diff options
Diffstat (limited to 'absl/debugging/symbolize_elf.inc')
| -rw-r--r-- | absl/debugging/symbolize_elf.inc | 72 |
1 files changed, 33 insertions, 39 deletions
diff --git a/absl/debugging/symbolize_elf.inc b/absl/debugging/symbolize_elf.inc index 37f77ca6..2bd7659f 100644 --- a/absl/debugging/symbolize_elf.inc +++ b/absl/debugging/symbolize_elf.inc @@ -4,7 +4,7 @@ // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // -// http://www.apache.org/licenses/LICENSE-2.0 +// https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, @@ -76,7 +76,7 @@ #include "absl/debugging/internal/vdso_support.h" namespace absl { -inline namespace lts_2018_12_18 { +inline namespace lts_2019_08_08 { // Value of argv[0]. Used by MaybeInitializeObjFile(). static char *argv0_value = nullptr; @@ -306,7 +306,7 @@ class Symbolizer { char *tmp_buf, int tmp_buf_size); enum { - SYMBOL_BUF_SIZE = 2048, + SYMBOL_BUF_SIZE = 3072, TMP_BUF_SIZE = 1024, SYMBOL_CACHE_LINES = 128, }; @@ -763,37 +763,27 @@ FindSymbolResult Symbolizer::GetSymbolFromObjectFile( } } - // Consult a regular symbol table first. - if (!GetSectionHeaderByType(obj.fd, obj.elf_header.e_shnum, - obj.elf_header.e_shoff, SHT_SYMTAB, &symtab, - tmp_buf, tmp_buf_size)) { - return SYMBOL_NOT_FOUND; - } - if (!ReadFromOffsetExact( - obj.fd, &strtab, sizeof(strtab), - obj.elf_header.e_shoff + symtab.sh_link * sizeof(symtab))) { - return SYMBOL_NOT_FOUND; - } - const FindSymbolResult rc = - FindSymbol(pc, obj.fd, out, out_size, relocation, &strtab, &symtab, - opd_ptr, tmp_buf, tmp_buf_size); - if (rc != SYMBOL_NOT_FOUND) { - return rc; // Found the symbol in a regular symbol table. + // Consult a regular symbol table, then fall back to the dynamic symbol table. + for (const auto symbol_table_type : {SHT_SYMTAB, SHT_DYNSYM}) { + if (!GetSectionHeaderByType(obj.fd, obj.elf_header.e_shnum, + obj.elf_header.e_shoff, symbol_table_type, + &symtab, tmp_buf, tmp_buf_size)) { + continue; + } + if (!ReadFromOffsetExact( + obj.fd, &strtab, sizeof(strtab), + obj.elf_header.e_shoff + symtab.sh_link * sizeof(symtab))) { + continue; + } + const FindSymbolResult rc = + FindSymbol(pc, obj.fd, out, out_size, relocation, &strtab, &symtab, + opd_ptr, tmp_buf, tmp_buf_size); + if (rc != SYMBOL_NOT_FOUND) { + return rc; + } } - // If the symbol is not found, then consult a dynamic symbol table. - if (!GetSectionHeaderByType(obj.fd, obj.elf_header.e_shnum, - obj.elf_header.e_shoff, SHT_DYNSYM, &symtab, - tmp_buf, tmp_buf_size)) { - return SYMBOL_NOT_FOUND; - } - if (!ReadFromOffsetExact( - obj.fd, &strtab, sizeof(strtab), - obj.elf_header.e_shoff + symtab.sh_link * sizeof(symtab))) { - return SYMBOL_NOT_FOUND; - } - return FindSymbol(pc, obj.fd, out, out_size, relocation, &strtab, &symtab, - opd_ptr, tmp_buf, tmp_buf_size); + return SYMBOL_NOT_FOUND; } namespace { @@ -926,6 +916,14 @@ static const char *GetHex(const char *start, const char *end, return p; } +// Normally we are only interested in "r?x" maps. +// On the PowerPC, function pointers point to descriptors in the .opd +// section. The descriptors themselves are not executable code, so +// we need to relax the check below to "r??". +static bool ShouldUseMapping(const char *const flags) { + return flags[0] == 'r' && (kPlatformUsesOPDSections || flags[2] == 'x'); +} + // Read /proc/self/maps and run "callback" for each mmapped file found. If // "callback" returns false, stop scanning and return true. Else continue // scanning /proc/self/maps. Return true if no parse error is found. @@ -995,12 +993,8 @@ static ABSL_ATTRIBUTE_NOINLINE bool ReadAddrMap( return false; } - // Check flags. Normally we are only interested in "r-x" maps. On - // the PowerPC, function pointers point to descriptors in the .opd - // section. The descriptors themselves are not executable code. So - // we need to relax the check below to "r**". - if (memcmp(flags_start, "r-x", 3) != 0 && // Not a "r-x" map. - !(kPlatformUsesOPDSections && flags_start[0] == 'r')) { + // Check flags. + if (!ShouldUseMapping(flags_start)) { continue; // We skip this map. } ++cursor; // Skip ' '. @@ -1475,5 +1469,5 @@ bool Symbolize(const void *pc, char *out, int out_size) { return ok; } -} // inline namespace lts_2018_12_18 +} // inline namespace lts_2019_08_08 } // namespace absl |