[parch] sched: task_times() explosion avoidance for tasks with >2^32 acrued ticks

[Mike Galbraith]

If stime + utime > 2^32, and lower 32 are 0 when user calls getrusage(),
you've got a dead box.

Signed-off-by: Mike Galbraith <efault@xxxxxx>

 kernel/sched/core.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 82ad284..0ac2cac 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3151,7 +3151,7 @@ void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 	 */
 	rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
 
-	if (total) {
+	if (total && total == (__force u32) total) {
 		u64 temp = (__force u64) rtime;
 
 		temp *= (__force u64) utime;
@@ -3184,7 +3184,7 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 	total = cputime.utime + cputime.stime;
 	rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
 
-	if (total) {
+	if (total && total == (__force u32) total) {
 		u64 temp = (__force u64) rtime;
 
 		temp *= (__force u64) cputime.utime;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/