From cad90e5381d840cf2296aaac9b3eff71a30b7c5b Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 20 Dec 2022 20:13:23 +1000 Subject: objtool: Tolerate STT_NOTYPE symbols at end of section Hand-written asm often contains non-function symbols in executable sections. _end symbols for finding the size of instruction blocks for runtime processing is one such usage. optprobe_template_end is one example that causes the warning: objtool: optprobe_template_end(): can't find starting instruction This is because the symbol happens to be at the end of the file (and therefore end of a section in the object file). So ignore end-of-section STT_NOTYPE symbols instead of bailing out because an instruction can't be found. While we're here, add a more descriptive warning for STT_FUNC symbols found at the end of a section. [ This also solves a PowerPC regression reported by Sathvika Vasireddy. ] Reported-by: Naveen N. Rao Reported-by: Sathvika Vasireddy Signed-off-by: Nicholas Piggin Signed-off-by: Ingo Molnar Acked-by: Sathvika Vasireddy Link: https://lore.kernel.org/r/20221220101323.3119939-1-npiggin@gmail.com --- tools/objtool/check.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'tools') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4350be739f4f..4b7c8b33069e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -427,6 +427,15 @@ static int decode_instructions(struct objtool_file *file) if (func->type != STT_NOTYPE && func->type != STT_FUNC) continue; + if (func->offset == sec->sh.sh_size) { + /* Heuristic: likely an "end" symbol */ + if (func->type == STT_NOTYPE) + continue; + WARN("%s(): STT_FUNC at end of section", + func->name); + return -1; + } + if (func->return_thunk || func->alias != func) continue; -- cgit v1.2.3