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| author | H.J. Lu <hjl.tools@gmail.com> | 2021-01-26 20:48:45 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2021-01-29 03:58:11 -0800 |
| commit | 04dff6fc0d4ad44fc4491f89fed6574380b78251 (patch) | |
| tree | f90662c888d04e6323ab67a8035ff42a49394425 /sysdeps/x86/cpu-features.c | |
| parent | 6032ae6514d2c8d47246f96626b5d8adc218b92d (diff) | |
| download | glibc-04dff6fc0d4ad44fc4491f89fed6574380b78251.tar.gz glibc-04dff6fc0d4ad44fc4491f89fed6574380b78251.tar.xz glibc-04dff6fc0d4ad44fc4491f89fed6574380b78251.zip | |
x86: Properly set usable CET feature bits [BZ #26625]
commit 94cd37ebb293321115a36a422b091fdb72d2fb08
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Sep 16 05:27:32 2020 -0700
x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625]
broke
GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with:
1. Revert commit 94cd37ebb293321115a36a422b091fdb72d2fb08.
2. Clears the usable CET feature bits if kernel doesn't support CET.
3. Add GLIBC_TUNABLES tests without dlopen.
4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches
_get_ssp.
5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled
with GLIBC_TUNABLES.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/x86/cpu-features.c')
| -rw-r--r-- | sysdeps/x86/cpu-features.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index 6496512a0d..73b0a4dc9a 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -75,6 +75,7 @@ update_usable (struct cpu_features *cpu_features) CPU_FEATURE_SET_USABLE (cpu_features, PREFETCHWT1); CPU_FEATURE_SET_USABLE (cpu_features, OSPKE); CPU_FEATURE_SET_USABLE (cpu_features, WAITPKG); + CPU_FEATURE_SET_USABLE (cpu_features, SHSTK); CPU_FEATURE_SET_USABLE (cpu_features, GFNI); CPU_FEATURE_SET_USABLE (cpu_features, RDPID); CPU_FEATURE_SET_USABLE (cpu_features, RDRAND); @@ -84,6 +85,7 @@ update_usable (struct cpu_features *cpu_features) CPU_FEATURE_SET_USABLE (cpu_features, FSRM); CPU_FEATURE_SET_USABLE (cpu_features, SERIALIZE); CPU_FEATURE_SET_USABLE (cpu_features, TSXLDTRK); + CPU_FEATURE_SET_USABLE (cpu_features, IBT); CPU_FEATURE_SET_USABLE (cpu_features, LAHF64_SAHF64); CPU_FEATURE_SET_USABLE (cpu_features, LZCNT); CPU_FEATURE_SET_USABLE (cpu_features, SSE4A); @@ -705,6 +707,11 @@ no_cpuid: /* Check CET status. */ unsigned int cet_status = get_cet_status (); + if ((cet_status & GNU_PROPERTY_X86_FEATURE_1_IBT) == 0) + CPU_FEATURE_UNSET (cpu_features, IBT) + if ((cet_status & GNU_PROPERTY_X86_FEATURE_1_SHSTK) == 0) + CPU_FEATURE_UNSET (cpu_features, SHSTK) + if (cet_status) { GL(dl_x86_feature_1) = cet_status; @@ -720,9 +727,9 @@ no_cpuid: GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK */ unsigned int cet_feature = 0; - if (!HAS_CPU_FEATURE (IBT)) + if (!CPU_FEATURE_USABLE (IBT)) cet_feature |= GNU_PROPERTY_X86_FEATURE_1_IBT; - if (!HAS_CPU_FEATURE (SHSTK)) + if (!CPU_FEATURE_USABLE (SHSTK)) cet_feature |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; if (cet_feature) |