| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 080/118] dm bufio: initialize read-only module parameters | Date | Wed, 18 Dec 2013 13:11:57 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka <mpatocka@redhat.com>
commit 4cb57ab4a2e61978f3a9b7d4f53988f30d61c27f upstream.
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 initializes the variables in the module init routine, so that user-supplied values are ignored.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-bufio.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -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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