diff options
author | Lorenzo Stoakes <lstoakes@gmail.com> | 2016-10-13 01:20:13 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 21:55:16 +0100 |
commit | 2b29980eb75bc7dcb23ed0436fe805ac6e684542 (patch) | |
tree | d88fce1140a7d2fd22fa268abf2c3d80bfd26b9b /mm | |
parent | ff099ed77421a5dc8206bb61e5a598b28ab39ebb (diff) |
mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
commit c164154f66f0c9b02673f07aa4f044f1d9c70274 upstream.
This removes the 'write' and 'force' use from get_user_pages_unlocked()
and replaces them with 'gup_flags' to make the use of FOLL_FORCE
explicit in callers as use of this flag can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 4.4:
- Also update calls from process_vm_rw_single_vec() and async_pf_execute()
- Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/gup.c | 14 | ||||
-rw-r--r-- | mm/nommu.c | 11 | ||||
-rw-r--r-- | mm/process_vm_access.c | 6 | ||||
-rw-r--r-- | mm/util.c | 2 |
4 files changed, 12 insertions, 21 deletions
@@ -797,17 +797,10 @@ EXPORT_SYMBOL(__get_user_pages_unlocked); */ long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages) + struct page **pages, unsigned int gup_flags) { - unsigned int flags = FOLL_TOUCH; - - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; - return __get_user_pages_unlocked(tsk, mm, start, nr_pages, - pages, flags); + pages, gup_flags | FOLL_TOUCH); } EXPORT_SYMBOL(get_user_pages_unlocked); @@ -1427,7 +1420,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, pages += nr; ret = get_user_pages_unlocked(current, mm, start, - nr_pages - nr, write, 0, pages); + nr_pages - nr, pages, + write ? FOLL_WRITE : 0); /* Have to be a bit careful with return values */ if (nr > 0) { diff --git a/mm/nommu.c b/mm/nommu.c index f5322195dbcd..e249e06579fb 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -224,17 +224,10 @@ EXPORT_SYMBOL(__get_user_pages_unlocked); long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages) + struct page **pages, unsigned int gup_flags) { - unsigned int flags = 0; - - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; - return __get_user_pages_unlocked(tsk, mm, start, nr_pages, - pages, flags); + pages, gup_flags); } EXPORT_SYMBOL(get_user_pages_unlocked); diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 5d453e58ddbf..1b5a6104c5fc 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -88,19 +88,23 @@ static int process_vm_rw_single_vec(unsigned long addr, ssize_t rc = 0; unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES / sizeof(struct pages *); + unsigned int flags = 0; /* Work out address and page range required */ if (len == 0) return 0; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; + if (vm_write) + flags |= FOLL_WRITE; + while (!rc && nr_pages && iov_iter_count(iter)) { int pages = min(nr_pages, max_pages_per_loop); size_t bytes; /* Get the pages we're interested in */ pages = get_user_pages_unlocked(task, mm, pa, pages, - vm_write, 0, process_pages); + process_pages, flags); if (pages <= 0) return -EFAULT; diff --git a/mm/util.c b/mm/util.c index 5fae5b9c2885..db39235970c6 100644 --- a/mm/util.c +++ b/mm/util.c @@ -278,7 +278,7 @@ int __weak get_user_pages_fast(unsigned long start, { struct mm_struct *mm = current->mm; return get_user_pages_unlocked(current, mm, start, nr_pages, - write, 0, pages); + pages, write ? FOLL_WRITE : 0); } EXPORT_SYMBOL_GPL(get_user_pages_fast); |