diff options
| author | Jim Blackler <jimblackler@google.com> | 2019-07-03 17:33:51 +0100 |
|---|---|---|
| committer | Jim Blackler <jimblackler@google.com> | 2019-07-09 13:45:40 +0100 |
| commit | d657433f124d1d5d521ee3ba8f3486e9169012e4 (patch) | |
| tree | 97bd185f260ee565cc7007b256d204fc59a9f38f | |
| parent | c93a1fab248c46487da803590a0f1cec135cd96a (diff) | |
ANDROID: Fixes to locking around handle_lmk_event
get_task_struct used to reserve 'selected' outside rcu_read_lock block.
Remove the need for get_task_mm, removing the possibility of lock issues there.
Bug: 133479338
Signed-off-by: Jim Blackler <jimblackler@google.com>
Change-Id: I1399e2f669242c04e0e397bc09c987358aa97a0a
| -rw-r--r-- | drivers/staging/android/lowmemorykiller.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index d5f5bd4a2d5c..25362cba1397 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -94,21 +94,15 @@ struct lmk_event { struct list_head list; }; -void handle_lmk_event(struct task_struct *selected, short min_score_adj) +void handle_lmk_event(struct task_struct *selected, int selected_tasksize, + short min_score_adj) { int head; int tail; struct lmk_event *events; struct lmk_event *event; int res; - long rss_in_pages = -1; char taskname[MAX_TASKNAME]; - struct mm_struct *mm = get_task_mm(selected); - - if (mm) { - rss_in_pages = get_mm_rss(mm); - mmput(mm); - } res = get_cmdline(selected, taskname, MAX_TASKNAME - 1); @@ -147,7 +141,7 @@ void handle_lmk_event(struct task_struct *selected, short min_score_adj) event->maj_flt = selected->maj_flt; event->oom_score_adj = selected->signal->oom_score_adj; event->start_time = nsec_to_clock_t(selected->real_start_time); - event->rss_in_pages = rss_in_pages; + event->rss_in_pages = selected_tasksize; event->min_score_adj = min_score_adj; event_buffer.head = (head + 1) & (MAX_BUFFERED_EVENTS - 1); @@ -346,15 +340,17 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) free); lowmem_deathpending_timeout = jiffies + HZ; rem += selected_tasksize; + get_task_struct(selected); } lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n", sc->nr_to_scan, sc->gfp_mask, rem); rcu_read_unlock(); - if (selected) - handle_lmk_event(selected, min_score_adj); - + if (selected) { + handle_lmk_event(selected, selected_tasksize, min_score_adj); + put_task_struct(selected); + } return rem; } |