[PARISC] More useful readwrite lock helpers
[linux-3.10.git] / ipc / shm.c
index 06cd5c9..f806a2e 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/mman.h>
-#include <linux/proc_fs.h>
 #include <linux/shmem_fs.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/ptrace.h>
+#include <linux/seq_file.h>
+#include <linux/mutex.h>
+
 #include <asm/uaccess.h>
 
 #include "util.h"
 
-#define shm_flags      shm_perm.mode
-
 static struct file_operations shm_file_operations;
 static struct vm_operations_struct shm_vm_ops;
 
@@ -49,7 +51,7 @@ static int newseg (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);
 #ifdef CONFIG_PROC_FS
-static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
 size_t shm_ctlmax = SHMMAX;
@@ -61,9 +63,10 @@ static int shm_tot; /* total number of shared memory pages */
 void __init shm_init (void)
 {
        ipc_init_ids(&shm_ids, 1);
-#ifdef CONFIG_PROC_FS
-       create_proc_read_entry("sysvipc/shm", 0, NULL, sysvipc_shm_read_proc, NULL);
-#endif
+       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);
 }
 
 static inline int shm_checkid(struct shmid_kernel *s, int id)
@@ -107,7 +110,7 @@ static void shm_open (struct vm_area_struct *shmd)
  *
  * @shp: struct to free
  *
- * It has to be called with shp and shm_ids.sem locked,
+ * 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)
@@ -137,7 +140,7 @@ static void shm_close (struct vm_area_struct *shmd)
        int id = file->f_dentry->d_inode->i_ino;
        struct shmid_kernel *shp;
 
-       down (&shm_ids.sem);
+       mutex_lock(&shm_ids.mutex);
        /* remove from the list of attaches of the shm segment */
        if(!(shp = shm_lock(id)))
                BUG();
@@ -145,30 +148,38 @@ static void shm_close (struct vm_area_struct *shmd)
        shp->shm_dtim = get_seconds();
        shp->shm_nattch--;
        if(shp->shm_nattch == 0 &&
-          shp->shm_flags & SHM_DEST)
+          shp->shm_perm.mode & SHM_DEST)
                shm_destroy (shp);
        else
                shm_unlock(shp);
-       up (&shm_ids.sem);
+       mutex_unlock(&shm_ids.mutex);
 }
 
 static int shm_mmap(struct file * file, struct vm_area_struct * vma)
 {
-       file_accessed(file);
-       vma->vm_ops = &shm_vm_ops;
-       shm_inc(file->f_dentry->d_inode->i_ino);
-       return 0;
+       int ret;
+
+       ret = shmem_mmap(file, vma);
+       if (ret == 0) {
+               vma->vm_ops = &shm_vm_ops;
+               shm_inc(file->f_dentry->d_inode->i_ino);
+       }
+
+       return ret;
 }
 
 static struct file_operations shm_file_operations = {
-       .mmap   = shm_mmap
+       .mmap   = shm_mmap,
+#ifndef CONFIG_MMU
+       .get_unmapped_area = shmem_get_unmapped_area,
+#endif
 };
 
 static 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 */
        .nopage = shmem_nopage,
-#ifdef CONFIG_NUMA
+#if defined(CONFIG_NUMA) && defined(CONFIG_SHMEM)
        .set_policy = shmem_set_policy,
        .get_policy = shmem_get_policy,
 #endif
@@ -194,7 +205,7 @@ static int newseg (key_t key, int shmflg, size_t size)
                return -ENOMEM;
 
        shp->shm_perm.key = key;
-       shp->shm_flags = (shmflg & S_IRWXUGO);
+       shp->shm_perm.mode = (shmflg & S_IRWXUGO);
        shp->mlock_user = NULL;
 
        shp->shm_perm.security = NULL;
@@ -209,8 +220,16 @@ static int newseg (key_t key, int shmflg, size_t size)
                file = hugetlb_zero_setup(size);
                shp->mlock_user = current->user;
        } 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;
                sprintf (name, "SYSV%08x", key);
-               file = shmem_file_setup(name, size, VM_ACCOUNT);
+               file = shmem_file_setup(name, size, acctflag);
        }
        error = PTR_ERR(file);
        if (IS_ERR(file))
@@ -230,10 +249,11 @@ static int newseg (key_t key, int shmflg, size_t size)
        shp->id = shm_buildid(id,shp->shm_perm.seq);
        shp->shm_file = file;
        file->f_dentry->d_inode->i_ino = shp->id;
-       if (shmflg & SHM_HUGETLB)
-               set_file_hugepages(file);
-       else
+
+       /* Hugetlb ops would have already been assigned. */
+       if (!(shmflg & SHM_HUGETLB))
                file->f_op = &shm_file_operations;
+
        shm_tot += numpages;
        shm_unlock(shp);
        return shp->id;
@@ -251,7 +271,7 @@ asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
        struct shmid_kernel *shp;
        int err, id = 0;
 
-       down(&shm_ids.sem);
+       mutex_lock(&shm_ids.mutex);
        if (key == IPC_PRIVATE) {
                err = newseg(key, shmflg, size);
        } else if ((id = ipc_findkey(&shm_ids, key)) == -1) {
@@ -277,7 +297,7 @@ asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
                }
                shm_unlock(shp);
        }
-       up(&shm_ids.sem);
+       mutex_unlock(&shm_ids.mutex);
 
        return err;
 }
@@ -325,7 +345,7 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
 
                out->uid        = tbuf.shm_perm.uid;
                out->gid        = tbuf.shm_perm.gid;
-               out->mode       = tbuf.shm_flags;
+               out->mode       = tbuf.shm_perm.mode;
 
                return 0;
            }
@@ -338,7 +358,7 @@ static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __
 
                out->uid        = tbuf_old.shm_perm.uid;
                out->gid        = tbuf_old.shm_perm.gid;
-               out->mode       = tbuf_old.shm_flags;
+               out->mode       = tbuf_old.shm_perm.mode;
 
                return 0;
            }
@@ -448,14 +468,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        return err;
 
                memset(&shm_info,0,sizeof(shm_info));
-               down(&shm_ids.sem);
+               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;
                shm_info.swap_attempts = 0;
                shm_info.swap_successes = 0;
                err = shm_ids.max_id;
-               up(&shm_ids.sem);
+               mutex_unlock(&shm_ids.mutex);
                if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
                        err = -EFAULT;
                        goto out;
@@ -540,13 +560,13 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        if (!is_file_hugepages(shp->shm_file)) {
                                err = shmem_lock(shp->shm_file, 1, user);
                                if (!err) {
-                                       shp->shm_flags |= 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_flags &= ~SHM_LOCKED;
+                       shp->shm_perm.mode &= ~SHM_LOCKED;
                        shp->mlock_user = NULL;
                }
                shm_unlock(shp);
@@ -564,7 +584,7 @@ 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.
                 */
-               down(&shm_ids.sem);
+               mutex_lock(&shm_ids.mutex);
                shp = shm_lock(shmid);
                err = -EINVAL;
                if (shp == NULL) 
@@ -585,13 +605,13 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        goto out_unlock_up;
 
                if (shp->shm_nattch){
-                       shp->shm_flags |= SHM_DEST;
+                       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);
-               up(&shm_ids.sem);
+               mutex_unlock(&shm_ids.mutex);
                goto out;
        }
 
@@ -601,13 +621,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                        err = -EFAULT;
                        goto out;
                }
-               if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode)))
-                       return err;
-               down(&shm_ids.sem);
+               mutex_lock(&shm_ids.mutex);
                shp = shm_lock(shmid);
                err=-EINVAL;
                if(shp==NULL)
                        goto out_up;
+               if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid,
+                                       setbuf.mode, &(shp->shm_perm))))
+                       goto out_unlock_up;
                err = shm_checkid(shp,shmid);
                if(err)
                        goto out_unlock_up;
@@ -624,7 +645,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
                
                shp->shm_perm.uid = setbuf.uid;
                shp->shm_perm.gid = setbuf.gid;
-               shp->shm_flags = (shp->shm_flags & ~S_IRWXUGO)
+               shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
                        | (setbuf.mode & S_IRWXUGO);
                shp->shm_ctim = get_seconds();
                break;
@@ -639,7 +660,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
 out_unlock_up:
        shm_unlock(shp);
 out_up:
-       up(&shm_ids.sem);
+       mutex_unlock(&shm_ids.mutex);
        goto out;
 out_unlock:
        shm_unlock(shp);
@@ -752,16 +773,16 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
 invalid:
        up_write(&current->mm->mmap_sem);
 
-       down (&shm_ids.sem);
+       mutex_lock(&shm_ids.mutex);
        if(!(shp = shm_lock(shmid)))
                BUG();
        shp->shm_nattch--;
        if(shp->shm_nattch == 0 &&
-          shp->shm_flags & SHM_DEST)
+          shp->shm_perm.mode & SHM_DEST)
                shm_destroy (shp);
        else
                shm_unlock(shp);
-       up (&shm_ids.sem);
+       mutex_unlock(&shm_ids.mutex);
 
        *raddr = (unsigned long) user_addr;
        err = 0;
@@ -771,6 +792,18 @@ out:
        return err;
 }
 
+asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
+{
+       unsigned long ret;
+       long err;
+
+       err = do_shmat(shmid, shmaddr, shmflg, &ret);
+       if (err)
+               return err;
+       force_successful_syscall_return();
+       return (long)ret;
+}
+
 /*
  * detach and kill segment if marked destroyed.
  * The work is done in shm_close.
@@ -783,6 +816,9 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
        loff_t size = 0;
        int retval = -EINVAL;
 
+       if (addr & ~PAGE_MASK)
+               return retval;
+
        down_write(&mm->mmap_sem);
 
        /*
@@ -839,6 +875,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
         * could possibly have landed at. Also cast things to loff_t to
         * prevent overflows and make comparisions vs. equal-width types.
         */
+       size = PAGE_ALIGN(size);
        while (vma && (loff_t)(vma->vm_end - addr) <= size) {
                next = vma->vm_next;
 
@@ -855,63 +892,32 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
 }
 
 #ifdef CONFIG_PROC_FS
-static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data)
+static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
 {
-       off_t pos = 0;
-       off_t begin = 0;
-       int i, len = 0;
-
-       down(&shm_ids.sem);
-       len += sprintf(buffer, "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n");
-
-       for(i = 0; i <= shm_ids.max_id; i++) {
-               struct shmid_kernel* shp;
+       struct shmid_kernel *shp = it;
+       char *format;
 
-               shp = shm_lock(i);
-               if(shp!=NULL) {
 #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"
-                       char *format;
 
-                       if (sizeof(size_t) <= sizeof(int))
-                               format = SMALL_STRING;
-                       else
-                               format = BIG_STRING;
-                       len += sprintf(buffer + len, format,
-                               shp->shm_perm.key,
-                               shm_buildid(i, shp->shm_perm.seq),
-                               shp->shm_flags,
-                               shp->shm_segsz,
-                               shp->shm_cprid,
-                               shp->shm_lprid,
-                               is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
-                               shp->shm_perm.uid,
-                               shp->shm_perm.gid,
-                               shp->shm_perm.cuid,
-                               shp->shm_perm.cgid,
-                               shp->shm_atim,
-                               shp->shm_dtim,
-                               shp->shm_ctim);
-                       shm_unlock(shp);
-
-                       pos += len;
-                       if(pos < offset) {
-                               len = 0;
-                               begin = pos;
-                       }
-                       if(pos > offset + length)
-                               goto done;
-               }
-       }
-       *eof = 1;
-done:
-       up(&shm_ids.sem);
-       *start = buffer + (offset - begin);
-       len -= (offset - begin);
-       if(len > length)
-               len = length;
-       if(len < 0)
-               len = 0;
-       return len;
+       if (sizeof(size_t) <= sizeof(int))
+               format = SMALL_STRING;
+       else
+               format = BIG_STRING;
+       return seq_printf(s, format,
+                         shp->shm_perm.key,
+                         shp->id,
+                         shp->shm_perm.mode,
+                         shp->shm_segsz,
+                         shp->shm_cprid,
+                         shp->shm_lprid,
+                         is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
+                         shp->shm_perm.uid,
+                         shp->shm_perm.gid,
+                         shp->shm_perm.cuid,
+                         shp->shm_perm.cgid,
+                         shp->shm_atim,
+                         shp->shm_dtim,
+                         shp->shm_ctim);
 }
 #endif