Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | Re: [PATCH] tools/objtool: tolerate STT_NOTYPE symbols at end of section | Date | Tue, 20 Dec 2022 14:21:48 +0000 |
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Le 20/12/2022 à 11:13, Nicholas Piggin a écrit : > 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.
There's a patch to solve this already as far as I understand. They seem different.
See https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20221208072813.25799-1-sv@linux.ibm.com/
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > tools/objtool/check.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > 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; >
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