Messages in this thread | | | From | Nick Desaulniers <> | Date | Fri, 27 Sep 2019 13:24:50 -0700 | Subject | Re: [PATCH 00/22] x86, objtool: several fixes/improvements |
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On Thu, Jul 18, 2019 at 3:26 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Tue, Jul 16, 2019 at 4:17 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > > > > > 2) There's also an issue in clang where a large switch table had a bunch > > > > > of unused (bad) entries. It's not a code correctness issue, but > > > > > hopefully it can get fixed in clang anyway. See patch 20/22 for more > > > > > details. > > > > > > Thanks for the report, let's follow up on steps for me to reproduce. > > > > Just to clarify, there are two clang issues. Both of them were reported > > originally by Arnd, IIRC. > > > > 1) The one described above and in patch 20, where the switch table is > > mostly unused entries. Not a real bug, but it's a bit sloppy and > > wasteful, and objtool doesn't know how to interpret it. > > Thanks for the concise reports. Will follow up on these in: > https://github.com/ClangBuiltLinux/linux/issues/611
Following up on this one; in one of the test cases we determined that the default destination of an exhaustive switch wasn't getting cleaned up properly, and is being fixed in: https://reviews.llvm.org/D68131 https://bugs.llvm.org/show_bug.cgi?id=43129 I'm not sure that was the precise issue you described, or if there's more than one bug here, but hopefully it will help.
> > > > > 2) The bug with the noreturn call site having a different stack size > > depending on which code path was taken. > > and: > https://github.com/ClangBuiltLinux/linux/issues/612 -- Thanks, ~Nick Desaulniers
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