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authorStuart Menefy <stuart.menefy@st.com>2011-01-31 17:50:29 (GMT)
committerPaul Mundt <lethal@linux-sh.org>2011-02-15 07:24:31 (GMT)
commita25bbe12224e649fe12cba7a2fa920180a35c8a9 (patch)
tree2c4b07a6e106551b70f3c48e5ce32824e3168a1e
parenta086536858ad0eb51c58074af2fc2c89ba9c1f5e (diff)
downloadlinux-a25bbe12224e649fe12cba7a2fa920180a35c8a9.tar.xz
sh: Flush executable pages in copy_user_highpage
This resolves a problem seen when using the Android dynamic linker. Sometimes the dynamic linker would seg-fault at start up and this was eventually traced to the handling of a COW fault for a page which was being modified by the linker. If there was no cache aliasing between the kernel and the user page, the page was not flushed, leaving the newly copied data in the D-cache. However when executing instructions from that page, the I-cache is filled directly from external memory, rather than the D-cache, and causing garbage to be executed. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
-rw-r--r--arch/sh/mm/cache.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index 88d3dc3..5a580ea 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -108,7 +108,8 @@ void copy_user_highpage(struct page *to, struct page *from,
kunmap_atomic(vfrom, KM_USER0);
}
- if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
+ if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK) ||
+ (vma->vm_flags & VM_EXEC))
__flush_purge_region(vto, PAGE_SIZE);
kunmap_atomic(vto, KM_USER1);