glibc/sysdeps/s390/dl-diagnostics-cpu.c

38 lines
1.4 KiB
C
Raw Permalink Normal View History

S390: Add new s390 platform z17. 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
2025-04-29 11:28:58 +00:00
/* Print CPU diagnostics data in ld.so. s390 version.
Copyright (C) 2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <dl-diagnostics.h>
#include <ldsodefs.h>
#include <cpu-features.h>
static void
print_cpu_features_value (const char *label, uint64_t value)
{
_dl_printf ("s390.cpu_features.");
_dl_diagnostics_print_labeled_value (label, value);
}
void
_dl_diagnostics_cpu (void)
{
const struct cpu_features *cpu_features = &GLRO(dl_s390_cpu_features);
print_cpu_features_value ("hwcap", cpu_features->hwcap);
print_cpu_features_value ("stfle_orig", cpu_features->stfle_orig);
print_cpu_features_value ("stfle_filtered", cpu_features->stfle_filtered);
}