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-rw-r--r--ipc/msg.c28
-rw-r--r--ipc/sem.c155
-rw-r--r--ipc/shm.c26
-rw-r--r--ipc/util.c65
-rw-r--r--ipc/util.h23
5 files changed, 114 insertions, 183 deletions
diff --git a/ipc/msg.c b/ipc/msg.c
index 104926dc72be..5b25e0755656 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -97,11 +97,11 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
static void msg_rcu_free(struct rcu_head *head)
{
- struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
- struct msg_queue *msq = ipc_rcu_to_struct(p);
+ struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
+ struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
security_msg_queue_free(msq);
- ipc_rcu_free(head);
+ kvfree(msq);
}
/**
@@ -114,12 +114,12 @@ static void msg_rcu_free(struct rcu_head *head)
static int newque(struct ipc_namespace *ns, struct ipc_params *params)
{
struct msg_queue *msq;
- int id, retval;
+ int retval;
key_t key = params->key;
int msgflg = params->flg;
- msq = ipc_rcu_alloc(sizeof(*msq));
- if (!msq)
+ msq = kvmalloc(sizeof(*msq), GFP_KERNEL);
+ if (unlikely(!msq))
return -ENOMEM;
msq->q_perm.mode = msgflg & S_IRWXUGO;
@@ -128,7 +128,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
msq->q_perm.security = NULL;
retval = security_msg_queue_alloc(msq);
if (retval) {
- ipc_rcu_putref(msq, ipc_rcu_free);
+ kvfree(msq);
return retval;
}
@@ -142,10 +142,10 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
INIT_LIST_HEAD(&msq->q_senders);
/* ipc_addid() locks msq upon success. */
- id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
- if (id < 0) {
- ipc_rcu_putref(msq, msg_rcu_free);
- return id;
+ retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
+ if (retval < 0) {
+ call_rcu(&msq->q_perm.rcu, msg_rcu_free);
+ return retval;
}
ipc_unlock_object(&msq->q_perm);
@@ -249,7 +249,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
free_msg(msg);
}
atomic_sub(msq->q_cbytes, &ns->msg_bytes);
- ipc_rcu_putref(msq, msg_rcu_free);
+ ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
}
/*
@@ -688,7 +688,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
/* enqueue the sender and prepare to block */
ss_add(msq, &s, msgsz);
- if (!ipc_rcu_getref(msq)) {
+ if (!ipc_rcu_getref(&msq->q_perm)) {
err = -EIDRM;
goto out_unlock0;
}
@@ -700,7 +700,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
rcu_read_lock();
ipc_lock_object(&msq->q_perm);
- ipc_rcu_putref(msq, msg_rcu_free);
+ ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
/* raced with RMID? */
if (!ipc_valid_object(&msq->q_perm)) {
err = -EIDRM;
diff --git a/ipc/sem.c b/ipc/sem.c
index 947dc2348271..9e70cd7a17da 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -87,24 +87,6 @@
#include <linux/uaccess.h>
#include "util.h"
-/* One semaphore structure for each semaphore in the system. */
-struct sem {
- int semval; /* current value */
- /*
- * PID of the process that last modified the semaphore. For
- * Linux, specifically these are:
- * - semop
- * - semctl, via SETVAL and SETALL.
- * - at task exit when performing undo adjustments (see exit_sem).
- */
- int sempid;
- spinlock_t lock; /* spinlock for fine-grained semtimedop */
- struct list_head pending_alter; /* pending single-sop operations */
- /* that alter the semaphore */
- struct list_head pending_const; /* pending single-sop operations */
- /* that do not alter the semaphore*/
- time_t sem_otime; /* candidate for sem_otime */
-} ____cacheline_aligned_in_smp;
/* One queue for each sleeping process in the system. */
struct sem_queue {
@@ -175,7 +157,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
* sem_array.sem_undo
*
* b) global or semaphore sem_lock() for read/write:
- * sem_array.sem_base[i].pending_{const,alter}:
+ * sem_array.sems[i].pending_{const,alter}:
*
* c) special:
* sem_undo_list.list_proc:
@@ -250,7 +232,7 @@ static void unmerge_queues(struct sem_array *sma)
*/
list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
struct sem *curr;
- curr = &sma->sem_base[q->sops[0].sem_num];
+ curr = &sma->sems[q->sops[0].sem_num];
list_add_tail(&q->list, &curr->pending_alter);
}
@@ -270,7 +252,7 @@ static void merge_queues(struct sem_array *sma)
{
int i;
for (i = 0; i < sma->sem_nsems; i++) {
- struct sem *sem = sma->sem_base + i;
+ struct sem *sem = &sma->sems[i];
list_splice_init(&sem->pending_alter, &sma->pending_alter);
}
@@ -278,11 +260,11 @@ static void merge_queues(struct sem_array *sma)
static void sem_rcu_free(struct rcu_head *head)
{
- struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
- struct sem_array *sma = ipc_rcu_to_struct(p);
+ struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
+ struct sem_array *sma = container_of(p, struct sem_array, sem_perm);
security_sem_free(sma);
- ipc_rcu_free(head);
+ kvfree(sma);
}
/*
@@ -306,7 +288,7 @@ static void complexmode_enter(struct sem_array *sma)
sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS;
for (i = 0; i < sma->sem_nsems; i++) {
- sem = sma->sem_base + i;
+ sem = &sma->sems[i];
spin_lock(&sem->lock);
spin_unlock(&sem->lock);
}
@@ -366,7 +348,7 @@ static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
*
* Both facts are tracked by use_global_mode.
*/
- sem = sma->sem_base + sops->sem_num;
+ sem = &sma->sems[sops->sem_num];
/*
* Initial check for use_global_lock. Just an optimization,
@@ -421,7 +403,7 @@ static inline void sem_unlock(struct sem_array *sma, int locknum)
complexmode_tryleave(sma);
ipc_unlock_object(&sma->sem_perm);
} else {
- struct sem *sem = sma->sem_base + locknum;
+ struct sem *sem = &sma->sems[locknum];
spin_unlock(&sem->lock);
}
}
@@ -456,7 +438,7 @@ static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns
static inline void sem_lock_and_putref(struct sem_array *sma)
{
sem_lock(sma, NULL, -1);
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
}
static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
@@ -464,6 +446,24 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
ipc_rmid(&sem_ids(ns), &s->sem_perm);
}
+static struct sem_array *sem_alloc(size_t nsems)
+{
+ struct sem_array *sma;
+ size_t size;
+
+ if (nsems > (INT_MAX - sizeof(*sma)) / sizeof(sma->sems[0]))
+ return NULL;
+
+ size = sizeof(*sma) + nsems * sizeof(sma->sems[0]);
+ sma = kvmalloc(size, GFP_KERNEL);
+ if (unlikely(!sma))
+ return NULL;
+
+ memset(sma, 0, size);
+
+ return sma;
+}
+
/**
* newary - Create a new semaphore set
* @ns: namespace
@@ -473,10 +473,8 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
*/
static int newary(struct ipc_namespace *ns, struct ipc_params *params)
{
- int id;
int retval;
struct sem_array *sma;
- int size;
key_t key = params->key;
int nsems = params->u.nsems;
int semflg = params->flg;
@@ -487,29 +485,24 @@ 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);
- sma = ipc_rcu_alloc(size);
+ sma = sem_alloc(nsems);
if (!sma)
return -ENOMEM;
- memset(sma, 0, size);
-
sma->sem_perm.mode = (semflg & S_IRWXUGO);
sma->sem_perm.key = key;
sma->sem_perm.security = NULL;
retval = security_sem_alloc(sma);
if (retval) {
- ipc_rcu_putref(sma, ipc_rcu_free);
+ kvfree(sma);
return retval;
}
- sma->sem_base = (struct sem *) &sma[1];
-
for (i = 0; i < nsems; i++) {
- INIT_LIST_HEAD(&sma->sem_base[i].pending_alter);
- INIT_LIST_HEAD(&sma->sem_base[i].pending_const);
- spin_lock_init(&sma->sem_base[i].lock);
+ INIT_LIST_HEAD(&sma->sems[i].pending_alter);
+ INIT_LIST_HEAD(&sma->sems[i].pending_const);
+ spin_lock_init(&sma->sems[i].lock);
}
sma->complex_count = 0;
@@ -520,10 +513,10 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
sma->sem_nsems = nsems;
sma->sem_ctime = get_seconds();
- id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
- if (id < 0) {
- ipc_rcu_putref(sma, sem_rcu_free);
- return id;
+ retval = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
+ if (retval < 0) {
+ call_rcu(&sma->sem_perm.rcu, sem_rcu_free);
+ return retval;
}
ns->used_sems += nsems;
@@ -612,7 +605,7 @@ static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q)
un = q->undo;
for (sop = sops; sop < sops + nsops; sop++) {
- curr = sma->sem_base + sop->sem_num;
+ curr = &sma->sems[sop->sem_num];
sem_op = sop->sem_op;
result = curr->semval;
@@ -639,7 +632,7 @@ static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q)
sop--;
pid = q->pid;
while (sop >= sops) {
- sma->sem_base[sop->sem_num].sempid = pid;
+ sma->sems[sop->sem_num].sempid = pid;
sop--;
}
@@ -661,7 +654,7 @@ undo:
sop--;
while (sop >= sops) {
sem_op = sop->sem_op;
- sma->sem_base[sop->sem_num].semval -= sem_op;
+ sma->sems[sop->sem_num].semval -= sem_op;
if (sop->sem_flg & SEM_UNDO)
un->semadj[sop->sem_num] += sem_op;
sop--;
@@ -692,7 +685,7 @@ static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
* until the operations can go through.
*/
for (sop = sops; sop < sops + nsops; sop++) {
- curr = sma->sem_base + sop->sem_num;
+ curr = &sma->sems[sop->sem_num];
sem_op = sop->sem_op;
result = curr->semval;
@@ -716,7 +709,7 @@ static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
}
for (sop = sops; sop < sops + nsops; sop++) {
- curr = sma->sem_base + sop->sem_num;
+ curr = &sma->sems[sop->sem_num];
sem_op = sop->sem_op;
result = curr->semval;
@@ -815,7 +808,7 @@ static int wake_const_ops(struct sem_array *sma, int semnum,
if (semnum == -1)
pending_list = &sma->pending_const;
else
- pending_list = &sma->sem_base[semnum].pending_const;
+ pending_list = &sma->sems[semnum].pending_const;
list_for_each_entry_safe(q, tmp, pending_list, list) {
int error = perform_atomic_semop(sma, q);
@@ -856,7 +849,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
for (i = 0; i < nsops; i++) {
int num = sops[i].sem_num;
- if (sma->sem_base[num].semval == 0) {
+ if (sma->sems[num].semval == 0) {
got_zero = 1;
semop_completed |= wake_const_ops(sma, num, wake_q);
}
@@ -867,7 +860,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
* Assume all were changed.
*/
for (i = 0; i < sma->sem_nsems; i++) {
- if (sma->sem_base[i].semval == 0) {
+ if (sma->sems[i].semval == 0) {
got_zero = 1;
semop_completed |= wake_const_ops(sma, i, wake_q);
}
@@ -909,7 +902,7 @@ static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *w
if (semnum == -1)
pending_list = &sma->pending_alter;
else
- pending_list = &sma->sem_base[semnum].pending_alter;
+ pending_list = &sma->sems[semnum].pending_alter;
again:
list_for_each_entry_safe(q, tmp, pending_list, list) {
@@ -922,7 +915,7 @@ again:
* be in the per semaphore pending queue, and decrements
* cannot be successful if the value is already 0.
*/
- if (semnum != -1 && sma->sem_base[semnum].semval == 0)
+ if (semnum != -1 && sma->sems[semnum].semval == 0)
break;
error = perform_atomic_semop(sma, q);
@@ -959,9 +952,9 @@ again:
static void set_semotime(struct sem_array *sma, struct sembuf *sops)
{
if (sops == NULL) {
- sma->sem_base[0].sem_otime = get_seconds();
+ sma->sems[0].sem_otime = get_seconds();
} else {
- sma->sem_base[sops[0].sem_num].sem_otime =
+ sma->sems[sops[0].sem_num].sem_otime =
get_seconds();
}
}
@@ -1067,9 +1060,9 @@ static int count_semcnt(struct sem_array *sma, ushort semnum,
semcnt = 0;
/* First: check the simple operations. They are easy to evaluate */
if (count_zero)
- l = &sma->sem_base[semnum].pending_const;
+ l = &sma->sems[semnum].pending_const;
else
- l = &sma->sem_base[semnum].pending_alter;
+ l = &sma->sems[semnum].pending_alter;
list_for_each_entry(q, l, list) {
/* all task on a per-semaphore list sleep on exactly
@@ -1124,7 +1117,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
}
for (i = 0; i < sma->sem_nsems; i++) {
- struct sem *sem = sma->sem_base + i;
+ struct sem *sem = &sma->sems[i];
list_for_each_entry_safe(q, tq, &sem->pending_const, list) {
unlink_queue(sma, q);
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
@@ -1142,7 +1135,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
wake_up_q(&wake_q);
ns->used_sems -= sma->sem_nsems;
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
}
static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
@@ -1174,9 +1167,9 @@ static time_t get_semotime(struct sem_array *sma)
int i;
time_t res;
- res = sma->sem_base[0].sem_otime;
+ res = sma->sems[0].sem_otime;
for (i = 1; i < sma->sem_nsems; i++) {
- time_t to = sma->sem_base[i].sem_otime;
+ time_t to = sma->sems[i].sem_otime;
if (to > res)
res = to;
@@ -1325,7 +1318,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
return -EIDRM;
}
- curr = &sma->sem_base[semnum];
+ curr = &sma->sems[semnum];
ipc_assert_locked_object(&sma->sem_perm);
list_for_each_entry(un, &sma->list_id, list_id)
@@ -1382,15 +1375,16 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
goto out_unlock;
}
if (nsems > SEMMSL_FAST) {
- if (!ipc_rcu_getref(sma)) {
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
err = -EIDRM;
goto out_unlock;
}
sem_unlock(sma, -1);
rcu_read_unlock();
- sem_io = ipc_alloc(sizeof(ushort)*nsems);
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
if (sem_io == NULL) {
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return -ENOMEM;
}
@@ -1402,7 +1396,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
}
}
for (i = 0; i < sma->sem_nsems; i++)
- sem_io[i] = sma->sem_base[i].semval;
+ sem_io[i] = sma->sems[i].semval;
sem_unlock(sma, -1);
rcu_read_unlock();
err = 0;
@@ -1415,29 +1409,30 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
int i;
struct sem_undo *un;
- if (!ipc_rcu_getref(sma)) {
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
err = -EIDRM;
goto out_rcu_wakeup;
}
rcu_read_unlock();
if (nsems > SEMMSL_FAST) {
- sem_io = ipc_alloc(sizeof(ushort)*nsems);
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
if (sem_io == NULL) {
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return -ENOMEM;
}
}
if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
err = -EFAULT;
goto out_free;
}
for (i = 0; i < nsems; i++) {
if (sem_io[i] > SEMVMX) {
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
err = -ERANGE;
goto out_free;
}
@@ -1450,8 +1445,8 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
}
for (i = 0; i < nsems; i++) {
- sma->sem_base[i].semval = sem_io[i];
- sma->sem_base[i].sempid = task_tgid_vnr(current);
+ sma->sems[i].semval = sem_io[i];
+ sma->sems[i].sempid = task_tgid_vnr(current);
}
ipc_assert_locked_object(&sma->sem_perm);
@@ -1476,7 +1471,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
err = -EIDRM;
goto out_unlock;
}
- curr = &sma->sem_base[semnum];
+ curr = &sma->sems[semnum];
switch (cmd) {
case GETVAL:
@@ -1500,7 +1495,7 @@ out_rcu_wakeup:
wake_up_q(&wake_q);
out_free:
if (sem_io != fast_sem_io)
- ipc_free(sem_io);
+ kvfree(sem_io);
return err;
}
@@ -1719,7 +1714,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
}
nsems = sma->sem_nsems;
- if (!ipc_rcu_getref(sma)) {
+ if (!ipc_rcu_getref(&sma->sem_perm)) {
rcu_read_unlock();
un = ERR_PTR(-EIDRM);
goto out;
@@ -1729,7 +1724,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
/* step 2: allocate new undo structure */
new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
if (!new) {
- ipc_rcu_putref(sma, sem_rcu_free);
+ ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return ERR_PTR(-ENOMEM);
}
@@ -1932,7 +1927,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
*/
if (nsops == 1) {
struct sem *curr;
- curr = &sma->sem_base[sops->sem_num];
+ curr = &sma->sems[sops->sem_num];
if (alter) {
if (sma->complex_count) {
@@ -2146,7 +2141,7 @@ 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->sems[i];
if (un->semadj[i]) {
semaphore->semval += un->semadj[i];
/*
diff --git a/ipc/shm.c b/ipc/shm.c
index f45c7959b264..28a444861a8f 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -174,11 +174,12 @@ static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
static void shm_rcu_free(struct rcu_head *head)
{
- struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
- struct shmid_kernel *shp = ipc_rcu_to_struct(p);
-
+ struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm,
+ rcu);
+ struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel,
+ shm_perm);
security_shm_free(shp);
- ipc_rcu_free(head);
+ kvfree(shp);
}
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
@@ -241,7 +242,7 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
user_shm_unlock(i_size_read(file_inode(shm_file)),
shp->mlock_user);
fput(shm_file);
- ipc_rcu_putref(shp, shm_rcu_free);
+ ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
}
/*
@@ -529,7 +530,6 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
struct file *file;
char name[13];
- int id;
vm_flags_t acctflag = 0;
if (size < SHMMIN || size > ns->shm_ctlmax)
@@ -542,8 +542,8 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
ns->shm_tot + numpages > ns->shm_ctlall)
return -ENOSPC;
- shp = ipc_rcu_alloc(sizeof(*shp));
- if (!shp)
+ shp = kvmalloc(sizeof(*shp), GFP_KERNEL);
+ if (unlikely(!shp))
return -ENOMEM;
shp->shm_perm.key = key;
@@ -553,7 +553,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
shp->shm_perm.security = NULL;
error = security_shm_alloc(shp);
if (error) {
- ipc_rcu_putref(shp, ipc_rcu_free);
+ kvfree(shp);
return error;
}
@@ -598,11 +598,9 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
shp->shm_file = file;
shp->shm_creator = current;
- id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
- if (id < 0) {
- error = id;
+ error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+ if (error < 0)
goto no_id;
- }
list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
@@ -624,7 +622,7 @@ no_id:
user_shm_unlock(size, shp->mlock_user);
fput(file);
no_file:
- ipc_rcu_putref(shp, shm_rcu_free);
+ call_rcu(&shp->shm_perm.rcu, shm_rcu_free);
return error;
}
diff --git a/ipc/util.c b/ipc/util.c
index caec7b1bfaa3..1a2cb02467ab 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -232,6 +232,7 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
idr_preload(GFP_KERNEL);
+ atomic_set(&new->refcount, 1);
spin_lock_init(&new->lock);
new->deleted = false;
rcu_read_lock();
@@ -394,70 +395,18 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
ipcp->deleted = true;
}
-/**
- * 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
- */
-void *ipc_alloc(int size)
-{
- return kvmalloc(size, GFP_KERNEL);
-}
-
-/**
- * ipc_free - free ipc space
- * @ptr: pointer returned by ipc_alloc
- *
- * Free a block created with ipc_alloc().
- */
-void ipc_free(void *ptr)
+int ipc_rcu_getref(struct kern_ipc_perm *ptr)
{
- kvfree(ptr);
+ return atomic_inc_not_zero(&ptr->refcount);
}
-/**
- * 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.
- */
-void *ipc_rcu_alloc(int size)
+void ipc_rcu_putref(struct kern_ipc_perm *ptr,
+ void (*func)(struct rcu_head *head))
{
- /*
- * We prepend the allocation with the rcu struct
- */
- struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size);
- if (unlikely(!out))
- return NULL;
- atomic_set(&out->refcount, 1);
- return out + 1;
-}
-
-int ipc_rcu_getref(void *ptr)
-{
- struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
-
- return atomic_inc_not_zero(&p->refcount);
-}
-
-void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head))
-{
- struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
-
- if (!atomic_dec_and_test(&p->refcount))
+ if (!atomic_dec_and_test(&ptr->refcount))
return;
- call_rcu(&p->rcu, func);
-}
-
-void ipc_rcu_free(struct rcu_head *head)
-{
- struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
-
- kvfree(p);
+ call_rcu(&ptr->rcu, func);
}
/**
diff --git a/ipc/util.h b/ipc/util.h
index 60ddccca464d..c692010e6f0a 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -47,13 +47,6 @@ static inline void msg_exit_ns(struct ipc_namespace *ns) { }
static inline void shm_exit_ns(struct ipc_namespace *ns) { }
#endif
-struct ipc_rcu {
- struct rcu_head rcu;
- atomic_t refcount;
-} ____cacheline_aligned_in_smp;
-
-#define ipc_rcu_to_struct(p) ((void *)(p+1))
-
/*
* Structure that holds the parameters needed by the ipc operations
* (see after)
@@ -114,22 +107,18 @@ void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
/* must be called with ipcp locked */
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);
-
/*
* For allocation that need to be freed by RCU.
* Objects are reference counted, they start with reference count 1.
* getref increases the refcount, the putref call that reduces the recount
* to 0 schedules the rcu destruction. Caller must guarantee locking.
+ *
+ * refcount is initialized by ipc_addid(), before that point call_rcu()
+ * must be used.
*/
-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);
+int ipc_rcu_getref(struct kern_ipc_perm *ptr);
+void ipc_rcu_putref(struct kern_ipc_perm *ptr,
+ void (*func)(struct rcu_head *head));
struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.