From c02c30093254189a6ef55fed415a4ffb55a74cdf Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Fri, 13 Oct 2017 15:57:37 -0700 Subject: mm/madvise.c: add description for MADV_WIPEONFORK and MADV_KEEPONFORK mm/madvise.c has a brief description about all MADV_ flags. Add a description for the newly added MADV_WIPEONFORK and MADV_KEEPONFORK. Although man page has the similar information, but it'd better to keep the consistent with other flags. Link: http://lkml.kernel.org/r/1506117328-88228-1-git-send-email-yang.s@alibaba-inc.com Signed-off-by: Yang Shi Reviewed-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/madvise.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'mm/madvise.c') diff --git a/mm/madvise.c b/mm/madvise.c index 25bade36e9ca..fd70d6aabc3e 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -757,6 +757,9 @@ madvise_behavior_valid(int behavior) * MADV_DONTFORK - omit this area from child's address space when forking: * typically, to avoid COWing pages pinned by get_user_pages(). * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. + * MADV_WIPEONFORK - present the child process with zero-filled memory in this + * range after a fork. + * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK * MADV_HWPOISON - trigger memory error handler as if the given memory range * were corrupted by unrecoverable hardware memory failure. * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. @@ -777,7 +780,9 @@ madvise_behavior_valid(int behavior) * zero - success * -EINVAL - start + len < 0, start is not page-aligned, * "behavior" is not a valid value, or application - * is attempting to release locked or shared pages. + * is attempting to release locked or shared pages, + * or the specified address range includes file, Huge TLB, + * MAP_SHARED or VMPFNMAP range. * -ENOMEM - addresses in the specified range are not currently * mapped, or are outside the AS of the process. * -EIO - an I/O error occurred while paging in data. -- cgit v1.2.3