[PATCH 26/29] x86/fpu: Inline copy_user_to_fpregs_zeroing()

From: Sebastian Andrzej Siewior
Date: Wed Nov 28 2018 - 17:21:38 EST


Start refactoring __fpu__restore_sig() by inlining
copy_user_to_fpregs_zeroing().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
arch/x86/kernel/fpu/signal.c | 42 ++++++++++++++++--------------------
1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 6e516eeaea328..c66356b168b39 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -221,28 +221,6 @@ sanitize_restored_xstate(union fpregs_state *state,
}
}

-/*
- * Restore the extended state if present. Otherwise, restore the FP/SSE state.
- */
-static inline int copy_user_to_fpregs_zeroing(void __user *buf, u64 xbv, int fx_only)
-{
- if (use_xsave()) {
- if ((unsigned long)buf % 64 || fx_only) {
- u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE;
- copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
- return copy_user_to_fxregs(buf);
- } else {
- u64 init_bv = xfeatures_mask & ~xbv;
- if (unlikely(init_bv))
- copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
- return copy_user_to_xregs(buf, xbv);
- }
- } else if (use_fxsr()) {
- return copy_user_to_fxregs(buf);
- } else
- return copy_user_to_fregs(buf);
-}
-
static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
{
int ia32_fxstate = (buf != buf_fx);
@@ -321,11 +299,29 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
kfree(tmp);
return err;
} else {
+ int ret;
+
/*
* For 64-bit frames and 32-bit fsave frames, restore the user
* state to the registers directly (with exceptions handled).
*/
- if (copy_user_to_fpregs_zeroing(buf_fx, xfeatures, fx_only)) {
+ if (use_xsave()) {
+ if ((unsigned long)buf_fx % 64 || fx_only) {
+ u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE;
+ copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
+ ret = copy_user_to_fxregs(buf_fx);
+ } else {
+ u64 init_bv = xfeatures_mask & ~xfeatures;
+ if (unlikely(init_bv))
+ copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
+ ret = copy_user_to_xregs(buf_fx, xfeatures);
+ }
+ } else if (use_fxsr()) {
+ ret = copy_user_to_fxregs(buf_fx);
+ } else
+ ret = copy_user_to_fregs(buf_fx);
+
+ if (ret) {
fpu__clear(fpu);
return -1;
}
--
2.20.0.rc1