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 <pra...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/exceptions-64s.S | 13 ++++++++++++-
arch/powerpc/mm/fault.c | 5 +++--
2 files changed, 15 insertions(+), 3 deletions(-)
Index: linux-2.6.ppc64_test/arch/powerpc/kernel/exceptions-64s.S
===================================================================
--- linux-2.6.ppc64_test.orig/arch/powerpc/kernel/exceptions-64s.S
+++ linux-2.6.ppc64_test/arch/powerpc/kernel/exceptions-64s.S
@@ -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_dabrma...@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_ISER
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
Index: linux-2.6.ppc64_test/arch/powerpc/mm/fault.c
===================================================================
--- linux-2.6.ppc64_test.orig/arch/powerpc/mm/fault.c
+++ linux-2.6.ppc64_test/arch/powerpc/mm/fault.c
@@ -151,13 +151,14 @@ int __kprobes do_page_fault(struct pt_re
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))
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