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In <sys/platform/x86.h>, define CPU features as enum instead of using the C preprocessor magic to make it easier to wrap this functionality in other languages. Move the C preprocessor magic to internal header for better GCC codegen when more than one features are checked in a single expression as in x86-64 dl-hwcaps-subdirs.c. 1. Rename COMMON_CPUID_INDEX_XXX to CPUID_INDEX_XXX. 2. Move CPUID_INDEX_MAX to sysdeps/x86/include/cpu-features.h. 3. Remove struct cpu_features and __x86_get_cpu_features from <sys/platform/x86.h>. 4. Add __x86_get_cpuid_feature_leaf to <sys/platform/x86.h> and put it in libc. 5. Make __get_cpu_features() private to glibc. 6. Replace __x86_get_cpu_features(N) with __get_cpu_features(). 7. Add _dl_x86_get_cpu_features to GLIBC_PRIVATE. 8. Use a single enum index for each CPU feature detection. 9. Pass the CPUID feature leaf to __x86_get_cpuid_feature_leaf. 10. Return zero struct cpuid_feature for the older glibc binary with a smaller CPUID_INDEX_MAX [BZ #27104]. 11. Inside glibc, use the C preprocessor magic so that cpu_features data can be loaded just once leading to more compact code for glibc. 256 bits are used for each CPUID leaf. Some leaves only contain a few features. We can add exceptions to such leaves. But it will increase code sizes and it is harder to provide backward/forward compatibilities when new features are added to such leaves in the future. When new leaves are added, _rtld_global_ro offsets will change which leads to race condition during in-place updates. We may avoid in-place updates by 1. Rename the old glibc. 2. Install the new glibc. 3. Remove the old glibc. NB: A function, __x86_get_cpuid_feature_leaf , is used to avoid the copy relocation issue with IFUNC resolver as shown in IFUNC resolver tests.
104 lines
2.9 KiB
C
104 lines
2.9 KiB
C
/* Check ISA level on dlopened shared object.
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Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <elf.h>
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#include <get-isa-level.h>
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#include <support/xdlfcn.h>
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#include <support/check.h>
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#include <support/test-driver.h>
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static void
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do_test_1 (const char *modname, bool fail)
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{
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int (*fp) (void);
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void *h;
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h = dlopen (modname, RTLD_LAZY);
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if (h == NULL)
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{
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const char *err = dlerror ();
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if (fail)
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{
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if (strstr (err, "CPU ISA level is lower than required") == NULL)
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FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
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return;
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}
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FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
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}
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if (fail)
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FAIL_EXIT1 ("dlopen '%s' should have failed\n", modname);
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fp = xdlsym (h, "test");
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if (fp () != 0)
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FAIL_EXIT1 ("test () != 0\n");
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dlclose (h);
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}
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static int
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do_test (void)
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{
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const struct cpu_features *cpu_features = __get_cpu_features ();
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unsigned int isa_level = get_isa_level (cpu_features);
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bool has_isa_baseline = ((isa_level & GNU_PROPERTY_X86_ISA_1_BASELINE)
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== GNU_PROPERTY_X86_ISA_1_BASELINE);
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bool has_isa_v2 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V2)
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== GNU_PROPERTY_X86_ISA_1_V2);
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bool has_isa_v3 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V3)
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== GNU_PROPERTY_X86_ISA_1_V3);
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bool has_isa_v4 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V4)
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== GNU_PROPERTY_X86_ISA_1_V4);
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if (!has_isa_baseline)
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{
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do_test_1 ("tst-isa-level-mod-1-baseline.so", true);
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return EXIT_SUCCESS;
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}
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do_test_1 ("tst-isa-level-mod-1-baseline.so", false);
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/* Skip on x86-64-v4 platforms since dlopen v4 module always works. */
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if (has_isa_v4)
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return EXIT_SUCCESS;
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do_test_1 ("tst-isa-level-mod-1-v4.so", true);
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/* Skip on x86-64-v3 platforms since dlopen v3 module always works. */
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if (has_isa_v3)
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return EXIT_SUCCESS;
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do_test_1 ("tst-isa-level-mod-1-v3.so", true);
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/* Skip on x86-64-v2 platforms since dlopen v2 module always works. */
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if (has_isa_v2)
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return EXIT_SUCCESS;
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do_test_1 ("tst-isa-level-mod-1-v2.so", true);
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return EXIT_SUCCESS;
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}
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#include <support/test-driver.c>
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