michael@0: // Copyright (c) 2012, Google Inc.
michael@0: // All rights reserved.
michael@0: //
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: // notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: // copyright notice, this list of conditions and the following disclaimer
michael@0: // in the documentation and/or other materials provided with the
michael@0: // distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: // contributors may be used to endorse or promote products derived from
michael@0: // this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
michael@0: // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: //
michael@0: // elfutils.h: Utilities for dealing with ELF files.
michael@0: //
michael@0: 
michael@0: #ifndef COMMON_LINUX_ELFUTILS_H__
michael@0: #define COMMON_LINUX_ELFUTILS_H__
michael@0: 
michael@0: #include <elf.h>
michael@0: #include <link.h>
michael@0: #include <stdint.h>
michael@0: 
michael@0: namespace google_breakpad {
michael@0: 
michael@0: // Traits classes so consumers can write templatized code to deal
michael@0: // with specific ELF bits.
michael@0: struct ElfClass32 {
michael@0:   typedef Elf32_Addr Addr;
michael@0:   typedef Elf32_Ehdr Ehdr;
michael@0:   typedef Elf32_Nhdr Nhdr;
michael@0:   typedef Elf32_Phdr Phdr;
michael@0:   typedef Elf32_Shdr Shdr;
michael@0:   typedef Elf32_Half Half;
michael@0:   typedef Elf32_Off Off;
michael@0:   typedef Elf32_Word Word;
michael@0:   static const int kClass = ELFCLASS32;
michael@0:   static const size_t kAddrSize = sizeof(Elf32_Addr);
michael@0: };
michael@0: 
michael@0: struct ElfClass64 {
michael@0:   typedef Elf64_Addr Addr;
michael@0:   typedef Elf64_Ehdr Ehdr;
michael@0:   typedef Elf64_Nhdr Nhdr;
michael@0:   typedef Elf64_Phdr Phdr;
michael@0:   typedef Elf64_Shdr Shdr;
michael@0:   typedef Elf64_Half Half;
michael@0:   typedef Elf64_Off Off;
michael@0:   typedef Elf64_Word Word;
michael@0:   static const int kClass = ELFCLASS64;
michael@0:   static const size_t kAddrSize = sizeof(Elf64_Addr);
michael@0: };
michael@0: 
michael@0: bool IsValidElf(const void* elf_header);
michael@0: int ElfClass(const void* elf_base);
michael@0: 
michael@0: // Attempt to find a section named |section_name| of type |section_type|
michael@0: // in the ELF binary data at |elf_mapped_base|. On success, returns true
michael@0: // and sets |*section_start| to point to the start of the section data,
michael@0: // and |*section_size| to the size of the section's data. If |elfclass|
michael@0: // is not NULL, set |*elfclass| to the ELF file class.
michael@0: bool FindElfSection(const void *elf_mapped_base,
michael@0:                     const char *section_name,
michael@0:                     uint32_t section_type,
michael@0:                     const void **section_start,
michael@0:                     int *section_size,
michael@0:                     int *elfclass);
michael@0: 
michael@0: // Internal helper method, exposed for convenience for callers
michael@0: // that already have more info.
michael@0: template<typename ElfClass>
michael@0: const typename ElfClass::Shdr*
michael@0: FindElfSectionByName(const char* name,
michael@0:                      typename ElfClass::Word section_type,
michael@0:                      const typename ElfClass::Shdr* sections,
michael@0:                      const char* section_names,
michael@0:                      const char* names_end,
michael@0:                      int nsection);
michael@0: 
michael@0: // Attempt to find the first segment of type |segment_type| in the ELF
michael@0: // binary data at |elf_mapped_base|. On success, returns true and sets
michael@0: // |*segment_start| to point to the start of the segment data, and
michael@0: // and |*segment_size| to the size of the segment's data. If |elfclass|
michael@0: // is not NULL, set |*elfclass| to the ELF file class.
michael@0: bool FindElfSegment(const void *elf_mapped_base,
michael@0:                     uint32_t segment_type,
michael@0:                     const void **segment_start,
michael@0:                     int *segment_size,
michael@0:                     int *elfclass);
michael@0: 
michael@0: // Convert an offset from an Elf header into a pointer to the mapped
michael@0: // address in the current process. Takes an extra template parameter
michael@0: // to specify the return type to avoid having to dynamic_cast the
michael@0: // result.
michael@0: template<typename ElfClass, typename T>
michael@0: const T*
michael@0: GetOffset(const typename ElfClass::Ehdr* elf_header,
michael@0:           typename ElfClass::Off offset);
michael@0: 
michael@0: }  // namespace google_breakpad
michael@0: 
michael@0: #endif  // COMMON_LINUX_ELFUTILS_H__