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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-13 05:50:43 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-13 05:50:43 +0200 |
| commit | 5e6f1fee60a3d80582146835ac01d9808748434f (patch) | |
| tree | 49452a45442283463705a17408b66c7650c7e405 | |
| parent | Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff) | |
| parent | sched/fair: Do not re-read ->h_load_next during hierarchical load calculation (diff) | |
| download | linux-5e6f1fee60a3d80582146835ac01d9808748434f.tar.xz linux-5e6f1fee60a3d80582146835ac01d9808748434f.zip | |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
"Fix a NULL pointer dereference crash in certain environments"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Do not re-read ->h_load_next during hierarchical load calculation
| -rw-r--r-- | kernel/sched/fair.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index fdab7eb6f351..40bd1e27b1b7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7784,10 +7784,10 @@ static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq) if (cfs_rq->last_h_load_update == now) return; - cfs_rq->h_load_next = NULL; + WRITE_ONCE(cfs_rq->h_load_next, NULL); for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); - cfs_rq->h_load_next = se; + WRITE_ONCE(cfs_rq->h_load_next, se); if (cfs_rq->last_h_load_update == now) break; } @@ -7797,7 +7797,7 @@ static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq) cfs_rq->last_h_load_update = now; } - while ((se = cfs_rq->h_load_next) != NULL) { + while ((se = READ_ONCE(cfs_rq->h_load_next)) != NULL) { load = cfs_rq->h_load; load = div64_ul(load * se->avg.load_avg, cfs_rq_load_avg(cfs_rq) + 1); |