* /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
*
* SMP-threaded, sysctl's added
- * (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
+ * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
* Enforced range limit on SEM_UNDO
* (c) 2001 Red Hat Inc <alan@redhat.com>
* Lockless wakeup
#include <linux/time.h>
#include <linux/smp_lock.h>
#include <linux/security.h>
-#include <linux/vs_base.h>
-
+#include <linux/syscalls.h>
+#include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include "util.h"
static int newary (key_t, int, int);
static void freeary (struct sem_array *sma, int id);
#ifdef CONFIG_PROC_FS
-static int sysvipc_sem_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
#endif
#define SEMMSL_FAST 256 /* 512 bytes on stack */
{
used_sems = 0;
ipc_init_ids(&sem_ids,sc_semmni);
-
-#ifdef CONFIG_PROC_FS
- create_proc_read_entry("sysvipc/sem", 0, NULL, sysvipc_sem_read_proc, NULL);
-#endif
+ ipc_init_proc_interface("sysvipc/sem",
+ " key semid perms nsems uid gid cuid cgid otime ctime\n",
+ &sem_ids,
+ sysvipc_sem_proc_show);
}
/*
sma->sem_perm.mode = (semflg & S_IRWXUGO);
sma->sem_perm.key = key;
- sma->sem_perm.xid = current->xid;
+ sma->sem_perm.xid = vx_current_xid();
sma->sem_perm.security = NULL;
retval = security_sem_alloc(sma);
}
used_sems += nsems;
+ sma->sem_id = sem_buildid(id, sma->sem_perm.seq);
sma->sem_base = (struct sem *) &sma[1];
/* sma->sem_pending = NULL; */
sma->sem_pending_last = &sma->sem_pending;
sma->sem_ctime = get_seconds();
sem_unlock(sma);
- return sem_buildid(id, sma->sem_perm.seq);
+ return sma->sem_id;
}
asmlinkage long sys_semget (key_t key, int nsems, int semflg)
if (error <= 0) {
struct sem_queue *n;
remove_from_queue(sma,q);
- n = q->next;
q->status = IN_WAKEUP;
+ /*
+ * Continue scanning. The next operation
+ * that must be checked depends on the type of the
+ * completed operation:
+ * - if the operation modified the array, then
+ * restart from the head of the queue and
+ * check for threads that might be waiting
+ * for semaphore values to become 0.
+ * - if the operation didn't modify the array,
+ * then just continue.
+ */
+ if (q->alter)
+ n = sma->sem_pending;
+ else
+ n = q->next;
wake_up_process(q->sleeper);
/* hands-off: q will disappear immediately after
* writing q->status.
*/
+ smp_wmb();
q->status = error;
q = n;
} else {
n = q->next;
q->status = IN_WAKEUP;
wake_up_process(q->sleeper); /* doesn't sleep */
+ smp_wmb();
q->status = -EIDRM; /* hands-off q */
q = n;
}
struct semid64_ds tbuf;
int id;
- if(semid >= sem_ids.size)
+ if(semid >= sem_ids.entries->size)
return -EINVAL;
memset(&tbuf,0,sizeof(tbuf));
if(cmd == IPC_SET) {
if(copy_semid_from_user (&setbuf, arg.buf, version))
return -EFAULT;
+ if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode)))
+ return err;
}
sma = sem_lock(semid);
if(sma==NULL)
struct sem_undo_list *undo_list;
undo_list = current->sysvsem.undo_list;
- if ((undo_list != NULL) && (atomic_read(&undo_list->refcnt) != 1))
+ if (undo_list)
spin_lock(&undo_list->lock);
}
struct sem_undo_list *undo_list;
undo_list = current->sysvsem.undo_list;
- if ((undo_list != NULL) && (atomic_read(&undo_list->refcnt) != 1))
+ if (undo_list)
spin_unlock(&undo_list->lock);
}
if (undo_list == NULL)
return -ENOMEM;
memset(undo_list, 0, size);
- /* don't initialize unodhd->lock here. It's done
- * in copy_semundo() instead.
- */
+ spin_lock_init(&undo_list->lock);
atomic_set(&undo_list->refcnt, 1);
current->sysvsem.undo_list = undo_list;
}
struct sembuf fast_sops[SEMOPM_FAST];
struct sembuf* sops = fast_sops, *sop;
struct sem_undo *un;
- int undos = 0, decrease = 0, alter = 0, max;
+ int undos = 0, alter = 0, max;
struct sem_queue queue;
unsigned long jiffies_left = 0;
if (sop->sem_num >= max)
max = sop->sem_num;
if (sop->sem_flg & SEM_UNDO)
- undos++;
- if (sop->sem_op < 0)
- decrease = 1;
- if (sop->sem_op > 0)
+ undos = 1;
+ if (sop->sem_op != 0)
alter = 1;
}
- alter |= decrease;
retry_undos:
if (undos) {
goto out_unlock_free;
error = try_atomic_semop (sma, sops, nsops, un, current->tgid);
- if (error <= 0)
- goto update;
+ if (error <= 0) {
+ if (alter && error == 0)
+ update_queue (sma);
+ goto out_unlock_free;
+ }
/* We need to sleep on this operation, so we put the current
* task into the pending queue and go to sleep.
queue.undo = un;
queue.pid = current->tgid;
queue.id = semid;
+ queue.alter = alter;
if (alter)
append_to_queue(sma ,&queue);
else
remove_from_queue(sma,&queue);
goto out_unlock_free;
-update:
- if (alter)
- update_queue (sma);
out_unlock_free:
sem_unlock(sma);
out_free:
error = get_undo_list(&undo_list);
if (error)
return error;
- if (atomic_read(&undo_list->refcnt) == 1)
- spin_lock_init(&undo_list->lock);
atomic_inc(&undo_list->refcnt);
tsk->sysvsem.undo_list = undo_list;
} else
}
#ifdef CONFIG_PROC_FS
-static int sysvipc_sem_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
{
- off_t pos = 0;
- off_t begin = 0;
- int i, len = 0;
+ struct sem_array *sma = it;
- len += sprintf(buffer, " key semid perms nsems uid gid cuid cgid otime ctime\n");
- down(&sem_ids.sem);
-
- for(i = 0; i <= sem_ids.max_id; i++) {
- struct sem_array *sma;
- sma = sem_lock(i);
- if (sma) {
- if (!vx_check(sma->sem_perm.xid, VX_IDENT)) {
- sem_unlock(sma);
- continue;
- }
- len += sprintf(buffer + len, "%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
- sma->sem_perm.key,
- sem_buildid(i,sma->sem_perm.seq),
- sma->sem_perm.mode,
- sma->sem_nsems,
- sma->sem_perm.uid,
- sma->sem_perm.gid,
- sma->sem_perm.cuid,
- sma->sem_perm.cgid,
- sma->sem_otime,
- sma->sem_ctime);
- sem_unlock(sma);
+ if (!vx_check(sma->sem_perm.xid, VX_IDENT))
+ return 0;
- pos += len;
- if(pos < offset) {
- len = 0;
- begin = pos;
- }
- if(pos > offset + length)
- goto done;
- }
- }
- *eof = 1;
-done:
- up(&sem_ids.sem);
- *start = buffer + (offset - begin);
- len -= (offset - begin);
- if(len > length)
- len = length;
- if(len < 0)
- len = 0;
- return len;
+ return seq_printf(s,
+ "%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
+ sma->sem_perm.key,
+ sma->sem_id,
+ sma->sem_perm.mode,
+ sma->sem_nsems,
+ sma->sem_perm.uid,
+ sma->sem_perm.gid,
+ sma->sem_perm.cuid,
+ sma->sem_perm.cgid,
+ sma->sem_otime,
+ sma->sem_ctime);
}
#endif