Commit 3d703477 authored by Eric Biggers's avatar Eric Biggers Committed by Ingo Molnar

x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate()

We now have this field in hdr.xfeatures.
Signed-off-by: default avatarEric 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.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent af2c4322
...@@ -1197,7 +1197,6 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) ...@@ -1197,7 +1197,6 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf)
{ {
unsigned int offset, size; unsigned int offset, size;
int i; int i;
u64 xfeatures;
u64 allowed_features; u64 allowed_features;
struct xstate_header hdr; struct xstate_header hdr;
...@@ -1207,20 +1206,18 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) ...@@ -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)) if (__copy_from_user(&hdr, ubuf + offset, size))
return -EFAULT; return -EFAULT;
xfeatures = hdr.xfeatures;
/* /*
* Reject if the user sets any disabled or supervisor features: * Reject if the user sets any disabled or supervisor features:
*/ */
allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR; allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
if (xfeatures & ~allowed_features) if (hdr.xfeatures & ~allowed_features)
return -EINVAL; return -EINVAL;
for (i = 0; i < XFEATURE_MAX; i++) { for (i = 0; i < XFEATURE_MAX; i++) {
u64 mask = ((u64)1 << i); u64 mask = ((u64)1 << i);
if (xfeatures & mask) { if (hdr.xfeatures & mask) {
void *dst = __raw_xsave_addr(xsave, 1 << i); void *dst = __raw_xsave_addr(xsave, 1 << i);
offset = xstate_offsets[i]; offset = xstate_offsets[i];
...@@ -1231,7 +1228,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) ...@@ -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); offset = offsetof(struct fxregs_state, mxcsr);
size = MXCSR_AND_FLAGS_SIZE; size = MXCSR_AND_FLAGS_SIZE;
if (__copy_from_user(&xsave->i387.mxcsr, ubuf + offset, 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) ...@@ -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: * Add back in the features that came in from userspace:
*/ */
xsave->header.xfeatures |= xfeatures; xsave->header.xfeatures |= hdr.xfeatures;
return 0; return 0;
} }
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