From cdcec1b77001e7f2cd10dccfc6d9b6d5d3f1f3ea Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 23 Jun 2021 14:02:28 +0200 Subject: x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing() 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 Signed-off-by: Borislav Petkov Reviewed-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210623121457.377341297@linutronix.de --- arch/x86/kernel/fpu/signal.c | 36 +++++++++++++++--------------------- 1 file changed, 15 insertions(+), 21 deletions(-) (limited to 'arch/x86/kernel/fpu/signal.c') diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index d55241038871..a1a70134e1fe 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -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; - - r = xrstor_from_user_sigframe(buf, xbv); - if (!r && unlikely(init_bv)) - os_xrstor(&init_fpstate.xsave, init_bv); - return r; - } + if (likely(!fx_only)) + ret = xrstor_from_user_sigframe(buf, xrestore); + else + ret = fxrstor_from_user_sigframe(buf); + + 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) { -- cgit v1.2.3