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Re: [PATCHv2] Fix float128 IFUNC relocations on ppc64le [BZ #21707]
Nix <nix@esperi.org.uk> writes:
> On 8 Jul 2017, Tulio Magno Quites Machado Filho said this:
>
>> diff --git a/csu/libc-start.c b/csu/libc-start.c
>> index c2dd159..84b7f99 100644
>> --- a/csu/libc-start.c
>> +++ b/csu/libc-start.c
>> @@ -188,12 +188,15 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
>>
>> ARCH_INIT_CPU_FEATURES ();
>>
>> - /* Perform IREL{,A} relocations. */
>> - apply_irel ();
>> -
>> /* The stack guard goes into the TCB, so initialize it early. */
>> __libc_setup_tls ();
>>
>> + /* Perform IREL{,A} relocations.
>> + Note: the relocations must happen after TLS initialization so that
>> + IFUNC resolvers can benefit from thread-local storage, e.g. powerpc's
>> + hwcap and platform fields available in the TCB. */
>> + apply_irel ();
>> +
>> /* Set up the stack checker's canary. */
>> uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);
>> # ifdef THREAD_SET_STACK_GUARD
>
> Note: I originally moved this above __libc_setup_tls() so that IFUNCs
> could be stack-protected on statically-linked applications, but
> subsequently found that this caused trouble with dynamically-linked
> programs, so ended up de-protecting all the IFUNC resolvers anyway.
> (See commit 003a27e8195470f470f4d9384ca70d4e9fc8bd1b.)
>
> If this passes make check with --enable-stack-protector=all, I'm happy
> with it.
Tested and confirmed no new failures with --enable-stack-protector=all.
By the way, I noticed 2 unrelated failures:
https://sourceware.org/bugzilla/show_bug.cgi?id=21744
https://sourceware.org/bugzilla/show_bug.cgi?id=21745
--
Tulio Magno