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 | 12 ++++++++++++
arch/powerpc/mm/fault.c | 2 +-
2 files changed, 13 insertions(+), 1 deletion(-)
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
@@ -735,6 +735,9 @@ _STATIC(do_hash_page)
std r3,_DAR(r1)
std r4,_DSISR(r1)
+ andis. r0,r4,0x0040 /* Data Address Breakpoint match? */
+ bne- handle_dabr_fault
+
andis. r0,r4,0xa450 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
BEGIN_FTR_SECTION
@@ -823,6 +826,15 @@ 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:
+ /* Populate the pt_regs structure */
+ 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
@@ -151,7 +151,7 @@ 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_PPC64))
if (error_code & DSISR_DABRMATCH) {
/* DABR match */
do_dabr(regs, address, error_code);
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
