From 5085b1d0df9c4b6f0f32b100f88611bc2beb3c09 Mon Sep 17 00:00:00 2001 From: Joshua Peraza Date: Tue, 29 Oct 2019 17:55:54 -0700 Subject: [PATCH] linux, client: set module name from DT_SONAME 3e56ef9d changed dump_syms to set the module name from DT_SONAME expecting that clients were already using DT_SONAME when it was present. The Breakpad client previously only used DT_SONAME as the name for a module if it detected that it was likely mapped from a zip file. This patch updates the Breakpad Linux client to always use the DT_SONAME in minidumps if it's present. Also included are changes to address comments that were missed from that review. Bug: 1016924 Change-Id: I4aae8c05e6793d4b0598049a8964ddd4cb0c6194 Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1889231 Reviewed-by: Mark Mentovai Reviewed-by: Mike Frysinger --- .../linux/minidump_writer/linux_dumper.cc | 44 ++++++++++++------- src/common/linux/dump_symbols.cc | 12 +++-- 2 files changed, 32 insertions(+), 24 deletions(-) diff --git a/src/client/linux/minidump_writer/linux_dumper.cc b/src/client/linux/minidump_writer/linux_dumper.cc index 5653133e..1112035b 100644 --- a/src/client/linux/minidump_writer/linux_dumper.cc +++ b/src/client/linux/minidump_writer/linux_dumper.cc @@ -473,19 +473,26 @@ void LinuxDumper::GetMappingEffectiveNameAndPath(const MappingInfo& mapping, size_t file_name_size) { my_strlcpy(file_path, mapping.name, file_path_size); - // If an executable is mapped from a non-zero offset, this is likely because - // the executable was loaded directly from inside an archive file (e.g., an - // apk on Android). We try to find the name of the shared object (SONAME) by - // looking in the file for ELF sections. - bool mapped_from_archive = false; - if (mapping.exec && mapping.offset != 0) { - mapped_from_archive = - ElfFileSoName(*this, mapping, file_name, file_name_size); + // Tools such as minidump_stackwalk use the name of the module to look up + // symbols produced by dump_syms. dump_syms will prefer to use a module's + // DT_SONAME as the module name, if one exists, and will fall back to the + // filesystem name of the module. + + // Just use the filesystem name if no SONAME is present. + if (!ElfFileSoName(*this, mapping, file_name, file_name_size)) { + // file_path := /path/to/libname.so + // file_name := libname.so + const char* basename = my_strrchr(file_path, '/'); + basename = basename == NULL ? file_path : (basename + 1); + my_strlcpy(file_name, basename, file_name_size); + return; } - if (mapped_from_archive) { - // Some tools (e.g., stackwalk) extract the basename from the pathname. In - // this case, we append the file_name to the mapped archive path as follows: + if (mapping.exec && mapping.offset != 0) { + // If an executable is mapped from a non-zero offset, this is likely because + // the executable was loaded directly from inside an archive file (e.g., an + // apk on Android). + // In this case, we append the file_name to the mapped archive path: // file_name := libname.so // file_path := /path/to/ARCHIVE.APK/libname.so if (my_strlen(file_path) + 1 + my_strlen(file_name) < file_path_size) { @@ -493,12 +500,15 @@ void LinuxDumper::GetMappingEffectiveNameAndPath(const MappingInfo& mapping, my_strlcat(file_path, file_name, file_path_size); } } else { - // Common case: - // file_path := /path/to/libname.so - // file_name := libname.so - const char* basename = my_strrchr(file_path, '/'); - basename = basename == NULL ? file_path : (basename + 1); - my_strlcpy(file_name, basename, file_name_size); + // Otherwise, replace the basename with the SONAME. + char* basename = const_cast(my_strrchr(file_path, '/')); + if (basename) { + my_strlcpy(basename + 1, file_name, + file_path_size - my_strlen(file_path) + + my_strlen(basename + 1)); + } else { + my_strlcpy(file_path, file_name, file_path_size); + } } } diff --git a/src/common/linux/dump_symbols.cc b/src/common/linux/dump_symbols.cc index e561ad94..0eea2b54 100644 --- a/src/common/linux/dump_symbols.cc +++ b/src/common/linux/dump_symbols.cc @@ -963,13 +963,11 @@ bool InitModuleForElfClass(const typename ElfClass::Ehdr* elf_header, return false; } - string name; - char name_buf[NAME_MAX]; - memset(name_buf, 0, sizeof(name_buf)); - name = google_breakpad::ElfFileSoNameFromMappedFile(elf_header, name_buf, - sizeof(name_buf)) - ? name_buf - : google_breakpad::BaseName(obj_filename); + char name_buf[NAME_MAX] = {}; + std::string name = google_breakpad::ElfFileSoNameFromMappedFile( + elf_header, name_buf, sizeof(name_buf)) + ? name_buf + : google_breakpad::BaseName(obj_filename); // Add an extra "0" at the end. PDB files on Windows have an 'age' // number appended to the end of the file identifier; this isn't