diff --git a/libunwind/src/AddressSpace.hpp b/libunwind/src/AddressSpace.hpp --- a/libunwind/src/AddressSpace.hpp +++ b/libunwind/src/AddressSpace.hpp @@ -497,32 +497,40 @@ #if !defined(Elf_Phdr) typedef ElfW(Phdr) Elf_Phdr; #endif +#if !defined(Elf_Addr) + typedef ElfW(Addr) Elf_Addr; +#endif + + Elf_Addr image_base = pinfo->dlpi_addr; + +#if defined(__ANDROID__) && __ANDROID_API__ < 18 + if (image_base == 0) { + // Normally, an image base of 0 indicates a non-PIE executable. On + // versions of Android prior to API 18, the dynamic linker reported a + // dlpi_addr of 0 for PIE executables. Compute the true image base + // using the PT_PHDR segment. + // See https://github.com/android/ndk/issues/505. + for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) { + const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i]; + if (phdr->p_type == PT_PHDR) { + image_base = reinterpret_cast(pinfo->dlpi_phdr) - + phdr->p_vaddr; + break; + } + } + } +#endif #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) #if !defined(_LIBUNWIND_SUPPORT_DWARF_INDEX) #error "_LIBUNWIND_SUPPORT_DWARF_UNWIND requires _LIBUNWIND_SUPPORT_DWARF_INDEX on this platform." #endif size_t object_length; -#if defined(__ANDROID__) -#if !defined(Elf_Addr) - typedef ElfW(Addr) Elf_Addr; -#endif - Elf_Addr image_base = - pinfo->dlpi_phnum - ? reinterpret_cast(pinfo->dlpi_phdr) - - reinterpret_cast(pinfo->dlpi_phdr) - ->p_offset - : 0; -#endif for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) { const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i]; if (phdr->p_type == PT_LOAD) { - uintptr_t begin = pinfo->dlpi_addr + phdr->p_vaddr; -#if defined(__ANDROID__) - if (pinfo->dlpi_addr == 0 && phdr->p_vaddr < image_base) - begin = begin + image_base; -#endif + uintptr_t begin = image_base + phdr->p_vaddr; uintptr_t end = begin + phdr->p_memsz; if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) { cbdata->sects->dso_base = begin; @@ -531,11 +539,7 @@ } } else if (phdr->p_type == PT_GNU_EH_FRAME) { EHHeaderParser::EHHeaderInfo hdrInfo; - uintptr_t eh_frame_hdr_start = pinfo->dlpi_addr + phdr->p_vaddr; -#if defined(__ANDROID__) - if (pinfo->dlpi_addr == 0 && phdr->p_vaddr < image_base) - eh_frame_hdr_start = eh_frame_hdr_start + image_base; -#endif + uintptr_t eh_frame_hdr_start = image_base + phdr->p_vaddr; cbdata->sects->dwarf_index_section = eh_frame_hdr_start; cbdata->sects->dwarf_index_section_length = phdr->p_memsz; found_hdr = EHHeaderParser::decodeEHHdr( @@ -556,12 +560,12 @@ for (Elf_Half i = 0; i < pinfo->dlpi_phnum; i++) { const Elf_Phdr *phdr = &pinfo->dlpi_phdr[i]; if (phdr->p_type == PT_LOAD) { - uintptr_t begin = pinfo->dlpi_addr + phdr->p_vaddr; + uintptr_t begin = image_base + phdr->p_vaddr; uintptr_t end = begin + phdr->p_memsz; if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) found_obj = true; } else if (phdr->p_type == PT_ARM_EXIDX) { - uintptr_t exidx_start = pinfo->dlpi_addr + phdr->p_vaddr; + uintptr_t exidx_start = image_base + phdr->p_vaddr; cbdata->sects->arm_section = exidx_start; cbdata->sects->arm_section_length = phdr->p_memsz; found_hdr = true;