The glibc-hwcaps subdirectories are extended by "z17". Libraries are loaded if
the z17 facility bits are active:
- Miscellaneous-instruction-extensions facility 4
- Vector-enhancements-facility 3
- Vector-Packed-Decimal-Enhancement Facility 3
- CPU: Concurrent-Functions Facility
tst-glibc-hwcaps.c is extended in order to test z17 via new marker6.
In case of running on a z17 with a kernel not recognizing z17 yet,
AT_PLATFORM will be z900 but vector-bit in AT_HWCAP is set. This situation
is now recognized and this testcase does not fail.
A fatal glibc error is dumped if glibc was build with architecture
level set for z17, but run on an older machine (See dl-hwcap-check.h).
Note, you might get an SIGILL before this check if you don't use:
configure --with-rtld-early-cflags=-march=<older-machine>
ld.so --list-diagnostics now also dumps information about s390.cpu_features.
Independent from z17, the s390x kernel won't introduce new HWCAP-Bits if there
is no special handling needed in kernel itself. For z17, we don't have new
HWCAP flags, but have to check the facility bits retrieved by
stfle-instruction.
Instead of storing all the stfle-bits (currently four 64bit values) in the
cpu_features struct, we now only store those bits, which are needed within
glibc itself. Note that we have this list twice, one with original values and
the other one which can be filtered with GLIBC_TUNABLES=glibc.cpu.hwcaps.
Those new fields are stored in so far reserved space in cpu_features struct.
Thus processes started in between the update of glibc package and we e.g. have
a new ld.so and an old libc.so, won't crash. The glibc internal ifunc-resolvers
would not select the best optimized variant.
The users of stfle-bits are also updated:
- parsing of GLIBC_TUNABLES=glibc.cpu.hwcaps
- glibc internal ifunc-resolvers
- __libc_ifunc_impl_list
- sysconf
Remove unused _dl_hwcap_string defines. As a result many dl-procinfo.h headers
can be removed. This also removes target specific _dl_procinfo implementations
which only printed HWCAP strings using dl_hwcap_string.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
This patch adds support to query cache information on s390
via sysconf() function - e.g. with _SC_LEVEL1_ICACHE_SIZE.
The attributes size, linesize and assoc can be queried
for cache level 1 - 4 via "extract cpu attribute" instruction,
which was first available with z10.
* NEWS: Mention sysconf() cache information support for s390.
* sysdeps/unix/sysv/linux/s390/sysconf.c: New File.
