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Diffstat (limited to 'ipc')
-rw-r--r--ipc/mqueue.c46
-rw-r--r--ipc/msg.c12
-rw-r--r--ipc/sem.c31
-rw-r--r--ipc/shm.c32
-rw-r--r--ipc/util.c44
-rw-r--r--ipc/util.h3
6 files changed, 109 insertions, 59 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 8031464ed4ae..5becca9be867 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -144,7 +144,7 @@ struct mqueue_inode_info {
struct pid *notify_owner;
u32 notify_self_exec_id;
struct user_namespace *notify_user_ns;
- struct user_struct *user; /* user who created, for accounting */
+ struct ucounts *ucounts; /* user who created, for accounting */
struct sock *notify_sock;
struct sk_buff *notify_cookie;
@@ -292,7 +292,6 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
struct ipc_namespace *ipc_ns, umode_t mode,
struct mq_attr *attr)
{
- struct user_struct *u = current_user();
struct inode *inode;
int ret = -ENOMEM;
@@ -321,7 +320,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->notify_owner = NULL;
info->notify_user_ns = NULL;
info->qsize = 0;
- info->user = NULL; /* set when all is ok */
+ info->ucounts = NULL; /* set when all is ok */
info->msg_tree = RB_ROOT;
info->msg_tree_rightmost = NULL;
info->node_cache = NULL;
@@ -371,19 +370,23 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
if (mq_bytes + mq_treesize < mq_bytes)
goto out_inode;
mq_bytes += mq_treesize;
- spin_lock(&mq_lock);
- if (u->mq_bytes + mq_bytes < u->mq_bytes ||
- u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
+ info->ucounts = get_ucounts(current_ucounts());
+ if (info->ucounts) {
+ long msgqueue;
+
+ spin_lock(&mq_lock);
+ msgqueue = inc_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, mq_bytes);
+ if (msgqueue == LONG_MAX || msgqueue > rlimit(RLIMIT_MSGQUEUE)) {
+ dec_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, mq_bytes);
+ spin_unlock(&mq_lock);
+ put_ucounts(info->ucounts);
+ info->ucounts = NULL;
+ /* mqueue_evict_inode() releases info->messages */
+ ret = -EMFILE;
+ goto out_inode;
+ }
spin_unlock(&mq_lock);
- /* mqueue_evict_inode() releases info->messages */
- ret = -EMFILE;
- goto out_inode;
}
- u->mq_bytes += mq_bytes;
- spin_unlock(&mq_lock);
-
- /* all is ok */
- info->user = get_uid(u);
} else if (S_ISDIR(mode)) {
inc_nlink(inode);
/* Some things misbehave if size == 0 on a directory */
@@ -497,7 +500,6 @@ static void mqueue_free_inode(struct inode *inode)
static void mqueue_evict_inode(struct inode *inode)
{
struct mqueue_inode_info *info;
- struct user_struct *user;
struct ipc_namespace *ipc_ns;
struct msg_msg *msg, *nmsg;
LIST_HEAD(tmp_msg);
@@ -520,8 +522,7 @@ static void mqueue_evict_inode(struct inode *inode)
free_msg(msg);
}
- user = info->user;
- if (user) {
+ if (info->ucounts) {
unsigned long mq_bytes, mq_treesize;
/* Total amount of bytes accounted for the mqueue */
@@ -533,7 +534,7 @@ static void mqueue_evict_inode(struct inode *inode)
info->attr.mq_msgsize);
spin_lock(&mq_lock);
- user->mq_bytes -= mq_bytes;
+ dec_rlimit_ucounts(info->ucounts, UCOUNT_RLIMIT_MSGQUEUE, mq_bytes);
/*
* get_ns_from_inode() ensures that the
* (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
@@ -543,7 +544,8 @@ static void mqueue_evict_inode(struct inode *inode)
if (ipc_ns)
ipc_ns->mq_queues_count--;
spin_unlock(&mq_lock);
- free_uid(user);
+ put_ucounts(info->ucounts);
+ info->ucounts = NULL;
}
if (ipc_ns)
put_ipc_ns(ipc_ns);
@@ -1004,12 +1006,14 @@ static inline void __pipelined_op(struct wake_q_head *wake_q,
struct mqueue_inode_info *info,
struct ext_wait_queue *this)
{
+ struct task_struct *task;
+
list_del(&this->list);
- get_task_struct(this->task);
+ task = get_task_struct(this->task);
/* see MQ_BARRIER for purpose/pairing */
smp_store_release(&this->state, STATE_READY);
- wake_q_add_safe(wake_q, this->task);
+ wake_q_add_safe(wake_q, task);
}
/* pipelined_send() - send a message directly to the task waiting in
diff --git a/ipc/msg.c b/ipc/msg.c
index acd1bc7af55a..6810276d6bb9 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -130,7 +130,7 @@ static void msg_rcu_free(struct rcu_head *head)
struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
security_msg_queue_free(&msq->q_perm);
- kvfree(msq);
+ kfree(msq);
}
/**
@@ -147,7 +147,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
key_t key = params->key;
int msgflg = params->flg;
- msq = kvmalloc(sizeof(*msq), GFP_KERNEL);
+ msq = kmalloc(sizeof(*msq), GFP_KERNEL);
if (unlikely(!msq))
return -ENOMEM;
@@ -157,7 +157,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
msq->q_perm.security = NULL;
retval = security_msg_queue_alloc(&msq->q_perm);
if (retval) {
- kvfree(msq);
+ kfree(msq);
return retval;
}
@@ -251,11 +251,13 @@ 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) {
- get_task_struct(msr->r_tsk);
+ struct task_struct *r_tsk;
+
+ r_tsk = get_task_struct(msr->r_tsk);
/* see MSG_BARRIER for purpose/pairing */
smp_store_release(&msr->r_msg, ERR_PTR(res));
- wake_q_add_safe(wake_q, msr->r_tsk);
+ wake_q_add_safe(wake_q, r_tsk);
}
}
diff --git a/ipc/sem.c b/ipc/sem.c
index e0ec239680cb..971e75d28364 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -217,6 +217,8 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
* this smp_load_acquire(), this is guaranteed because the smp_load_acquire()
* is inside a spin_lock() and after a write from 0 to non-zero a
* spin_lock()+spin_unlock() is done.
+ * To prevent the compiler/cpu temporarily writing 0 to use_global_lock,
+ * READ_ONCE()/WRITE_ONCE() is used.
*
* 2) queue.status: (SEM_BARRIER_2)
* Initialization is done while holding sem_lock(), so no further barrier is
@@ -342,10 +344,10 @@ static void complexmode_enter(struct sem_array *sma)
* Nothing to do, just reset the
* counter until we return to simple mode.
*/
- sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
+ WRITE_ONCE(sma->use_global_lock, USE_GLOBAL_LOCK_HYSTERESIS);
return;
}
- sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
+ WRITE_ONCE(sma->use_global_lock, USE_GLOBAL_LOCK_HYSTERESIS);
for (i = 0; i < sma->sem_nsems; i++) {
sem = &sma->sems[i];
@@ -371,7 +373,8 @@ static void complexmode_tryleave(struct sem_array *sma)
/* See SEM_BARRIER_1 for purpose/pairing */
smp_store_release(&sma->use_global_lock, 0);
} else {
- sma->use_global_lock--;
+ WRITE_ONCE(sma->use_global_lock,
+ sma->use_global_lock-1);
}
}
@@ -412,7 +415,7 @@ static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
* Initial check for use_global_lock. Just an optimization,
* no locking, no memory barrier.
*/
- if (!sma->use_global_lock) {
+ if (!READ_ONCE(sma->use_global_lock)) {
/*
* It appears that no complex operation is around.
* Acquire the per-semaphore lock.
@@ -784,12 +787,14 @@ would_block:
static inline void wake_up_sem_queue_prepare(struct sem_queue *q, int error,
struct wake_q_head *wake_q)
{
- get_task_struct(q->sleeper);
+ struct task_struct *sleeper;
+
+ sleeper = get_task_struct(q->sleeper);
/* see SEM_BARRIER_2 for purpose/pairing */
smp_store_release(&q->status, error);
- wake_q_add_safe(wake_q, q->sleeper);
+ wake_q_add_safe(wake_q, sleeper);
}
static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
@@ -1152,7 +1157,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
un->semid = -1;
list_del_rcu(&un->list_proc);
spin_unlock(&un->ulp->lock);
- kfree_rcu(un, rcu);
+ kvfree_rcu(un, rcu);
}
/* Wake up all pending processes and let them fail with EIDRM. */
@@ -1935,7 +1940,8 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
rcu_read_unlock();
/* step 2: allocate new undo structure */
- new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
+ new = kvzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems,
+ GFP_KERNEL);
if (!new) {
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return ERR_PTR(-ENOMEM);
@@ -1947,7 +1953,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
if (!ipc_valid_object(&sma->sem_perm)) {
sem_unlock(sma, -1);
rcu_read_unlock();
- kfree(new);
+ kvfree(new);
un = ERR_PTR(-EIDRM);
goto out;
}
@@ -1958,7 +1964,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
*/
un = lookup_undo(ulp, semid);
if (un) {
- kfree(new);
+ kvfree(new);
goto success;
}
/* step 5: initialize & link new undo structure */
@@ -2418,7 +2424,7 @@ void exit_sem(struct task_struct *tsk)
rcu_read_unlock();
wake_up_q(&wake_q);
- kfree_rcu(un, rcu);
+ kvfree_rcu(un, rcu);
}
kfree(ulp);
}
@@ -2433,7 +2439,8 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
/*
* The proc interface isn't aware of sem_lock(), it calls
- * ipc_lock_object() directly (in sysvipc_find_ipc).
+ * ipc_lock_object(), i.e. spin_lock(&sma->sem_perm.lock).
+ * (in sysvipc_find_ipc)
* In order to stay compatible with sem_lock(), we must
* enter / leave complex_mode.
*/
diff --git a/ipc/shm.c b/ipc/shm.c
index febd88daba8c..748933e376ca 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -60,7 +60,7 @@ struct shmid_kernel /* private to the kernel */
time64_t shm_ctim;
struct pid *shm_cprid;
struct pid *shm_lprid;
- struct user_struct *mlock_user;
+ struct ucounts *mlock_ucounts;
/* The task created the shm object. NULL if the task is dead. */
struct task_struct *shm_creator;
@@ -222,7 +222,7 @@ static void shm_rcu_free(struct rcu_head *head)
struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel,
shm_perm);
security_shm_free(&shp->shm_perm);
- kvfree(shp);
+ kfree(shp);
}
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
@@ -286,10 +286,10 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
shm_rmid(ns, shp);
shm_unlock(shp);
if (!is_file_hugepages(shm_file))
- shmem_lock(shm_file, 0, shp->mlock_user);
- else if (shp->mlock_user)
+ shmem_lock(shm_file, 0, shp->mlock_ucounts);
+ else if (shp->mlock_ucounts)
user_shm_unlock(i_size_read(file_inode(shm_file)),
- shp->mlock_user);
+ shp->mlock_ucounts);
fput(shm_file);
ipc_update_pid(&shp->shm_cprid, NULL);
ipc_update_pid(&shp->shm_lprid, NULL);
@@ -619,18 +619,18 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
ns->shm_tot + numpages > ns->shm_ctlall)
return -ENOSPC;
- shp = kvmalloc(sizeof(*shp), GFP_KERNEL);
+ shp = kmalloc(sizeof(*shp), GFP_KERNEL);
if (unlikely(!shp))
return -ENOMEM;
shp->shm_perm.key = key;
shp->shm_perm.mode = (shmflg & S_IRWXUGO);
- shp->mlock_user = NULL;
+ shp->mlock_ucounts = NULL;
shp->shm_perm.security = NULL;
error = security_shm_alloc(&shp->shm_perm);
if (error) {
- kvfree(shp);
+ kfree(shp);
return error;
}
@@ -650,7 +650,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
if (shmflg & SHM_NORESERVE)
acctflag = VM_NORESERVE;
file = hugetlb_file_setup(name, hugesize, acctflag,
- &shp->mlock_user, HUGETLB_SHMFS_INODE,
+ &shp->mlock_ucounts, HUGETLB_SHMFS_INODE,
(shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
} else {
/*
@@ -698,8 +698,8 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
no_id:
ipc_update_pid(&shp->shm_cprid, NULL);
ipc_update_pid(&shp->shm_lprid, NULL);
- if (is_file_hugepages(file) && shp->mlock_user)
- user_shm_unlock(size, shp->mlock_user);
+ if (is_file_hugepages(file) && shp->mlock_ucounts)
+ user_shm_unlock(size, shp->mlock_ucounts);
fput(file);
ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
return error;
@@ -1105,12 +1105,12 @@ static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd)
goto out_unlock0;
if (cmd == SHM_LOCK) {
- struct user_struct *user = current_user();
+ struct ucounts *ucounts = current_ucounts();
- err = shmem_lock(shm_file, 1, user);
+ err = shmem_lock(shm_file, 1, ucounts);
if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
shp->shm_perm.mode |= SHM_LOCKED;
- shp->mlock_user = user;
+ shp->mlock_ucounts = ucounts;
}
goto out_unlock0;
}
@@ -1118,9 +1118,9 @@ static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd)
/* SHM_UNLOCK */
if (!(shp->shm_perm.mode & SHM_LOCKED))
goto out_unlock0;
- shmem_lock(shm_file, 0, shp->mlock_user);
+ shmem_lock(shm_file, 0, shp->mlock_ucounts);
shp->shm_perm.mode &= ~SHM_LOCKED;
- shp->mlock_user = NULL;
+ shp->mlock_ucounts = NULL;
get_file(shm_file);
ipc_unlock_object(&shp->shm_perm);
rcu_read_unlock();
diff --git a/ipc/util.c b/ipc/util.c
index cfa0045e748d..0027e47626b7 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -64,6 +64,7 @@
#include <linux/memory.h>
#include <linux/ipc_namespace.h>
#include <linux/rhashtable.h>
+#include <linux/log2.h>
#include <asm/unistd.h>
@@ -451,6 +452,41 @@ static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
}
/**
+ * ipc_search_maxidx - search for the highest assigned index
+ * @ids: ipc identifier set
+ * @limit: known upper limit for highest assigned index
+ *
+ * The function determines the highest assigned index in @ids. It is intended
+ * to be called when ids->max_idx needs to be updated.
+ * Updating ids->max_idx is necessary when the current highest index ipc
+ * object is deleted.
+ * If no ipc object is allocated, then -1 is returned.
+ *
+ * ipc_ids.rwsem needs to be held by the caller.
+ */
+static int ipc_search_maxidx(struct ipc_ids *ids, int limit)
+{
+ int tmpidx;
+ int i;
+ int retval;
+
+ i = ilog2(limit+1);
+
+ retval = 0;
+ for (; i >= 0; i--) {
+ tmpidx = retval | (1<<i);
+ /*
+ * "0" is a possible index value, thus search using
+ * e.g. 15,7,3,1,0 instead of 16,8,4,2,1.
+ */
+ tmpidx = tmpidx-1;
+ if (idr_get_next(&ids->ipcs_idr, &tmpidx))
+ retval |= (1<<i);
+ }
+ return retval - 1;
+}
+
+/**
* ipc_rmid - remove an ipc identifier
* @ids: ipc identifier set
* @ipcp: ipc perm structure containing the identifier to remove
@@ -468,11 +504,9 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
ipcp->deleted = true;
if (unlikely(idx == ids->max_idx)) {
- do {
- idx--;
- if (idx == -1)
- break;
- } while (!idr_find(&ids->ipcs_idr, idx));
+ idx = ids->max_idx-1;
+ if (idx >= 0)
+ idx = ipc_search_maxidx(ids, idx);
ids->max_idx = idx;
}
}
diff --git a/ipc/util.h b/ipc/util.h
index 5766c61aed0e..2dd7ce0416d8 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -145,6 +145,9 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
* ipc_get_maxidx - get the highest assigned index
* @ids: ipc identifier set
*
+ * The function returns the highest assigned index for @ids. The function
+ * doesn't scan the idr tree, it uses a cached value.
+ *
* Called with ipc_ids.rwsem held for reading.
*/
static inline int ipc_get_maxidx(struct ipc_ids *ids)
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-08 23:23:39 +0300