This is a note to let you know that I've just added the patch titled perf symbol: correction while adjusting symbol to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-symbol-correction-while-adjusting-symbol.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e3275a4d2a52819b29ee54b21b387f7495bf5eff Author: Ajay Kaher <akaher@xxxxxxxxxx> Date: Wed Nov 23 15:48:16 2022 +0530 perf symbol: correction while adjusting symbol [ Upstream commit 6f520ce17920b3cdfbd2479b3ccf27f9706219d0 ] perf doesn't provide proper symbol information for specially crafted .debug files. Sometimes .debug file may not have similar program header as runtime ELF file. For example if we generate .debug file using objcopy --only-keep-debug resulting file will not contain .text, .data and other runtime sections. That means corresponding program headers will have zero FileSiz and modified Offset. Example: program header of text section of libxxx.so: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x00000000003d3000 0x00000000003d3000 0x00000000003d3000 0x000000000055ae80 0x000000000055ae80 R E 0x1000 Same program header after executing: objcopy --only-keep-debug libxxx.so libxxx.so.debug LOAD 0x0000000000001000 0x00000000003d3000 0x00000000003d3000 0x0000000000000000 0x000000000055ae80 R E 0x1000 Offset and FileSiz have been changed. Following formula will not provide correct value, if program header taken from .debug file (syms_ss): sym.st_value -= phdr.p_vaddr - phdr.p_offset; Correct program header information is located inside runtime ELF file (runtime_ss). Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols") Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Alexey Makhalov <amakhalov@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Leo Yan <leo.yan@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Srivatsa S. Bhat <srivatsab@xxxxxxxxxx> Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Cc: Vasavi Sirnapalli <vsirnapalli@xxxxxxxxxx> Link: http://lore.kernel.org/lkml/1669198696-50547-1-git-send-email-akaher@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 6c183df191aa..fd42f768e584 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1292,7 +1292,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss, (!used_opd && syms_ss->adjust_symbols)) { GElf_Phdr phdr; - if (elf_read_program_header(syms_ss->elf, + if (elf_read_program_header(runtime_ss->elf, (u64)sym.st_value, &phdr)) { pr_debug4("%s: failed to find program header for " "symbol: %s st_value: %#" PRIx64 "\n",