semctl(): separate all layout-dependent copyin/copyout
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/ipc/sem.c b/ipc/sem.c
index 9e70cd7..c8029c6 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1177,112 +1177,95 @@ static time_t get_semotime(struct sem_array *sma)
return res;
}
-static int semctl_nolock(struct ipc_namespace *ns, int semid,
- int cmd, int version, void __user *p)
+static int semctl_stat(struct ipc_namespace *ns, int semid,
+ int cmd, struct semid64_ds *semid64)
{
- int err;
struct sem_array *sma;
+ int id = 0;
+ int err;
- switch (cmd) {
- case IPC_INFO:
- case SEM_INFO:
- {
- struct seminfo seminfo;
- int max_id;
+ memset(semid64, 0, sizeof(*semid64));
- err = security_sem_semctl(NULL, cmd);
- if (err)
- return err;
-
- memset(&seminfo, 0, sizeof(seminfo));
- seminfo.semmni = ns->sc_semmni;
- seminfo.semmns = ns->sc_semmns;
- seminfo.semmsl = ns->sc_semmsl;
- seminfo.semopm = ns->sc_semopm;
- seminfo.semvmx = SEMVMX;
- seminfo.semmnu = SEMMNU;
- seminfo.semmap = SEMMAP;
- seminfo.semume = SEMUME;
- down_read(&sem_ids(ns).rwsem);
- if (cmd == SEM_INFO) {
- seminfo.semusz = sem_ids(ns).in_use;
- seminfo.semaem = ns->used_sems;
- } else {
- seminfo.semusz = SEMUSZ;
- seminfo.semaem = SEMAEM;
- }
- max_id = ipc_get_maxid(&sem_ids(ns));
- up_read(&sem_ids(ns).rwsem);
- if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
- return -EFAULT;
- return (max_id < 0) ? 0 : max_id;
- }
- case IPC_STAT:
- case SEM_STAT:
- {
- struct semid64_ds tbuf;
- int id = 0;
-
- memset(&tbuf, 0, sizeof(tbuf));
-
- rcu_read_lock();
- if (cmd == SEM_STAT) {
- sma = sem_obtain_object(ns, semid);
- if (IS_ERR(sma)) {
- err = PTR_ERR(sma);
- goto out_unlock;
- }
- id = sma->sem_perm.id;
- } else {
- sma = sem_obtain_object_check(ns, semid);
- if (IS_ERR(sma)) {
- err = PTR_ERR(sma);
- goto out_unlock;
- }
- }
-
- err = -EACCES;
- if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
+ rcu_read_lock();
+ if (cmd == SEM_STAT) {
+ sma = sem_obtain_object(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
goto out_unlock;
-
- err = security_sem_semctl(sma, cmd);
- if (err)
+ }
+ id = sma->sem_perm.id;
+ } else {
+ sma = sem_obtain_object_check(ns, semid);
+ if (IS_ERR(sma)) {
+ err = PTR_ERR(sma);
goto out_unlock;
+ }
+ }
- kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
- tbuf.sem_otime = get_semotime(sma);
- tbuf.sem_ctime = sma->sem_ctime;
- tbuf.sem_nsems = sma->sem_nsems;
- rcu_read_unlock();
- if (copy_semid_to_user(p, &tbuf, version))
- return -EFAULT;
- return id;
- }
- default:
- return -EINVAL;
- }
+ err = -EACCES;
+ if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
+ goto out_unlock;
+
+ err = security_sem_semctl(sma, cmd);
+ if (err)
+ goto out_unlock;
+
+ kernel_to_ipc64_perm(&sma->sem_perm, &semid64->sem_perm);
+ semid64->sem_otime = get_semotime(sma);
+ semid64->sem_ctime = sma->sem_ctime;
+ semid64->sem_nsems = sma->sem_nsems;
+ rcu_read_unlock();
+ return id;
+
out_unlock:
rcu_read_unlock();
return err;
}
+static int semctl_info(struct ipc_namespace *ns, int semid,
+ int cmd, void __user *p)
+{
+ struct seminfo seminfo;
+ int max_id;
+ int err;
+
+ err = security_sem_semctl(NULL, cmd);
+ if (err)
+ return err;
+
+ memset(&seminfo, 0, sizeof(seminfo));
+ seminfo.semmni = ns->sc_semmni;
+ seminfo.semmns = ns->sc_semmns;
+ seminfo.semmsl = ns->sc_semmsl;
+ seminfo.semopm = ns->sc_semopm;
+ seminfo.semvmx = SEMVMX;
+ seminfo.semmnu = SEMMNU;
+ seminfo.semmap = SEMMAP;
+ seminfo.semume = SEMUME;
+ down_read(&sem_ids(ns).rwsem);
+ if (cmd == SEM_INFO) {
+ seminfo.semusz = sem_ids(ns).in_use;
+ seminfo.semaem = ns->used_sems;
+ } else {
+ seminfo.semusz = SEMUSZ;
+ seminfo.semaem = SEMAEM;
+ }
+ max_id = ipc_get_maxid(&sem_ids(ns));
+ up_read(&sem_ids(ns).rwsem);
+ if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
+ return -EFAULT;
+ return (max_id < 0) ? 0 : max_id;
+}
+
static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
- unsigned long arg)
+ int val)
{
struct sem_undo *un;
struct sem_array *sma;
struct sem *curr;
- int err, val;
+ int err;
DEFINE_WAKE_Q(wake_q);
-#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
- /* big-endian 64bit */
- val = arg >> 32;
-#else
- /* 32bit or little-endian 64bit */
- val = arg;
-#endif
-
if (val > SEMVMX || val < 0)
return -ERANGE;
@@ -1531,23 +1514,17 @@ copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
* NOTE: no locks must be held, the rwsem is taken inside this function.
*/
static int semctl_down(struct ipc_namespace *ns, int semid,
- int cmd, int version, void __user *p)
+ int cmd, struct semid64_ds *semid64)
{
struct sem_array *sma;
int err;
- struct semid64_ds semid64;
struct kern_ipc_perm *ipcp;
- if (cmd == IPC_SET) {
- if (copy_semid_from_user(&semid64, p, version))
- return -EFAULT;
- }
-
down_write(&sem_ids(ns).rwsem);
rcu_read_lock();
ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,
- &semid64.sem_perm, 0);
+ &semid64->sem_perm, 0);
if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp);
goto out_unlock1;
@@ -1567,7 +1544,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
goto out_up;
case IPC_SET:
sem_lock(sma, NULL, -1);
- err = ipc_update_perm(&semid64.sem_perm, ipcp);
+ err = ipc_update_perm(&semid64->sem_perm, ipcp);
if (err)
goto out_unlock0;
sma->sem_ctime = get_seconds();
@@ -1591,6 +1568,8 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
int version;
struct ipc_namespace *ns;
void __user *p = (void __user *)arg;
+ struct semid64_ds semid64;
+ int err;
if (semid < 0)
return -EINVAL;
@@ -1601,9 +1580,15 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
switch (cmd) {
case IPC_INFO:
case SEM_INFO:
+ return semctl_info(ns, semid, cmd, p);
case IPC_STAT:
case SEM_STAT:
- return semctl_nolock(ns, semid, cmd, version, p);
+ err = semctl_stat(ns, semid, cmd, &semid64);
+ if (err < 0)
+ return err;
+ if (copy_semid_to_user(p, &semid64, version))
+ err = -EFAULT;
+ return err;
case GETALL:
case GETVAL:
case GETPID:
@@ -1611,11 +1596,22 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
case GETZCNT:
case SETALL:
return semctl_main(ns, semid, semnum, cmd, p);
- case SETVAL:
- return semctl_setval(ns, semid, semnum, arg);
- case IPC_RMID:
+ case SETVAL: {
+ int val;
+#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
+ /* big-endian 64bit */
+ val = arg >> 32;
+#else
+ /* 32bit or little-endian 64bit */
+ val = arg;
+#endif
+ return semctl_setval(ns, semid, semnum, val);
+ }
case IPC_SET:
- return semctl_down(ns, semid, cmd, version, p);
+ if (copy_semid_from_user(&semid64, p, version))
+ return -EFAULT;
+ case IPC_RMID:
+ return semctl_down(ns, semid, cmd, &semid64);
default:
return -EINVAL;
}
