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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-19 18:39:47 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-19 18:39:47 +0300
commit63ae602cea637ee4a6490d940c0da5d78bd0bbe0 (patch)
tree5da1eec3756fec9d62455c498442944a7f35149b /arch/s390
parent1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (diff)
parentf307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9 (diff)
downloadlinux-63ae602cea637ee4a6490d940c0da5d78bd0bbe0.tar.xz
Merge branch 'gup_flag-cleanups'
Merge the gup_flags cleanups from Lorenzo Stoakes: "This patch series adjusts functions in the get_user_pages* family such that desired FOLL_* flags are passed as an argument rather than implied by flags. The purpose of this change is to make the use of FOLL_FORCE explicit so it is easier to grep for and clearer to callers that this flag is being used. The use of FOLL_FORCE is an issue as it overrides missing VM_READ/VM_WRITE flags for the VMA whose pages we are reading from/writing to, which can result in surprising behaviour. The patch series came out of the discussion around commit 38e088546522 ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"), which addressed a BUG_ON() being triggered when a page was faulted in with PROT_NONE set but having been overridden by FOLL_FORCE. do_numa_page() was run on the assumption the page _must_ be one marked for NUMA node migration as an actual PROT_NONE page would have been dealt with prior to this code path, however FOLL_FORCE introduced a situation where this assumption did not hold. See https://marc.info/?l=linux-mm&m=147585445805166 for the patch proposal" Additionally, there's a fix for an ancient bug related to FOLL_FORCE and FOLL_WRITE by me. [ This branch was rebased recently to add a few more acked-by's and reviewed-by's ] * gup_flag-cleanups: mm: replace access_process_vm() write parameter with gup_flags mm: replace access_remote_vm() write parameter with gup_flags mm: replace __access_remote_vm() write parameter with gup_flags mm: replace get_user_pages_remote() write/force parameters with gup_flags mm: replace get_user_pages() write/force parameters with gup_flags mm: replace get_vaddr_frames() write/force parameters with gup_flags mm: replace get_user_pages_locked() write/force parameters with gup_flags mm: replace get_user_pages_unlocked() write/force parameters with gup_flags mm: remove write/force parameters from __get_user_pages_unlocked() mm: remove write/force parameters from __get_user_pages_locked() mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/mm/gup.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index adb0c34bf431..18d4107e10ee 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -266,7 +266,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
/* Try to get the remaining pages with get_user_pages */
start += nr << PAGE_SHIFT;
pages += nr;
- ret = get_user_pages_unlocked(start, nr_pages - nr, write, 0, pages);
+ ret = get_user_pages_unlocked(start, nr_pages - nr, pages,
+ write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0)
ret = (ret < 0) ? nr : ret + nr;