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Commit 6aa6dbfc authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar
Browse files

x86/fpu: Get rid of x87 math exception helpers 



... and integrate their functionality into their single user
fpu__exception_code().

No functionality change.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459837795-2588-7-git-send-email-bp@alien8.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent de82fbc3

arch/x86/kernel/fpu/core.c

+13 −31
Original line number Diff line number Diff line
@@ -506,33 +506,6 @@ void fpu__clear(struct fpu *fpu) 
 * x87 math exception handling:

 */



static inline unsigned short get_fpu_cwd(struct fpu *fpu)

{

	if (boot_cpu_has(X86_FEATURE_FXSR)) {

		return fpu->state.fxsave.cwd;

	} else {

		return (unsigned short)fpu->state.fsave.cwd;

	}

}



static inline unsigned short get_fpu_swd(struct fpu *fpu)

{

	if (boot_cpu_has(X86_FEATURE_FXSR)) {

		return fpu->state.fxsave.swd;

	} else {

		return (unsigned short)fpu->state.fsave.swd;

	}

}



static inline unsigned short get_fpu_mxcsr(struct fpu *fpu)

{

	if (boot_cpu_has(X86_FEATURE_XMM)) {

		return fpu->state.fxsave.mxcsr;

	} else {

		return MXCSR_DEFAULT;

	}

}



int fpu__exception_code(struct fpu *fpu, int trap_nr)

{

	int err;
@@ -547,10 +520,15 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr) 
		 * so if this combination doesn't produce any single exception,

		 * then we have a bad program that isn't synchronizing its FPU usage

		 * and it will suffer the consequences since we won't be able to

		 * fully reproduce the context of the exception

		 * fully reproduce the context of the exception.

		 */

		cwd = get_fpu_cwd(fpu);

		swd = get_fpu_swd(fpu);

		if (boot_cpu_has(X86_FEATURE_FXSR)) {

			cwd = fpu->state.fxsave.cwd;

			swd = fpu->state.fxsave.swd;

		} else {

			cwd = (unsigned short)fpu->state.fsave.cwd;

			swd = (unsigned short)fpu->state.fsave.swd;

		}



		err = swd & ~cwd;

	} else {
@@ -560,7 +538,11 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr) 
		 * unmasked exception was caught we must mask the exception mask bits

		 * at 0x1f80, and then use these to mask the exception bits at 0x3f.

		 */

		unsigned short mxcsr = get_fpu_mxcsr(fpu);

		unsigned short mxcsr = MXCSR_DEFAULT;



		if (boot_cpu_has(X86_FEATURE_XMM))

			mxcsr = fpu->state.fxsave.mxcsr;



		err = ~(mxcsr >> 7) & mxcsr;

	}