Re: objtool crashes on clang output (drivers/hwmon/pmbus/adm1275.o)

From: Nick Desaulniers
Date: Tue Jul 16 2019 - 16:24:40 EST


On Fri, Jul 12, 2019 at 1:41 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Fri, Jul 12, 2019 at 6:59 PM 'Nick Desaulniers' via Clang Built
> Linux <clang-built-linux@xxxxxxxxxxxxxxxx> wrote:
> > > The issue still needs to get fixed in clang regardless. There are other
> > > noreturn functions in the kernel and this problem could easily pop back
> > > up.
> >
> > Sure, thanks for the report. Arnd, can you help us get a more minimal
> > test case to understand the issue better?
>
> I reduced it to this testcase:
>
> int a, b;
> void __reiserfs_panic(int, ...) __attribute__((noreturn));
> void balance_internal() {
> if (a)
> __reiserfs_panic(0, "", __func__, "", 2, __func__, a);
> if (b)
> __reiserfs_panic(0, "", __func__, "", 5, __func__, a, 0);
> }
>
> https://godbolt.org/z/Byfvmx

Is this the same issue as Josh pointed out? IIUC, Josh pointed to a
jump destination that was past a `push %rbp`, and I don't see it in
your link. (Or, did I miss it?)
--
Thanks,
~Nick Desaulniers