From 023a53557ea0e987b002e9a844242ef0b0aa1eb3 Mon Sep 17 00:00:00 2001 From: Nadia Derbey Date: Thu, 18 Oct 2007 23:40:51 -0700 Subject: [PATCH] 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/msg.c | 62 ++++++++++++++++++------------------- ipc/sem.c | 70 ++++++++++++++++++++---------------------- ipc/shm.c | 90 +++++++++++++++++++++++++++++------------------------- ipc/util.c | 23 ++------------ ipc/util.h | 43 +++++++++++++++++++++++--- 5 files changed, 152 insertions(+), 136 deletions(-) diff --git a/ipc/msg.c b/ipc/msg.c index c2ee26f0105..74e67203567 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -73,10 +73,7 @@ static struct ipc_ids init_msg_ids; #define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS])) -#define msg_lock(ns, id) ((struct msg_queue*)ipc_lock(&msg_ids(ns), id)) #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) -#define msg_checkid(ns, msq, msgid) \ - ipc_checkid(&msg_ids(ns), &msq->q_perm, msgid) #define msg_buildid(ns, id, seq) \ ipc_buildid(&msg_ids(ns), id, seq) @@ -139,6 +136,17 @@ void __init msg_init(void) IPC_MSG_IDS, sysvipc_msg_proc_show); } +static inline struct msg_queue *msg_lock(struct ipc_namespace *ns, int id) +{ + return (struct msg_queue *) ipc_lock(&msg_ids(ns), id); +} + +static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, + int id) +{ + return (struct msg_queue *) ipc_lock_check(&msg_ids(ns), id); +} + static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) { ipc_rmid(&msg_ids(ns), &s->q_perm); @@ -445,18 +453,15 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) if (!buf) return -EFAULT; - memset(&tbuf, 0, sizeof(tbuf)); - - msq = msg_lock(ns, msqid); - if (msq == NULL) - return -EINVAL; - if (cmd == MSG_STAT) { + msq = msg_lock(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); success_return = msq->q_perm.id; } else { - err = -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock; + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); success_return = 0; } err = -EACCES; @@ -467,6 +472,8 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) if (err) goto out_unlock; + memset(&tbuf, 0, sizeof(tbuf)); + kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); tbuf.msg_stime = msq->q_stime; tbuf.msg_rtime = msq->q_rtime; @@ -494,14 +501,12 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) } mutex_lock(&msg_ids(ns).mutex); - msq = msg_lock(ns, msqid); - err = -EINVAL; - if (msq == NULL) + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) { + err = PTR_ERR(msq); goto out_up; + } - err = -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock_up; ipcp = &msq->q_perm; err = audit_ipc_obj(ipcp); @@ -644,14 +649,11 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext, msg->m_type = mtype; msg->m_ts = msgsz; - msq = msg_lock(ns, msqid); - err = -EINVAL; - if (msq == NULL) + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) { + err = PTR_ERR(msq); goto out_free; - - err= -EIDRM; - if (msg_checkid(ns, msq, msqid)) - goto out_unlock_free; + } for (;;) { struct msg_sender s; @@ -758,13 +760,9 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext, mode = convert_mode(&msgtyp, msgflg); ns = current->nsproxy->ipc_ns; - msq = msg_lock(ns, msqid); - if (msq == NULL) - return -EINVAL; - - msg = ERR_PTR(-EIDRM); - if (msg_checkid(ns, msq, msqid)) - goto out_unlock; + msq = msg_lock_check(ns, msqid); + if (IS_ERR(msq)) + return PTR_ERR(msq); for (;;) { struct msg_receiver msr_d; diff --git a/ipc/sem.c b/ipc/sem.c index 6af226af0b9..673d63da52c 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -88,7 +88,6 @@ #define sem_ids(ns) (*((ns)->ids[IPC_SEM_IDS])) -#define sem_lock(ns, id) ((struct sem_array*)ipc_lock(&sem_ids(ns), id)) #define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm) #define sem_checkid(ns, sma, semid) \ ipc_checkid(&sem_ids(ns),&sma->sem_perm,semid) @@ -175,6 +174,17 @@ void __init sem_init (void) IPC_SEM_IDS, sysvipc_sem_proc_show); } +static inline struct sem_array *sem_lock(struct ipc_namespace *ns, int id) +{ + return (struct sem_array *) ipc_lock(&sem_ids(ns), id); +} + +static inline struct sem_array *sem_lock_check(struct ipc_namespace *ns, + int id) +{ + return (struct sem_array *) ipc_lock_check(&sem_ids(ns), id); +} + static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) { ipc_rmid(&sem_ids(ns), &s->sem_perm); @@ -599,11 +609,9 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum, struct semid64_ds tbuf; int id; - memset(&tbuf,0,sizeof(tbuf)); - sma = sem_lock(ns, semid); - if(sma == NULL) - return -EINVAL; + if (IS_ERR(sma)) + return PTR_ERR(sma); err = -EACCES; if (ipcperms (&sma->sem_perm, S_IRUGO)) @@ -615,6 +623,8 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum, id = sma->sem_perm.id; + memset(&tbuf, 0, sizeof(tbuf)); + kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm); tbuf.sem_otime = sma->sem_otime; tbuf.sem_ctime = sma->sem_ctime; @@ -643,16 +653,12 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, ushort* sem_io = fast_sem_io; int nsems; - sma = sem_lock(ns, semid); - if(sma==NULL) - return -EINVAL; + sma = sem_lock_check(ns, semid); + if (IS_ERR(sma)) + return PTR_ERR(sma); nsems = sma->sem_nsems; - err=-EIDRM; - if (sem_checkid(ns,sma,semid)) - goto out_unlock; - err = -EACCES; if (ipcperms (&sma->sem_perm, (cmd==SETVAL||cmd==SETALL)?S_IWUGO:S_IRUGO)) goto out_unlock; @@ -864,14 +870,10 @@ static int semctl_down(struct ipc_namespace *ns, int semid, int semnum, if(copy_semid_from_user (&setbuf, arg.buf, version)) return -EFAULT; } - sma = sem_lock(ns, semid); - if(sma==NULL) - return -EINVAL; + sma = sem_lock_check(ns, semid); + if (IS_ERR(sma)) + return PTR_ERR(sma); - if (sem_checkid(ns,sma,semid)) { - err=-EIDRM; - goto out_unlock; - } ipcp = &sma->sem_perm; err = audit_ipc_obj(ipcp); @@ -1055,15 +1057,10 @@ static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid) goto out; /* no undo structure around - allocate one. */ - sma = sem_lock(ns, semid); - un = ERR_PTR(-EINVAL); - if(sma==NULL) - goto out; - un = ERR_PTR(-EIDRM); - if (sem_checkid(ns,sma,semid)) { - sem_unlock(sma); - goto out; - } + sma = sem_lock_check(ns, semid); + if (IS_ERR(sma)) + return ERR_PTR(PTR_ERR(sma)); + nsems = sma->sem_nsems; ipc_rcu_getref(sma); sem_unlock(sma); @@ -1169,15 +1166,14 @@ retry_undos: } else un = NULL; - sma = sem_lock(ns, semid); - error=-EINVAL; - if(sma==NULL) + sma = sem_lock_check(ns, semid); + if (IS_ERR(sma)) { + error = PTR_ERR(sma); goto out_free; - error = -EIDRM; - if (sem_checkid(ns,sma,semid)) - goto out_unlock_free; + } + /* - * semid identifies are not unique - find_undo may have + * semid identifiers are not unique - find_undo may have * allocated an undo structure, it was invalidated by an RMID * and now a new array with received the same id. Check and retry. */ @@ -1243,7 +1239,7 @@ retry_undos: } sma = sem_lock(ns, semid); - if(sma==NULL) { + if (IS_ERR(sma)) { BUG_ON(queue.prev != NULL); error = -EIDRM; goto out_free; @@ -1343,7 +1339,7 @@ void exit_sem(struct task_struct *tsk) if(semid == -1) continue; sma = sem_lock(ns, semid); - if (sma == NULL) + if (IS_ERR(sma)) continue; if (u->semid == -1) diff --git a/ipc/shm.c b/ipc/shm.c index 8cf1cf3d5be..8241264941a 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) diff --git a/ipc/util.c b/ipc/util.c index e72865f677a..9b0c4e7753a 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -678,7 +678,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) out = idr_find(&ids->ipcs_idr, lid); if (out == NULL) { rcu_read_unlock(); - return NULL; + return ERR_PTR(-EINVAL); } spin_lock(&out->lock); @@ -689,36 +689,17 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id) if (out->deleted) { spin_unlock(&out->lock); rcu_read_unlock(); - return NULL; + return ERR_PTR(-EINVAL); } return out; } -void ipc_lock_by_ptr(struct kern_ipc_perm *perm) -{ - rcu_read_lock(); - spin_lock(&perm->lock); -} - -void ipc_unlock(struct kern_ipc_perm* perm) -{ - spin_unlock(&perm->lock); - rcu_read_unlock(); -} - int ipc_buildid(struct ipc_ids* ids, int id, int seq) { return SEQ_MULTIPLIER*seq + id; } -int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid) -{ - if(uid/SEQ_MULTIPLIER != ipcp->seq) - return 1; - return 0; -} - #ifdef __ARCH_WANT_IPC_PARSE_VERSION diff --git a/ipc/util.h b/ipc/util.h index 1546eda7d99..c4b0a9865bf 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -11,6 +11,7 @@ #define _IPC_UTIL_H #include +#include #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) { -- 2.20.1