Some module parameters in dm-bufio are read-only. These parameters inform
the user about memory consumption. They are not supposed to be changed by
the user.
However, despite being read-only, these parameters can be set on modprobe
or insmod command line, for example:
modprobe dm-bufio current_allocated_bytes=12345
The kernel doesn't expect that these variables can be non-zero at module
initialization and if the user sets them, it results in BUG.
This patch initializates the variables in the module init routine, so that
user-supplied values are ignored.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: stable@xxxxxxxxxx # 3.2+
---
drivers/md/dm-bufio.c | 5 +++++
1 file changed, 5 insertions(+)
Index: linux-3.13-rc2/drivers/md/dm-bufio.c
===================================================================
--- linux-3.13-rc2.orig/drivers/md/dm-bufio.c 2013-12-05 23:23:02.000000000 +0100
+++ linux-3.13-rc2/drivers/md/dm-bufio.c 2013-12-05 23:26:37.000000000 +0100
@@ -1717,6 +1717,11 @@ static int __init dm_bufio_init(void)
{
__u64 mem;
+ dm_bufio_allocated_kmem_cache = 0;
+ dm_bufio_allocated_get_free_pages = 0;
+ dm_bufio_allocated_vmalloc = 0;
+ dm_bufio_current_allocated = 0;
+
memset(&dm_bufio_caches, 0, sizeof dm_bufio_caches);
memset(&dm_bufio_cache_names, 0, sizeof dm_bufio_cache_names);
--
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