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| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2020-01-09 13:14:52 -0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-02-12 15:43:34 +0100 |
| commit | e70b100806d63fb79775858ea92e1a716da46186 (patch) | |
| tree | ab9fcc22a0c0f9c48f0138b6efe1296b08cfb69b | |
| parent | 49a91d61aed1db01097b51a24c77137eb348a0bf (diff) | |
| download | linux-e70b100806d63fb79775858ea92e1a716da46186.tar.gz linux-e70b100806d63fb79775858ea92e1a716da46186.tar.bz2 linux-e70b100806d63fb79775858ea92e1a716da46186.zip | |
x86/fpu/xstate: Warn when checking alignment of disabled xfeatures
An XSAVES component's alignment/offset is meaningful only when the
feature is enabled. Return zero and WARN_ONCE on checking alignment of
disabled features.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20200109211452.27369-4-yu-cheng.yu@intel.com
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index edcaacd583d8..73fe5979629c 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -325,6 +325,13 @@ static int xfeature_is_aligned(int xfeature_nr) u32 eax, ebx, ecx, edx; CHECK_XFEATURE(xfeature_nr); + + if (!xfeature_enabled(xfeature_nr)) { + WARN_ONCE(1, "Checking alignment of disabled xfeature %d\n", + xfeature_nr); + return 0; + } + cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); /* * The value returned by ECX[1] indicates the alignment |