[PATCH 04/13] android/sw_sync: use get_unused_fd_flags(0) instead of get_unused_fd()

From: Yann Droneaud
Date: Tue Jul 02 2013 - 12:43:27 EST


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/sw_sync.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/android/sw_sync.c b/drivers/staging/android/sw_sync.c
index 765c757..a4ed0b9 100644
--- a/drivers/staging/android/sw_sync.c
+++ b/drivers/staging/android/sw_sync.c
@@ -163,7 +163,7 @@ static int sw_sync_release(struct inode *inode, struct file *file)
static long sw_sync_ioctl_create_fence(struct sw_sync_timeline *obj,
unsigned long arg)
{
- int fd = get_unused_fd();
+ int fd = get_unused_fd_flags(0);
int err;
struct sync_pt *pt;
struct sync_fence *fence;
--
1.8.3.1

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