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>
diff --git a/ipc/shm.c b/ipc/shm.c
index 8cf1cf3..8241264 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -59,8 +59,6 @@
#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
-#define shm_lock(ns, id) \
- ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
#define shm_unlock(shp) \
ipc_unlock(&(shp)->shm_perm)
#define shm_buildid(ns, id, seq) \
@@ -139,12 +137,15 @@
IPC_SHM_IDS, sysvipc_shm_proc_show);
}
-static inline int shm_checkid(struct ipc_namespace *ns,
- struct shmid_kernel *s, int id)
+static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
- if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
- return -EIDRM;
- return 0;
+ return (struct shmid_kernel *) ipc_lock(&shm_ids(ns), id);
+}
+
+static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
+ int id)
+{
+ return (struct shmid_kernel *) ipc_lock_check(&shm_ids(ns), id);
}
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
@@ -167,7 +168,7 @@
struct shmid_kernel *shp;
shp = shm_lock(sfd->ns, sfd->id);
- BUG_ON(!shp);
+ BUG_ON(IS_ERR(shp));
shp->shm_atim = get_seconds();
shp->shm_lprid = task_tgid_vnr(current);
shp->shm_nattch++;
@@ -213,7 +214,7 @@
mutex_lock(&shm_ids(ns).mutex);
/* remove from the list of attaches of the shm segment */
shp = shm_lock(ns, sfd->id);
- BUG_ON(!shp);
+ BUG_ON(IS_ERR(shp));
shp->shm_lprid = task_tgid_vnr(current);
shp->shm_dtim = get_seconds();
shp->shm_nattch--;
@@ -662,17 +663,25 @@
{
struct shmid64_ds tbuf;
int result;
- memset(&tbuf, 0, sizeof(tbuf));
- shp = shm_lock(ns, shmid);
- if(shp==NULL) {
- err = -EINVAL;
+
+ if (!buf) {
+ err = -EFAULT;
goto out;
- } else if (cmd == SHM_STAT) {
+ }
+
+ if (cmd == SHM_STAT) {
+ shp = shm_lock(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out;
+ }
result = shp->shm_perm.id;
} else {
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock;
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out;
+ }
result = 0;
}
err=-EACCES;
@@ -681,6 +690,7 @@
err = security_shm_shmctl(shp, cmd);
if (err)
goto out_unlock;
+ memset(&tbuf, 0, sizeof(tbuf));
kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
tbuf.shm_segsz = shp->shm_segsz;
tbuf.shm_atime = shp->shm_atim;
@@ -699,14 +709,11 @@
case SHM_LOCK:
case SHM_UNLOCK:
{
- shp = shm_lock(ns, shmid);
- if(shp==NULL) {
- err = -EINVAL;
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out;
}
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock;
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
@@ -756,13 +763,11 @@
* the name away when the usage hits zero.
*/
mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
- err = -EINVAL;
- if (shp == NULL)
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out_up;
- err = shm_checkid(ns, shp, shmid);
- if(err)
- goto out_unlock_up;
+ }
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
@@ -786,18 +791,21 @@
case IPC_SET:
{
+ if (!buf) {
+ err = -EFAULT;
+ goto out;
+ }
+
if (copy_shmid_from_user (&setbuf, buf, version)) {
err = -EFAULT;
goto out;
}
mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
- err=-EINVAL;
- if(shp==NULL)
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out_up;
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock_up;
+ }
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
goto out_unlock_up;
@@ -903,13 +911,11 @@
* additional creator id...
*/
ns = current->nsproxy->ipc_ns;
- shp = shm_lock(ns, shmid);
- if(shp == NULL)
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out;
-
- err = shm_checkid(ns, shp,shmid);
- if (err)
- goto out_unlock;
+ }
err = -EACCES;
if (ipcperms(&shp->shm_perm, acc_mode))
@@ -970,7 +976,7 @@
out_nattch:
mutex_lock(&shm_ids(ns).mutex);
shp = shm_lock(ns, shmid);
- BUG_ON(!shp);
+ BUG_ON(IS_ERR(shp));
shp->shm_nattch--;
if(shp->shm_nattch == 0 &&
shp->shm_perm.mode & SHM_DEST)