| commit | 41f67ccbe92b4fd09e1062b383e55e407ae5bfa1 | |
| author | Stefan Liebler <stli@linux.ibm.com> | |
| Thu, 2 Feb 2023 13:57:50 +0000 (2 14:57 +0100) | ||
| committer | Stefan Liebler <stli@linux.ibm.com> | |
| Tue, 7 Feb 2023 08:19:27 +0000 (7 09:19 +0100) | ||
| tree | dfda0fd844157445add9ab30f59eeea659b38dcc | treesnapshot (tar.gz zip) |
| parent | 0b9d2d4a76508fdcbd9f421cdd98bf324c22af3c | commitdiff |
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.
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.
12 files changed: