diff options
Diffstat (limited to 'compiler-rt/lib/sanitizer_common/sanitizer_linux.cc')
| -rw-r--r-- | compiler-rt/lib/sanitizer_common/sanitizer_linux.cc | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc index bbc41f471bb..4b6373661c7 100644 --- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc +++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc @@ -29,6 +29,7 @@ #include <dlfcn.h> #include <errno.h> #include <fcntl.h> +#include <link.h> #include <pthread.h> #include <sched.h> #include <sys/mman.h> @@ -638,6 +639,42 @@ bool LibraryNameIs(const char *full_name, const char *base_name) { return (name[base_name_length] == '-' || name[base_name_length] == '.'); } +// Call cb for each region mapped by map. +void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) { + typedef ElfW(Phdr) Elf_Phdr; + typedef ElfW(Ehdr) Elf_Ehdr; + char *base = (char *)map->l_addr; + Elf_Ehdr *ehdr = (Elf_Ehdr *)base; + char *phdrs = base + ehdr->e_phoff; + char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize; + + // Find the segment with the minimum base so we can "relocate" the p_vaddr + // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC + // objects have a non-zero base. + uptr preferred_base = ~0ULL; + for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { + Elf_Phdr *phdr = (Elf_Phdr *)iter; + if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr) + preferred_base = (uptr)phdr->p_vaddr; + } + + // Compute the delta from the real base to get a relocation delta. + sptr delta = (uptr)base - preferred_base; + // Now we can figure out what the loader really mapped. + for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { + Elf_Phdr *phdr = (Elf_Phdr *)iter; + if (phdr->p_type == PT_LOAD) { + uptr seg_start = phdr->p_vaddr + delta; + uptr seg_end = seg_start + phdr->p_memsz; + // None of these values are aligned. We consider the ragged edges of the + // load command as defined, since they are mapped from the file. + seg_start = RoundDownTo(seg_start, GetPageSizeCached()); + seg_end = RoundUpTo(seg_end, GetPageSizeCached()); + cb((void *)seg_start, seg_end - seg_start); + } + } +} + } // namespace __sanitizer #endif // SANITIZER_LINUX |
