The patch titled
memcg: res_counter_read_u64(): fix potential races on 32-bit machines
has been added to the -mm tree. Its filename is
memcg-res_counter_read_u64-fix-potential-races-on-32-bit-machines.patch
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------------------------------------------------------
Subject: memcg: res_counter_read_u64(): fix potential races on 32-bit machines
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
res_counter_read_u64 reads u64 value without lock. It's dangerous in a
32bit environment. Add locking.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/res_counter.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff -puN kernel/res_counter.c~memcg-res_counter_read_u64-fix-potential-races-on-32-bit-machines kernel/res_counter.c
--- a/kernel/res_counter.c~memcg-res_counter_read_u64-fix-potential-races-on-32-bit-machines
+++ a/kernel/res_counter.c
@@ -126,10 +126,24 @@ ssize_t res_counter_read(struct res_coun
pos, buf, s - buf);
}
+#if BITS_PER_LONG == 32
+u64 res_counter_read_u64(struct res_counter *counter, int member)
+{
+ unsigned long flags;
+ u64 ret;
+
+ spin_lock_irqsave(&counter->lock, flags);
+ ret = *res_counter_member(counter, member);
+ spin_unlock_irqrestore(&counter->lock, flags);
+
+ return ret;
+}
+#else
u64 res_counter_read_u64(struct res_counter *counter, int member)
{
return *res_counter_member(counter, member);
}
+#endif
int res_counter_memparse_write_strategy(const char *buf,
unsigned long long *res)
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
memsw-handle-swapaccount-kernel-parameter-correctly.patch
memsw-deprecate-noswapaccount-kernel-parameter-and-schedule-it-for-removal.patch
oom-suppress-nodes-that-are-not-allowed-from-meminfo-on-oom-kill.patch
oom-suppress-show_mem-for-many-nodes-in-irq-context-on-page-alloc-failure.patch
oom-suppress-nodes-that-are-not-allowed-from-meminfo-on-page-alloc-failure.patch
mm-add-replace_page_cache_page-function.patch
memcg-res_counter_read_u64-fix-potential-races-on-32-bit-machines.patch
memcg-fix-ugly-initialization-of-return-value-is-in-caller.patch
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