devm_memremap_release(): fix memremap'd addr handling

toshikani · torvalds · commit 9273a8bbf58a · 2016-02-18T16:23:24.000-08:00
The pmem driver calls devm_memremap() to map a persistent memory range.
When the pmem driver is unloaded, this memremap'd range is not released
so the kernel will leak a vma.

Fix devm_memremap_release() to handle a given memremap'd address
properly.

Signed-off-by: Toshi Kani &lt;toshi.kani@hpe.com&gt;
Acked-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/kernel/memremap.c b/kernel/memremap.c
@@ -114,7 +114,7 @@ EXPORT_SYMBOL(memunmap);
 
 static void devm_memremap_release(struct device *dev, void *res)
 {
-	memunmap(res);
+	memunmap(*(void **)res);
 }
 
 static int devm_memremap_match(struct device *dev, void *res, void *match_data)

Original file line number	Diff line number	Diff line change
`@@ -114,7 +114,7 @@ EXPORT_SYMBOL(memunmap);`
`114`	`114`
`115`	`115`	`static void devm_memremap_release(struct device dev, void res)`
`116`	`116`	`{`
`117`		`- memunmap(res);`
	`117`	`+ memunmap((void *)res);`
`118`	`118`	`}`
`119`	`119`
`120`	`120`	`static int devm_memremap_match(struct device dev, void res, void *match_data)`