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x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing()

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Now that user_xfeatures is correctly set when xsave is enabled, remove
the duplicated initialization of components.

Rename the function while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210623121457.377341297@linutronix.de
This commit is contained in:
Thomas Gleixner 2021-06-23 14:02:28 +02:00 committed by Borislav Petkov
parent 1258a8c896
commit cdcec1b770
1 changed files with 14 additions and 20 deletions
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34
arch/x86/kernel/fpu/signal.c
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@ -251,33 +251,27 @@ sanitize_restored_user_xstate(union fpregs_state *state,
}
/*
* Restore the extended state if present. Otherwise, restore the FP/SSE state.
* Restore the FPU state directly from the userspace signal frame.
*/
static int copy_user_to_fpregs_zeroing(void __user *buf, u64 xbv, int fx_only)
static int restore_fpregs_from_user(void __user *buf, u64 xrestore, bool fx_only)
{
u64 init_bv;
int r;
if (use_xsave()) {
if (fx_only) {
init_bv = xfeatures_mask_uabi() & ~XFEATURE_MASK_FPSSE;
u64 init_bv = xfeatures_mask_uabi() & ~xrestore;
int ret;
r = fxrstor_from_user_sigframe(buf);
if (!r)
os_xrstor(&init_fpstate.xsave, init_bv);
return r;
} else {
init_bv = xfeatures_mask_uabi() & ~xbv;
if (likely(!fx_only))
ret = xrstor_from_user_sigframe(buf, xrestore);
else
ret = fxrstor_from_user_sigframe(buf);
r = xrstor_from_user_sigframe(buf, xbv);
if (!r && unlikely(init_bv))
os_xrstor(&init_fpstate.xsave, init_bv);
return r;
}
if (!ret && unlikely(init_bv))
os_xrstor(&init_fpstate.xsave, init_bv);
return ret;
} else if (use_fxsr()) {
return fxrstor_from_user_sigframe(buf);
} else
} else {
return frstor_from_user_sigframe(buf);
}
}
static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
@ -314,7 +308,7 @@ static int __fpu_restore_sig(void __user *buf, void __user *buf_fx,
*/
fpregs_lock();
pagefault_disable();
ret = copy_user_to_fpregs_zeroing(buf_fx, user_xfeatures, fx_only);
ret = restore_fpregs_from_user(buf_fx, user_xfeatures, fx_only);
pagefault_enable();
if (!ret) {