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powerpc: Disable interrupts for data breakpoint exceptions

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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: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
K.Prasad 2010-03-29 23:59:25 +00:00 committed by Benjamin Herrenschmidt
parent 578b7cd151
commit 9c7cc234dc
2 changed files with 15 additions and 3 deletions
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13
arch/powerpc/kernel/exceptions-64s.S
View file

@ -735,8 +735,11 @@ _STATIC(do_hash_page)
std r3,_DAR(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 */
andis. r0,r4,DSISR_DABRMATCH@h
bne- handle_dabr_fault
BEGIN_FTR_SECTION
andis. r0,r4,0x0020 /* Is it a segment table fault? */
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
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. */
handle_page_fault:
ENABLE_INTS

5
arch/powerpc/mm/fault.c
View file

@ -151,13 +151,14 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
if (!user_mode(regs) && (address >= TASK_SIZE))
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) {
/* DABR match */
do_dabr(regs, address, error_code);
return 0;
}
#endif /* !(CONFIG_4xx || CONFIG_BOOKE)*/
#endif
if (in_atomic() || mm == NULL) {
if (!user_mode(regs))