ACPI / processor: Rename acpi_(un)map_lsapic() to acpi_(un)map_cpu()

[cascardo/linux.git] / ipc / shm.c

diff --git a/ipc/shm.c b/ipc/shm.c
index 0145479..19633b4 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -219,7 +219,8 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
        if (!is_file_hugepages(shm_file))
                shmem_lock(shm_file, 0, shp->mlock_user);
        else if (shp->mlock_user)
-               user_shm_unlock(file_inode(shm_file)->i_size, shp->mlock_user);
+               user_shm_unlock(i_size_read(file_inode(shm_file)),
+                               shp->mlock_user);
        fput(shm_file);
        ipc_rcu_putref(shp, shm_rcu_free);
 }
@@ -1229,6 +1230,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
        int retval = -EINVAL;
 #ifdef CONFIG_MMU
        loff_t size = 0;
+       struct file *file;
        struct vm_area_struct *next;
 #endif
 
@@ -1245,7 +1247,8 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
         *   started at address shmaddr. It records it's size and then unmaps
         *   it.
         * - Then it unmaps all shm vmas that started at shmaddr and that
-        *   are within the initially determined size.
+        *   are within the initially determined size and that are from the
+        *   same shm segment from which we determined the size.
         * Errors from do_munmap are ignored: the function only fails if
         * it's called with invalid parameters or if it's called to unmap
         * a part of a vma. Both calls in this function are for full vmas,
@@ -1271,8 +1274,14 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
                if ((vma->vm_ops == &shm_vm_ops) &&
                        (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
 
-
-                       size = file_inode(vma->vm_file)->i_size;
+                       /*
+                        * Record the file of the shm segment being
+                        * unmapped.  With mremap(), someone could place
+                        * page from another segment but with equal offsets
+                        * in the range we are unmapping.
+                        */
+                       file = vma->vm_file;
+                       size = i_size_read(file_inode(vma->vm_file));
                        do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
                        /*
                         * We discovered the size of the shm segment, so
@@ -1298,8 +1307,8 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
 
                /* finding a matching vma now does not alter retval */
                if ((vma->vm_ops == &shm_vm_ops) &&
-                       (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
-
+                   ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
+                   (vma->vm_file == file))
                        do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
                vma = next;
        }