From: Andrew Morton <akpm@linux-foundation.org>
Date: Wed, 4 Jun 2014 23:05:54 +0000 (-0700)
Subject: arch/unicore32/mm/ioremap.c: return NULL on invalid pfn
X-Git-Tag: android-x86-4.4-r2~1023^2~16^2~258
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=2accff4ef5c5831a9cc6319394a9f61cc9de8534;p=android-x86%2Fkernel.git

arch/unicore32/mm/ioremap.c: return NULL on invalid pfn

__uc32_ioremap_pfn_caller() should return NULL when the pfn is found to be
invalid.

From a recommendation by Guan Xuetao.

Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/unicore32/mm/ioremap.c b/arch/unicore32/mm/ioremap.c
index a0840fa05431..bf012b2b71a9 100644
--- a/arch/unicore32/mm/ioremap.c
+++ b/arch/unicore32/mm/ioremap.c
@@ -143,11 +143,13 @@ void __iomem *__uc32_ioremap_pfn_caller(unsigned long pfn,
 	/*
 	 * Don't allow RAM to be mapped
 	 */
-	if (pfn_valid(pfn))
+	if (pfn_valid(pfn)) {
 		WARN(1, "BUG: Your driver calls ioremap() on\n"
 			"system memory.  This leads to architecturally\n"
 			"unpredictable behaviour, and ioremap() will fail in\n"
 			"the next kernel release. Please fix your driver.\n");
+		return NULL;
+	}
 
 	type = get_mem_type(mtype);
 	if (!type)