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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/cpu-features.c | |
| parent | e6350be7e9cae8f71c96c1f06eab61b9acb227c8 (diff) | |
| download | glibc-0aac205a814a8511e98d02b91a8dc908f1c53cde.tar.gz glibc-0aac205a814a8511e98d02b91a8dc908f1c53cde.tar.xz glibc-0aac205a814a8511e98d02b91a8dc908f1c53cde.zip | |
x86: Update _dl_tlsdesc_dynamic to preserve caller-saved registers
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/cpu-features.c')
| -rw-r--r-- | sysdeps/x86/cpu-features.c | 56 |
1 files changed, 54 insertions, 2 deletions
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index 25e6622a79..835113b42f 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -27,8 +27,13 @@ extern void TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *) attribute_hidden; -#if defined SHARED && defined __x86_64__ -# include <dl-plt-rewrite.h> +#if defined SHARED +extern void _dl_tlsdesc_dynamic_fxsave (void) attribute_hidden; +extern void _dl_tlsdesc_dynamic_xsave (void) attribute_hidden; +extern void _dl_tlsdesc_dynamic_xsavec (void) attribute_hidden; + +# ifdef __x86_64__ +# include <dl-plt-rewrite.h> static void TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp) @@ -47,6 +52,15 @@ TUNABLE_CALLBACK (set_plt_rewrite) (tunable_val_t *valp) : plt_rewrite_jmp); } } +# else +extern void _dl_tlsdesc_dynamic_fnsave (void) attribute_hidden; +# endif +#endif + +#ifdef __x86_64__ +extern void _dl_runtime_resolve_fxsave (void) attribute_hidden; +extern void _dl_runtime_resolve_xsave (void) attribute_hidden; +extern void _dl_runtime_resolve_xsavec (void) attribute_hidden; #endif #ifdef __LP64__ @@ -1130,6 +1144,44 @@ no_cpuid: TUNABLE_CALLBACK (set_x86_shstk)); #endif + if (GLRO(dl_x86_cpu_features).xsave_state_size != 0) + { + if (CPU_FEATURE_USABLE_P (cpu_features, XSAVEC)) + { +#ifdef __x86_64__ + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_xsavec; +#endif +#ifdef SHARED + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_xsavec; +#endif + } + else + { +#ifdef __x86_64__ + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_xsave; +#endif +#ifdef SHARED + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_xsave; +#endif + } + } + else + { +#ifdef __x86_64__ + GLRO(dl_x86_64_runtime_resolve) = _dl_runtime_resolve_fxsave; +# ifdef SHARED + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fxsave; +# endif +#else +# ifdef SHARED + if (CPU_FEATURE_USABLE_P (cpu_features, FXSR)) + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fxsave; + else + GLRO(dl_x86_tlsdesc_dynamic) = _dl_tlsdesc_dynamic_fnsave; +# endif +#endif + } + #ifdef SHARED # ifdef __x86_64__ TUNABLE_GET (plt_rewrite, tunable_val_t *, |