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Commit 9f2f79e3 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

powerpc: Disable interrupts in 64-bit kernel FP and vector faults 



If we get a floating point, altivec or vsx unavaible interrupt in
kernel, we trigger a kernel error. There is no point preserving
the interrupt state, in fact, that can even make debugging harder
as the processor state might change (we may even preempt) between
taking the exception and landing in a debugger.

So just make those 3 disable interrupts unconditionally.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
---

v2: On BookE only disable when hitting the kernel unavailable
    path, otherwise it will fail to restore softe as
    fast_exception_return doesn't do it.
parent a546498f

arch/powerpc/kernel/exceptions-64e.S

+3 −4
Original line number Diff line number Diff line
@@ -354,9 +354,9 @@ interrupt_end_book3e: 
	/* we can probably do a shorter exception entry for that one... */

	EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)

	bne	1f			/* if from user, just load it up */

	INTS_DISABLE_ALL

	bl	.save_nvgprs

	addi	r3,r1,STACK_FRAME_OVERHEAD

	INTS_RESTORE_HARD

	bl	.kernel_fp_unavailable_exception

	BUG_OPCODE

1:	ld	r12,_MSR(r1)
@@ -391,10 +391,9 @@ interrupt_end_book3e: 
/* Auxiliary Processor Unavailable Interrupt */

	START_EXCEPTION(ap_unavailable);

	NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)

	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)

	addi	r3,r1,STACK_FRAME_OVERHEAD

	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_DISABLE_ALL)

	bl	.save_nvgprs

	INTS_RESTORE_HARD

	addi	r3,r1,STACK_FRAME_OVERHEAD

	bl	.unknown_exception

	b	.ret_from_except

arch/powerpc/kernel/exceptions-64s.S

+3 −3
Original line number Diff line number Diff line
@@ -762,8 +762,8 @@ fp_unavailable_common: 
	EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)

	bne	1f			/* if from user, just load it up */

	bl	.save_nvgprs

	DISABLE_INTS

	addi	r3,r1,STACK_FRAME_OVERHEAD

	ENABLE_INTS

	bl	.kernel_fp_unavailable_exception

	BUG_OPCODE

1:	bl	.load_up_fpu
@@ -782,8 +782,8 @@ BEGIN_FTR_SECTION 
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)

#endif

	bl	.save_nvgprs

	DISABLE_INTS

	addi	r3,r1,STACK_FRAME_OVERHEAD

	ENABLE_INTS

	bl	.altivec_unavailable_exception

	b	.ret_from_except
@@ -798,8 +798,8 @@ BEGIN_FTR_SECTION 
END_FTR_SECTION_IFSET(CPU_FTR_VSX)

#endif

	bl	.save_nvgprs

	DISABLE_INTS

	addi	r3,r1,STACK_FRAME_OVERHEAD

	ENABLE_INTS

	bl	.vsx_unavailable_exception

	b	.ret_from_except

arch/powerpc/kernel/traps.c

+3 −0
Original line number Diff line number Diff line
@@ -247,6 +247,9 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) 
				   addr, regs->nip, regs->link, code);

	}



	if (!arch_irq_disabled_regs(regs))

		local_irq_enable();



	memset(&info, 0, sizeof(info));

	info.si_signo = signr;

	info.si_code = code;