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-rw-r--r--ipc/compat.c30
-rw-r--r--ipc/compat_mq.c2
-rw-r--r--ipc/ipc_sysctl.c14
-rw-r--r--ipc/mq_sysctl.c18
-rw-r--r--ipc/mqueue.c28
-rw-r--r--ipc/msg.c46
-rw-r--r--ipc/sem.c178
-rw-r--r--ipc/shm.c49
-rw-r--r--ipc/util.c290
-rw-r--r--ipc/util.h28
10 files changed, 350 insertions, 333 deletions
diff --git a/ipc/compat.c b/ipc/compat.c
index 892f6585dd60..f486b0096a67 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -197,7 +197,7 @@ static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
static inline int get_compat_semid64_ds(struct semid64_ds *s64,
struct compat_semid64_ds __user *up64)
{
- if (!access_ok (VERIFY_READ, up64, sizeof(*up64)))
+ if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
return -EFAULT;
return __get_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
}
@@ -205,7 +205,7 @@ static inline int get_compat_semid64_ds(struct semid64_ds *s64,
static inline int get_compat_semid_ds(struct semid64_ds *s,
struct compat_semid_ds __user *up)
{
- if (!access_ok (VERIFY_READ, up, sizeof(*up)))
+ if (!access_ok(VERIFY_READ, up, sizeof(*up)))
return -EFAULT;
return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
}
@@ -215,7 +215,7 @@ static inline int put_compat_semid64_ds(struct semid64_ds *s64,
{
int err;
- if (!access_ok (VERIFY_WRITE, up64, sizeof(*up64)))
+ if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
return -EFAULT;
err = __put_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
err |= __put_user(s64->sem_otime, &up64->sem_otime);
@@ -229,7 +229,7 @@ static inline int put_compat_semid_ds(struct semid64_ds *s,
{
int err;
- if (!access_ok (VERIFY_WRITE, up, sizeof(*up)))
+ if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
return -EFAULT;
err = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
err |= __put_user(s->sem_otime, &up->sem_otime);
@@ -288,11 +288,11 @@ static long do_compat_semctl(int first, int second, int third, u32 pad)
break;
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_semid64_ds(&s64, compat_ptr(pad));
- } else {
+ else
err = get_compat_semid_ds(&s64, compat_ptr(pad));
- }
+
up64 = compat_alloc_user_space(sizeof(s64));
if (copy_to_user(up64, &s64, sizeof(s64)))
err = -EFAULT;
@@ -376,12 +376,12 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
struct compat_ipc_kludge ipck;
if (!uptr)
return -EINVAL;
- if (copy_from_user (&ipck, uptr, sizeof(ipck)))
+ if (copy_from_user(&ipck, uptr, sizeof(ipck)))
return -EFAULT;
uptr = compat_ptr(ipck.msgp);
fifth = ipck.msgtyp;
}
- return do_msgrcv(first, uptr, second, fifth, third,
+ return do_msgrcv(first, uptr, second, (s32)fifth, third,
compat_do_msg_fill);
}
case MSGGET:
@@ -515,11 +515,11 @@ long compat_sys_msgctl(int first, int second, void __user *uptr)
break;
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_msqid64(&m64, uptr);
- } else {
+ else
err = get_compat_msqid(&m64, uptr);
- }
+
if (err)
break;
p = compat_alloc_user_space(sizeof(m64));
@@ -702,11 +702,11 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
case IPC_SET:
- if (version == IPC_64) {
+ if (version == IPC_64)
err = get_compat_shmid64_ds(&s64, uptr);
- } else {
+ else
err = get_compat_shmid_ds(&s64, uptr);
- }
+
if (err)
break;
p = compat_alloc_user_space(sizeof(s64));
diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c
index 380ea4fe08e7..63d7c6de335b 100644
--- a/ipc/compat_mq.c
+++ b/ipc/compat_mq.c
@@ -64,7 +64,7 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name,
return sys_mq_open(u_name, oflag, mode, p);
}
-static int compat_prepare_timeout(struct timespec __user * *p,
+static int compat_prepare_timeout(struct timespec __user **p,
const struct compat_timespec __user *u)
{
struct timespec ts;
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index b0e99deb6d05..17028648cfeb 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -164,21 +164,21 @@ static struct ctl_table ipc_kern_table[] = {
{
.procname = "shmmax",
.data = &init_ipc_ns.shm_ctlmax,
- .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
},
{
.procname = "shmall",
.data = &init_ipc_ns.shm_ctlall,
- .maxlen = sizeof (init_ipc_ns.shm_ctlall),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlall),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
},
{
.procname = "shmmni",
.data = &init_ipc_ns.shm_ctlmni,
- .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
+ .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
.mode = 0644,
.proc_handler = proc_ipc_dointvec,
},
@@ -194,7 +194,7 @@ static struct ctl_table ipc_kern_table[] = {
{
.procname = "msgmax",
.data = &init_ipc_ns.msg_ctlmax,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = &zero,
@@ -203,7 +203,7 @@ static struct ctl_table ipc_kern_table[] = {
{
.procname = "msgmni",
.data = &init_ipc_ns.msg_ctlmni,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
.mode = 0644,
.proc_handler = proc_ipc_callback_dointvec_minmax,
.extra1 = &zero,
@@ -212,7 +212,7 @@ static struct ctl_table ipc_kern_table[] = {
{
.procname = "msgmnb",
.data = &init_ipc_ns.msg_ctlmnb,
- .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
+ .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = &zero,
@@ -221,7 +221,7 @@ static struct ctl_table ipc_kern_table[] = {
{
.procname = "sem",
.data = &init_ipc_ns.sem_ctls,
- .maxlen = 4*sizeof (int),
+ .maxlen = 4*sizeof(int),
.mode = 0644,
.proc_handler = proc_ipc_dointvec,
},
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
index 383d638340b8..5bb8bfe67149 100644
--- a/ipc/mq_sysctl.c
+++ b/ipc/mq_sysctl.c
@@ -22,6 +22,16 @@ static void *get_mq(ctl_table *table)
return which;
}
+static int proc_mq_dointvec(ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table mq_table;
+ memcpy(&mq_table, table, sizeof(mq_table));
+ mq_table.data = get_mq(table);
+
+ return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
+}
+
static int proc_mq_dointvec_minmax(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -33,12 +43,10 @@ static int proc_mq_dointvec_minmax(ctl_table *table, int write,
lenp, ppos);
}
#else
+#define proc_mq_dointvec NULL
#define proc_mq_dointvec_minmax NULL
#endif
-static int msg_queues_limit_min = MIN_QUEUESMAX;
-static int msg_queues_limit_max = HARD_QUEUESMAX;
-
static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = HARD_MSGMAX;
@@ -51,9 +59,7 @@ static ctl_table mq_sysctls[] = {
.data = &init_ipc_ns.mq_queues_max,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_mq_dointvec_minmax,
- .extra1 = &msg_queues_limit_min,
- .extra2 = &msg_queues_limit_max,
+ .proc_handler = proc_mq_dointvec,
},
{
.procname = "msg_max",
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 95827ce2f3c7..c3b31179122c 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -6,7 +6,7 @@
*
* Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
* Lockless receive & send, fd based notify:
- * Manfred Spraul (manfred@colorfullife.com)
+ * Manfred Spraul (manfred@colorfullife.com)
*
* Audit: George Wilson (ltcgcw@us.ibm.com)
*
@@ -73,7 +73,7 @@ struct mqueue_inode_info {
struct mq_attr attr;
struct sigevent notify;
- struct pid* notify_owner;
+ struct pid *notify_owner;
struct user_namespace *notify_user_ns;
struct user_struct *user; /* user who created, for accounting */
struct sock *notify_sock;
@@ -92,7 +92,7 @@ static void remove_notification(struct mqueue_inode_info *info);
static struct kmem_cache *mqueue_inode_cachep;
-static struct ctl_table_header * mq_sysctl_table;
+static struct ctl_table_header *mq_sysctl_table;
static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
{
@@ -433,9 +433,9 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry,
error = -EACCES;
goto out_unlock;
}
- if (ipc_ns->mq_queues_count >= HARD_QUEUESMAX ||
- (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
- !capable(CAP_SYS_RESOURCE))) {
+
+ if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
+ !capable(CAP_SYS_RESOURCE)) {
error = -ENOSPC;
goto out_unlock;
}
@@ -466,13 +466,13 @@ out_unlock:
static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = dentry->d_inode;
dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
dir->i_size -= DIRENT_SIZE;
- drop_nlink(inode);
- dput(dentry);
- return 0;
+ drop_nlink(inode);
+ dput(dentry);
+ return 0;
}
/*
@@ -622,7 +622,7 @@ static struct ext_wait_queue *wq_get_first_waiter(
static inline void set_cookie(struct sk_buff *skb, char code)
{
- ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
+ ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
}
/*
@@ -1303,11 +1303,11 @@ retry:
out_fput:
fdput(f);
out:
- if (sock) {
+ if (sock)
netlink_detachskb(sock, nc);
- } else if (nc) {
+ else if (nc)
dev_kfree_skb(nc);
- }
+
return ret;
}
diff --git a/ipc/msg.c b/ipc/msg.c
index 558aa91186b6..649853105a5d 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -253,8 +253,14 @@ static void expunge_all(struct msg_queue *msq, int res)
struct msg_receiver *msr, *t;
list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
- msr->r_msg = NULL;
+ msr->r_msg = NULL; /* initialize expunge ordering */
wake_up_process(msr->r_tsk);
+ /*
+ * Ensure that the wakeup is visible before setting r_msg as
+ * the receiving end depends on it: either spinning on a nil,
+ * or dealing with -EAGAIN cases. See lockless receive part 1
+ * and 2 in do_msgrcv().
+ */
smp_mb();
msr->r_msg = ERR_PTR(res);
}
@@ -318,7 +324,7 @@ SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
static inline unsigned long
copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
@@ -363,7 +369,7 @@ copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
static inline unsigned long
copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
@@ -375,9 +381,9 @@ copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;
- out->msg_perm.uid = tbuf_old.msg_perm.uid;
- out->msg_perm.gid = tbuf_old.msg_perm.gid;
- out->msg_perm.mode = tbuf_old.msg_perm.mode;
+ out->msg_perm.uid = tbuf_old.msg_perm.uid;
+ out->msg_perm.gid = tbuf_old.msg_perm.gid;
+ out->msg_perm.mode = tbuf_old.msg_perm.mode;
if (tbuf_old.msg_qbytes == 0)
out->msg_qbytes = tbuf_old.msg_lqbytes;
@@ -606,13 +612,13 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
static int testmsg(struct msg_msg *msg, long type, int mode)
{
- switch(mode)
+ switch (mode)
{
case SEARCH_ANY:
case SEARCH_NUMBER:
return 1;
case SEARCH_LESSEQUAL:
- if (msg->m_type <=type)
+ if (msg->m_type <= type)
return 1;
break;
case SEARCH_EQUAL:
@@ -638,15 +644,22 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
list_del(&msr->r_list);
if (msr->r_maxsize < msg->m_ts) {
+ /* initialize pipelined send ordering */
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
- smp_mb();
+ smp_mb(); /* see barrier comment below */
msr->r_msg = ERR_PTR(-E2BIG);
} else {
msr->r_msg = NULL;
msq->q_lrpid = task_pid_vnr(msr->r_tsk);
msq->q_rtime = get_seconds();
wake_up_process(msr->r_tsk);
+ /*
+ * Ensure that the wakeup is visible before
+ * setting r_msg, as the receiving end depends
+ * on it. See lockless receive part 1 and 2 in
+ * do_msgrcv().
+ */
smp_mb();
msr->r_msg = msg;
@@ -654,6 +667,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
}
}
}
+
return 0;
}
@@ -696,7 +710,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
goto out_unlock0;
/* raced with RMID? */
- if (msq->q_perm.deleted) {
+ if (!ipc_valid_object(&msq->q_perm)) {
err = -EIDRM;
goto out_unlock0;
}
@@ -716,6 +730,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
goto out_unlock0;
}
+ /* enqueue the sender and prepare to block */
ss_add(msq, &s);
if (!ipc_rcu_getref(msq)) {
@@ -731,7 +746,8 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
ipc_lock_object(&msq->q_perm);
ipc_rcu_putref(msq, ipc_rcu_free);
- if (msq->q_perm.deleted) {
+ /* raced with RMID? */
+ if (!ipc_valid_object(&msq->q_perm)) {
err = -EIDRM;
goto out_unlock0;
}
@@ -885,6 +901,8 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
return -EINVAL;
if (msgflg & MSG_COPY) {
+ if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
+ return -EINVAL;
copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
if (IS_ERR(copy))
return PTR_ERR(copy);
@@ -909,7 +927,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
ipc_lock_object(&msq->q_perm);
/* raced with RMID? */
- if (msq->q_perm.deleted) {
+ if (!ipc_valid_object(&msq->q_perm)) {
msg = ERR_PTR(-EIDRM);
goto out_unlock0;
}
@@ -983,7 +1001,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
* wake_up_process(). There is a race with exit(), see
* ipc/mqueue.c for the details.
*/
- msg = (struct msg_msg*)msr_d.r_msg;
+ msg = (struct msg_msg *)msr_d.r_msg;
while (msg == NULL) {
cpu_relax();
msg = (struct msg_msg *)msr_d.r_msg;
@@ -1004,7 +1022,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
/* Lockless receive, part 4:
* Repeat test after acquiring the spinlock.
*/
- msg = (struct msg_msg*)msr_d.r_msg;
+ msg = (struct msg_msg *)msr_d.r_msg;
if (msg != ERR_PTR(-EAGAIN))
goto out_unlock0;
diff --git a/ipc/sem.c b/ipc/sem.c
index db9d241af133..bee555417312 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -188,7 +188,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
}
#endif
-void __init sem_init (void)
+void __init sem_init(void)
{
sem_init_ns(&init_ipc_ns);
ipc_init_proc_interface("sysvipc/sem",
@@ -225,7 +225,7 @@ static void unmerge_queues(struct sem_array *sma)
}
/**
- * merge_queues - Merge single semop queues into global queue
+ * merge_queues - merge single semop queues into global queue
* @sma: semaphore array
*
* This function merges all per-semaphore queues into the global queue.
@@ -394,7 +394,7 @@ static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns,
/* ipc_rmid() may have already freed the ID while sem_lock
* was spinning: verify that the structure is still valid
*/
- if (!ipcp->deleted)
+ if (ipc_valid_object(ipcp))
return container_of(ipcp, struct sem_array, sem_perm);
sem_unlock(sma, *locknum);
@@ -445,11 +445,11 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
* * call wake_up_process
* * set queue.status to the final value.
* - the previously blocked thread checks queue.status:
- * * if it's IN_WAKEUP, then it must wait until the value changes
- * * if it's not -EINTR, then the operation was completed by
- * update_queue. semtimedop can return queue.status without
- * performing any operation on the sem array.
- * * otherwise it must acquire the spinlock and check what's up.
+ * * if it's IN_WAKEUP, then it must wait until the value changes
+ * * if it's not -EINTR, then the operation was completed by
+ * update_queue. semtimedop can return queue.status without
+ * performing any operation on the sem array.
+ * * otherwise it must acquire the spinlock and check what's up.
*
* The two-stage algorithm is necessary to protect against the following
* races:
@@ -474,7 +474,6 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
*
* Called with sem_ids.rwsem held (as a writer)
*/
-
static int newary(struct ipc_namespace *ns, struct ipc_params *params)
{
int id;
@@ -491,12 +490,12 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
if (ns->used_sems + nsems > ns->sc_semmns)
return -ENOSPC;
- size = sizeof (*sma) + nsems * sizeof (struct sem);
+ size = sizeof(*sma) + nsems * sizeof(struct sem);
sma = ipc_rcu_alloc(size);
- if (!sma) {
+ if (!sma)
return -ENOMEM;
- }
- memset (sma, 0, size);
+
+ memset(sma, 0, size);
sma->sem_perm.mode = (semflg & S_IRWXUGO);
sma->sem_perm.key = key;
@@ -584,10 +583,11 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
}
-/** perform_atomic_semop - Perform (if possible) a semaphore operation
+/**
+ * perform_atomic_semop - Perform (if possible) a semaphore operation
* @sma: semaphore array
* @sops: array with operations that should be checked
- * @nsems: number of sops
+ * @nsops: number of operations
* @un: undo array
* @pid: pid that did the change
*
@@ -595,19 +595,18 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
* Returns 1 if the operation is impossible, the caller must sleep.
* Negative values are error codes.
*/
-
static int perform_atomic_semop(struct sem_array *sma, struct sembuf *sops,
int nsops, struct sem_undo *un, int pid)
{
int result, sem_op;
struct sembuf *sop;
- struct sem * curr;
+ struct sem *curr;
for (sop = sops; sop < sops + nsops; sop++) {
curr = sma->sem_base + sop->sem_num;
sem_op = sop->sem_op;
result = curr->semval;
-
+
if (!sem_op && result)
goto would_block;
@@ -616,25 +615,24 @@ static int perform_atomic_semop(struct sem_array *sma, struct sembuf *sops,
goto would_block;
if (result > SEMVMX)
goto out_of_range;
+
if (sop->sem_flg & SEM_UNDO) {
int undo = un->semadj[sop->sem_num] - sem_op;
- /*
- * Exceeding the undo range is an error.
- */
+ /* Exceeding the undo range is an error. */
if (undo < (-SEMAEM - 1) || undo > SEMAEM)
goto out_of_range;
+ un->semadj[sop->sem_num] = undo;
}
+
curr->semval = result;
}
sop--;
while (sop >= sops) {
sma->sem_base[sop->sem_num].sempid = pid;
- if (sop->sem_flg & SEM_UNDO)
- un->semadj[sop->sem_num] -= sop->sem_op;
sop--;
}
-
+
return 0;
out_of_range:
@@ -650,7 +648,10 @@ would_block:
undo:
sop--;
while (sop >= sops) {
- sma->sem_base[sop->sem_num].semval -= sop->sem_op;
+ sem_op = sop->sem_op;
+ sma->sem_base[sop->sem_num].semval -= sem_op;
+ if (sop->sem_flg & SEM_UNDO)
+ un->semadj[sop->sem_num] += sem_op;
sop--;
}
@@ -680,7 +681,7 @@ static void wake_up_sem_queue_prepare(struct list_head *pt,
}
/**
- * wake_up_sem_queue_do(pt) - do the actual wake-up
+ * wake_up_sem_queue_do - do the actual wake-up
* @pt: list of tasks to be woken up
*
* Do the actual wake-up.
@@ -746,7 +747,7 @@ static int check_restart(struct sem_array *sma, struct sem_queue *q)
}
/**
- * wake_const_ops(sma, semnum, pt) - Wake up non-alter tasks
+ * wake_const_ops - wake up non-alter tasks
* @sma: semaphore array.
* @semnum: semaphore that was modified.
* @pt: list head for the tasks that must be woken up.
@@ -796,15 +797,14 @@ static int wake_const_ops(struct sem_array *sma, int semnum,
}
/**
- * do_smart_wakeup_zero(sma, sops, nsops, pt) - wakeup all wait for zero tasks
+ * do_smart_wakeup_zero - wakeup all wait for zero tasks
* @sma: semaphore array
* @sops: operations that were performed
* @nsops: number of operations
* @pt: list head of the tasks that must be woken up.
*
- * do_smart_wakeup_zero() checks all required queue for wait-for-zero
- * operations, based on the actual changes that were performed on the
- * semaphore array.
+ * Checks all required queue for wait-for-zero operations, based
+ * on the actual changes that were performed on the semaphore array.
* The function returns 1 if at least one operation was completed successfully.
*/
static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
@@ -848,7 +848,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
/**
- * update_queue(sma, semnum): Look for tasks that can be completed.
+ * update_queue - look for tasks that can be completed.
* @sma: semaphore array.
* @semnum: semaphore that was modified.
* @pt: list head for the tasks that must be woken up.
@@ -918,7 +918,7 @@ again:
}
/**
- * set_semotime(sma, sops) - set sem_otime
+ * set_semotime - set sem_otime
* @sma: semaphore array
* @sops: operations that modified the array, may be NULL
*
@@ -936,7 +936,7 @@ static void set_semotime(struct sem_array *sma, struct sembuf *sops)
}
/**
- * do_smart_update(sma, sops, nsops, otime, pt) - optimized update_queue
+ * do_smart_update - optimized update_queue
* @sma: semaphore array
* @sops: operations that were performed
* @nsops: number of operations
@@ -998,21 +998,21 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
* The counts we return here are a rough approximation, but still
* warrant that semncnt+semzcnt>0 if the task is on the pending queue.
*/
-static int count_semncnt (struct sem_array * sma, ushort semnum)
+static int count_semncnt(struct sem_array *sma, ushort semnum)
{
int semncnt;
- struct sem_queue * q;
+ struct sem_queue *q;
semncnt = 0;
list_for_each_entry(q, &sma->sem_base[semnum].pending_alter, list) {
- struct sembuf * sops = q->sops;
+ struct sembuf *sops = q->sops;
BUG_ON(sops->sem_num != semnum);
if ((sops->sem_op < 0) && !(sops->sem_flg & IPC_NOWAIT))
semncnt++;
}
list_for_each_entry(q, &sma->pending_alter, list) {
- struct sembuf * sops = q->sops;
+ struct sembuf *sops = q->sops;
int nsops = q->nsops;
int i;
for (i = 0; i < nsops; i++)
@@ -1024,21 +1024,21 @@ static int count_semncnt (struct sem_array * sma, ushort semnum)
return semncnt;
}
-static int count_semzcnt (struct sem_array * sma, ushort semnum)
+static int count_semzcnt(struct sem_array *sma, ushort semnum)
{
int semzcnt;
- struct sem_queue * q;
+ struct sem_queue *q;
semzcnt = 0;
list_for_each_entry(q, &sma->sem_base[semnum].pending_const, list) {
- struct sembuf * sops = q->sops;
+ struct sembuf *sops = q->sops;
BUG_ON(sops->sem_num != semnum);
if ((sops->sem_op == 0) && !(sops->sem_flg & IPC_NOWAIT))
semzcnt++;
}
list_for_each_entry(q, &sma->pending_const, list) {
- struct sembuf * sops = q->sops;
+ struct sembuf *sops = q->sops;
int nsops = q->nsops;
int i;
for (i = 0; i < nsops; i++)
@@ -1108,7 +1108,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
@@ -1151,7 +1151,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
int err;
struct sem_array *sma;
- switch(cmd) {
+ switch (cmd) {
case IPC_INFO:
case SEM_INFO:
{
@@ -1162,7 +1162,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
if (err)
return err;
- memset(&seminfo,0,sizeof(seminfo));
+ memset(&seminfo, 0, sizeof(seminfo));
seminfo.semmni = ns->sc_semmni;
seminfo.semmns = ns->sc_semmns;
seminfo.semmsl = ns->sc_semmsl;
@@ -1183,7 +1183,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
up_read(&sem_ids(ns).rwsem);
if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
return -EFAULT;
- return (max_id < 0) ? 0: max_id;
+ return (max_id < 0) ? 0 : max_id;
}
case IPC_STAT:
case SEM_STAT:
@@ -1239,7 +1239,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
{
struct sem_undo *un;
struct sem_array *sma;
- struct sem* curr;
+ struct sem *curr;
int err;
struct list_head tasks;
int val;
@@ -1282,7 +1282,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
sem_lock(sma, NULL, -1);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
sem_unlock(sma, -1);
rcu_read_unlock();
return -EIDRM;
@@ -1309,10 +1309,10 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int cmd, void __user *p)
{
struct sem_array *sma;
- struct sem* curr;
+ struct sem *curr;
int err, nsems;
ushort fast_sem_io[SEMMSL_FAST];
- ushort* sem_io = fast_sem_io;
+ ushort *sem_io = fast_sem_io;
struct list_head tasks;
INIT_LIST_HEAD(&tasks);
@@ -1342,11 +1342,11 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int i;
sem_lock(sma, NULL, -1);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
goto out_unlock;
}
- if(nsems > SEMMSL_FAST) {
+ if (nsems > SEMMSL_FAST) {
if (!ipc_rcu_getref(sma)) {
err = -EIDRM;
goto out_unlock;
@@ -1354,14 +1354,14 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
sem_unlock(sma, -1);
rcu_read_unlock();
sem_io = ipc_alloc(sizeof(ushort)*nsems);
- if(sem_io == NULL) {
+ if (sem_io == NULL) {
ipc_rcu_putref(sma, ipc_rcu_free);
return -ENOMEM;
}
rcu_read_lock();
sem_lock_and_putref(sma);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
goto out_unlock;
}
@@ -1371,7 +1371,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
sem_unlock(sma, -1);
rcu_read_unlock();
err = 0;
- if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
+ if (copy_to_user(array, sem_io, nsems*sizeof(ushort)))
err = -EFAULT;
goto out_free;
}
@@ -1386,15 +1386,15 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
}
rcu_read_unlock();
- if(nsems > SEMMSL_FAST) {
+ if (nsems > SEMMSL_FAST) {
sem_io = ipc_alloc(sizeof(ushort)*nsems);
- if(sem_io == NULL) {
+ if (sem_io == NULL) {
ipc_rcu_putref(sma, ipc_rcu_free);
return -ENOMEM;
}
}
- if (copy_from_user (sem_io, p, nsems*sizeof(ushort))) {
+ if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
ipc_rcu_putref(sma, ipc_rcu_free);
err = -EFAULT;
goto out_free;
@@ -1409,7 +1409,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
}
rcu_read_lock();
sem_lock_and_putref(sma);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
goto out_unlock;
}
@@ -1435,7 +1435,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
goto out_rcu_wakeup;
sem_lock(sma, NULL, -1);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
err = -EIDRM;
goto out_unlock;
}
@@ -1449,10 +1449,10 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
err = curr->sempid;
goto out_unlock;
case GETNCNT:
- err = count_semncnt(sma,semnum);
+ err = count_semncnt(sma, semnum);
goto out_unlock;
case GETZCNT:
- err = count_semzcnt(sma,semnum);
+ err = count_semzcnt(sma, semnum);
goto out_unlock;
}
@@ -1462,7 +1462,7 @@ out_rcu_wakeup:
rcu_read_unlock();
wake_up_sem_queue_do(&tasks);
out_free:
- if(sem_io != fast_sem_io)
+ if (sem_io != fast_sem_io)
ipc_free(sem_io, sizeof(ushort)*nsems);
return err;
}
@@ -1470,7 +1470,7 @@ out_free:
static inline unsigned long
copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
@@ -1479,7 +1479,7 @@ copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
{
struct semid_ds tbuf_old;
- if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+ if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
return -EFAULT;
out->sem_perm.uid = tbuf_old.sem_perm.uid;
@@ -1506,7 +1506,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
struct semid64_ds semid64;
struct kern_ipc_perm *ipcp;
- if(cmd == IPC_SET) {
+ if (cmd == IPC_SET) {
if (copy_semid_from_user(&semid64, p, version))
return -EFAULT;
}
@@ -1566,7 +1566,7 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
version = ipc_parse_version(&cmd);
ns = current->nsproxy->ipc_ns;
- switch(cmd) {
+ switch (cmd) {
case IPC_INFO:
case SEM_INFO:
case IPC_STAT:
@@ -1634,7 +1634,7 @@ static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
{
struct sem_undo *un;
- assert_spin_locked(&ulp->lock);
+ assert_spin_locked(&ulp->lock);
un = __lookup_undo(ulp, semid);
if (un) {
@@ -1645,7 +1645,7 @@ static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
}
/**
- * find_alloc_undo - Lookup (and if not present create) undo array
+ * find_alloc_undo - lookup (and if not present create) undo array
* @ns: namespace
* @semid: semaphore array id
*
@@ -1670,7 +1670,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
spin_lock(&ulp->lock);
un = lookup_undo(ulp, semid);
spin_unlock(&ulp->lock);
- if (likely(un!=NULL))
+ if (likely(un != NULL))
goto out;
/* no undo structure around - allocate one. */
@@ -1699,7 +1699,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
/* step 3: Acquire the lock on semaphore array */
rcu_read_lock();
sem_lock_and_putref(sma);
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
sem_unlock(sma, -1);
rcu_read_unlock();
kfree(new);
@@ -1735,7 +1735,7 @@ out:
/**
- * get_queue_result - Retrieve the result code from sem_queue
+ * get_queue_result - retrieve the result code from sem_queue
* @q: Pointer to queue structure
*
* Retrieve the return code from the pending queue. If IN_WAKEUP is found in
@@ -1765,7 +1765,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
int error = -EINVAL;
struct sem_array *sma;
struct sembuf fast_sops[SEMOPM_FAST];
- struct sembuf* sops = fast_sops, *sop;
+ struct sembuf *sops = fast_sops, *sop;
struct sem_undo *un;
int undos = 0, alter = 0, max, locknum;
struct sem_queue queue;
@@ -1779,13 +1779,13 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
return -EINVAL;
if (nsops > ns->sc_semopm)
return -E2BIG;
- if(nsops > SEMOPM_FAST) {
- sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
- if(sops==NULL)
+ if (nsops > SEMOPM_FAST) {
+ sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
+ if (sops == NULL)
return -ENOMEM;
}
- if (copy_from_user (sops, tsops, nsops * sizeof(*tsops))) {
- error=-EFAULT;
+ if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
+ error = -EFAULT;
goto out_free;
}
if (timeout) {
@@ -1846,7 +1846,15 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
error = -EIDRM;
locknum = sem_lock(sma, sops, nsops);
- if (sma->sem_perm.deleted)
+ /*
+ * We eventually might perform the following check in a lockless
+ * fashion, considering ipc_valid_object() locking constraints.
+ * If nsops == 1 and there is no contention for sem_perm.lock, then
+ * only a per-semaphore lock is held and it's OK to proceed with the
+ * check below. More details on the fine grained locking scheme
+ * entangled here and why it's RMID race safe on comments at sem_lock()
+ */
+ if (!ipc_valid_object(&sma->sem_perm))
goto out_unlock_free;
/*
* semid identifiers are not unique - find_alloc_undo may have
@@ -1959,10 +1967,8 @@ sleep_again:
* If queue.status != -EINTR we are woken up by another process.
* Leave without unlink_queue(), but with sem_unlock().
*/
-
- if (error != -EINTR) {
+ if (error != -EINTR)
goto out_unlock_free;
- }
/*
* If an interrupt occurred we have to clean up the queue
@@ -1984,7 +1990,7 @@ out_rcu_wakeup:
rcu_read_unlock();
wake_up_sem_queue_do(&tasks);
out_free:
- if(sops != fast_sops)
+ if (sops != fast_sops)
kfree(sops);
return error;
}
@@ -2068,7 +2074,7 @@ void exit_sem(struct task_struct *tsk)
sem_lock(sma, NULL, -1);
/* exit_sem raced with IPC_RMID, nothing to do */
- if (sma->sem_perm.deleted) {
+ if (!ipc_valid_object(&sma->sem_perm)) {
sem_unlock(sma, -1);
rcu_read_unlock();
continue;
@@ -2093,7 +2099,7 @@ void exit_sem(struct task_struct *tsk)
/* perform adjustments registered in un */
for (i = 0; i < sma->sem_nsems; i++) {
- struct sem * semaphore = &sma->sem_base[i];
+ struct sem *semaphore = &sma->sem_base[i];
if (un->semadj[i]) {
semaphore->semval += un->semadj[i];
/*
@@ -2107,7 +2113,7 @@ void exit_sem(struct task_struct *tsk)
* Linux caps the semaphore value, both at 0
* and at SEMVMX.
*
- * Manfred <manfred@colorfullife.com>
+ * Manfred <manfred@colorfullife.com>
*/
if (semaphore->semval < 0)
semaphore->semval = 0;
diff --git a/ipc/shm.c b/ipc/shm.c
index 7a51443a51d6..76459616a7fa 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -67,7 +67,7 @@ static const struct vm_operations_struct shm_vm_ops;
static int newseg(struct ipc_namespace *, struct ipc_params *);
static void shm_open(struct vm_area_struct *vma);
static void shm_close(struct vm_area_struct *vma);
-static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
#ifdef CONFIG_PROC_FS
static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
#endif
@@ -91,7 +91,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
struct shmid_kernel *shp;
shp = container_of(ipcp, struct shmid_kernel, shm_perm);
- if (shp->shm_nattch){
+ if (shp->shm_nattch) {
shp->shm_perm.mode |= SHM_DEST;
/* Do not find it any more */
shp->shm_perm.key = IPC_PRIVATE;
@@ -116,7 +116,7 @@ static int __init ipc_ns_init(void)
pure_initcall(ipc_ns_init);
-void __init shm_init (void)
+void __init shm_init(void)
{
ipc_init_proc_interface("sysvipc/shm",
#if BITS_PER_LONG <= 32
@@ -248,7 +248,7 @@ static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
*/
static void shm_close(struct vm_area_struct *vma)
{
- struct file * file = vma->vm_file;
+ struct file *file = vma->vm_file;
struct shm_file_data *sfd = shm_file_data(file);
struct shmid_kernel *shp;
struct ipc_namespace *ns = sfd->ns;
@@ -379,7 +379,7 @@ static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
}
#endif
-static int shm_mmap(struct file * file, struct vm_area_struct * vma)
+static int shm_mmap(struct file *file, struct vm_area_struct *vma)
{
struct shm_file_data *sfd = shm_file_data(file);
int ret;
@@ -477,7 +477,6 @@ static const struct vm_operations_struct shm_vm_ops = {
*
* Called with shm_ids.rwsem held as a writer.
*/
-
static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
{
key_t key = params->key;
@@ -486,7 +485,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
int error;
struct shmid_kernel *shp;
size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- struct file * file;
+ struct file *file;
char name[13];
int id;
vm_flags_t acctflag = 0;
@@ -512,7 +511,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
return error;
}
- sprintf (name, "SYSV%08x", key);
+ sprintf(name, "SYSV%08x", key);
if (shmflg & SHM_HUGETLB) {
struct hstate *hs;
size_t hugesize;
@@ -533,7 +532,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
} else {
/*
* Do not allow no accounting for OVERCOMMIT_NEVER, even
- * if it's asked for.
+ * if it's asked for.
*/
if ((shmflg & SHM_NORESERVE) &&
sysctl_overcommit_memory != OVERCOMMIT_NEVER)
@@ -628,7 +627,7 @@ SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
@@ -655,7 +654,7 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
static inline unsigned long
copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
if (copy_from_user(out, buf, sizeof(*out)))
return -EFAULT;
@@ -680,14 +679,14 @@ copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
{
- switch(version) {
+ switch (version) {
case IPC_64:
return copy_to_user(buf, in, sizeof(*in));
case IPC_OLD:
{
struct shminfo out;
- if(in->shmmax > INT_MAX)
+ if (in->shmmax > INT_MAX)
out.shmmax = INT_MAX;
else
out.shmmax = (int)in->shmmax;
@@ -846,14 +845,14 @@ static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
shminfo.shmall = ns->shm_ctlall;
shminfo.shmmin = SHMMIN;
- if(copy_shminfo_to_user (buf, &shminfo, version))
+ if (copy_shminfo_to_user(buf, &shminfo, version))
return -EFAULT;
down_read(&shm_ids(ns).rwsem);
err = ipc_get_maxid(&shm_ids(ns));
up_read(&shm_ids(ns).rwsem);
- if(err<0)
+ if (err < 0)
err = 0;
goto out;
}
@@ -864,7 +863,7 @@ static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
memset(&shm_info, 0, sizeof(shm_info));
down_read(&shm_ids(ns).rwsem);
shm_info.used_ids = shm_ids(ns).in_use;
- shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
+ shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
shm_info.shm_tot = ns->shm_tot;
shm_info.swap_attempts = 0;
shm_info.swap_successes = 0;
@@ -975,6 +974,13 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
goto out_unlock1;
ipc_lock_object(&shp->shm_perm);
+
+ /* check if shm_destroy() is tearing down shp */
+ if (!ipc_valid_object(&shp->shm_perm)) {
+ err = -EIDRM;
+ goto out_unlock0;
+ }
+
if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
kuid_t euid = current_euid();
if (!uid_eq(euid, shp->shm_perm.uid) &&
@@ -989,13 +995,6 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
}
shm_file = shp->shm_file;
-
- /* check if shm_destroy() is tearing down shp */
- if (shm_file == NULL) {
- err = -EIDRM;
- goto out_unlock0;
- }
-
if (is_file_hugepages(shm_file))
goto out_unlock0;
@@ -1047,7 +1046,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
struct shmid_kernel *shp;
unsigned long addr;
unsigned long size;
- struct file * file;
+ struct file *file;
int err;
unsigned long flags;
unsigned long prot;
@@ -1116,7 +1115,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
ipc_lock_object(&shp->shm_perm);
/* check if shm_destroy() is tearing down shp */
- if (shp->shm_file == NULL) {
+ if (!ipc_valid_object(&shp->shm_perm)) {
ipc_unlock_object(&shp->shm_perm);
err = -EIDRM;
goto out_unlock;
diff --git a/ipc/util.c b/ipc/util.c
index 3ae17a4ace5b..e1b4c6db8aa0 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -110,15 +110,15 @@ static struct notifier_block ipc_memory_nb = {
};
/**
- * ipc_init - initialise IPC subsystem
+ * ipc_init - initialise ipc subsystem
*
- * The various system5 IPC resources (semaphores, messages and shared
- * memory) are initialised
- * A callback routine is registered into the memory hotplug notifier
- * chain: since msgmni scales to lowmem this callback routine will be
- * called upon successful memory add / remove to recompute msmgni.
+ * The various sysv ipc resources (semaphores, messages and shared
+ * memory) are initialised.
+ *
+ * A callback routine is registered into the memory hotplug notifier
+ * chain: since msgmni scales to lowmem this callback routine will be
+ * called upon successful memory add / remove to recompute msmgni.
*/
-
static int __init ipc_init(void)
{
sem_init();
@@ -131,39 +131,29 @@ static int __init ipc_init(void)
__initcall(ipc_init);
/**
- * ipc_init_ids - initialise IPC identifiers
- * @ids: Identifier set
+ * ipc_init_ids - initialise ipc identifiers
+ * @ids: ipc identifier set
*
- * Set up the sequence range to use for the ipc identifier range (limited
- * below IPCMNI) then initialise the ids idr.
+ * Set up the sequence range to use for the ipc identifier range (limited
+ * below IPCMNI) then initialise the ids idr.
*/
-
void ipc_init_ids(struct ipc_ids *ids)
{
- init_rwsem(&ids->rwsem);
-
ids->in_use = 0;
ids->seq = 0;
ids->next_id = -1;
- {
- int seq_limit = INT_MAX/SEQ_MULTIPLIER;
- if (seq_limit > USHRT_MAX)
- ids->seq_max = USHRT_MAX;
- else
- ids->seq_max = seq_limit;
- }
-
+ init_rwsem(&ids->rwsem);
idr_init(&ids->ipcs_idr);
}
#ifdef CONFIG_PROC_FS
static const struct file_operations sysvipc_proc_fops;
/**
- * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface.
- * @path: Path in procfs
- * @header: Banner to be printed at the beginning of the file.
- * @ids: ipc id table to iterate.
- * @show: show routine.
+ * ipc_init_proc_interface - create a proc interface for sysipc types using a seq_file interface.
+ * @path: Path in procfs
+ * @header: Banner to be printed at the beginning of the file.
+ * @ids: ipc id table to iterate.
+ * @show: show routine.
*/
void __init ipc_init_proc_interface(const char *path, const char *header,
int ids, int (*show)(struct seq_file *, void *))
@@ -184,23 +174,21 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
NULL, /* parent dir */
&sysvipc_proc_fops,
iface);
- if (!pde) {
+ if (!pde)
kfree(iface);
- }
}
#endif
/**
- * ipc_findkey - find a key in an ipc identifier set
- * @ids: Identifier set
- * @key: The key to find
+ * ipc_findkey - find a key in an ipc identifier set
+ * @ids: ipc identifier set
+ * @key: key to find
*
- * Requires ipc_ids.rwsem locked.
- * Returns the LOCKED pointer to the ipc structure if found or NULL
- * if not.
- * If key is found ipc points to the owning ipc structure
+ * Returns the locked pointer to the ipc structure if found or NULL
+ * otherwise. If key is found ipc points to the owning ipc structure
+ *
+ * Called with ipc_ids.rwsem held.
*/
-
static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
{
struct kern_ipc_perm *ipc;
@@ -227,12 +215,11 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
}
/**
- * ipc_get_maxid - get the last assigned id
- * @ids: IPC identifier set
+ * ipc_get_maxid - get the last assigned id
+ * @ids: ipc identifier set
*
- * Called with ipc_ids.rwsem held.
+ * Called with ipc_ids.rwsem held.
*/
-
int ipc_get_maxid(struct ipc_ids *ids)
{
struct kern_ipc_perm *ipc;
@@ -258,19 +245,19 @@ int ipc_get_maxid(struct ipc_ids *ids)
}
/**
- * ipc_addid - add an IPC identifier
- * @ids: IPC identifier set
- * @new: new IPC permission set
- * @size: limit for the number of used ids
+ * ipc_addid - add an ipc identifier
+ * @ids: ipc identifier set
+ * @new: new ipc permission set
+ * @size: limit for the number of used ids
*
- * Add an entry 'new' to the IPC ids idr. The permissions object is
- * initialised and the first free entry is set up and the id assigned
- * is returned. The 'new' entry is returned in a locked state on success.
- * On failure the entry is not locked and a negative err-code is returned.
+ * Add an entry 'new' to the ipc ids idr. The permissions object is
+ * initialised and the first free entry is set up and the id assigned
+ * is returned. The 'new' entry is returned in a locked state on success.
+ * On failure the entry is not locked and a negative err-code is returned.
*
- * Called with writer ipc_ids.rwsem held.
+ * Called with writer ipc_ids.rwsem held.
*/
-int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
+int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
{
kuid_t euid;
kgid_t egid;
@@ -286,7 +273,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
idr_preload(GFP_KERNEL);
spin_lock_init(&new->lock);
- new->deleted = 0;
+ new->deleted = false;
rcu_read_lock();
spin_lock(&new->lock);
@@ -308,7 +295,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
if (next_id < 0) {
new->seq = ids->seq++;
- if (ids->seq > ids->seq_max)
+ if (ids->seq > IPCID_SEQ_MAX)
ids->seq = 0;
} else {
new->seq = ipcid_to_seqx(next_id);
@@ -320,14 +307,14 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
}
/**
- * ipcget_new - create a new ipc object
- * @ns: namespace
- * @ids: IPC identifer set
- * @ops: the actual creation routine to call
- * @params: its parameters
- *
- * This routine is called by sys_msgget, sys_semget() and sys_shmget()
- * when the key is IPC_PRIVATE.
+ * ipcget_new - create a new ipc object
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is IPC_PRIVATE.
*/
static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params)
@@ -341,19 +328,19 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
}
/**
- * ipc_check_perms - check security and permissions for an IPC
- * @ns: IPC namespace
- * @ipcp: ipc permission set
- * @ops: the actual security routine to call
- * @params: its parameters
+ * ipc_check_perms - check security and permissions for an ipc object
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @ops: the actual security routine to call
+ * @params: its parameters
*
- * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
- * when the key is not IPC_PRIVATE and that key already exists in the
- * ids IDR.
+ * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE and that key already exists in the
+ * ds IDR.
*
- * On success, the IPC id is returned.
+ * On success, the ipc id is returned.
*
- * It is called with ipc_ids.rwsem and ipcp->lock held.
+ * It is called with ipc_ids.rwsem and ipcp->lock held.
*/
static int ipc_check_perms(struct ipc_namespace *ns,
struct kern_ipc_perm *ipcp,
@@ -374,18 +361,18 @@ static int ipc_check_perms(struct ipc_namespace *ns,
}
/**
- * ipcget_public - get an ipc object or create a new one
- * @ns: namespace
- * @ids: IPC identifer set
- * @ops: the actual creation routine to call
- * @params: its parameters
- *
- * This routine is called by sys_msgget, sys_semget() and sys_shmget()
- * when the key is not IPC_PRIVATE.
- * It adds a new entry if the key is not found and does some permission
- * / security checkings if the key is found.
- *
- * On success, the ipc id is returned.
+ * ipcget_public - get an ipc object or create a new one
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
+ * @ops: the actual creation routine to call
+ * @params: its parameters
+ *
+ * This routine is called by sys_msgget, sys_semget() and sys_shmget()
+ * when the key is not IPC_PRIVATE.
+ * It adds a new entry if the key is not found and does some permission
+ * / security checkings if the key is found.
+ *
+ * On success, the ipc id is returned.
*/
static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params)
@@ -431,39 +418,33 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
/**
- * ipc_rmid - remove an IPC identifier
- * @ids: IPC identifier set
- * @ipcp: ipc perm structure containing the identifier to remove
+ * ipc_rmid - remove an ipc identifier
+ * @ids: ipc identifier set
+ * @ipcp: ipc perm structure containing the identifier to remove
*
- * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
- * before this function is called, and remain locked on the exit.
+ * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
+ * before this function is called, and remain locked on the exit.
*/
-
void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
{
int lid = ipcid_to_idx(ipcp->id);
idr_remove(&ids->ipcs_idr, lid);
-
ids->in_use--;
-
- ipcp->deleted = 1;
-
- return;
+ ipcp->deleted = true;
}
/**
- * ipc_alloc - allocate ipc space
- * @size: size desired
+ * ipc_alloc - allocate ipc space
+ * @size: size desired
*
- * Allocate memory from the appropriate pools and return a pointer to it.
- * NULL is returned if the allocation fails
+ * Allocate memory from the appropriate pools and return a pointer to it.
+ * NULL is returned if the allocation fails
*/
-
void *ipc_alloc(int size)
{
void *out;
- if(size > PAGE_SIZE)
+ if (size > PAGE_SIZE)
out = vmalloc(size);
else
out = kmalloc(size, GFP_KERNEL);
@@ -471,28 +452,27 @@ void *ipc_alloc(int size)
}
/**
- * ipc_free - free ipc space
- * @ptr: pointer returned by ipc_alloc
- * @size: size of block
+ * ipc_free - free ipc space
+ * @ptr: pointer returned by ipc_alloc
+ * @size: size of block
*
- * Free a block created with ipc_alloc(). The caller must know the size
- * used in the allocation call.
+ * Free a block created with ipc_alloc(). The caller must know the size
+ * used in the allocation call.
*/
-
-void ipc_free(void* ptr, int size)
+void ipc_free(void *ptr, int size)
{
- if(size > PAGE_SIZE)
+ if (size > PAGE_SIZE)
vfree(ptr);
else
kfree(ptr);
}
/**
- * ipc_rcu_alloc - allocate ipc and rcu space
- * @size: size desired
+ * ipc_rcu_alloc - allocate ipc and rcu space
+ * @size: size desired
*
- * Allocate memory for the rcu header structure + the object.
- * Returns the pointer to the object or NULL upon failure.
+ * Allocate memory for the rcu header structure + the object.
+ * Returns the pointer to the object or NULL upon failure.
*/
void *ipc_rcu_alloc(int size)
{
@@ -534,17 +514,16 @@ void ipc_rcu_free(struct rcu_head *head)
}
/**
- * ipcperms - check IPC permissions
- * @ns: IPC namespace
- * @ipcp: IPC permission set
- * @flag: desired permission set.
+ * ipcperms - check ipc permissions
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @flag: desired permission set
*
- * Check user, group, other permissions for access
- * to ipc resources. return 0 if allowed
+ * Check user, group, other permissions for access
+ * to ipc resources. return 0 if allowed
*
- * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
+ * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
*/
-
int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
{
kuid_t euid = current_euid();
@@ -572,16 +551,14 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
*/
/**
- * kernel_to_ipc64_perm - convert kernel ipc permissions to user
- * @in: kernel permissions
- * @out: new style IPC permissions
+ * kernel_to_ipc64_perm - convert kernel ipc permissions to user
+ * @in: kernel permissions
+ * @out: new style ipc permissions
*
- * Turn the kernel object @in into a set of permissions descriptions
- * for returning to userspace (@out).
+ * Turn the kernel object @in into a set of permissions descriptions
+ * for returning to userspace (@out).
*/
-
-
-void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
{
out->key = in->key;
out->uid = from_kuid_munged(current_user_ns(), in->uid);
@@ -593,15 +570,14 @@ void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
}
/**
- * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
- * @in: new style IPC permissions
- * @out: old style IPC permissions
+ * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
+ * @in: new style ipc permissions
+ * @out: old style ipc permissions
*
- * Turn the new style permissions object @in into a compatibility
- * object and store it into the @out pointer.
+ * Turn the new style permissions object @in into a compatibility
+ * object and store it into the @out pointer.
*/
-
-void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
{
out->key = in->key;
SET_UID(out->uid, in->uid);
@@ -635,8 +611,8 @@ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
}
/**
- * ipc_lock - Lock an ipc structure without rwsem held
- * @ids: IPC identifier set
+ * ipc_lock - lock an ipc structure without rwsem held
+ * @ids: ipc identifier set
* @id: ipc id to look for
*
* Look for an id in the ipc ids idr and lock the associated ipc object.
@@ -657,7 +633,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
/* ipc_rmid() may have already freed the ID while ipc_lock
* was spinning: here verify that the structure is still valid
*/
- if (!out->deleted)
+ if (ipc_valid_object(out))
return out;
spin_unlock(&out->lock);
@@ -693,11 +669,11 @@ out:
/**
* ipcget - Common sys_*get() code
- * @ns : namsepace
- * @ids : IPC identifier set
- * @ops : operations to be called on ipc object creation, permission checks
- * and further checks
- * @params : the parameters needed by the previous operations.
+ * @ns: namsepace
+ * @ids: ipc identifier set
+ * @ops: operations to be called on ipc object creation, permission checks
+ * and further checks
+ * @params: the parameters needed by the previous operations.
*
* Common routine called by sys_msgget(), sys_semget() and sys_shmget().
*/
@@ -711,7 +687,7 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
}
/**
- * ipc_update_perm - update the permissions of an IPC.
+ * ipc_update_perm - update the permissions of an ipc object
* @in: the permission given as input.
* @out: the permission of the ipc to set.
*/
@@ -732,7 +708,7 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
/**
* ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
- * @ns: the ipc namespace
+ * @ns: ipc namespace
* @ids: the table of ids where to look for the ipc
* @id: the id of the ipc to retrieve
* @cmd: the cmd to check
@@ -779,15 +755,14 @@ err:
/**
- * ipc_parse_version - IPC call version
- * @cmd: pointer to command
+ * ipc_parse_version - ipc call version
+ * @cmd: pointer to command
*
- * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
- * The @cmd value is turned from an encoding command and version into
- * just the command code.
+ * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
+ * The @cmd value is turned from an encoding command and version into
+ * just the command code.
*/
-
-int ipc_parse_version (int *cmd)
+int ipc_parse_version(int *cmd)
{
if (*cmd & IPC_64) {
*cmd ^= IPC_64;
@@ -824,7 +799,7 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
if (total >= ids->in_use)
return NULL;
- for ( ; pos < IPCMNI; pos++) {
+ for (; pos < IPCMNI; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) {
*new_pos = pos + 1;
@@ -927,8 +902,10 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
goto out;
ret = seq_open(file, &sysvipc_proc_seqops);
- if (ret)
- goto out_kfree;
+ if (ret) {
+ kfree(iter);
+ goto out;
+ }
seq = file->private_data;
seq->private = iter;
@@ -937,9 +914,6 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
out:
return ret;
-out_kfree:
- kfree(iter);
- goto out;
}
static int sysvipc_proc_release(struct inode *inode, struct file *file)
diff --git a/ipc/util.h b/ipc/util.h
index 59d78aa94987..9c47d6f6c7b4 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -15,9 +15,9 @@
#define SEQ_MULTIPLIER (IPCMNI)
-void sem_init (void);
-void msg_init (void);
-void shm_init (void);
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
struct ipc_namespace;
@@ -100,6 +100,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
/* must be called with ids->rwsem acquired for writing */
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
@@ -116,8 +117,8 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
/* for rare, potentially huge allocations.
* both function can sleep
*/
-void* ipc_alloc(int size);
-void ipc_free(void* ptr, int size);
+void *ipc_alloc(int size);
+void ipc_free(void *ptr, int size);
/*
* For allocation that need to be freed by RCU.
@@ -125,7 +126,7 @@ void ipc_free(void* ptr, int size);
* getref increases the refcount, the putref call that reduces the recount
* to 0 schedules the rcu destruction. Caller must guarantee locking.
*/
-void* ipc_rcu_alloc(int size);
+void *ipc_rcu_alloc(int size);
int ipc_rcu_getref(void *ptr);
void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head));
void ipc_rcu_free(struct rcu_head *head);
@@ -144,7 +145,7 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
/* On IA-64, we always use the "64-bit version" of the IPC structures. */
# define ipc_parse_version(cmd) IPC_64
#else
-int ipc_parse_version (int *cmd);
+int ipc_parse_version(int *cmd);
#endif
extern void free_msg(struct msg_msg *msg);
@@ -185,6 +186,19 @@ static inline void ipc_unlock(struct kern_ipc_perm *perm)
rcu_read_unlock();
}
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+ return !perm->deleted;
+}
+
struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.