#include <linux/capability.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
-#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/nsproxy.h>
#include <linux/mount.h>
+#include <linux/ipc_namespace.h>
#include <asm/uaccess.h>
static const struct file_operations shm_file_operations;
static struct vm_operations_struct shm_vm_ops;
-static struct ipc_ids init_shm_ids;
-
-#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
+#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
#define shm_unlock(shp) \
ipc_unlock(&(shp)->shm_perm)
-#define shm_buildid(ns, id, seq) \
- ipc_buildid(&shm_ids(ns), id, seq)
+#define shm_buildid(id, seq) ipc_buildid(id, seq)
static int newseg(struct ipc_namespace *, struct ipc_params *);
static void shm_open(struct vm_area_struct *vma);
static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
#endif
-static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void shm_init_ns(struct ipc_namespace *ns)
{
- ns->ids[IPC_SHM_IDS] = ids;
ns->shm_ctlmax = SHMMAX;
ns->shm_ctlall = SHMALL;
ns->shm_ctlmni = SHMMNI;
ns->shm_tot = 0;
- ipc_init_ids(ids);
+ ipc_init_ids(&ns->ids[IPC_SHM_IDS]);
}
-static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
+/*
+ * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
+ * Only shm_ids.rw_mutex remains locked on exit.
+ */
+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){
shp->shm_perm.mode |= SHM_DEST;
/* Do not find it any more */
shm_destroy(ns, shp);
}
-int shm_init_ns(struct ipc_namespace *ns)
+#ifdef CONFIG_IPC_NS
+void shm_exit_ns(struct ipc_namespace *ns)
{
- struct ipc_ids *ids;
-
- ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
- if (ids == NULL)
- return -ENOMEM;
-
- __shm_init_ns(ns, ids);
- return 0;
+ free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
}
+#endif
-void shm_exit_ns(struct ipc_namespace *ns)
+void __init shm_init (void)
{
- struct shmid_kernel *shp;
- int next_id;
- int total, in_use;
-
- mutex_lock(&shm_ids(ns).mutex);
+ shm_init_ns(&init_ipc_ns);
+ ipc_init_proc_interface("sysvipc/shm",
+ " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
+ IPC_SHM_IDS, sysvipc_shm_proc_show);
+}
- in_use = shm_ids(ns).in_use;
+/*
+ * shm_lock_(check_)down routines are called in the paths where the rw_mutex
+ * is held to protect access to the idr tree.
+ */
+static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id);
- for (total = 0, next_id = 0; total < in_use; next_id++) {
- shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
- if (shp == NULL)
- continue;
- ipc_lock_by_ptr(&shp->shm_perm);
- do_shm_rmid(ns, shp);
- total++;
- }
- mutex_unlock(&shm_ids(ns).mutex);
+ if (IS_ERR(ipcp))
+ return (struct shmid_kernel *)ipcp;
- kfree(ns->ids[IPC_SHM_IDS]);
- ns->ids[IPC_SHM_IDS] = NULL;
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
}
-void __init shm_init (void)
+static inline struct shmid_kernel *shm_lock_check_down(
+ struct ipc_namespace *ns,
+ int id)
{
- __shm_init_ns(&init_ipc_ns, &init_shm_ids);
- ipc_init_proc_interface("sysvipc/shm",
- " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
- IPC_SHM_IDS, sysvipc_shm_proc_show);
+ struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return (struct shmid_kernel *)ipcp;
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
}
+/*
+ * shm_lock_(check_) routines are called in the paths where the rw_mutex
+ * is not held.
+ */
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
- return (struct shmid_kernel *) ipc_lock(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return (struct shmid_kernel *)ipcp;
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
}
static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
int id)
{
- return (struct shmid_kernel *) ipc_lock_check(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
+
+ if (IS_ERR(ipcp))
+ return (struct shmid_kernel *)ipcp;
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
}
static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
/*
* shm_destroy - free the struct shmid_kernel
*
+ * @ns: namespace
* @shp: struct to free
*
- * It has to be called with shp and shm_ids.mutex locked,
+ * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
* but returns with shp unlocked and freed.
*/
static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
struct shmid_kernel *shp;
struct ipc_namespace *ns = sfd->ns;
- mutex_lock(&shm_ids(ns).mutex);
+ down_write(&shm_ids(ns).rw_mutex);
/* remove from the list of attaches of the shm segment */
- shp = shm_lock(ns, sfd->id);
+ shp = shm_lock_down(ns, sfd->id);
BUG_ON(IS_ERR(shp));
shp->shm_lprid = task_tgid_vnr(current);
shp->shm_dtim = get_seconds();
shm_destroy(ns, shp);
else
shm_unlock(shp);
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
}
static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if (sfd->vm_ops->get_policy)
pol = sfd->vm_ops->get_policy(vma, addr);
- else if (vma->vm_policy)
+ else if (vma->vm_policy) {
pol = vma->vm_policy;
- else
+ mpol_get(pol); /* get_vma_policy() expects this */
+ } else
pol = current->mempolicy;
return pol;
}
#endif
};
+/**
+ * newseg - Create a new shared memory segment
+ * @ns: namespace
+ * @params: ptr to the structure that contains key, size and shmflg
+ *
+ * Called with shm_ids.rw_mutex held as a writer.
+ */
+
static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
{
key_t key = params->key;
if (IS_ERR(file))
goto no_file;
- error = -ENOSPC;
id = shm_addid(ns, shp);
- if(id == -1)
+ if (id < 0) {
+ error = id;
goto no_id;
+ }
shp->shm_cprid = task_tgid_vnr(current);
shp->shm_lprid = 0;
shp->shm_ctim = get_seconds();
shp->shm_segsz = size;
shp->shm_nattch = 0;
- shp->shm_perm.id = shm_buildid(ns, id, shp->shm_perm.seq);
+ shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq);
shp->shm_file = file;
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
return error;
}
-static inline int shm_security(void *shp, int shmflg)
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
{
- return security_shm_associate((struct shmid_kernel *) shp, shmflg);
+ struct shmid_kernel *shp;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ return security_shm_associate(shp, shmflg);
}
-static inline int shm_more_checks(void *shp, struct ipc_params *params)
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
+ struct ipc_params *params)
{
- if (((struct shmid_kernel *)shp)->shm_segsz < params->u.size)
+ struct shmid_kernel *shp;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ if (shp->shm_segsz < params->u.size)
return -EINVAL;
return 0;
}
}
+/*
+ * Called with shm_ids.rw_mutex held as a reader
+ */
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
unsigned long *swp)
{
struct shmid_kernel *shp;
struct inode *inode;
- /*
- * idr_find() is called via shm_get(), so with shm_ids.mutex
- * locked. Since ipc_addid() is also called with
- * shm_ids.mutex down, there is no need to add read barriers
- * here to gurantee the writes in ipc_addid() are seen in
- * order here (for Alpha).
- * However idr_find() itself does not necessary require
- * ipc_ids.mutex down. So if idr_find() is used by other
- * places without ipc_ids.mutex down, then it needs read
- * read memory barriers as ipc_lock() does.
- */
-
shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
if (shp == NULL)
continue;
shminfo.shmmin = SHMMIN;
if(copy_shminfo_to_user (buf, &shminfo, version))
return -EFAULT;
- /* reading a integer is always atomic */
+
+ down_read(&shm_ids(ns).rw_mutex);
err = ipc_get_maxid(&shm_ids(ns));
+ up_read(&shm_ids(ns).rw_mutex);
+
if(err<0)
err = 0;
goto out;
return err;
memset(&shm_info,0,sizeof(shm_info));
- mutex_lock(&shm_ids(ns).mutex);
+ down_read(&shm_ids(ns).rw_mutex);
shm_info.used_ids = shm_ids(ns).in_use;
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;
err = ipc_get_maxid(&shm_ids(ns));
- mutex_unlock(&shm_ids(ns).mutex);
+ up_read(&shm_ids(ns).rw_mutex);
if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
err = -EFAULT;
goto out;
* Instead we set a destroyed flag, and then blow
* the name away when the usage hits zero.
*/
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock_check(ns, shmid);
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_check_down(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
goto out_up;
if (err)
goto out_unlock_up;
- do_shm_rmid(ns, shp);
- mutex_unlock(&shm_ids(ns).mutex);
+ do_shm_rmid(ns, &shp->shm_perm);
+ up_write(&shm_ids(ns).rw_mutex);
goto out;
}
err = -EFAULT;
goto out;
}
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock_check(ns, shmid);
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_check_down(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
goto out_up;
out_unlock_up:
shm_unlock(shp);
out_up:
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
goto out;
out_unlock:
shm_unlock(shp);
fput(file);
out_nattch:
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_down(ns, shmid);
BUG_ON(IS_ERR(shp));
shp->shm_nattch--;
if(shp->shm_nattch == 0 &&
shm_destroy(ns, shp);
else
shm_unlock(shp);
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
out:
return err;
git.samba.org / sfrench / cifs-2.6.git / blobdiff