Commit e0d3602f authored Apr 03, 2019 by Sebastian Andrzej Siewior Committed by Borislav Petkov Apr 11, 2019

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@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-21-bigeasy@linutronix.de

parent 0d714dba

arch/x86/kernel/fpu/signal.c

+19 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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