From 5060b91513b866f774da15dfd82157864c4b1683 Mon Sep 17 00:00:00 2001 From: Yu-cheng Yu Date: Mon, 11 Jul 2016 09:18:55 -0700 Subject: [PATCH] x86/fpu/xstate: Return NULL for disabled xstate component address It is an error to request a disabled XSAVE/XSAVES component address. For that case, make __raw_xsave_addr() return a NULL and issue a warning. Signed-off-by: Yu-cheng Yu Signed-off-by: Fenghua Yu Reviewed-by: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Ravi V Shankar Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1468253937-40008-3-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/xstate.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index f8d1aff10f69..4fb8dd7697c5 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -760,6 +760,11 @@ void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask) { int feature_nr = fls64(xstate_feature_mask) - 1; + if (!xfeature_enabled(feature_nr)) { + WARN_ON_FPU(1); + return NULL; + } + return (void *)xsave + xstate_comp_offsets[feature_nr]; } /* -- 2.30.2