + { + elf_uncompress_failed (); + return 0; + } + offset -= 4; + + /* The index comes just before the footer. */ + if (unlikely (offset < index_size + header_size)) + { + elf_uncompress_failed (); + return 0; + } + + footer_offset = offset; + offset -= index_size; + index_offset = offset; + + /* The index starts with a zero byte. */ + if (unlikely (compressed[offset] != 0)) + { + elf_uncompress_failed (); + return 0; + } + ++offset; + + /* Next is the number of blocks. We expect zero blocks for an empty + stream, and otherwise a single block. */ + if (unlikely (compressed[offset] == 0)) + { + *uncompressed = NULL; + *uncompressed_size = 0; + return 1; + } + if (unlikely (compressed[offset] != 1)) + { + elf_uncompress_failed (); + return 0; + } + ++offset; + + /* Next is the compressed size and the uncompressed size. */ + if (!elf_lzma_varint (compressed, compressed_size, &offset, + &index_compressed_size)) + return 0; + if (!elf_lzma_varint (compressed, compressed_size, &offset, + &index_uncompressed_size)) + return 0; + + /* Pad to a four byte boundary. */ + offset = (offset + 3) &~ (size_t) 3; + + /* Next is a CRC of the index. */ + computed_crc = elf_crc32 (0, compressed + index_offset, + offset - index_offset); + stream_crc = (compressed[offset] + | (compressed[offset + 1] << 8) + | (compressed[offset + 2] << 16) + | (compressed[offset + 3] << 24)); + if (unlikely (computed_crc != stream_crc)) + { + elf_uncompress_failed (); + return 0; + } + offset += 4; + + /* We should now be back at the footer. */ + if (unlikely (offset != footer_offset)) + { + elf_uncompress_failed (); + return 0; + } + + /* Allocate space to hold the uncompressed data. If we succeed in + uncompressing the LZMA data, we never free this memory. */ + mem = (unsigned char *) backtrace_alloc (state, index_uncompressed_size, + error_callback, data); + if (unlikely (mem == NULL)) + return 0; + *uncompressed = mem; + *uncompressed_size = index_uncompressed_size; + + /* Allocate space for probabilities. */ + probs = ((uint16_t *) + backtrace_alloc (state, + LZMA_PROB_TOTAL_COUNT * sizeof (uint16_t), + error_callback, data)); + if (unlikely (probs == NULL)) + { + backtrace_free (state, mem, index_uncompressed_size, error_callback, + data); + return 0; + } + + /* Uncompress the block, which follows the header. */ + offset = 12; + if (!elf_uncompress_lzma_block (compressed, compressed_size, check, probs, + mem, index_uncompressed_size, &offset)) + { + backtrace_free (state, mem, index_uncompressed_size, error_callback, + data); + return 0; + } + + compressed_block_size = offset - 12; + if (unlikely (compressed_block_size + != ((index_compressed_size + 3) &~ (size_t) 3))) + { + elf_uncompress_failed (); + backtrace_free (state, mem, index_uncompressed_size, error_callback, + data); + return 0; + } + + offset = (offset + 3) &~ (size_t) 3; + if (unlikely (offset != index_offset)) + { + elf_uncompress_failed (); + backtrace_free (state, mem, index_uncompressed_size, error_callback, + data); + return 0; + } + + return 1; +} + +/* This function is a hook for testing the LZMA support. It is only + used by tests. */ + +int +backtrace_uncompress_lzma (struct backtrace_state *state, + const unsigned char *compressed, + size_t compressed_size, + backtrace_error_callback error_callback, + void *data, unsigned char **uncompressed, + size_t *uncompressed_size) +{ + return elf_uncompress_lzma (state, compressed, compressed_size, + error_callback, data, uncompressed, + uncompressed_size); +} + +/* 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 + elf_add will need to be called on the descriptor again after + base_address is determined. */ + +static int +elf_add (struct backtrace_state *state, const char *filename, int descriptor, + const unsigned char *memory, size_t memory_size, + uintptr_t base_address, backtrace_error_callback error_callback, + void *data, fileline *fileline_fn, int *found_sym, int *found_dwarf, + struct dwarf_data **fileline_entry, int exe, int debuginfo, + const char *with_buildid_data, uint32_t with_buildid_size) +{ + struct elf_view ehdr_view; + b_elf_ehdr ehdr; + off_t shoff; + unsigned int shnum; + unsigned int shstrndx; + struct elf_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 elf_view names_view; + int names_view_valid; + const char *names; + unsigned int symtab_shndx; + unsigned int dynsym_shndx; + unsigned int i; + struct debug_section_info sections[DEBUG_MAX]; + struct debug_section_info zsections[DEBUG_MAX]; + struct elf_view symtab_view; + int symtab_view_valid; + struct elf_view strtab_view; + int strtab_view_valid; + struct elf_view buildid_view; + int buildid_view_valid; + const char *buildid_data; + uint32_t buildid_size; + struct elf_view debuglink_view; + int debuglink_view_valid; + const char *debuglink_name; + uint32_t debuglink_crc; + struct elf_view debugaltlink_view; + int debugaltlink_view_valid; + const char *debugaltlink_name; + const char *debugaltlink_buildid_data; + uint32_t debugaltlink_buildid_size; + struct elf_view gnu_debugdata_view; + int gnu_debugdata_view_valid; + size_t gnu_debugdata_size; + unsigned char *gnu_debugdata_uncompressed; + size_t gnu_debugdata_uncompressed_size; + off_t min_offset; + off_t max_offset; + off_t debug_size; + struct elf_view debug_view; + int debug_view_valid; + unsigned int using_debug_view; + uint16_t *zdebug_table; + struct elf_view split_debug_view[DEBUG_MAX]; + unsigned char split_debug_view_valid[DEBUG_MAX]; + struct elf_ppc64_opd_data opd_data, *opd; + struct dwarf_sections dwarf_sections; + + if (!debuginfo) + { + *found_sym = 0; + *found_dwarf = 0; + } + + shdrs_view_valid = 0; + 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; + debugaltlink_view_valid = 0; + debugaltlink_name = NULL; + debugaltlink_buildid_data = NULL; + debugaltlink_buildid_size = 0; + gnu_debugdata_view_valid = 0; + gnu_debugdata_size = 0; + debug_view_valid = 0; + memset (&split_debug_view_valid[0], 0, sizeof split_debug_view_valid); + opd = NULL; + + if (!elf_get_view (state, descriptor, memory, memory_size, 0, sizeof ehdr, + error_callback, data, &ehdr_view)) + goto fail; + + memcpy (&ehdr, ehdr_view.view.data, sizeof ehdr); + + elf_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) + { + 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.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 elf_view shdr_view; + const b_elf_shdr *shdr; + + if (!elf_get_view (state, descriptor, memory, memory_size, shoff, + sizeof shdr, error_callback, data, &shdr_view)) + goto fail; + + shdr = (const b_elf_shdr *) shdr_view.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; + } + + elf_release_view (state, &shdr_view, error_callback, data); + } + + if (shnum == 0 || shstrndx == 0) + goto fail; + + /* To translate PC to file/line when using DWARF, we need to find + the .debug_info and .debug_line sections. */ + + /* Read the section headers, skipping the first one. */ + + if (!elf_get_view (state, descriptor, memory, memory_size, + shoff + sizeof (b_elf_shdr), + (shnum - 1) * sizeof (b_elf_shdr), + error_callback, data, &shdrs_view)) + goto fail; + shdrs_view_valid = 1; + shdrs = (const b_elf_shdr *) shdrs_view.view.data; + + /* Read the section names. */ + + shstrhdr = &shdrs[shstrndx - 1]; + shstr_size = shstrhdr->sh_size; + shstr_off = shstrhdr->sh_offset; + + if (!elf_get_view (state, descriptor, memory, memory_size, shstr_off, + shstrhdr->sh_size, error_callback, data, &names_view)) + goto fail; + names_view_valid = 1; + names = (const char *) names_view.view.data; + + symtab_shndx = 0; + dynsym_shndx = 0; + + memset (sections, 0, sizeof sections); + memset (zsections, 0, sizeof zsections); + + /* Look for the symbol table. */ + for (i = 1; i < shnum; ++i) + { + const b_elf_shdr *shdr; + unsigned int sh_name; + const char *name; + int j; + + shdr = &shdrs[i - 1]; + + if (shdr->sh_type == SHT_SYMTAB) + symtab_shndx = i; + else if (shdr->sh_type == SHT_DYNSYM) + dynsym_shndx = i; + + sh_name = shdr->sh_name; + if (sh_name >= shstr_size) + { + error_callback (data, "ELF section name out of range", 0); + goto fail; + } + + name = names + sh_name; + + for (j = 0; j < (int) DEBUG_MAX; ++j) + { + if (strcmp (name, dwarf_section_names[j]) == 0) + { + sections[j].offset = shdr->sh_offset; + sections[j].size = shdr->sh_size; + sections[j].compressed = (shdr->sh_flags & SHF_COMPRESSED) != 0; + break; + } + } + + if (name[0] == '.' && name[1] == 'z') + { + for (j = 0; j < (int) DEBUG_MAX; ++j) + { + if (strcmp (name + 2, dwarf_section_names[j] + 1) == 0) + { + zsections[j].offset = shdr->sh_offset; + zsections[j].size = shdr->sh_size; + 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 || with_buildid_data != NULL) + && !buildid_view_valid + && strcmp (name, ".note.gnu.build-id") == 0) + { + const b_elf_note *note; + + if (!elf_get_view (state, descriptor, memory, memory_size, + shdr->sh_offset, shdr->sh_size, error_callback, + data, &buildid_view)) + goto fail; + + buildid_view_valid = 1; + note = (const b_elf_note *) buildid_view.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; + } + + if (with_buildid_size != 0) + { + if (buildid_size != with_buildid_size) + goto fail; + + if (memcmp (buildid_data, with_buildid_data, buildid_size) != 0) + goto fail; + } + } + + /* 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 (!elf_get_view (state, descriptor, memory, memory_size, + shdr->sh_offset, shdr->sh_size, error_callback, + data, &debuglink_view)) + goto fail; + + debuglink_view_valid = 1; + debuglink_data = (const char *) debuglink_view.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 (!debugaltlink_view_valid + && strcmp (name, ".gnu_debugaltlink") == 0) + { + const char *debugaltlink_data; + size_t debugaltlink_name_len; + + if (!elf_get_view (state, descriptor, memory, memory_size, + shdr->sh_offset, shdr->sh_size, error_callback, + data, &debugaltlink_view)) + goto fail; + + debugaltlink_view_valid = 1; + debugaltlink_data = (const char *) debugaltlink_view.view.data; + debugaltlink_name = debugaltlink_data; + debugaltlink_name_len = strnlen (debugaltlink_data, shdr->sh_size); + if (debugaltlink_name_len < shdr->sh_size) + { + /* Include terminating zero. */ + debugaltlink_name_len += 1; + + debugaltlink_buildid_data + = debugaltlink_data + debugaltlink_name_len; + debugaltlink_buildid_size = shdr->sh_size - debugaltlink_name_len; + } + } + + if (!gnu_debugdata_view_valid + && strcmp (name, ".gnu_debugdata") == 0) + { + if (!elf_get_view (state, descriptor, memory, memory_size, + shdr->sh_offset, shdr->sh_size, error_callback, + data, &gnu_debugdata_view)) + goto fail; + + gnu_debugdata_size = shdr->sh_size; + gnu_debugdata_view_valid = 1; + } + + /* Read the .opd section on PowerPC64 ELFv1. */ + if (ehdr.e_machine == EM_PPC64 + && (ehdr.e_flags & EF_PPC64_ABI) < 2 + && shdr->sh_type == SHT_PROGBITS + && strcmp (name, ".opd") == 0) + { + if (!elf_get_view (state, descriptor, memory, memory_size, + shdr->sh_offset, shdr->sh_size, error_callback, + data, &opd_data.view)) + goto fail; + + opd = &opd_data; + opd->addr = shdr->sh_addr; + opd->data = (const char *) opd_data.view.view.data; + opd->size = shdr->sh_size; + } + } + + if (symtab_shndx == 0) + symtab_shndx = dynsym_shndx; + if (symtab_shndx != 0 && !debuginfo) + { + const b_elf_shdr *symtab_shdr; + unsigned int strtab_shndx; + const b_elf_shdr *strtab_shdr; + struct elf_syminfo_data *sdata; + + symtab_shdr = &shdrs[symtab_shndx - 1]; + strtab_shndx = symtab_shdr->sh_link; + if (strtab_shndx >= shnum) + { + error_callback (data, + "ELF symbol table strtab link out of range", 0); + goto fail; + } + strtab_shdr = &shdrs[strtab_shndx - 1]; + + if (!elf_get_view (state, descriptor, memory, memory_size, + symtab_shdr->sh_offset, symtab_shdr->sh_size, + error_callback, data, &symtab_view)) + goto fail; + symtab_view_valid = 1; + + if (!elf_get_view (state, descriptor, memory, memory_size, + strtab_shdr->sh_offset, strtab_shdr->sh_size, + error_callback, data, &strtab_view)) + goto fail; + strtab_view_valid = 1; + + sdata = ((struct elf_syminfo_data *) + backtrace_alloc (state, sizeof *sdata, error_callback, data)); + if (sdata == NULL) + goto fail; + + if (!elf_initialize_syminfo (state, base_address, + symtab_view.view.data, symtab_shdr->sh_size, + strtab_view.view.data, strtab_shdr->sh_size, + error_callback, data, sdata, opd)) + { + backtrace_free (state, sdata, sizeof *sdata, error_callback, data); + goto fail; + } + + /* We no longer need the symbol table, but we hold on to the + string table permanently. */ + elf_release_view (state, &symtab_view, error_callback, data); + symtab_view_valid = 0; + strtab_view_valid = 0; + + *found_sym = 1; + + elf_add_syminfo_data (state, sdata); + } + + elf_release_view (state, &shdrs_view, error_callback, data); + shdrs_view_valid = 0; + elf_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) + { + int ret; + + elf_release_view (state, &buildid_view, error_callback, data); + if (debuglink_view_valid) + elf_release_view (state, &debuglink_view, error_callback, data); + if (debugaltlink_view_valid) + elf_release_view (state, &debugaltlink_view, error_callback, data); + ret = elf_add (state, "", d, NULL, 0, base_address, error_callback, + data, fileline_fn, found_sym, found_dwarf, NULL, 0, + 1, NULL, 0); + if (ret < 0) + backtrace_close (d, error_callback, data); + else if (descriptor >= 0) + backtrace_close (descriptor, error_callback, data); + return ret; + } + } + + if (buildid_view_valid) + { + elf_release_view (state, &buildid_view, error_callback, data); + buildid_view_valid = 0; + } + + if (opd) + { + elf_release_view (state, &opd->view, error_callback, data); + opd = NULL; + } + + if (debuglink_name != NULL) + { + int d; + + d = elf_open_debugfile_by_debuglink (state, filename, debuglink_name, + debuglink_crc, error_callback, + data); + if (d >= 0) + { + int ret; + + elf_release_view (state, &debuglink_view, error_callback, data); + if (debugaltlink_view_valid) + elf_release_view (state, &debugaltlink_view, error_callback, data); + ret = elf_add (state, "", d, NULL, 0, base_address, error_callback, + data, fileline_fn, found_sym, found_dwarf, NULL, 0, + 1, NULL, 0); + if (ret < 0) + backtrace_close (d, error_callback, data); + else if (descriptor >= 0) + backtrace_close(descriptor, error_callback, data); + return ret; + } + } + + if (debuglink_view_valid) + { + elf_release_view (state, &debuglink_view, error_callback, data); + debuglink_view_valid = 0; + } + + struct dwarf_data *fileline_altlink = NULL; + if (debugaltlink_name != NULL) + { + int d; + + d = elf_open_debugfile_by_debuglink (state, filename, debugaltlink_name, + 0, error_callback, data); + if (d >= 0) + { + int ret; + + ret = elf_add (state, filename, d, NULL, 0, base_address, + error_callback, data, fileline_fn, found_sym, + found_dwarf, &fileline_altlink, 0, 1, + debugaltlink_buildid_data, debugaltlink_buildid_size); + elf_release_view (state, &debugaltlink_view, error_callback, data); + debugaltlink_view_valid = 0; + if (ret < 0) + { + backtrace_close (d, error_callback, data); + return ret; + } + } + } + + if (debugaltlink_view_valid) + { + elf_release_view (state, &debugaltlink_view, error_callback, data); + debugaltlink_view_valid = 0; + } + + if (gnu_debugdata_view_valid) + { + int ret; + + ret = elf_uncompress_lzma (state, + ((const unsigned char *) + gnu_debugdata_view.view.data), + gnu_debugdata_size, error_callback, data, + &gnu_debugdata_uncompressed, + &gnu_debugdata_uncompressed_size); + + elf_release_view (state, &gnu_debugdata_view, error_callback, data); + gnu_debugdata_view_valid = 0; + + if (ret) + { + ret = elf_add (state, filename, -1, gnu_debugdata_uncompressed, + gnu_debugdata_uncompressed_size, base_address, + error_callback, data, fileline_fn, found_sym, + found_dwarf, NULL, 0, 0, NULL, 0); + if (ret >= 0 && descriptor >= 0) + backtrace_close(descriptor, error_callback, data); + return ret; + } + } + + /* Read all the debug sections in a single view, since they are + probably adjacent in the file. If any of sections are + uncompressed, we never release this view. */ + + min_offset = 0; + max_offset = 0; + debug_size = 0; + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + off_t end; + + if (sections[i].size != 0) + { + if (min_offset == 0 || sections[i].offset < min_offset) + min_offset = sections[i].offset; + end = sections[i].offset + sections[i].size; + if (end > max_offset) + max_offset = end; + debug_size += sections[i].size; + } + if (zsections[i].size != 0) + { + if (min_offset == 0 || zsections[i].offset < min_offset) + min_offset = zsections[i].offset; + end = zsections[i].offset + zsections[i].size; + if (end > max_offset) + max_offset = end; + debug_size += zsections[i].size; + } + } + if (min_offset == 0 || max_offset == 0) + { + if (descriptor >= 0) + { + if (!backtrace_close (descriptor, error_callback, data)) + goto fail; + } + return 1; + } + + /* If the total debug section size is large, assume that there are + gaps between the sections, and read them individually. */ + + if (max_offset - min_offset < 0x20000000 + || max_offset - min_offset < debug_size + 0x10000) + { + if (!elf_get_view (state, descriptor, memory, memory_size, min_offset, + max_offset - min_offset, error_callback, data, + &debug_view)) + goto fail; + debug_view_valid = 1; + } + else + { + memset (&split_debug_view[0], 0, sizeof split_debug_view); + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + struct debug_section_info *dsec; + + if (sections[i].size != 0) + dsec = §ions[i]; + else if (zsections[i].size != 0) + dsec = &zsections[i]; + else + continue; + + if (!elf_get_view (state, descriptor, memory, memory_size, + dsec->offset, dsec->size, error_callback, data, + &split_debug_view[i])) + goto fail; + split_debug_view_valid[i] = 1; + + if (sections[i].size != 0) + sections[i].data = ((const unsigned char *) + split_debug_view[i].view.data); + else + zsections[i].data = ((const unsigned char *) + split_debug_view[i].view.data); + } + } + + /* We've read all we need from the executable. */ + if (descriptor >= 0) + { + if (!backtrace_close (descriptor, error_callback, data)) + goto fail; + descriptor = -1; + } + + using_debug_view = 0; + if (debug_view_valid) + { + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + if (sections[i].size == 0) + sections[i].data = NULL; + else + { + sections[i].data = ((const unsigned char *) debug_view.view.data + + (sections[i].offset - min_offset)); + ++using_debug_view; + } + + if (zsections[i].size == 0) + zsections[i].data = NULL; + else + zsections[i].data = ((const unsigned char *) debug_view.view.data + + (zsections[i].offset - min_offset)); + } + } + + /* Uncompress the old format (--compress-debug-sections=zlib-gnu). */ + + zdebug_table = NULL; + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + if (sections[i].size == 0 && zsections[i].size > 0) + { + unsigned char *uncompressed_data; + size_t uncompressed_size; + + if (zdebug_table == NULL) + { + zdebug_table = ((uint16_t *) + backtrace_alloc (state, ZDEBUG_TABLE_SIZE, + error_callback, data)); + if (zdebug_table == NULL) + goto fail; + } + + uncompressed_data = NULL; + uncompressed_size = 0; + if (!elf_uncompress_zdebug (state, zsections[i].data, + zsections[i].size, zdebug_table, + error_callback, data, + &uncompressed_data, &uncompressed_size)) + goto fail; + sections[i].data = uncompressed_data; + sections[i].size = uncompressed_size; + sections[i].compressed = 0; + + if (split_debug_view_valid[i]) + { + elf_release_view (state, &split_debug_view[i], + error_callback, data); + split_debug_view_valid[i] = 0; + } + } + } + + /* Uncompress the official ELF format + (--compress-debug-sections=zlib-gabi). */ + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + unsigned char *uncompressed_data; + size_t uncompressed_size; + + if (sections[i].size == 0 || !sections[i].compressed) + continue; + + if (zdebug_table == NULL) + { + zdebug_table = ((uint16_t *) + backtrace_alloc (state, ZDEBUG_TABLE_SIZE, + error_callback, data)); + if (zdebug_table == NULL) + goto fail; + } + + uncompressed_data = NULL; + uncompressed_size = 0; + if (!elf_uncompress_chdr (state, sections[i].data, sections[i].size, + zdebug_table, error_callback, data, + &uncompressed_data, &uncompressed_size)) + goto fail; + sections[i].data = uncompressed_data; + sections[i].size = uncompressed_size; + sections[i].compressed = 0; + + if (debug_view_valid) + --using_debug_view; + else if (split_debug_view_valid[i]) + { + elf_release_view (state, &split_debug_view[i], error_callback, data); + split_debug_view_valid[i] = 0; + } + } + + if (zdebug_table != NULL) + backtrace_free (state, zdebug_table, ZDEBUG_TABLE_SIZE, + error_callback, data); + + if (debug_view_valid && using_debug_view == 0) + { + elf_release_view (state, &debug_view, error_callback, data); + debug_view_valid = 0; + } + + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + dwarf_sections.data[i] = sections[i].data; + dwarf_sections.size[i] = sections[i].size; + } + + if (!backtrace_dwarf_add (state, base_address, &dwarf_sections, + ehdr.e_ident[EI_DATA] == ELFDATA2MSB, + fileline_altlink, + error_callback, data, fileline_fn, + fileline_entry)) + goto fail; + + *found_dwarf = 1; + + return 1; + + fail: + if (shdrs_view_valid) + elf_release_view (state, &shdrs_view, error_callback, data); + if (names_view_valid) + elf_release_view (state, &names_view, error_callback, data); + if (symtab_view_valid) + elf_release_view (state, &symtab_view, error_callback, data); + if (strtab_view_valid) + elf_release_view (state, &strtab_view, error_callback, data); + if (debuglink_view_valid) + elf_release_view (state, &debuglink_view, error_callback, data); + if (debugaltlink_view_valid) + elf_release_view (state, &debugaltlink_view, error_callback, data); + if (gnu_debugdata_view_valid) + elf_release_view (state, &gnu_debugdata_view, error_callback, data); + if (buildid_view_valid) + elf_release_view (state, &buildid_view, error_callback, data); + if (debug_view_valid) + elf_release_view (state, &debug_view, error_callback, data); + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + if (split_debug_view_valid[i]) + elf_release_view (state, &split_debug_view[i], error_callback, data); + } + if (opd) + elf_release_view (state, &opd->view, error_callback, data); + if (descriptor >= 0) + backtrace_close (descriptor, error_callback, data); + return 0; +} + +/* Data passed to phdr_callback. */ + +struct phdr_data +{ + struct backtrace_state *state; + backtrace_error_callback error_callback; + void *data; + fileline *fileline_fn; + int *found_sym; + int *found_dwarf; + const char *exe_filename; + int exe_descriptor; +}; + +/* Callback passed to dl_iterate_phdr. Load debug info from shared + libraries. */ + +static int +#ifdef __i386__ +__attribute__ ((__force_align_arg_pointer__)) +#endif +phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED, + void *pdata) +{ + struct phdr_data *pd = (struct phdr_data *) pdata; + const char *filename; + int descriptor; + int does_not_exist; + fileline elf_fileline_fn; + int found_dwarf; + + /* 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 + phdr_callback to be for the PIE. */ + if (info->dlpi_name == NULL || info->dlpi_name[0] == '\0') + { + if (pd->exe_descriptor == -1) + return 0; + filename = pd->exe_filename; + descriptor = pd->exe_descriptor; + pd->exe_descriptor = -1; + } + else + { + if (pd->exe_descriptor != -1) + { + backtrace_close (pd->exe_descriptor, pd->error_callback, pd->data); + 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, filename, descriptor, NULL, 0, info->dlpi_addr, + pd->error_callback, pd->data, &elf_fileline_fn, pd->found_sym, + &found_dwarf, NULL, 0, 0, NULL, 0)) + { + if (found_dwarf) + { + *pd->found_dwarf = 1; + *pd->fileline_fn = elf_fileline_fn; + } + } + + return 0; +} + +/* Initialize the backtrace data we need from an ELF executable. At + the ELF level, all we need to do is find the debug info + sections. */ + +int +backtrace_initialize (struct backtrace_state *state, const char *filename, + int descriptor, backtrace_error_callback error_callback, + void *data, fileline *fileline_fn) +{ + int ret; + int found_sym; + int found_dwarf; + fileline elf_fileline_fn = elf_nodebug; + struct phdr_data pd; + + ret = elf_add (state, filename, descriptor, NULL, 0, 0, error_callback, data, + &elf_fileline_fn, &found_sym, &found_dwarf, NULL, 1, 0, NULL, + 0); + if (!ret) + return 0; + + pd.state = state; + pd.error_callback = error_callback; + pd.data = data; + pd.fileline_fn = &elf_fileline_fn; + pd.found_sym = &found_sym; + pd.found_dwarf = &found_dwarf; + pd.exe_filename = filename; + pd.exe_descriptor = ret < 0 ? descriptor : -1; + + dl_iterate_phdr (phdr_callback, (void *) &pd); + + if (!state->threaded) + { + if (found_sym) + state->syminfo_fn = elf_syminfo; + else if (state->syminfo_fn == NULL) + state->syminfo_fn = elf_nosyms; + } + else + { + if (found_sym) + backtrace_atomic_store_pointer (&state->syminfo_fn, elf_syminfo); + else + (void) __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, + elf_nosyms); + } + + if (!state->threaded) + *fileline_fn = state->fileline_fn; + else + *fileline_fn = backtrace_atomic_load_pointer (&state->fileline_fn); + + if (*fileline_fn == NULL || *fileline_fn == elf_nodebug) + *fileline_fn = elf_fileline_fn; + + return 1; +} |