]> nv-tegra.nvidia Code Review - linux-3.10.git/blobdiff - ipc/shm.c
ipc: simplify rcu_read_lock() in semctl_nolock()
[linux-3.10.git] / ipc / shm.c
index 8241264941a2aa4ddae64122260506c277f83152..8247c49ec073c236d183ead9f51ab1f4b3779337 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
 #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>
 
@@ -53,16 +54,12 @@ struct shm_file_data {
 #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
 
 static const struct file_operations shm_file_operations;
-static struct vm_operations_struct shm_vm_ops;
+static const 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)
 
 static int newseg(struct ipc_namespace *, struct ipc_params *);
 static void shm_open(struct vm_area_struct *vma);
@@ -72,18 +69,25 @@ static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
 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_rmid_forced = 0;
        ns->shm_tot = 0;
-       ipc_init_ids(ids);
+       ipc_init_ids(&shm_ids(ns));
 }
 
-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 */
@@ -93,59 +97,62 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
                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);
+       idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
 }
+#endif
 
-void shm_exit_ns(struct ipc_namespace *ns)
+static int __init ipc_ns_init(void)
 {
-       struct shmid_kernel *shp;
-       int next_id;
-       int total, in_use;
-
-       mutex_lock(&shm_ids(ns).mutex);
-
-       in_use = shm_ids(ns).in_use;
-
-       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);
-
-       kfree(ns->ids[IPC_SHM_IDS]);
-       ns->ids[IPC_SHM_IDS] = NULL;
+       shm_init_ns(&init_ipc_ns);
+       return 0;
 }
 
+pure_initcall(ipc_ns_init);
+
 void __init shm_init (void)
 {
-       __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",
+#if BITS_PER_LONG <= 32
+                               "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime        rss       swap\n",
+#else
+                               "       key      shmid perms                  size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime                   rss                  swap\n",
+#endif
                                IPC_SHM_IDS, sysvipc_shm_proc_show);
 }
 
+/*
+ * shm_lock_(check_) routines are called in the paths where the rw_mutex
+ * is not necessarily 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 void shm_lock_by_ptr(struct shmid_kernel *ipcp)
+{
+       rcu_read_lock();
+       spin_lock(&ipcp->shm_perm.lock);
 }
 
 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)
@@ -153,12 +160,6 @@ static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
        ipc_rmid(&shm_ids(ns), &s->shm_perm);
 }
 
-static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
-{
-       return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
-}
-
-
 
 /* This is called by fork, once for every shm attach. */
 static void shm_open(struct vm_area_struct *vma)
@@ -178,9 +179,10 @@ static void shm_open(struct vm_area_struct *vma)
 /*
  * 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)
@@ -190,14 +192,31 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
        shm_unlock(shp);
        if (!is_file_hugepages(shp->shm_file))
                shmem_lock(shp->shm_file, 0, shp->mlock_user);
-       else
-               user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
+       else if (shp->mlock_user)
+               user_shm_unlock(file_inode(shp->shm_file)->i_size,
                                                shp->mlock_user);
        fput (shp->shm_file);
        security_shm_free(shp);
        ipc_rcu_putref(shp);
 }
 
+/*
+ * shm_may_destroy - identifies whether shm segment should be destroyed now
+ *
+ * Returns true if and only if there are no active users of the segment and
+ * one of the following is true:
+ *
+ * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
+ *
+ * 2) sysctl kernel.shm_rmid_forced is set to 1.
+ */
+static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+{
+       return (shp->shm_nattch == 0) &&
+              (ns->shm_rmid_forced ||
+               (shp->shm_perm.mode & SHM_DEST));
+}
+
 /*
  * remove the attach descriptor vma.
  * free memory for segment if it is marked destroyed.
@@ -211,19 +230,95 @@ static void shm_close(struct vm_area_struct *vma)
        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);
        BUG_ON(IS_ERR(shp));
        shp->shm_lprid = task_tgid_vnr(current);
        shp->shm_dtim = get_seconds();
        shp->shm_nattch--;
-       if(shp->shm_nattch == 0 &&
-          shp->shm_perm.mode & SHM_DEST)
+       if (shm_may_destroy(ns, shp))
                shm_destroy(ns, shp);
        else
                shm_unlock(shp);
-       mutex_unlock(&shm_ids(ns).mutex);
+       up_write(&shm_ids(ns).rw_mutex);
+}
+
+/* Called with ns->shm_ids(ns).rw_mutex locked */
+static int shm_try_destroy_current(int id, void *p, void *data)
+{
+       struct ipc_namespace *ns = data;
+       struct kern_ipc_perm *ipcp = p;
+       struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+       if (shp->shm_creator != current)
+               return 0;
+
+       /*
+        * Mark it as orphaned to destroy the segment when
+        * kernel.shm_rmid_forced is changed.
+        * It is noop if the following shm_may_destroy() returns true.
+        */
+       shp->shm_creator = NULL;
+
+       /*
+        * Don't even try to destroy it.  If shm_rmid_forced=0 and IPC_RMID
+        * is not set, it shouldn't be deleted here.
+        */
+       if (!ns->shm_rmid_forced)
+               return 0;
+
+       if (shm_may_destroy(ns, shp)) {
+               shm_lock_by_ptr(shp);
+               shm_destroy(ns, shp);
+       }
+       return 0;
+}
+
+/* Called with ns->shm_ids(ns).rw_mutex locked */
+static int shm_try_destroy_orphaned(int id, void *p, void *data)
+{
+       struct ipc_namespace *ns = data;
+       struct kern_ipc_perm *ipcp = p;
+       struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+       /*
+        * We want to destroy segments without users and with already
+        * exit'ed originating process.
+        *
+        * As shp->* are changed under rw_mutex, it's safe to skip shp locking.
+        */
+       if (shp->shm_creator != NULL)
+               return 0;
+
+       if (shm_may_destroy(ns, shp)) {
+               shm_lock_by_ptr(shp);
+               shm_destroy(ns, shp);
+       }
+       return 0;
+}
+
+void shm_destroy_orphaned(struct ipc_namespace *ns)
+{
+       down_write(&shm_ids(ns).rw_mutex);
+       if (shm_ids(ns).in_use)
+               idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
+       up_write(&shm_ids(ns).rw_mutex);
+}
+
+
+void exit_shm(struct task_struct *task)
+{
+       struct ipc_namespace *ns = task->nsproxy->ipc_ns;
+
+       if (shm_ids(ns).in_use == 0)
+               return;
+
+       /* Destroy all already created segments, but not mapped yet */
+       down_write(&shm_ids(ns).rw_mutex);
+       if (shm_ids(ns).in_use)
+               idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns);
+       up_write(&shm_ids(ns).rw_mutex);
 }
 
 static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -256,8 +351,7 @@ static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
                pol = sfd->vm_ops->get_policy(vma, addr);
        else if (vma->vm_policy)
                pol = vma->vm_policy;
-       else
-               pol = current->mempolicy;
+
        return pol;
 }
 #endif
@@ -290,46 +384,60 @@ static int shm_release(struct inode *ino, struct file *file)
        return 0;
 }
 
-static int shm_fsync(struct file *file, struct dentry *dentry, int datasync)
+static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
-       int (*fsync) (struct file *, struct dentry *, int datasync);
        struct shm_file_data *sfd = shm_file_data(file);
-       int ret = -EINVAL;
 
-       fsync = sfd->file->f_op->fsync;
-       if (fsync)
-               ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync);
-       return ret;
+       if (!sfd->file->f_op->fsync)
+               return -EINVAL;
+       return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
 }
 
-static unsigned long shm_get_unmapped_area(struct file *file,
-       unsigned long addr, unsigned long len, unsigned long pgoff,
-       unsigned long flags)
+static long shm_fallocate(struct file *file, int mode, loff_t offset,
+                         loff_t len)
 {
        struct shm_file_data *sfd = shm_file_data(file);
-       return get_unmapped_area(sfd->file, addr, len, pgoff, flags);
+
+       if (!sfd->file->f_op->fallocate)
+               return -EOPNOTSUPP;
+       return sfd->file->f_op->fallocate(file, mode, offset, len);
 }
 
-int is_file_shm_hugepages(struct file *file)
+static unsigned long shm_get_unmapped_area(struct file *file,
+       unsigned long addr, unsigned long len, unsigned long pgoff,
+       unsigned long flags)
 {
-       int ret = 0;
-
-       if (file->f_op == &shm_file_operations) {
-               struct shm_file_data *sfd;
-               sfd = shm_file_data(file);
-               ret = is_file_hugepages(sfd->file);
-       }
-       return ret;
+       struct shm_file_data *sfd = shm_file_data(file);
+       return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
+                                               pgoff, flags);
 }
 
 static const struct file_operations shm_file_operations = {
        .mmap           = shm_mmap,
        .fsync          = shm_fsync,
        .release        = shm_release,
+#ifndef CONFIG_MMU
+       .get_unmapped_area      = shm_get_unmapped_area,
+#endif
+       .llseek         = noop_llseek,
+       .fallocate      = shm_fallocate,
+};
+
+static const struct file_operations shm_file_operations_huge = {
+       .mmap           = shm_mmap,
+       .fsync          = shm_fsync,
+       .release        = shm_release,
        .get_unmapped_area      = shm_get_unmapped_area,
+       .llseek         = noop_llseek,
+       .fallocate      = shm_fallocate,
 };
 
-static struct vm_operations_struct shm_vm_ops = {
+int is_file_shm_hugepages(struct file *file)
+{
+       return file->f_op == &shm_file_operations_huge;
+}
+
+static const struct vm_operations_struct shm_vm_ops = {
        .open   = shm_open,     /* callback for a new vm-area open */
        .close  = shm_close,    /* callback for when the vm-area is released */
        .fault  = shm_fault,
@@ -339,6 +447,14 @@ static struct vm_operations_struct shm_vm_ops = {
 #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;
@@ -346,10 +462,11 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
        size_t size = params->u.size;
        int error;
        struct shmid_kernel *shp;
-       int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
+       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)
                return -EINVAL;
@@ -374,28 +491,31 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 
        sprintf (name, "SYSV%08x", key);
        if (shmflg & SHM_HUGETLB) {
-               /* hugetlb_file_setup takes care of mlock user accounting */
-               file = hugetlb_file_setup(name, size);
-               shp->mlock_user = current->user;
+               /* hugetlb_file_setup applies strict accounting */
+               if (shmflg & SHM_NORESERVE)
+                       acctflag = VM_NORESERVE;
+               file = hugetlb_file_setup(name, 0, size, acctflag,
+                                 &shp->mlock_user, HUGETLB_SHMFS_INODE,
+                               (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
        } else {
-               int acctflag = VM_ACCOUNT;
                /*
                 * Do not allow no accounting for OVERCOMMIT_NEVER, even
                 * if it's asked for.
                 */
                if  ((shmflg & SHM_NORESERVE) &&
                                sysctl_overcommit_memory != OVERCOMMIT_NEVER)
-                       acctflag = 0;
+                       acctflag = VM_NORESERVE;
                file = shmem_file_setup(name, size, acctflag);
        }
        error = PTR_ERR(file);
        if (IS_ERR(file))
                goto no_file;
 
-       error = -ENOSPC;
-       id = shm_addid(ns, shp);
-       if(id == -1) 
+       id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
+       if (id < 0) {
+               error = id;
                goto no_id;
+       }
 
        shp->shm_cprid = task_tgid_vnr(current);
        shp->shm_lprid = 0;
@@ -403,13 +523,13 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
        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_file = file;
+       shp->shm_creator = current;
        /*
         * shmid gets reported as "inode#" in /proc/pid/maps.
         * proc-ps tools use this. Changing this will break them.
         */
-       file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
+       file_inode(file)->i_ino = shp->shm_perm.id;
 
        ns->shm_tot += numpages;
        error = shp->shm_perm.id;
@@ -417,6 +537,8 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
        return error;
 
 no_id:
+       if (is_file_hugepages(file) && shp->mlock_user)
+               user_shm_unlock(size, shp->mlock_user);
        fput(file);
 no_file:
        security_shm_free(shp);
@@ -424,20 +546,33 @@ no_file:
        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;
 }
 
-asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 {
        struct ipc_namespace *ns;
        struct ipc_ops shm_ops;
@@ -465,6 +600,7 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
            {
                struct shmid_ds out;
 
+               memset(&out, 0, sizeof(out));
                ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
                out.shm_segsz   = in->shm_segsz;
                out.shm_atime   = in->shm_atime;
@@ -481,28 +617,14 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
        }
 }
 
-struct shm_setbuf {
-       uid_t   uid;
-       gid_t   gid;
-       mode_t  mode;
-};     
-
-static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
+static inline unsigned long
+copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 {
        switch(version) {
        case IPC_64:
-           {
-               struct shmid64_ds tbuf;
-
-               if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
+               if (copy_from_user(out, buf, sizeof(*out)))
                        return -EFAULT;
-
-               out->uid        = tbuf.shm_perm.uid;
-               out->gid        = tbuf.shm_perm.gid;
-               out->mode       = tbuf.shm_perm.mode;
-
                return 0;
-           }
        case IPC_OLD:
            {
                struct shmid_ds tbuf_old;
@@ -510,9 +632,9 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
                if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
                        return -EFAULT;
 
-               out->uid        = tbuf_old.shm_perm.uid;
-               out->gid        = tbuf_old.shm_perm.gid;
-               out->mode       = tbuf_old.shm_perm.mode;
+               out->shm_perm.uid       = tbuf_old.shm_perm.uid;
+               out->shm_perm.gid       = tbuf_old.shm_perm.gid;
+               out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 
                return 0;
            }
@@ -547,6 +669,37 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
        }
 }
 
+/*
+ * Calculate and add used RSS and swap pages of a shm.
+ * Called with shm_ids.rw_mutex held as a reader
+ */
+static void shm_add_rss_swap(struct shmid_kernel *shp,
+       unsigned long *rss_add, unsigned long *swp_add)
+{
+       struct inode *inode;
+
+       inode = file_inode(shp->shm_file);
+
+       if (is_file_hugepages(shp->shm_file)) {
+               struct address_space *mapping = inode->i_mapping;
+               struct hstate *h = hstate_file(shp->shm_file);
+               *rss_add += pages_per_huge_page(h) * mapping->nrpages;
+       } else {
+#ifdef CONFIG_SHMEM
+               struct shmem_inode_info *info = SHMEM_I(inode);
+               spin_lock(&info->lock);
+               *rss_add += inode->i_mapping->nrpages;
+               *swp_add += info->swapped;
+               spin_unlock(&info->lock);
+#else
+               *rss_add += inode->i_mapping->nrpages;
+#endif
+       }
+}
+
+/*
+ * 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)
 {
@@ -559,45 +712,70 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
        in_use = shm_ids(ns).in_use;
 
        for (total = 0, next_id = 0; total < in_use; next_id++) {
+               struct kern_ipc_perm *ipc;
                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)
+               ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+               if (ipc == NULL)
                        continue;
+               shp = container_of(ipc, struct shmid_kernel, shm_perm);
 
-               inode = shp->shm_file->f_path.dentry->d_inode;
-
-               if (is_file_hugepages(shp->shm_file)) {
-                       struct address_space *mapping = inode->i_mapping;
-                       *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
-               } else {
-                       struct shmem_inode_info *info = SHMEM_I(inode);
-                       spin_lock(&info->lock);
-                       *rss += inode->i_mapping->nrpages;
-                       *swp += info->swapped;
-                       spin_unlock(&info->lock);
-               }
+               shm_add_rss_swap(shp, rss, swp);
 
                total++;
        }
 }
 
-asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
+/*
+ * This function handles some shmctl commands which require the rw_mutex
+ * to be held in write mode.
+ * NOTE: no locks must be held, the rw_mutex is taken inside this function.
+ */
+static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
+                      struct shmid_ds __user *buf, int version)
+{
+       struct kern_ipc_perm *ipcp;
+       struct shmid64_ds shmid64;
+       struct shmid_kernel *shp;
+       int err;
+
+       if (cmd == IPC_SET) {
+               if (copy_shmid_from_user(&shmid64, buf, version))
+                       return -EFAULT;
+       }
+
+       ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
+                              &shmid64.shm_perm, 0);
+       if (IS_ERR(ipcp))
+               return PTR_ERR(ipcp);
+
+       shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
+       err = security_shm_shmctl(shp, cmd);
+       if (err)
+               goto out_unlock;
+       switch (cmd) {
+       case IPC_RMID:
+               do_shm_rmid(ns, ipcp);
+               goto out_up;
+       case IPC_SET:
+               err = ipc_update_perm(&shmid64.shm_perm, ipcp);
+               if (err)
+                       goto out_unlock;
+               shp->shm_ctim = get_seconds();
+               break;
+       default:
+               err = -EINVAL;
+       }
+out_unlock:
+       shm_unlock(shp);
+out_up:
+       up_write(&shm_ids(ns).rw_mutex);
+       return err;
+}
+
+SYSCALL_DEFINE3(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;
@@ -619,7 +797,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                if (err)
                        return err;
 
-               memset(&shminfo,0,sizeof(shminfo));
+               memset(&shminfo, 0, sizeof(shminfo));
                shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
                shminfo.shmmax = ns->shm_ctlmax;
                shminfo.shmall = ns->shm_ctlall;
@@ -627,8 +805,11 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                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;
@@ -641,16 +822,16 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                if (err)
                        return err;
 
-               memset(&shm_info,0,sizeof(shm_info));
-               mutex_lock(&shm_ids(ns).mutex);
+               memset(&shm_info, 0, sizeof(shm_info));
+               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);
-               if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
+               up_read(&shm_ids(ns).rw_mutex);
+               if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
                        err = -EFAULT;
                        goto out;
                }
@@ -664,11 +845,6 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                struct shmid64_ds tbuf;
                int result;
 
-               if (!buf) {
-                       err = -EFAULT;
-                       goto out;
-               }
-
                if (cmd == SHM_STAT) {
                        shp = shm_lock(ns, shmid);
                        if (IS_ERR(shp)) {
@@ -684,8 +860,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        }
                        result = 0;
                }
-               err=-EACCES;
-               if (ipcperms (&shp->shm_perm, S_IRUGO))
+               err = -EACCES;
+               if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
                        goto out_unlock;
                err = security_shm_shmctl(shp, cmd);
                if (err)
@@ -709,139 +885,64 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
        case SHM_LOCK:
        case SHM_UNLOCK:
        {
+               struct file *shm_file;
+
                shp = shm_lock_check(ns, shmid);
                if (IS_ERR(shp)) {
                        err = PTR_ERR(shp);
                        goto out;
                }
 
-               err = audit_ipc_obj(&(shp->shm_perm));
-               if (err)
-                       goto out_unlock;
+               audit_ipc_obj(&(shp->shm_perm));
 
-               if (!capable(CAP_IPC_LOCK)) {
+               if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
+                       kuid_t euid = current_euid();
                        err = -EPERM;
-                       if (current->euid != shp->shm_perm.uid &&
-                           current->euid != shp->shm_perm.cuid)
+                       if (!uid_eq(euid, shp->shm_perm.uid) &&
+                           !uid_eq(euid, shp->shm_perm.cuid))
                                goto out_unlock;
-                       if (cmd == SHM_LOCK &&
-                           !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
+                       if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
                                goto out_unlock;
                }
 
                err = security_shm_shmctl(shp, cmd);
                if (err)
                        goto out_unlock;
-               
-               if(cmd==SHM_LOCK) {
-                       struct user_struct * user = current->user;
-                       if (!is_file_hugepages(shp->shm_file)) {
-                               err = shmem_lock(shp->shm_file, 1, user);
-                               if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
-                                       shp->shm_perm.mode |= SHM_LOCKED;
-                                       shp->mlock_user = user;
-                               }
-                       }
-               } else if (!is_file_hugepages(shp->shm_file)) {
-                       shmem_lock(shp->shm_file, 0, shp->mlock_user);
-                       shp->shm_perm.mode &= ~SHM_LOCKED;
-                       shp->mlock_user = NULL;
-               }
-               shm_unlock(shp);
-               goto out;
-       }
-       case IPC_RMID:
-       {
-               /*
-                *      We cannot simply remove the file. The SVID states
-                *      that the block remains until the last person
-                *      detaches from it, then is deleted. A shmat() on
-                *      an RMID segment is legal in older Linux and if 
-                *      we change it apps break...
-                *
-                *      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);
-               if (IS_ERR(shp)) {
-                       err = PTR_ERR(shp);
-                       goto out_up;
-               }
 
-               err = audit_ipc_obj(&(shp->shm_perm));
-               if (err)
-                       goto out_unlock_up;
+               shm_file = shp->shm_file;
+               if (is_file_hugepages(shm_file))
+                       goto out_unlock;
 
-               if (current->euid != shp->shm_perm.uid &&
-                   current->euid != shp->shm_perm.cuid && 
-                   !capable(CAP_SYS_ADMIN)) {
-                       err=-EPERM;
-                       goto out_unlock_up;
+               if (cmd == SHM_LOCK) {
+                       struct user_struct *user = current_user();
+                       err = shmem_lock(shm_file, 1, user);
+                       if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
+                               shp->shm_perm.mode |= SHM_LOCKED;
+                               shp->mlock_user = user;
+                       }
+                       goto out_unlock;
                }
 
-               err = security_shm_shmctl(shp, cmd);
-               if (err)
-                       goto out_unlock_up;
-
-               do_shm_rmid(ns, shp);
-               mutex_unlock(&shm_ids(ns).mutex);
+               /* SHM_UNLOCK */
+               if (!(shp->shm_perm.mode & SHM_LOCKED))
+                       goto out_unlock;
+               shmem_lock(shm_file, 0, shp->mlock_user);
+               shp->shm_perm.mode &= ~SHM_LOCKED;
+               shp->mlock_user = NULL;
+               get_file(shm_file);
+               shm_unlock(shp);
+               shmem_unlock_mapping(shm_file->f_mapping);
+               fput(shm_file);
                goto out;
        }
-
+       case IPC_RMID:
        case IPC_SET:
-       {
-               if (!buf) {
-                       err = -EFAULT;
-                       goto out;
-               }
-
-               if (copy_shmid_from_user (&setbuf, buf, version)) {
-                       err = -EFAULT;
-                       goto out;
-               }
-               mutex_lock(&shm_ids(ns).mutex);
-               shp = shm_lock_check(ns, shmid);
-               if (IS_ERR(shp)) {
-                       err = PTR_ERR(shp);
-                       goto out_up;
-               }
-               err = audit_ipc_obj(&(shp->shm_perm));
-               if (err)
-                       goto out_unlock_up;
-               err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
-               if (err)
-                       goto out_unlock_up;
-               err=-EPERM;
-               if (current->euid != shp->shm_perm.uid &&
-                   current->euid != shp->shm_perm.cuid && 
-                   !capable(CAP_SYS_ADMIN)) {
-                       goto out_unlock_up;
-               }
-
-               err = security_shm_shmctl(shp, cmd);
-               if (err)
-                       goto out_unlock_up;
-               
-               shp->shm_perm.uid = setbuf.uid;
-               shp->shm_perm.gid = setbuf.gid;
-               shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
-                       | (setbuf.mode & S_IRWXUGO);
-               shp->shm_ctim = get_seconds();
-               break;
-       }
-
+               err = shmctl_down(ns, shmid, cmd, buf, version);
+               return err;
        default:
-               err = -EINVAL;
-               goto out;
+               return -EINVAL;
        }
 
-       err = 0;
-out_unlock_up:
-       shm_unlock(shp);
-out_up:
-       mutex_unlock(&shm_ids(ns).mutex);
-       goto out;
 out_unlock:
        shm_unlock(shp);
 out:
@@ -855,7 +956,8 @@ out:
  * "raddr" thing points to kernel space, and there has to be a wrapper around
  * this.
  */
-long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
+long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
+             unsigned long shmlba)
 {
        struct shmid_kernel *shp;
        unsigned long addr;
@@ -865,19 +967,19 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        unsigned long flags;
        unsigned long prot;
        int acc_mode;
-       unsigned long user_addr;
        struct ipc_namespace *ns;
        struct shm_file_data *sfd;
        struct path path;
-       mode_t f_mode;
+       fmode_t f_mode;
+       unsigned long populate = 0;
 
        err = -EINVAL;
        if (shmid < 0)
                goto out;
        else if ((addr = (ulong)shmaddr)) {
-               if (addr & (SHMLBA-1)) {
+               if (addr & (shmlba - 1)) {
                        if (shmflg & SHM_RND)
-                               addr &= ~(SHMLBA-1);       /* round down */
+                               addr &= ~(shmlba - 1);     /* round down */
                        else
 #ifndef __ARCH_FORCE_SHMLBA
                                if (addr & ~PAGE_MASK)
@@ -918,15 +1020,15 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        }
 
        err = -EACCES;
-       if (ipcperms(&shp->shm_perm, acc_mode))
+       if (ipcperms(ns, &shp->shm_perm, acc_mode))
                goto out_unlock;
 
        err = security_shm_shmat(shp, shmaddr, shmflg);
        if (err)
                goto out_unlock;
 
-       path.dentry = dget(shp->shm_file->f_path.dentry);
-       path.mnt    = shp->shm_file->f_path.mnt;
+       path = shp->shm_file->f_path;
+       path_get(&path);
        shp->shm_nattch++;
        size = i_size_read(path.dentry->d_inode);
        shm_unlock(shp);
@@ -936,10 +1038,12 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        if (!sfd)
                goto out_put_dentry;
 
-       err = -ENOMEM;
-
-       file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
-       if (!file)
+       file = alloc_file(&path, f_mode,
+                         is_file_hugepages(shp->shm_file) ?
+                               &shm_file_operations_huge :
+                               &shm_file_operations);
+       err = PTR_ERR(file);
+       if (IS_ERR(file))
                goto out_free;
 
        file->private_data = sfd;
@@ -949,6 +1053,10 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
        sfd->file = shp->shm_file;
        sfd->vm_ops = NULL;
 
+       err = security_mmap_file(file, prot, flags);
+       if (err)
+               goto out_fput;
+
        down_write(&current->mm->mmap_sem);
        if (addr && !(shmflg & SHM_REMAP)) {
                err = -EINVAL;
@@ -963,27 +1071,29 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
                        goto invalid;
        }
                
-       user_addr = do_mmap (file, addr, size, prot, flags, 0);
-       *raddr = user_addr;
+       addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
+       *raddr = addr;
        err = 0;
-       if (IS_ERR_VALUE(user_addr))
-               err = (long)user_addr;
+       if (IS_ERR_VALUE(addr))
+               err = (long)addr;
 invalid:
        up_write(&current->mm->mmap_sem);
+       if (populate)
+               mm_populate(addr, populate);
 
+out_fput:
        fput(file);
 
 out_nattch:
-       mutex_lock(&shm_ids(ns).mutex);
+       down_write(&shm_ids(ns).rw_mutex);
        shp = shm_lock(ns, shmid);
        BUG_ON(IS_ERR(shp));
        shp->shm_nattch--;
-       if(shp->shm_nattch == 0 &&
-          shp->shm_perm.mode & SHM_DEST)
+       if (shm_may_destroy(ns, shp))
                shm_destroy(ns, shp);
        else
                shm_unlock(shp);
-       mutex_unlock(&shm_ids(ns).mutex);
+       up_write(&shm_ids(ns).rw_mutex);
 
 out:
        return err;
@@ -995,16 +1105,16 @@ out_unlock:
 out_free:
        kfree(sfd);
 out_put_dentry:
-       dput(path.dentry);
+       path_put(&path);
        goto out_nattch;
 }
 
-asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
+SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
 {
        unsigned long ret;
        long err;
 
-       err = do_shmat(shmid, shmaddr, shmflg, &ret);
+       err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
        if (err)
                return err;
        force_successful_syscall_return();
@@ -1015,13 +1125,16 @@ asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
  * detach and kill segment if marked destroyed.
  * The work is done in shm_close.
  */
-asmlinkage long sys_shmdt(char __user *shmaddr)
+SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
 {
        struct mm_struct *mm = current->mm;
-       struct vm_area_struct *vma, *next;
+       struct vm_area_struct *vma;
        unsigned long addr = (unsigned long)shmaddr;
-       loff_t size = 0;
        int retval = -EINVAL;
+#ifdef CONFIG_MMU
+       loff_t size = 0;
+       struct vm_area_struct *next;
+#endif
 
        if (addr & ~PAGE_MASK)
                return retval;
@@ -1050,6 +1163,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
         */
        vma = find_vma(mm, addr);
 
+#ifdef CONFIG_MMU
        while (vma) {
                next = vma->vm_next;
 
@@ -1062,7 +1176,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
                        (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
 
 
-                       size = vma->vm_file->f_path.dentry->d_inode->i_size;
+                       size = file_inode(vma->vm_file)->i_size;
                        do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
                        /*
                         * We discovered the size of the shm segment, so
@@ -1080,7 +1194,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
        /*
         * We need look no further than the maximum address a fragment
         * could possibly have landed at. Also cast things to loff_t to
-        * prevent overflows and make comparisions vs. equal-width types.
+        * prevent overflows and make comparisons vs. equal-width types.
         */
        size = PAGE_ALIGN(size);
        while (vma && (loff_t)(vma->vm_end - addr) <= size) {
@@ -1094,6 +1208,17 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
                vma = next;
        }
 
+#else /* CONFIG_MMU */
+       /* under NOMMU conditions, the exact address to be destroyed must be
+        * given */
+       retval = -EINVAL;
+       if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+               do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+               retval = 0;
+       }
+
+#endif
+
        up_write(&mm->mmap_sem);
        return retval;
 }
@@ -1101,17 +1226,22 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
 #ifdef CONFIG_PROC_FS
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
 {
+       struct user_namespace *user_ns = seq_user_ns(s);
        struct shmid_kernel *shp = it;
-       char *format;
+       unsigned long rss = 0, swp = 0;
 
-#define SMALL_STRING "%10d %10d  %4o %10u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
-#define BIG_STRING   "%10d %10d  %4o %21u %5u %5u  %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
+       shm_add_rss_swap(shp, &rss, &swp);
 
-       if (sizeof(size_t) <= sizeof(int))
-               format = SMALL_STRING;
-       else
-               format = BIG_STRING;
-       return seq_printf(s, format,
+#if BITS_PER_LONG <= 32
+#define SIZE_SPEC "%10lu"
+#else
+#define SIZE_SPEC "%21lu"
+#endif
+
+       return seq_printf(s,
+                         "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
+                         "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
+                         SIZE_SPEC " " SIZE_SPEC "\n",
                          shp->shm_perm.key,
                          shp->shm_perm.id,
                          shp->shm_perm.mode,
@@ -1119,12 +1249,14 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
                          shp->shm_cprid,
                          shp->shm_lprid,
                          shp->shm_nattch,
-                         shp->shm_perm.uid,
-                         shp->shm_perm.gid,
-                         shp->shm_perm.cuid,
-                         shp->shm_perm.cgid,
+                         from_kuid_munged(user_ns, shp->shm_perm.uid),
+                         from_kgid_munged(user_ns, shp->shm_perm.gid),
+                         from_kuid_munged(user_ns, shp->shm_perm.cuid),
+                         from_kgid_munged(user_ns, shp->shm_perm.cgid),
                          shp->shm_atim,
                          shp->shm_dtim,
-                         shp->shm_ctim);
+                         shp->shm_ctim,
+                         rss * PAGE_SIZE,
+                         swp * PAGE_SIZE);
 }
 #endif