From 3d703477bcfe8bb57079d97198cf1e342fe1fef9 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 24 Sep 2017 12:59:11 +0200 Subject: x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate() We now have this field in hdr.xfeatures. Signed-off-by: Eric Biggers Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Fenghua Yu Cc: Kees Cook Cc: Kevin Hao Cc: Linus Torvalds Cc: Michael Halcrow Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Wanpeng Li Cc: Yu-cheng Yu Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-9-mingo@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/xstate.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0cd7b73c25e8..b6d78b78b5c2 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1197,7 +1197,6 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) { unsigned int offset, size; int i; - u64 xfeatures; u64 allowed_features; struct xstate_header hdr; @@ -1207,20 +1206,18 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) if (__copy_from_user(&hdr, ubuf + offset, size)) return -EFAULT; - xfeatures = hdr.xfeatures; - /* * Reject if the user sets any disabled or supervisor features: */ allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR; - if (xfeatures & ~allowed_features) + if (hdr.xfeatures & ~allowed_features) return -EINVAL; for (i = 0; i < XFEATURE_MAX; i++) { u64 mask = ((u64)1 << i); - if (xfeatures & mask) { + if (hdr.xfeatures & mask) { void *dst = __raw_xsave_addr(xsave, 1 << i); offset = xstate_offsets[i]; @@ -1231,7 +1228,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) } } - if (xfeatures_mxcsr_quirk(xfeatures)) { + if (xfeatures_mxcsr_quirk(hdr.xfeatures)) { offset = offsetof(struct fxregs_state, mxcsr); size = MXCSR_AND_FLAGS_SIZE; if (__copy_from_user(&xsave->i387.mxcsr, ubuf + offset, size)) @@ -1247,7 +1244,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) /* * Add back in the features that came in from userspace: */ - xsave->header.xfeatures |= xfeatures; + xsave->header.xfeatures |= hdr.xfeatures; return 0; } -- cgit v1.2.3