[PATCH v1 1/5] memremap: Check for size parameter

[Andy Shevchenko]

There is no use of memremap() to be called with size = 0.
Simple return NULL pointer and allow callers to drop this check.

Fixes: 92281dee825f ("arch: introduce memremap()")
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Jaroslav Kysela <perex@xxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxxx>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 kernel/iomem.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/iomem.c b/kernel/iomem.c
index 62c92e43aa0d..bf7a5fc32760 100644
--- a/kernel/iomem.c
+++ b/kernel/iomem.c
@@ -74,6 +74,9 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
 				       IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
 	void *addr = NULL;
 
+	if (!size)
+		return NULL;
+
 	if (!flags)
 		return NULL;
 
-- 
2.24.0