Messages in this thread Patch in this message | | | From | Dan Streetman <> | Subject | [PATCH 6/6] mm/zpool: prevent zbud/zsmalloc from unloading when used | Date | Sat, 24 May 2014 15:06:09 -0400 |
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Add try_module_get() to pool creation functions for zbud and zsmalloc, and module_put() to pool destruction functions, since they now can be modules used via zpool. Without usage counting, they could be unloaded while pool(s) were active, resulting in an oops.
Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Weijie Yang <weijie.yang@samsung.com> ---
New for this patch set.
mm/zbud.c | 5 +++++ mm/zsmalloc.c | 5 +++++ 2 files changed, 10 insertions(+)
diff --git a/mm/zbud.c b/mm/zbud.c index 8a72cb1..2b3689c 100644 --- a/mm/zbud.c +++ b/mm/zbud.c @@ -282,6 +282,10 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops) pool = kmalloc(sizeof(struct zbud_pool), GFP_KERNEL); if (!pool) return NULL; + if (!try_module_get(THIS_MODULE)) { + kfree(pool); + return NULL; + } spin_lock_init(&pool->lock); for_each_unbuddied_list(i, 0) INIT_LIST_HEAD(&pool->unbuddied[i]); @@ -302,6 +306,7 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops) void zbud_destroy_pool(struct zbud_pool *pool) { kfree(pool); + module_put(THIS_MODULE); } /** diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 07c3130..2cc2647 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -946,6 +946,10 @@ struct zs_pool *zs_create_pool(gfp_t flags) pool = kzalloc(ovhd_size, GFP_KERNEL); if (!pool) return NULL; + if (!try_module_get(THIS_MODULE)) { + kfree(pool); + return NULL; + } for (i = 0; i < ZS_SIZE_CLASSES; i++) { int size; @@ -985,6 +989,7 @@ void zs_destroy_pool(struct zs_pool *pool) } } kfree(pool); + module_put(THIS_MODULE); } EXPORT_SYMBOL_GPL(zs_destroy_pool); -- 1.8.3.1
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