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| author | H.J. Lu <hjl.tools@gmail.com> | 2024-02-26 06:37:03 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2024-02-28 09:02:56 -0800 |
| commit | 0aac205a814a8511e98d02b91a8dc908f1c53cde (patch) | |
| tree | e9ad8dfa06abd2f6d9b521bb95e9b7cfaa0d7de7 /sysdeps/x86/tst-gnu2-tls2.c | |
| parent | e6350be7e9cae8f71c96c1f06eab61b9acb227c8 (diff) | |
| download | glibc-master.tar glibc-master.tar.gz glibc-master.tar.bz2 glibc-master.zip | |
Compiler generates the following instruction sequence for GNU2 dynamic
TLS access:
leaq tls_var@TLSDESC(%rip), %rax
call *tls_var@TLSCALL(%rax)
or
leal tls_var@TLSDESC(%ebx), %eax
call *tls_var@TLSCALL(%eax)
CALL instruction is transparent to compiler which assumes all registers,
except for EFLAGS and RAX/EAX, are unchanged after CALL. When
_dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow
path. __tls_get_addr is a normal function which doesn't preserve any
caller-saved registers. _dl_tlsdesc_dynamic saved and restored integer
caller-saved registers, but didn't preserve any other caller-saved
registers. Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE,
XSAVE and XSAVEC to save and restore all caller-saved registers. This
fixes BZ #31372.
Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic)
to optimize elf_machine_runtime_setup.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Diffstat (limited to 'sysdeps/x86/tst-gnu2-tls2.c')
| -rw-r--r-- | sysdeps/x86/tst-gnu2-tls2.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/sysdeps/x86/tst-gnu2-tls2.c b/sysdeps/x86/tst-gnu2-tls2.c new file mode 100644 index 0000000000..de900a423b --- /dev/null +++ b/sysdeps/x86/tst-gnu2-tls2.c @@ -0,0 +1,20 @@ +#ifndef __x86_64__ +#include <sys/platform/x86.h> + +#define IS_SUPPORTED() CPU_FEATURE_ACTIVE (SSE2) +#endif + +/* Clear XMM0...XMM7 */ +#define PREPARE_MALLOC() \ +{ \ + asm volatile ("xorps %%xmm0, %%xmm0" : : : "xmm0" ); \ + asm volatile ("xorps %%xmm1, %%xmm1" : : : "xmm1" ); \ + asm volatile ("xorps %%xmm2, %%xmm2" : : : "xmm2" ); \ + asm volatile ("xorps %%xmm3, %%xmm3" : : : "xmm3" ); \ + asm volatile ("xorps %%xmm4, %%xmm4" : : : "xmm4" ); \ + asm volatile ("xorps %%xmm5, %%xmm5" : : : "xmm5" ); \ + asm volatile ("xorps %%xmm6, %%xmm6" : : : "xmm6" ); \ + asm volatile ("xorps %%xmm7, %%xmm7" : : : "xmm7" ); \ +} + +#include <elf/tst-gnu2-tls2.c> |