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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-11-06 17:25:42 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-11-21 16:15:42 -0300 |
| commit | 4862d546c04bd2caf496d48335a546c0a44ad4a5 (patch) | |
| tree | 3e8bbae532c3dcc5ff93dde172500467aaaaf1f5 /sysdeps/x86/cpu-tunables.c | |
| parent | eb9291aaa6ff6af158a1436b881ef8b834559621 (diff) | |
| download | glibc-4862d546c04bd2caf496d48335a546c0a44ad4a5.zip glibc-4862d546c04bd2caf496d48335a546c0a44ad4a5.tar.gz glibc-4862d546c04bd2caf496d48335a546c0a44ad4a5.tar.bz2 | |
x86: Use dl-symbol-redir-ifunc.h on cpu-tunables
The dl-symbol-redir-ifunc.h redirects compiler-generated libcalls to
arch-specific memory implementations to avoid ifunc calls where it is not
yet possible. The memcmp-isa-default-impl.h aims to fix the same issue
by calling the specific memset implementation directly.
Using the memcmp symbol directly allows the compiler to inline the memset
calls (especially because _dl_tunable_set_hwcaps uses constants values),
generating better code.
Checked on x86_64-linux-gnu.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diffstat (limited to 'sysdeps/x86/cpu-tunables.c')
| -rw-r--r-- | sysdeps/x86/cpu-tunables.c | 39 |
1 files changed, 12 insertions, 27 deletions
diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c index 0d4f328..5697885 100644 --- a/sysdeps/x86/cpu-tunables.c +++ b/sysdeps/x86/cpu-tunables.c @@ -24,24 +24,11 @@ #include <string.h> #include <cpu-features.h> #include <ldsodefs.h> - -/* We can't use IFUNC memcmp nor strlen in init_cpu_features from libc.a - since IFUNC must be set up by init_cpu_features. */ -#if defined USE_MULTIARCH && !defined SHARED -# ifdef __x86_64__ -/* DEFAULT_MEMCMP by sysdeps/x86_64/memcmp-isa-default-impl.h. */ -# include <sysdeps/x86_64/memcmp-isa-default-impl.h> -# else -# define DEFAULT_MEMCMP __memcmp_ia32 -# endif -extern __typeof (memcmp) DEFAULT_MEMCMP; -#else -# define DEFAULT_MEMCMP memcmp -#endif +#include <dl-symbol-redir-ifunc.h> #define CHECK_GLIBC_IFUNC_CPU_OFF(f, cpu_features, name, len) \ _Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \ - if (!DEFAULT_MEMCMP (f, #name, len)) \ + if (memcmp (f, #name, len) == 0) \ { \ CPU_FEATURE_UNSET (cpu_features, name) \ break; \ @@ -51,7 +38,7 @@ extern __typeof (memcmp) DEFAULT_MEMCMP; which isn't available. */ #define CHECK_GLIBC_IFUNC_PREFERRED_OFF(f, cpu_features, name, len) \ _Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \ - if (!DEFAULT_MEMCMP (f, #name, len)) \ + if (memcmp (f, #name, len) == 0) \ { \ cpu_features->preferred[index_arch_##name] \ &= ~bit_arch_##name; \ @@ -62,7 +49,7 @@ extern __typeof (memcmp) DEFAULT_MEMCMP; #define CHECK_GLIBC_IFUNC_PREFERRED_BOTH(f, cpu_features, name, \ disable, len) \ _Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \ - if (!DEFAULT_MEMCMP (f, #name, len)) \ + if (memcmp (f, #name, len) == 0) \ { \ if (disable) \ cpu_features->preferred[index_arch_##name] &= ~bit_arch_##name; \ @@ -76,7 +63,7 @@ extern __typeof (memcmp) DEFAULT_MEMCMP; #define CHECK_GLIBC_IFUNC_PREFERRED_NEED_BOTH(f, cpu_features, name, \ need, disable, len) \ _Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \ - if (!DEFAULT_MEMCMP (f, #name, len)) \ + if (memcmp (f, #name, len) == 0) \ { \ if (disable) \ cpu_features->preferred[index_arch_##name] &= ~bit_arch_##name; \ @@ -177,7 +164,7 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp) CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, POPCNT, 6); CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSE4_1, 6); CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSE4_2, 6); - if (!DEFAULT_MEMCMP (n, "XSAVEC", 6)) + if (memcmp (n, "XSAVEC", 6) == 0) { /* Update xsave_state_size to XSAVE state size. */ cpu_features->xsave_state_size @@ -290,12 +277,11 @@ attribute_hidden void TUNABLE_CALLBACK (set_x86_ibt) (tunable_val_t *valp) { - if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0) + if (memcmp (valp->strval, "on", sizeof ("on")) == 0) GL(dl_x86_feature_control).ibt = cet_always_on; - else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0) + else if (memcmp (valp->strval, "off", sizeof ("off")) == 0) GL(dl_x86_feature_control).ibt = cet_always_off; - else if (DEFAULT_MEMCMP (valp->strval, "permissive", - sizeof ("permissive")) == 0) + else if (memcmp (valp->strval, "permissive", sizeof ("permissive")) == 0) GL(dl_x86_feature_control).ibt = cet_permissive; } @@ -303,12 +289,11 @@ attribute_hidden void TUNABLE_CALLBACK (set_x86_shstk) (tunable_val_t *valp) { - if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0) + if (memcmp (valp->strval, "on", sizeof ("on")) == 0) GL(dl_x86_feature_control).shstk = cet_always_on; - else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0) + else if (memcmp (valp->strval, "off", sizeof ("off")) == 0) GL(dl_x86_feature_control).shstk = cet_always_off; - else if (DEFAULT_MEMCMP (valp->strval, "permissive", - sizeof ("permissive")) == 0) + else if (memcmp (valp->strval, "permissive", sizeof ("permissive")) == 0) GL(dl_x86_feature_control).shstk = cet_permissive; } #endif |