[IA64] kprobes: fixup the pagefault exception caused by probehandlers

If the user-specified kprobe handler causes the page fault when accessing
user space address, fixup this fault since do_page_fault() should not
continue as the kprobe handler are run with preemption disabled.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 320cb7a91c9d..169ec3a7156c 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -771,6 +771,12 @@ static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
                  */
                 if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
                         return 1;
+                /*
+                 * In case the user-specified fault handler returned
+                 * zero, try to fix up.
+                 */
+                if (ia64_done_with_exception(regs))
+                        return 1;
 
                 /*
                  * Let ia64_do_page_fault() fix it.