From e0d3602f933367881bddfff310a744e6e61c284c Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 3 Apr 2019 18:41:49 +0200 Subject: [PATCH] x86/fpu: Inline copy_user_to_fpregs_zeroing() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Start refactoring __fpu__restore_sig() by inlining copy_user_to_fpregs_zeroing(). The original function remains and will be used to restore from userland memory if possible. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Reviewed-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: Andy Lutomirski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: "Jason A. Donenfeld" Cc: kvm ML Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Rik van Riel Cc: x86-ml Link: https://lkml.kernel.org/r/20190403164156.19645-21-bigeasy@linutronix.de --- arch/x86/kernel/fpu/signal.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 9b9dfdc96285..c2ff43fbbd07 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -337,11 +337,29 @@ 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; } -- 2.30.2