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Subject[RFC PATCH 5/8] ipc: shm: pass atomic parameter to do_munmap()
Date
It looks safe to do unlock/relock mmap_sem in the middle of shmat(), so
passing "false" here.

Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
---
ipc/shm.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/ipc/shm.c b/ipc/shm.c
index 4643865..1617523 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1537,7 +1537,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
*/
file = vma->vm_file;
size = i_size_read(file_inode(vma->vm_file));
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start,
+ NULL, false);
/*
* We discovered the size of the shm segment, so
* break out of here and fall through to the next
@@ -1564,7 +1565,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
if ((vma->vm_ops == &shm_vm_ops) &&
((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
(vma->vm_file == file))
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start,
+ NULL, false);
vma = next;
}

@@ -1573,7 +1575,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
* given
*/
if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start,
+ NULL, false);
retval = 0;
}

--
1.8.3.1
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