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author | Stefan Liebler <stli@linux.ibm.com> | 2023-02-02 14:57:50 +0100 |
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committer | Stefan Liebler <stli@linux.ibm.com> | 2023-02-07 09:19:27 +0100 |
commit | 41f67ccbe92b4fd09e1062b383e55e407ae5bfa1 (patch) | |
tree | dfda0fd844157445add9ab30f59eeea659b38dcc /sysdeps/s390/s390-64 | |
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/s390-64')
-rw-r--r-- | sysdeps/s390/s390-64/dl-machine.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sysdeps/s390/s390-64/dl-machine.h b/sysdeps/s390/s390-64/dl-machine.h index 10b1f00052..9fabb09750 100644 --- a/sysdeps/s390/s390-64/dl-machine.h +++ b/sysdeps/s390/s390-64/dl-machine.h @@ -29,6 +29,7 @@ #include <dl-irel.h> #include <dl-static-tls.h> #include <dl-machine-rel.h> +#include <cpu-features.c> #define ELF_MACHINE_IRELATIVE R_390_IRELATIVE @@ -220,6 +221,13 @@ dl_platform_init (void) if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0') /* Avoid an empty string which would disturb us. */ GLRO(dl_platform) = NULL; + +#ifdef SHARED + /* init_cpu_features has been called early from __libc_start_main in + static executable. */ + init_cpu_features (&GLRO(dl_s390_cpu_features)); +#endif + } static inline Elf64_Addr |