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authorVegard Nossum <vegard.nossum@oracle.com>2017-02-28 01:30:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-28 05:43:48 +0300
commitf1f1007644ffc8051a4c11427d58b1967ae7b75a (patch)
treee7e590cb1baa494b963d81b967a3f98d3c56f33e /fs
parent522b837c672eba9e9fb69f9f52bced0256dc6697 (diff)
downloadlinux-f1f1007644ffc8051a4c11427d58b1967ae7b75a.tar.xz
mm: add new mmgrab() helper
Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/' git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/base.c4
-rw-r--r--fs/userfaultfd.c2
2 files changed, 3 insertions, 3 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index b8f06273353e..5d51a188871b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -766,7 +766,7 @@ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
if (!IS_ERR_OR_NULL(mm)) {
/* ensure this mm_struct can't be freed */
- atomic_inc(&mm->mm_count);
+ mmgrab(mm);
/* but do not pin its memory */
mmput(mm);
}
@@ -1064,7 +1064,7 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
if (p) {
if (atomic_read(&p->mm->mm_users) > 1) {
mm = p->mm;
- atomic_inc(&mm->mm_count);
+ mmgrab(mm);
}
task_unlock(p);
}
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index e6e0a619cb3a..3c421d06a18e 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1847,7 +1847,7 @@ static struct file *userfaultfd_file_create(int flags)
ctx->released = false;
ctx->mm = current->mm;
/* prevent the mm struct to be freed */
- atomic_inc(&ctx->mm->mm_count);
+ mmgrab(ctx->mm);
file = anon_inode_getfile("[userfaultfd]", &userfaultfd_fops, ctx,
O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS));