From caac7e6d00d3ddc888bd8169e75a02f962efdcff Mon Sep 17 00:00:00 2001 From: Stas Sergeev Date: Tue, 9 Sep 2014 14:50:53 -0700 Subject: [PATCH] sh: get_user_pages_fast() must flush cache This patch avoids fuse hangs on sh4 by flushing the cache on get_user_pages_fast(). This is not necessary a good thing to do, but get_user_pages() does this, so get_user_pages_fast() should too. Please note the patch for mips arch that addresses the similar problem: https://kernel.googlesource.com/pub/scm/linux/kernel/git/ralf/linux/+/linux-3.4.50%5E!/#F0 They basically simply disable get_user_pages_fast() at all, using a fall-back to get_user_pages(). But my fix is different, it adds an explicit cache flushes. Signed-off-by: Stas Sergeev Cc: Geert Uytterhoeven Cc: Kamal Dasu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sh/mm/gup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/sh/mm/gup.c b/arch/sh/mm/gup.c index bf8daf9d9c9b..37458f38b220 100644 --- a/arch/sh/mm/gup.c +++ b/arch/sh/mm/gup.c @@ -105,6 +105,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); get_page(page); + __flush_anon_page(page, addr); + flush_dcache_page(page); pages[*nr] = page; (*nr)++;