The patch titled
oom: fix possible oom_dump_tasks NULL pointer
has been removed from the -mm tree. Its filename was
oom-fix-possible-oom_dump_tasks-null-pointer.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: oom: fix possible oom_dump_tasks NULL pointer
From: David Rientjes <rientjes@xxxxxxxxxx>
When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL
pointer for tasks that have detached mm's since task_lock() is not held
during the tasklist scan.
Fix this by checking for a NULL mm_struct pointer and avoiding the
dereference if the race occurred.
Acked-by: Nick Piggin <npiggin@xxxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff -puN mm/oom_kill.c~oom-fix-possible-oom_dump_tasks-null-pointer mm/oom_kill.c
--- a/mm/oom_kill.c~oom-fix-possible-oom_dump_tasks-null-pointer
+++ a/mm/oom_kill.c
@@ -284,22 +284,28 @@ static void dump_tasks(const struct mem_
printk(KERN_INFO "[ pid ] uid tgid total_vm rss cpu oom_adj "
"name\n");
do_each_thread(g, p) {
- /*
- * total_vm and rss sizes do not exist for tasks with a
- * detached mm so there's no need to report them.
- */
- if (!p->mm)
- continue;
+ struct mm_struct *mm;
+
if (mem && !task_in_mem_cgroup(p, mem))
continue;
if (!thread_group_leader(p))
continue;
task_lock(p);
+ mm = p->mm;
+ if (!mm) {
+ /*
+ * total_vm and rss sizes do not exist for tasks with no
+ * mm so there's no need to report them; they can't be
+ * oom killed anyway.
+ */
+ task_unlock(p);
+ continue;
+ }
printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n",
- p->pid, __task_cred(p)->uid, p->tgid,
- p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p),
- p->oomkilladj, p->comm);
+ p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm,
+ get_mm_rss(mm), (int)task_cpu(p), p->oomkilladj,
+ p->comm);
task_unlock(p);
} while_each_thread(g, p);
}
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
linux-next.patch
cpusets-restructure-the-function-cpuset_update_task_memory_state.patch
cpusets-update-tasks-page-slab-spread-flags-in-time.patch
cpusetmm-update-tasks-mems_allowed-in-time.patch
cpusetmm-update-tasks-mems_allowed-in-time-fix.patch
cpusetmm-update-tasks-mems_allowed-in-time-cleanup.patch
page-allocator-use-a-pre-calculated-value-instead-of-num_online_nodes-in-fast-paths-do-not-override-definition-of-node_set_online-with-macro.patch
mm-setup_per_zone_inactive_ratio-do-not-call-for-int_sqrt-if-not-needed.patch
mm-setup_per_zone_inactive_ratio-fix-comment-and-make-it-__init.patch
oom-fix-possible-oom_dump_tasks-null-pointer.patch
oom-move-oom_adj-value-from-task_struct-to-mm_struct.patch
oom-prevent-possible-oom_disable-livelock.patch
page-allocator-warn-if-__gfp_nofail-is-used-for-a-large-allocation.patch
memcg-add-file-based-rss-accounting.patch
memcg-add-file-based-rss-accounting-fix-mem_cgroup_update_mapped_file_stat-oops.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
