[PATCH 05/13] android/sync: use get_unused_fd_flags(0) instead of get_unused_fd()

[Yann Droneaud]

Macro get_unused_fd() is used to allocate a file descriptor with
default flags. Those default flags (0) can be "unsafe":
O_CLOEXEC must be used by default to not leak file descriptor
across exec().

Instead of macro get_unused_fd(), functions anon_inode_getfd()
or get_unused_fd_flags() should be used with flags given by userspace.
If not possible, flags should be set to O_CLOEXEC to provide userspace
with a default safe behavor.

In a further patch, get_unused_fd() will be removed so that
new code start using anon_inode_getfd() or get_unused_fd_flags()
with correct flags.

This patch replaces calls to get_unused_fd() with equivalent call to
get_unused_fd_flags(0) to preserve current behavor for existing code.

The hard coded flag value (0) should be reviewed on a per-subsystem basis,
and, if possible, set to O_CLOEXEC.

Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx>
---
 drivers/staging/android/sync.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
index 2996077..c40c743 100644
--- a/drivers/staging/android/sync.c
+++ b/drivers/staging/android/sync.c
@@ -697,7 +697,7 @@ static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
 
 static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
 {
-	int fd = get_unused_fd();
+	int fd = get_unused_fd_flags(0);
 	int err;
 	struct sync_fence *fence2, *fence3;
 	struct sync_merge_data data;
-- 
1.8.3.1

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