From 3277953de2f31dd03c6375e9a9f680ac37fc9d27 Mon Sep 17 00:00:00 2001
From: zhong jiang <zhongjiang@huawei.com>
Date: Tue, 24 Jan 2017 15:18:52 -0800
Subject: [PATCH] mm: do not export ioremap_page_range symbol for external
module
Recently, I've found cases in which ioremap_page_range was used
incorrectly, in external modules, leading to crashes. This can be
partly attributed to the fact that ioremap_page_range is lower-level,
with fewer protections, as compared to the other functions that an
external module would typically call. Those include:
ioremap_cache
ioremap_nocache
ioremap_prot
ioremap_uc
ioremap_wc
ioremap_wt
...each of which wraps __ioremap_caller, which in turn provides a safer
way to achieve the mapping.
Therefore, stop EXPORT-ing ioremap_page_range.
Link: http://lkml.kernel.org/r/1485173220-29010-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
lib/ioremap.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 86c8911b0e3a..a3e14ce92a56 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -144,4 +144,3 @@ int ioremap_page_range(unsigned long addr,
return err;
}
-EXPORT_SYMBOL_GPL(ioremap_page_range);
--
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