[PATCH] IPC namespace - shm

IPC namespace support for IPC shm code.

Signed-off-by: Pavel Emelianiov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 168 insertions, 86 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
index 940b0c9b13aa..bfbd317ec11c 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -15,6 +15,10 @@
  *
  * support for audit of ipc object properties and permission changes
  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
+ *
+ * namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
  */
 
 #include <linux/slab.h>
@@ -32,6 +36,7 @@
 #include <linux/ptrace.h>
 #include <linux/seq_file.h>
 #include <linux/mutex.h>
+#include <linux/nsproxy.h>
 
 #include <asm/uaccess.h>
 
@@ -40,59 +45,115 @@
 static struct file_operations shm_file_operations;
 static struct vm_operations_struct shm_vm_ops;
 
-static struct ipc_ids shm_ids;
+static struct ipc_ids init_shm_ids;
+
+#define shm_ids(ns)     (*((ns)->ids[IPC_SHM_IDS]))
 
-#define shm_lock(id)    ((struct shmid_kernel*)ipc_lock(&shm_ids,id))
-#define shm_unlock(shp) ipc_unlock(&(shp)->shm_perm)
-#define shm_get(id)     ((struct shmid_kernel*)ipc_get(&shm_ids,id))
-#define shm_buildid(id, seq) \
-        ipc_buildid(&shm_ids, id, seq)
+#define shm_lock(ns, id)                \
+        ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
+#define shm_unlock(shp)                 \
+        ipc_unlock(&(shp)->shm_perm)
+#define shm_get(ns, id)                 \
+        ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
+#define shm_buildid(ns, id, seq)        \
+        ipc_buildid(&shm_ids(ns), id, seq)
 
-static int newseg (key_t key, int shmflg, size_t size);
+static int newseg (struct ipc_namespace *ns, key_t key,
+                int shmflg, size_t size);
 static void shm_open (struct vm_area_struct *shmd);
 static void shm_close (struct vm_area_struct *shmd);
+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
 
-size_t  shm_ctlmax = SHMMAX;
-size_t  shm_ctlall = SHMALL;
-int     shm_ctlmni = SHMMNI;
+static void __ipc_init __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+{
+        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, 1);
+}
+
+static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+        if (shp->shm_nattch){
+                shp->shm_perm.mode |= SHM_DEST;
+                /* Do not find it any more */
+                shp->shm_perm.key = IPC_PRIVATE;
+                shm_unlock(shp);
+        } else
+                shm_destroy(ns, shp);
+}
+
+#ifdef CONFIG_IPC_NS
+int shm_init_ns(struct ipc_namespace *ns)
+{
+        struct ipc_ids *ids;
+
+        ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
+        if (ids == NULL)
+                return -ENOMEM;
 
-static int shm_tot; /* total number of shared memory pages */
+        __shm_init_ns(ns, ids);
+        return 0;
+}
+
+void shm_exit_ns(struct ipc_namespace *ns)
+{
+        int i;
+        struct shmid_kernel *shp;
+
+        mutex_lock(&shm_ids(ns).mutex);
+        for (i = 0; i <= shm_ids(ns).max_id; i++) {
+                shp = shm_lock(ns, i);
+                if (shp == NULL)
+                        continue;
+
+                do_shm_rmid(ns, shp);
+        }
+        mutex_unlock(&shm_ids(ns).mutex);
+
+        kfree(ns->ids[IPC_SHM_IDS]);
+        ns->ids[IPC_SHM_IDS] = NULL;
+}
+#endif
 
 void __init shm_init (void)
 {
-        ipc_init_ids(&shm_ids, 1);
+        __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",
-                                &shm_ids,
-                                sysvipc_shm_proc_show);
+                                IPC_SHM_IDS, sysvipc_shm_proc_show);
 }
 
-static inline int shm_checkid(struct shmid_kernel *s, int id)
+static inline int shm_checkid(struct ipc_namespace *ns,
+                struct shmid_kernel *s, int id)
 {
-        if (ipc_checkid(&shm_ids,&s->shm_perm,id))
+        if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
                 return -EIDRM;
         return 0;
 }
 
-static inline struct shmid_kernel *shm_rmid(int id)
+static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
 {
-        return (struct shmid_kernel *)ipc_rmid(&shm_ids,id);
+        return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
 }
 
-static inline int shm_addid(struct shmid_kernel *shp)
+static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
 {
-        return ipc_addid(&shm_ids, &shp->shm_perm, shm_ctlmni);
+        return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 }
 
 
 
-static inline void shm_inc (int id) {
+static inline void shm_inc(struct ipc_namespace *ns, int id)
+{
         struct shmid_kernel *shp;
 
-        shp = shm_lock(id);
+        shp = shm_lock(ns, id);
         BUG_ON(!shp);
         shp->shm_atim = get_seconds();
         shp->shm_lprid = current->tgid;
@@ -100,10 +161,13 @@ static inline void shm_inc (int id) {
         shm_unlock(shp);
 }
 
+#define shm_file_ns(file) (*((struct ipc_namespace **)&(file)->private_data))
+
 /* This is called by fork, once for every shm attach. */
-static void shm_open (struct vm_area_struct *shmd)
+static void shm_open(struct vm_area_struct *shmd)
 {
-        shm_inc (shmd->vm_file->f_dentry->d_inode->i_ino);
+        shm_inc(shm_file_ns(shmd->vm_file),
+                        shmd->vm_file->f_dentry->d_inode->i_ino);
 }
 
 /*
@@ -114,10 +178,10 @@ static void shm_open (struct vm_area_struct *shmd)
  * It has to be called with shp and shm_ids.mutex locked,
  * but returns with shp unlocked and freed.
  */
-static void shm_destroy (struct shmid_kernel *shp)
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 {
-        shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        shm_rmid (shp->id);
+        ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+        shm_rmid(ns, shp->id);
         shm_unlock(shp);
         if (!is_file_hugepages(shp->shm_file))
                 shmem_lock(shp->shm_file, 0, shp->mlock_user);
@@ -140,20 +204,23 @@ static void shm_close (struct vm_area_struct *shmd)
         struct file * file = shmd->vm_file;
         int id = file->f_dentry->d_inode->i_ino;
         struct shmid_kernel *shp;
+        struct ipc_namespace *ns;
 
-        mutex_lock(&shm_ids.mutex);
+        ns = shm_file_ns(file);
+
+        mutex_lock(&shm_ids(ns).mutex);
         /* remove from the list of attaches of the shm segment */
-        shp = shm_lock(id);
+        shp = shm_lock(ns, id);
         BUG_ON(!shp);
         shp->shm_lprid = current->tgid;
         shp->shm_dtim = get_seconds();
         shp->shm_nattch--;
         if(shp->shm_nattch == 0 &&
            shp->shm_perm.mode & SHM_DEST)
-                shm_destroy (shp);
+                shm_destroy(ns, shp);
         else
                 shm_unlock(shp);
-        mutex_unlock(&shm_ids.mutex);
+        mutex_unlock(&shm_ids(ns).mutex);
 }
 
 static int shm_mmap(struct file * file, struct vm_area_struct * vma)
@@ -165,14 +232,25 @@ static int shm_mmap(struct file * file, struct vm_area_struct * vma)
                 vma->vm_ops = &shm_vm_ops;
                 if (!(vma->vm_flags & VM_WRITE))
                         vma->vm_flags &= ~VM_MAYWRITE;
-                shm_inc(file->f_dentry->d_inode->i_ino);
+                shm_inc(shm_file_ns(file), file->f_dentry->d_inode->i_ino);
         }
 
         return ret;
 }
 
+static int shm_release(struct inode *ino, struct file *file)
+{
+        struct ipc_namespace *ns;
+
+        ns = shm_file_ns(file);
+        put_ipc_ns(ns);
+        shm_file_ns(file) = NULL;
+        return 0;
+}
+
 static struct file_operations shm_file_operations = {
-        .mmap   = shm_mmap,
+        .mmap           = shm_mmap,
+        .release        = shm_release,
 #ifndef CONFIG_MMU
         .get_unmapped_area = shmem_get_unmapped_area,
 #endif
@@ -188,7 +266,7 @@ static struct vm_operations_struct shm_vm_ops = {
 #endif
 };
 
-static int newseg (key_t key, int shmflg, size_t size)
+static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
 {
         int error;
         struct shmid_kernel *shp;
@@ -197,10 +275,10 @@ static int newseg (key_t key, int shmflg, size_t size)
         char name[13];
         int id;
 
-        if (size < SHMMIN || size > shm_ctlmax)
+        if (size < SHMMIN || size > ns->shm_ctlmax)
                 return -EINVAL;
 
-        if (shm_tot + numpages >= shm_ctlall)
+        if (ns->shm_tot + numpages >= ns->shm_ctlall)
                 return -ENOSPC;
 
         shp = ipc_rcu_alloc(sizeof(*shp));
@@ -239,7 +317,7 @@ static int newseg (key_t key, int shmflg, size_t size)
                 goto no_file;
 
         error = -ENOSPC;
-        id = shm_addid(shp);
+        id = shm_addid(ns, shp);
         if(id == -1) 
                 goto no_id;
 
@@ -249,15 +327,17 @@ static int newseg (key_t key, int shmflg, size_t size)
         shp->shm_ctim = get_seconds();
         shp->shm_segsz = size;
         shp->shm_nattch = 0;
-        shp->id = shm_buildid(id,shp->shm_perm.seq);
+        shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
         shp->shm_file = file;
         file->f_dentry->d_inode->i_ino = shp->id;
 
+        shm_file_ns(file) = get_ipc_ns(ns);
+
         /* Hugetlb ops would have already been assigned. */
         if (!(shmflg & SHM_HUGETLB))
                 file->f_op = &shm_file_operations;
 
-        shm_tot += numpages;
+        ns->shm_tot += numpages;
         shm_unlock(shp);
         return shp->id;
 
@@ -273,33 +353,36 @@ asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
 {
         struct shmid_kernel *shp;
         int err, id = 0;
+        struct ipc_namespace *ns;
+
+        ns = current->nsproxy->ipc_ns;
 
-        mutex_lock(&shm_ids.mutex);
+        mutex_lock(&shm_ids(ns).mutex);
         if (key == IPC_PRIVATE) {
-                err = newseg(key, shmflg, size);
-        } else if ((id = ipc_findkey(&shm_ids, key)) == -1) {
+                err = newseg(ns, key, shmflg, size);
+        } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
                 if (!(shmflg & IPC_CREAT))
                         err = -ENOENT;
                 else
-                        err = newseg(key, shmflg, size);
+                        err = newseg(ns, key, shmflg, size);
         } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
                 err = -EEXIST;
         } else {
-                shp = shm_lock(id);
+                shp = shm_lock(ns, id);
                 BUG_ON(shp==NULL);
                 if (shp->shm_segsz < size)
                         err = -EINVAL;
                 else if (ipcperms(&shp->shm_perm, shmflg))
                         err = -EACCES;
                 else {
-                        int shmid = shm_buildid(id, shp->shm_perm.seq);
+                        int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
                         err = security_shm_associate(shp, shmflg);
                         if (!err)
                                 err = shmid;
                 }
                 shm_unlock(shp);
         }
-        mutex_unlock(&shm_ids.mutex);
+        mutex_unlock(&shm_ids(ns).mutex);
 
         return err;
 }
@@ -395,18 +478,19 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
         }
 }
 
-static void shm_get_stat(unsigned long *rss, unsigned long *swp) 
+static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
+                unsigned long *swp)
 {
         int i;
 
         *rss = 0;
         *swp = 0;
 
-        for (i = 0; i <= shm_ids.max_id; i++) {
+        for (i = 0; i <= shm_ids(ns).max_id; i++) {
                 struct shmid_kernel *shp;
                 struct inode *inode;
 
-                shp = shm_get(i);
+                shp = shm_get(ns, i);
                 if(!shp)
                         continue;
 
@@ -430,6 +514,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
         struct shm_setbuf setbuf;
         struct shmid_kernel *shp;
         int err, version;
+        struct ipc_namespace *ns;
 
         if (cmd < 0 || shmid < 0) {
                 err = -EINVAL;
@@ -437,6 +522,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
         }
 
         version = ipc_parse_version(&cmd);
+        ns = current->nsproxy->ipc_ns;
 
         switch (cmd) { /* replace with proc interface ? */
         case IPC_INFO:
@@ -448,15 +534,15 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                         return err;
 
                 memset(&shminfo,0,sizeof(shminfo));
-                shminfo.shmmni = shminfo.shmseg = shm_ctlmni;
-                shminfo.shmmax = shm_ctlmax;
-                shminfo.shmall = shm_ctlall;
+                shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
+                shminfo.shmmax = ns->shm_ctlmax;
+                shminfo.shmall = ns->shm_ctlall;
 
                 shminfo.shmmin = SHMMIN;
                 if(copy_shminfo_to_user (buf, &shminfo, version))
                         return -EFAULT;
                 /* reading a integer is always atomic */
-                err= shm_ids.max_id;
+                err= shm_ids(ns).max_id;
                 if(err<0)
                         err = 0;
                 goto out;
@@ -470,14 +556,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                         return err;
 
                 memset(&shm_info,0,sizeof(shm_info));
-                mutex_lock(&shm_ids.mutex);
-                shm_info.used_ids = shm_ids.in_use;
-                shm_get_stat (&shm_info.shm_rss, &shm_info.shm_swp);
-                shm_info.shm_tot = shm_tot;
+                mutex_lock(&shm_ids(ns).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 = shm_ids.max_id;
-                mutex_unlock(&shm_ids.mutex);
+                err = shm_ids(ns).max_id;
+                mutex_unlock(&shm_ids(ns).mutex);
                 if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
                         err = -EFAULT;
                         goto out;
@@ -492,17 +578,17 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                 struct shmid64_ds tbuf;
                 int result;
                 memset(&tbuf, 0, sizeof(tbuf));
-                shp = shm_lock(shmid);
+                shp = shm_lock(ns, shmid);
                 if(shp==NULL) {
                         err = -EINVAL;
                         goto out;
                 } else if(cmd==SHM_STAT) {
                         err = -EINVAL;
-                        if (shmid > shm_ids.max_id)
+                        if (shmid > shm_ids(ns).max_id)
                                 goto out_unlock;
-                        result = shm_buildid(shmid, shp->shm_perm.seq);
+                        result = shm_buildid(ns, shmid, shp->shm_perm.seq);
                 } else {
-                        err = shm_checkid(shp,shmid);
+                        err = shm_checkid(ns, shp,shmid);
                         if(err)
                                 goto out_unlock;
                         result = 0;
@@ -534,12 +620,12 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
         case SHM_LOCK:
         case SHM_UNLOCK:
         {
-                shp = shm_lock(shmid);
+                shp = shm_lock(ns, shmid);
                 if(shp==NULL) {
                         err = -EINVAL;
                         goto out;
                 }
-                err = shm_checkid(shp,shmid);
+                err = shm_checkid(ns, shp,shmid);
                 if(err)
                         goto out_unlock;
 
@@ -590,12 +676,12 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                  *      Instead we set a destroyed flag, and then blow
                  *      the name away when the usage hits zero.
                  */
-                mutex_lock(&shm_ids.mutex);
-                shp = shm_lock(shmid);
+                mutex_lock(&shm_ids(ns).mutex);
+                shp = shm_lock(ns, shmid);
                 err = -EINVAL;
                 if (shp == NULL) 
                         goto out_up;
-                err = shm_checkid(shp, shmid);
+                err = shm_checkid(ns, shp, shmid);
                 if(err)
                         goto out_unlock_up;
 
@@ -614,14 +700,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                 if (err)
                         goto out_unlock_up;
 
-                if (shp->shm_nattch){
-                        shp->shm_perm.mode |= SHM_DEST;
-                        /* Do not find it any more */
-                        shp->shm_perm.key = IPC_PRIVATE;
-                        shm_unlock(shp);
-                } else
-                        shm_destroy (shp);
-                mutex_unlock(&shm_ids.mutex);
+                do_shm_rmid(ns, shp);
+                mutex_unlock(&shm_ids(ns).mutex);
                 goto out;
         }
 
@@ -631,12 +711,12 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                         err = -EFAULT;
                         goto out;
                 }
-                mutex_lock(&shm_ids.mutex);
-                shp = shm_lock(shmid);
+                mutex_lock(&shm_ids(ns).mutex);
+                shp = shm_lock(ns, shmid);
                 err=-EINVAL;
                 if(shp==NULL)
                         goto out_up;
-                err = shm_checkid(shp,shmid);
+                err = shm_checkid(ns, shp,shmid);
                 if(err)
                         goto out_unlock_up;
                 err = audit_ipc_obj(&(shp->shm_perm));
@@ -673,7 +753,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
 out_unlock_up:
         shm_unlock(shp);
 out_up:
-        mutex_unlock(&shm_ids.mutex);
+        mutex_unlock(&shm_ids(ns).mutex);
         goto out;
 out_unlock:
         shm_unlock(shp);
@@ -699,6 +779,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
         unsigned long prot;
         int acc_mode;
         void *user_addr;
+        struct ipc_namespace *ns;
 
         if (shmid < 0) {
                 err = -EINVAL;
@@ -737,12 +818,13 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
          * We cannot rely on the fs check since SYSV IPC does have an
          * additional creator id...
          */
-        shp = shm_lock(shmid);
+        ns = current->nsproxy->ipc_ns;
+        shp = shm_lock(ns, shmid);
         if(shp == NULL) {
                 err = -EINVAL;
                 goto out;
         }
-        err = shm_checkid(shp,shmid);
+        err = shm_checkid(ns, shp,shmid);
         if (err) {
                 shm_unlock(shp);
                 goto out;
@@ -783,16 +865,16 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
 invalid:
         up_write(&current->mm->mmap_sem);
 
-        mutex_lock(&shm_ids.mutex);
-        shp = shm_lock(shmid);
+        mutex_lock(&shm_ids(ns).mutex);
+        shp = shm_lock(ns, shmid);
         BUG_ON(!shp);
         shp->shm_nattch--;
         if(shp->shm_nattch == 0 &&
            shp->shm_perm.mode & SHM_DEST)
-                shm_destroy (shp);
+                shm_destroy(ns, shp);
         else
                 shm_unlock(shp);
-        mutex_unlock(&shm_ids.mutex);
+        mutex_unlock(&shm_ids(ns).mutex);
 
         *raddr = (unsigned long) user_addr;
         err = 0;