glibc/elf/tst-gnu2-tls2mod0.c
Adhemerval Zanella a8ba52bde5 arm: Update _dl_tlsdesc_dynamic to preserve caller-saved registers (BZ 31372)
ARM _dl_tlsdesc_dynamic slow path has two issues:

  * The ip/r12 is defined by AAPCS as a scratch register, and gcc is
    used to save the stack pointer before on some function calls.  So it
    should also be saved/restored as well.  It fixes the tst-gnu2-tls2.

  * None of the possible VFP registers are saved/restored.  ARM has the
    additional complexity to have different VFP bank sizes (depending of
    VFP support by the chip).

The tst-gnu2-tls2 test is extended to check for VFP registers, although
only for hardfp builds.  Different than setcontext, _dl_tlsdesc_dynamic
does not have  HWCAP_ARM_IWMMXT (I don't have a way to properly test
it and it is almost a decade since newer hardware was released).

With this patch there is no need to mark tst-gnu2-tls2 as XFAIL.

Checked on arm-linux-gnueabihf.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

(cherry picked from commit 64c7e34428)
2024-04-01 11:16:27 -07:00

33 lines
1.1 KiB
C

/* DSO used by tst-gnu2-tls2.
Copyright (C) 2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <tst-gnu2-tls2.h>
__thread struct tls tls_var0 __attribute__ ((visibility ("hidden")));
struct tls *
apply_tls (struct tls *p)
{
INIT_TLSDESC_CALL ();
BEFORE_TLSDESC_CALL ();
tls_var0 = *p;
struct tls *ret = &tls_var0;
AFTER_TLSDESC_CALL ();
return ret;
}