From 1872856ac3ed878ec621a02573cff56491d9f410 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Date: Tue, 13 Dec 2011 00:40:34 +0100 Subject: [PATCH] export __get_user_pages_fast() function commit 45888a0c6edc305495b6bd72a30e66bc40b324c6 upstream. Backport for stable kernel v2.6.32.y to v2.6.36.y. Needed for next patch: oprofile, x86: Fix nmi-unsafe callgraph support This function is used by KVM to pin process's page in the atomic context. Define the 'weak' function to avoid other architecture not support it Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- mm/util.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/util.c b/mm/util.c index b377ce430803..e48b493d40f8 100644 --- a/mm/util.c +++ b/mm/util.c @@ -233,6 +233,19 @@ void arch_pick_mmap_layout(struct mm_struct *mm) } #endif +/* + * Like get_user_pages_fast() except its IRQ-safe in that it won't fall + * back to the regular GUP. + * If the architecture not support this fucntion, simply return with no + * page pinned + */ +int __attribute__((weak)) __get_user_pages_fast(unsigned long start, + int nr_pages, int write, struct page **pages) +{ + return 0; +} +EXPORT_SYMBOL_GPL(__get_user_pages_fast); + /** * get_user_pages_fast() - pin user pages in memory * @start: starting user address -- 2.30.9