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Commit a73ad333 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86: unify the implementation of FPU traps 



On 32 bits, we may suffer IRQ 13, or supposedly we might have a buggy
implementation which gives spurious trap 16.  We did not check for
this on 64 bits, but there is no reason we can't make the code the
same in both cases.  Furthermore, this is presumably rare, so do the
spurious check last, instead of first.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 1fcccb00

arch/x86/kernel/traps.c

+4 −7
Original line number Diff line number Diff line
@@ -689,12 +689,7 @@ void math_error(void __user *ip) 
	cwd = get_fpu_cwd(task);

	swd = get_fpu_swd(task);



	err = swd & ~cwd & 0x3f;



#ifdef CONFIG_X86_32

	if (!err)

		return;

#endif

	err = swd & ~cwd;



	if (err & 0x001) {	/* Invalid op */

		/*
@@ -712,7 +707,9 @@ void math_error(void __user *ip) 
	} else if (err & 0x020) { /* Precision */

		info.si_code = FPE_FLTRES;

	} else {

		info.si_code = __SI_FAULT|SI_KERNEL; /* WTF? */

		/* If we're using IRQ 13, or supposedly even some trap 16

		   implementations, it's possible we get a spurious trap... */

		return;		/* Spurious trap, no error */

	}

	force_sig_info(SIGFPE, &info, task);

}