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| author | Lorenzo Stoakes <lstoakes@gmail.com> | 2016-10-13 01:20:11 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-18 14:13:36 -0700 |
| commit | 859110d7497cdd0e6b21010d6f777049d676382c (patch) | |
| tree | d2da6062b292dd6478a607bb8d564047d087144c | |
| parent | 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 (diff) | |
| download | linux-859110d7497cdd0e6b21010d6f777049d676382c.tar.gz linux-859110d7497cdd0e6b21010d6f777049d676382c.tar.bz2 linux-859110d7497cdd0e6b21010d6f777049d676382c.zip | |
mm: remove write/force parameters from __get_user_pages_locked()
This removes the redundant 'write' and 'force' parameters from
__get_user_pages_locked() 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>
| -rw-r--r-- | mm/gup.c | 47 |
1 files changed, 33 insertions, 14 deletions
@@ -739,7 +739,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -757,10 +756,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -856,9 +851,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -879,9 +880,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -973,9 +980,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -989,9 +1002,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); |