From a25bbe12224e649fe12cba7a2fa920180a35c8a9 Mon Sep 17 00:00:00 2001 From: Stuart Menefy <stuart.menefy@st.com> Date: Mon, 31 Jan 2011 17:50:29 +0000 Subject: [PATCH] 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> --- arch/sh/mm/cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c index 88d3dc3d30d50..5a580ea044298 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); -- GitLab