[IA64] Remove getting break_num by decoding instruction

break.b always sets cr.iim to 0 and the current code tries to
get the break_num by decoding instruction. However, their
seems to be a race condition while reading the regs->cr_iip,
as on other cpu the break.b at regs->cr_iip might have been
replaced with the original instruction as a result of
unregister_kprobe() and hence decoding instruction to
obtain break_num will result in wrong value in this case.

Also includes changes to kprobes.c which now has to handle
break number zero.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 801eeaeaf3de..2895d6e6062f 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -740,7 +740,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
         switch(val) {
         case DIE_BREAK:
                 /* err is break number from ia64_bad_break() */
-                if (args->err == 0x80200 || args->err == 0x80300)
+                if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0)
                         if (pre_kprobes_handler(args))
                                 ret = NOTIFY_STOP;
                 break;