[PATCH 4.4 052/342] devm_memremap: Fix error value when memremap failed

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Toshi Kani <toshi.k...@hpe.com>

commit 93f834df9c2d4e362dfdc4b05daa0a4e18814836 upstream.

devm_memremap() returns an ERR_PTR() value in case of error.
However, it returns NULL when memremap() failed.  This causes
the caller, such as the pmem driver, to proceed and oops later.

Change devm_memremap() to return ERR_PTR(-ENXIO) when memremap()
failed.

Signed-off-by: Toshi Kani <toshi.k...@hpe.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Reviewed-by: Ross Zwisler <ross.zwis...@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 kernel/memremap.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -133,8 +133,10 @@ void *devm_memremap(struct device *dev,
        if (addr) {
                *ptr = addr;
                devres_add(dev, ptr);
-       } else
+       } else {
                devres_free(ptr);
+               return ERR_PTR(-ENXIO);
+       }
 
        return addr;
 }