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Commit 9c7cc234 authored by K.Prasad's avatar K.Prasad Committed by Benjamin Herrenschmidt
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powerpc: Disable interrupts for data breakpoint exceptions 



Data address breakpoint exceptions are currently handled along with page-faults
which require interrupts to remain in enabled state. Since exception handling
for data breakpoints aren't pre-empt safe, we handle them separately.

Signed-off-by: default avatarK.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 578b7cd1

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

+12 −1
Original line number Original line Diff line number Diff line
@@ -735,8 +735,11 @@ _STATIC(do_hash_page) 
	std	r3,_DAR(r1)

	std	r3,_DAR(r1)

	std	r4,_DSISR(r1)

	std	r4,_DSISR(r1)





	andis.	r0,r4,0xa450		/* weird error? */

	andis.	r0,r4,0xa410		/* weird error? */

	bne-	handle_page_fault	/* if not, try to insert a HPTE */

	bne-	handle_page_fault	/* if not, try to insert a HPTE */

	andis.  r0,r4,DSISR_DABRMATCH@h

	bne-    handle_dabr_fault



BEGIN_FTR_SECTION

BEGIN_FTR_SECTION

	andis.	r0,r4,0x0020		/* Is it a segment table fault? */

	andis.	r0,r4,0x0020		/* Is it a segment table fault? */

	bne-	do_ste_alloc		/* If so handle it */

	bne-	do_ste_alloc		/* If so handle it */
@@ -823,6 +826,14 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES) 
	bl	.raw_local_irq_restore

	bl	.raw_local_irq_restore

	b	11f

	b	11f





/* We have a data breakpoint exception - handle it */

handle_dabr_fault:

	ld      r4,_DAR(r1)

	ld      r5,_DSISR(r1)

	addi    r3,r1,STACK_FRAME_OVERHEAD

	bl      .do_dabr

	b       .ret_from_except_lite



/* Here we have a page fault that hash_page can't handle. */

/* Here we have a page fault that hash_page can't handle. */

handle_page_fault:

handle_page_fault:

	ENABLE_INTS

	ENABLE_INTS

arch/powerpc/mm/fault.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -151,13 +151,14 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, 
	if (!user_mode(regs) && (address >= TASK_SIZE))

	if (!user_mode(regs) && (address >= TASK_SIZE))

		return SIGSEGV;

		return SIGSEGV;





#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))

#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || \

			     defined(CONFIG_PPC_BOOK3S_64))

  	if (error_code & DSISR_DABRMATCH) {

  	if (error_code & DSISR_DABRMATCH) {

		/* DABR match */

		/* DABR match */

		do_dabr(regs, address, error_code);

		do_dabr(regs, address, error_code);

		return 0;

		return 0;

	}

	}

#endif /* !(CONFIG_4xx || CONFIG_BOOKE)*/

#endif





	if (in_atomic() || mm == NULL) {

	if (in_atomic() || mm == NULL) {

		if (!user_mode(regs))

		if (!user_mode(regs))