perf/hw_breakpoint: Pass new breakpoint type to modify_breakpoint_slot()

We soon won't be able to rely on bp->attr anymore to get the new
type of the modifying breakpoint because the new attributes are going
to be copied only once we successfully modified the breakpoint slot.

This will fix the current misdesigned layout where the new attr are
copied to the modifying breakpoint before we actually know if the
modification will be validated.

In order to prepare for that, allow modify_breakpoint_slot() to take
the new breakpoint type.

Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 5 insertions, 5 deletions

diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index e7bc8d0a5972..71387703b5f1 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -345,13 +345,13 @@ void release_bp_slot(struct perf_event *bp)
 	mutex_unlock(&nr_bp_mutex);
 }
 
-static int __modify_bp_slot(struct perf_event *bp, u64 old_type)
+static int __modify_bp_slot(struct perf_event *bp, u64 old_type, u64 new_type)
 {
 	int err;
 
 	__release_bp_slot(bp, old_type);
 
-	err = __reserve_bp_slot(bp, bp->attr.bp_type);
+	err = __reserve_bp_slot(bp, new_type);
 	if (err) {
 		/*
 		 * Reserve the old_type slot back in case
@@ -367,12 +367,12 @@ static int __modify_bp_slot(struct perf_event *bp, u64 old_type)
 	return err;
 }
 
-static int modify_bp_slot(struct perf_event *bp, u64 old_type)
+static int modify_bp_slot(struct perf_event *bp, u64 old_type, u64 new_type)
 {
 	int ret;
 
 	mutex_lock(&nr_bp_mutex);
-	ret = __modify_bp_slot(bp, old_type);
+	ret = __modify_bp_slot(bp, old_type, new_type);
 	mutex_unlock(&nr_bp_mutex);
 	return ret;
 }
@@ -481,7 +481,7 @@ modify_user_hw_breakpoint_check(struct perf_event *bp, struct perf_event_attr *a
 
 	err = hw_breakpoint_parse(bp, attr, &hw);
 	if (!err && modify)
-		err = modify_bp_slot(bp, old_type);
+		err = modify_bp_slot(bp, old_type, bp->attr.bp_type);
 
 	if (err) {
 		bp->attr.bp_addr = old_addr;