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| author | Nadia Derbey <Nadia.Derbey@bull.net> | 2007-10-18 23:40:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 11:53:44 -0700 |
| commit | 023a53557ea0e987b002e9a844242ef0b0aa1eb3 (patch) | |
| tree | 7f3accdd7cb1d801607bf71e56b9b99e9c7ff7ca /ipc/util.h | |
| parent | 637c36634029e4e7c81112796dafc32d56355b4a (diff) | |
| download | linux-023a53557ea0e987b002e9a844242ef0b0aa1eb3.tar.bz2 | |
ipc: integrate ipc_checkid() into ipc_lock()
This patch introduces a new ipc_lock_check() routine interface:
. each time ipc_checkid() is called, this is done after calling ipc_lock().
ipc_checkid() is now called from inside ipc_lock_check().
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix RCU locking]
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/util.h')
| -rw-r--r-- | ipc/util.h | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/ipc/util.h b/ipc/util.h index 1546eda7d99e..c4b0a9865bf5 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -11,6 +11,7 @@ #define _IPC_UTIL_H #include <linux/idr.h> +#include <linux/err.h> #define USHRT_MAX 0xffff #define SEQ_MULTIPLIER (IPCMNI) @@ -103,11 +104,8 @@ void* ipc_rcu_alloc(int size); void ipc_rcu_getref(void *ptr); void ipc_rcu_putref(void *ptr); -struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); -void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); -void ipc_unlock(struct kern_ipc_perm* perm); +struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int); int ipc_buildid(struct ipc_ids* ids, int id, int seq); -int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); @@ -127,6 +125,43 @@ extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *, extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *, struct ipc_ops *, struct ipc_params *); +static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp, + int uid) +{ + if (uid / SEQ_MULTIPLIER != ipcp->seq) + return 1; + return 0; +} + +static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm) +{ + rcu_read_lock(); + spin_lock(&perm->lock); +} + +static inline void ipc_unlock(struct kern_ipc_perm *perm) +{ + spin_unlock(&perm->lock); + rcu_read_unlock(); +} + +static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, + int id) +{ + struct kern_ipc_perm *out; + + out = ipc_lock(ids, id); + if (IS_ERR(out)) + return out; + + if (ipc_checkid(ids, out, id)) { + ipc_unlock(out); + return ERR_PTR(-EIDRM); + } + + return out; +} + static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, struct ipc_ops *ops, struct ipc_params *params) { |