From ad00fed942a9a04cf3f46784bbd04a5f00dd4ab8 Mon Sep 17 00:00:00 2001 From: Andreas Gampe Date: Wed, 10 Dec 2014 20:51:45 -0800 Subject: [PATCH] ART: More ELF and oat file safety measures In an ELF file, look for a shstrtab section when loading in program-header-only mode. If the section is outside the file size, it strongly indicates a broken compile. When compiling oat files in the class linker, explicitly unlink on failure. This should catch cases when dex2oat is killed or crashes and doesn't have a chance to delete its (partial) output. Bug: 15567083 Change-Id: Ia0c75f151d91c6f26a71696967255d6d409ca882 --- runtime/class_linker.cc | 10 +++++++++- runtime/elf_file.cc | 14 ++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc index fb93a6e60..bf1963be7 100644 --- a/runtime/class_linker.cc +++ b/runtime/class_linker.cc @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -645,7 +646,14 @@ bool ClassLinker::GenerateOatFile(const char* dex_filename, argv.push_back(compiler_options[i].c_str()); } - return Exec(argv, error_msg); + if (!Exec(argv, error_msg)) { + // Manually delete the file. Ensures there is no garbage left over if the process unexpectedly + // died. Ignore unlink failure, propagate the original error. + TEMP_FAILURE_RETRY(unlink(oat_cache_filename)); + return false; + } + + return true; } const OatFile* ClassLinker::RegisterOatFile(const OatFile* oat_file) { diff --git a/runtime/elf_file.cc b/runtime/elf_file.cc index 6ec0712f0..29628f1e0 100644 --- a/runtime/elf_file.cc +++ b/runtime/elf_file.cc @@ -432,6 +432,20 @@ bool ElfFile::CheckSectionsExist(std::string* error_msg) const { return false; } + // We'd also like to confirm a shstrtab in program_header_only_ mode (else Open() does this for + // us). This is usually the last in an oat file, and a good indicator of whether writing was + // successful (or the process crashed and left garbage). + if (program_header_only_) { + // It might not be mapped, but we can compare against the file size. + int64_t offset = static_cast(GetHeader().e_shoff + + (GetHeader().e_shstrndx * GetHeader().e_shentsize)); + if (offset >= file_->GetLength()) { + *error_msg = StringPrintf("Shstrtab is not in the mapped ELF file: '%s'", + file_->GetPath().c_str()); + return false; + } + } + return true; } -- 2.11.0