From 023a53557ea0e987b002e9a844242ef0b0aa1eb3 Mon Sep 17 00:00:00 2001 From: Nadia Derbey Date: Thu, 18 Oct 2007 23:40:51 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/shm.c | 90 ++++++++++++++++++++++++++++++++++----------------------------- 1 file changed, 48 insertions(+), 42 deletions(-) (limited to 'ipc/shm.c') diff --git a/ipc/shm.c b/ipc/shm.c index 8cf1cf3d5bec..8241264941a2 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -59,8 +59,6 @@ static struct ipc_ids init_shm_ids; #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 @@ void __init shm_init (void) 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 @@ static void shm_open(struct vm_area_struct *vma) 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 @@ static void shm_close(struct vm_area_struct *vma) 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 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) { 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 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) 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 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) 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 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) * 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 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) 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 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) * 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 @@ invalid: 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) -- cgit v1.2.3-59-g8ed1b