Messages in this thread | | | Date | Thu, 17 Sep 2020 17:16:20 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] objtool: ignore unreachable trap after call to noreturn functions |
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On Thu, Sep 17, 2020 at 11:49:04AM +0300, Ilie Halip wrote: > With CONFIG_UBSAN_TRAP enabled, the compiler may insert a trap instruction > after a call to a noreturn function. In this case, objtool warns that the > ud2 instruction is unreachable. > > objtool silences similar warnings (trap after dead end instructions), so > expand that check to include dead end functions. > > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: Rong Chen <rong.a.chen@intel.com> > Cc: Marco Elver <elver@google.com> > Cc: Philip Li <philip.li@intel.com> > Cc: Borislav Petkov <bp@alien8.de> > Cc: kasan-dev@googlegroups.com > Cc: x86@kernel.org > Cc: clang-built-linux@googlegroups.com > BugLink: https://github.com/ClangBuiltLinux/linux/issues/1148 > Link: https://lore.kernel.org/lkml/CAKwvOdmptEpi8fiOyWUo=AiZJiX+Z+VHJOM2buLPrWsMTwLnyw@mail.gmail.com > Suggested-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
The patch looks good to me. Which versions of Clang do the trap after noreturn call? It would be good to have that in the commit message.
-- Josh
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