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x86/fpu: Split copy_user_to_xstate() into copy_kernel_to_xstate() & copy_user_to_xstate()

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  x86/fpu: Split copy_xstate_to_user() into copy_xstate_to_kernel() & copy_xstate_to_user()

No change in functionality.

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: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-12-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2017-09-23 14:59:54 +02:00
parent 8c0817f4a3
commit 79fecc2b75
3 changed files with 74 additions and 6 deletions
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66
arch/x86/kernel/fpu/xstate.c
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@@ -1084,7 +1084,71 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
}
/*
* Convert from a ptrace standard-format buffer to kernel XSAVES format
* Convert from a ptrace standard-format kernel buffer to kernel XSAVES format
* and copy to the target thread. This is called from xstateregs_set() and
* there we check the CPU has XSAVES and a whole standard-sized buffer
* exists.
*/
int copy_kernel_to_xstate(const void *kbuf, const void __user *ubuf,
struct xregs_state *xsave)
{
unsigned int offset, size;
int i;
u64 xfeatures;
u64 allowed_features;
offset = offsetof(struct xregs_state, header);
size = sizeof(xfeatures);
if (kbuf) {
memcpy(&xfeatures, kbuf + offset, size);
} else {
if (__copy_from_user(&xfeatures, ubuf + offset, size))
return -EFAULT;
}
/*
* Reject if the user sets any disabled or supervisor features:
*/
allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
if (xfeatures & ~allowed_features)
return -EINVAL;
for (i = 0; i < XFEATURE_MAX; i++) {
u64 mask = ((u64)1 << i);
if (xfeatures & mask) {
void *dst = __raw_xsave_addr(xsave, 1 << i);
offset = xstate_offsets[i];
size = xstate_sizes[i];
if (kbuf) {
memcpy(dst, kbuf + offset, size);
} else {
if (__copy_from_user(dst, ubuf + offset, size))
return -EFAULT;
}
}
}
/*
* The state that came in from userspace was user-state only.
* Mask all the user states out of 'xfeatures':
*/
xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
/*
* Add back in the features that came in from userspace:
*/
xsave->header.xfeatures |= xfeatures;
return 0;
}
/*
* Convert from a ptrace standard-format user-space buffer to kernel XSAVES format
* and copy to the target thread. This is called from xstateregs_set() and
* there we check the CPU has XSAVES and a whole standard-sized buffer
* exists.