diff options
author | Stefan Liebler <stli@linux.ibm.com> | 2023-02-02 14:57:50 +0100 |
---|---|---|
committer | Stefan Liebler <stli@linux.ibm.com> | 2023-02-07 09:19:27 +0100 |
commit | 41f67ccbe92b4fd09e1062b383e55e407ae5bfa1 (patch) | |
tree | dfda0fd844157445add9ab30f59eeea659b38dcc /sysdeps/s390/multiarch/ifunc-impl-list.c | |
parent | 0b9d2d4a76508fdcbd9f421cdd98bf324c22af3c (diff) | |
download | glibc-41f67ccbe92b4fd09e1062b383e55e407ae5bfa1.tar.gz glibc-41f67ccbe92b4fd09e1062b383e55e407ae5bfa1.tar.xz glibc-41f67ccbe92b4fd09e1062b383e55e407ae5bfa1.zip |
S390: Influence hwcaps/stfle via GLIBC_TUNABLES.
This patch enables the option to influence hwcaps and stfle bits used by the s390 specific ifunc-resolvers. The currently x86-specific tunable glibc.cpu.hwcaps is also used on s390x to achieve the task. In addition the user can also set a CPU arch-level like z13 instead of single HWCAP and STFLE features. Note that the tunable only handles the features which are really used in the IFUNC-resolvers. All others are ignored as the values are only used inside glibc. Thus we can influence: - HWCAP_S390_VXRS (z13) - HWCAP_S390_VXRS_EXT (z14) - HWCAP_S390_VXRS_EXT2 (z15) - STFLE_MIE3 (z15) The influenced hwcap/stfle-bits are stored in the s390-specific cpu_features struct which also contains reserved fields for future usage. The ifunc-resolvers and users of stfle bits are adjusted to use the information from cpu_features struct. On 31bit, the ELF_MACHINE_IRELATIVE macro is now also defined. Otherwise the new ifunc-resolvers segfaults as they depend on the not yet processed_rtld_global_ro@GLIBC_PRIVATE relocation.
Diffstat (limited to 'sysdeps/s390/multiarch/ifunc-impl-list.c')
-rw-r--r-- | sysdeps/s390/multiarch/ifunc-impl-list.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/sysdeps/s390/multiarch/ifunc-impl-list.c b/sysdeps/s390/multiarch/ifunc-impl-list.c index fd6b596bdf..1532258af2 100644 --- a/sysdeps/s390/multiarch/ifunc-impl-list.c +++ b/sysdeps/s390/multiarch/ifunc-impl-list.c @@ -19,6 +19,7 @@ #include <assert.h> #include <string.h> #include <wchar.h> +#include <cpu-features.h> #include <ifunc-impl-list.h> #include <ifunc-resolve.h> #include <ifunc-memset.h> @@ -78,14 +79,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, size_t i __attribute__ ((unused)) = max; /* Get hardware information. */ - unsigned long int dl_hwcap = GLRO (dl_hwcap); - unsigned long long stfle_bits = 0ULL; - if ((dl_hwcap & HWCAP_S390_STFLE) - && (dl_hwcap & HWCAP_S390_ZARCH) - && (dl_hwcap & HWCAP_S390_HIGH_GPRS)) - { - S390_STORE_STFLE (stfle_bits); - } + const struct cpu_features *features = &GLRO(dl_s390_cpu_features); + unsigned long int dl_hwcap = features->hwcap; + const unsigned long long * __attribute__((unused)) stfle_bits + = features->stfle_bits; #if HAVE_MEMSET_IFUNC IFUNC_IMPL (i, name, memset, |