The following commit has been merged into the x86/fpu branch of tip: Commit-ID: e70b100806d63fb79775858ea92e1a716da46186 Gitweb: https://git.kernel.org/tip/e70b100806d63fb79775858ea92e1a716da46186 Author: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> AuthorDate: Thu, 09 Jan 2020 13:14:52 -08:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Wed, 12 Feb 2020 15:43:34 +01:00 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@xxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200109211452.27369-4-yu-cheng.yu@xxxxxxxxx --- arch/x86/kernel/fpu/xstate.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index edcaacd..73fe597 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
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