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authorEric W. Biederman <ebiederm@xmission.com>2011-06-15 10:21:48 -0700
committerEric W. Biederman <ebiederm@xmission.com>2012-11-20 04:19:49 -0800
commit98f842e675f96ffac96e6c50315790912b2812be (patch)
treeed4dee9a6e54e3443e9f3f1614c8a2fcf9b31e0a /ipc/msgutil.c
parentproc: Fix the namespace inode permission checks. (diff)
downloadlinux-dev-98f842e675f96ffac96e6c50315790912b2812be.tar.xz
linux-dev-98f842e675f96ffac96e6c50315790912b2812be.zip
proc: Usable inode numbers for the namespace file descriptors.
Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'ipc/msgutil.c')
-rw-r--r--ipc/msgutil.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index 26143d377c95..6471f1bdae96 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -16,6 +16,7 @@
#include <linux/msg.h>
#include <linux/ipc_namespace.h>
#include <linux/utsname.h>
+#include <linux/proc_fs.h>
#include <asm/uaccess.h>
#include "util.h"
@@ -30,6 +31,7 @@ DEFINE_SPINLOCK(mq_lock);
struct ipc_namespace init_ipc_ns = {
.count = ATOMIC_INIT(1),
.user_ns = &init_user_ns,
+ .proc_inum = PROC_IPC_INIT_INO,
};
atomic_t nr_ipc_ns = ATOMIC_INIT(1);