From 3277953de2f31dd03c6375e9a9f680ac37fc9d27 Mon Sep 17 00:00:00 2001 From: zhong jiang 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 Reviewed-by: John Hubbard Suggested-by: John Hubbard Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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);