Commit-ID: e0d3602f933367881bddfff310a744e6e61c284c Gitweb: https://git.kernel.org/tip/e0d3602f933367881bddfff310a744e6e61c284c Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> AuthorDate: Wed, 3 Apr 2019 18:41:49 +0200 Committer: Borislav Petkov <bp@xxxxxxx> CommitDate: Thu, 11 Apr 2019 20:45:20 +0200 x86/fpu: Inline copy_user_to_fpregs_zeroing() 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 <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Cc: kvm ML <kvm@xxxxxxxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: x86-ml <x86@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20190403164156.19645-21-bigeasy@xxxxxxxxxxxxx --- 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; }
