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authorEric Biggers <ebiggers@google.com>2017-09-24 12:59:11 +0200
committerIngo Molnar <mingo@kernel.org>2017-09-26 09:43:48 +0200
commit3d703477bcfe8bb57079d97198cf1e342fe1fef9 (patch)
treeb531392801d72bb200f49859e9d1fc7eb09e593a /arch
parentaf2c4322d986a08a6e793b74b83a62b325019c20 (diff)
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 <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-9-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/fpu/xstate.c11
1 files changed, 4 insertions, 7 deletions
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;
}