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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/dl-procinfo.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/dl-procinfo.c')
-rw-r--r-- | sysdeps/s390/dl-procinfo.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/sysdeps/s390/dl-procinfo.c b/sysdeps/s390/dl-procinfo.c index 52fb6ac488..a6b61e8523 100644 --- a/sysdeps/s390/dl-procinfo.c +++ b/sysdeps/s390/dl-procinfo.c @@ -21,5 +21,42 @@ /* Needed by sysdeps/unix/sysv/linux/dl-vdso-setup.c (as included from sysdeps/generic/ldsodefs.h). */ + +/* All the #ifdefs in the definitions are quite irritating but + necessary if we want to avoid duplicating the information. There + are three different modes: + + - PROCINFO_DECL is defined. This means we are only interested in + declarations. + + - PROCINFO_DECL is not defined: + + + if SHARED is defined the file is included in an array + initializer. The .element = { ... } syntax is needed. + + + if SHARED is not defined a normal array initialization is + needed. + */ + +#ifndef PROCINFO_CLASS +# define PROCINFO_CLASS +#endif + +#if !IS_IN (ldconfig) +# if !defined PROCINFO_DECL && defined SHARED + ._dl_s390_cpu_features +# else +PROCINFO_CLASS struct cpu_features _dl_s390_cpu_features +# endif +# ifndef PROCINFO_DECL += { } +# endif +# if !defined SHARED || defined PROCINFO_DECL +; +# else +, +# endif +#endif + #undef PROCINFO_DECL #undef PROCINFO_CLASS |