Author: GeorgeHuyubo Date: 2025-01-07T10:31:18-08:00 New Revision: a15fedc399d5d1aa07c14531e5cd8d3efc583600
URL: https://github.com/llvm/llvm-project/commit/a15fedc399d5d1aa07c14531e5cd8d3efc583600 DIFF: https://github.com/llvm/llvm-project/commit/a15fedc399d5d1aa07c14531e5cd8d3efc583600.diff LOG: [lldb] Correct address calculation for reading segment data (#120655) This commit addresses a bug introduced in commit bcf654c, which prevented LLDB from parsing the GNU build ID for the main executable from a core file. The fix finds the `p_vaddr` of the first `PT_LOAD` segment as the `base_addr` and subtract this `base_addr` from the virtual address being read. Co-authored-by: George Hu <hy...@meta.com> Added: Modified: lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp index b3916cc913f7db..5f85f99ce7bddc 100644 --- a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp +++ b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp @@ -1031,6 +1031,8 @@ UUID ProcessElfCore::FindBuidIdInCoreMemory(lldb::addr_t address) { std::vector<uint8_t> ph_bytes; ph_bytes.resize(elf_header.e_phentsize); + lldb::addr_t base_addr = 0; + bool found_first_load_segment = false; for (unsigned int i = 0; i < elf_header.e_phnum; ++i) { byte_read = ReadMemory(ph_addr + i * elf_header.e_phentsize, ph_bytes.data(), elf_header.e_phentsize, error); @@ -1041,6 +1043,11 @@ UUID ProcessElfCore::FindBuidIdInCoreMemory(lldb::addr_t address) { offset = 0; elf::ELFProgramHeader program_header; program_header.Parse(program_header_data, &offset); + if (program_header.p_type == llvm::ELF::PT_LOAD && + !found_first_load_segment) { + base_addr = program_header.p_vaddr; + found_first_load_segment = true; + } if (program_header.p_type != llvm::ELF::PT_NOTE) continue; @@ -1049,7 +1056,7 @@ UUID ProcessElfCore::FindBuidIdInCoreMemory(lldb::addr_t address) { // We need to slide the address of the p_vaddr as these values don't get // relocated in memory. - const lldb::addr_t vaddr = program_header.p_vaddr + address; + const lldb::addr_t vaddr = program_header.p_vaddr + address - base_addr; byte_read = ReadMemory(vaddr, note_bytes.data(), program_header.p_memsz, error); if (byte_read != program_header.p_memsz) _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
