Re: [PATCH 02/13] ppc/cell: use get_unused_fd_flags(0) instead of get_unused_fd()

Hi Benjamin,

Le lundi 13 janvier 2014 à 10:06 +1100, Benjamin Herrenschmidt a écrit :

On Tue, 2013-07-02 at 18:39 +0200, Yann Droneaud wrote:

quoted

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 <redacted>

Should I merge this (v5 on patchwork) or let Al do it ?

Please merge it directly: patches from the previous patchsets were
picked individually by each subsystem maintainer after proper review
regarding setting close on exec flag by default.

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Thanks a lot.

quoted

---
 arch/powerpc/platforms/cell/spufs/inode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index f390042..88df441 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c

@@ -301,7 +301,7 @@ static int spufs_context_open(struct path *path)
 	int ret;
 	struct file *filp;
 
-	ret = get_unused_fd();
+	ret = get_unused_fd_flags(0);
 	if (ret < 0)
 		return ret;
 

@@ -518,7 +518,7 @@ static int spufs_gang_open(struct path *path)
 	int ret;
 	struct file *filp;
 
-	ret = get_unused_fd();
+	ret = get_unused_fd_flags(0);
 	if (ret < 0)
 		return ret;
 

Note:
latest patch (from v5 patchset) is at
http://lkml.kernel.org/r/fe27abcfab5563d36a3e5e58ff36e5500c39be6a.1388952061.git.ydroneaud@opteya.com
v5 patchset is at
http://lkml.kernel.org/r/cover.1388952061.git.ydroneaud@opteya.com

Regards.

-- 
Yann Droneaud
OPTEYA