The patch titled
Subject: memory-hotplug: fix store_mem_state() return value
has been added to the -mm tree. Its filename is
memory-hotplug-fix-store_mem_state-return-value.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/memory-hotplug-fix-store_mem_state-return-value.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/memory-hotplug-fix-store_mem_state-return-value.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>
Subject: memory-hotplug: fix store_mem_state() return value
Attempting to online memory which is already online will cause this:
1. store_mem_state() called with buf="online"
2. device_online() returns 1 because device is already online
3. store_mem_state() returns 1
4. calling code interprets this as 1-byte buffer read
5. store_mem_state() called again with buf="nline"
6. store_mem_state() returns -EINVAL
Example:
$ cat /sys/devices/system/memory/memory0/state
online
$ echo online > /sys/devices/system/memory/memory0/state
-bash: echo: write error: Invalid argument
Fix the return value of store_mem_state() so this doesn't happen.
Link: http://lkml.kernel.org/r/1472658241-32748-1-git-send-email-arbab@xxxxxxxxxxxxxxxxxx
Signed-off-by: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Yaowei Bai <baiyaowei@xxxxxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Chen Yucong <slaoub@xxxxxxxxx>
Cc: Andrew Banman <abanman@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN drivers/base/memory.c~memory-hotplug-fix-store_mem_state-return-value drivers/base/memory.c
--- a/drivers/base/memory.c~memory-hotplug-fix-store_mem_state-return-value
+++ a/drivers/base/memory.c
@@ -361,7 +361,7 @@ store_mem_state(struct device *dev,
err:
unlock_device_hotplug();
- if (ret)
+ if (ret < 0)
return ret;
return count;
}
_
Patches currently in -mm which might be from arbab@xxxxxxxxxxxxxxxxxx are
memory-hotplug-fix-store_mem_state-return-value.patch
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