diff options
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/mqueue.c | 11 | ||||
| -rw-r--r-- | ipc/namespace.c | 35 | ||||
| -rw-r--r-- | ipc/shm.c | 8 | ||||
| -rw-r--r-- | ipc/util.h | 2 |
4 files changed, 33 insertions, 23 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c index d09aa1c1e3e6..71881bddad25 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -608,7 +608,7 @@ out_unlock: return error; } -static int mqueue_create(struct user_namespace *mnt_userns, struct inode *dir, +static int mqueue_create(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { return mqueue_create_attr(dentry, mode, NULL); @@ -887,7 +887,7 @@ static int prepare_open(struct dentry *dentry, int oflag, int ro, if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) return -EINVAL; acc = oflag2acc[oflag & O_ACCMODE]; - return inode_permission(&init_user_ns, d_inode(dentry), acc); + return inode_permission(&nop_mnt_idmap, d_inode(dentry), acc); } static int do_mq_open(const char __user *u_name, int oflag, umode_t mode, @@ -979,7 +979,7 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) err = -ENOENT; } else { ihold(inode); - err = vfs_unlink(&init_user_ns, d_inode(dentry->d_parent), + err = vfs_unlink(&nop_mnt_idmap, d_inode(dentry->d_parent), dentry, NULL); } dput(dentry); @@ -1709,11 +1709,6 @@ void mq_clear_sbinfo(struct ipc_namespace *ns) ns->mq_mnt->mnt_sb->s_fs_info = NULL; } -void mq_put_mnt(struct ipc_namespace *ns) -{ - kern_unmount(ns->mq_mnt); -} - static int __init init_mqueue_fs(void) { int error; diff --git a/ipc/namespace.c b/ipc/namespace.c index 8316ea585733..6ecc30effd3e 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -19,6 +19,12 @@ #include "util.h" +/* + * The work queue is used to avoid the cost of synchronize_rcu in kern_unmount. + */ +static void free_ipc(struct work_struct *unused); +static DECLARE_WORK(free_ipc_work, free_ipc); + static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES); @@ -37,9 +43,18 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, int err; err = -ENOSPC; + again: ucounts = inc_ipc_namespaces(user_ns); - if (!ucounts) + if (!ucounts) { + /* + * IPC namespaces are freed asynchronously, by free_ipc_work. + * If frees were pending, flush_work will wait, and + * return true. Fail the allocation if no frees are pending. + */ + if (flush_work(&free_ipc_work)) + goto again; goto fail; + } err = -ENOMEM; ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL_ACCOUNT); @@ -130,10 +145,11 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, static void free_ipc_ns(struct ipc_namespace *ns) { - /* mq_put_mnt() waits for a grace period as kern_unmount() - * uses synchronize_rcu(). + /* + * Caller needs to wait for an RCU grace period to have passed + * after making the mount point inaccessible to new accesses. */ - mq_put_mnt(ns); + mntput(ns->mq_mnt); sem_exit_ns(ns); msg_exit_ns(ns); shm_exit_ns(ns); @@ -154,15 +170,16 @@ static void free_ipc(struct work_struct *unused) struct ipc_namespace *n, *t; llist_for_each_entry_safe(n, t, node, mnt_llist) + mnt_make_shortterm(n->mq_mnt); + + /* Wait for any last users to have gone away. */ + synchronize_rcu(); + + llist_for_each_entry_safe(n, t, node, mnt_llist) free_ipc_ns(n); } /* - * The work queue is used to avoid the cost of synchronize_rcu in kern_unmount. - */ -static DECLARE_WORK(free_ipc_work, free_ipc); - -/* * put_ipc_ns - drop a reference to an ipc namespace. * @ns: the namespace to put * diff --git a/ipc/shm.c b/ipc/shm.c index bd2fcc4d454e..60e45e7045d4 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1786,8 +1786,8 @@ long ksys_shmdt(char __user *shmaddr) */ 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, NULL); - mas_pause(&vmi.mas); + do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, + NULL, false); /* * We discovered the size of the shm segment, so * break out of here and fall through to the next @@ -1811,8 +1811,8 @@ long ksys_shmdt(char __user *shmaddr) if ((vma->vm_ops == &shm_vm_ops) && ((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, NULL); - mas_pause(&vmi.mas); + do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, + NULL, false); } vma = vma_next(&vmi); diff --git a/ipc/util.h b/ipc/util.h index b2906e366539..67bdd2aa2c28 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -56,10 +56,8 @@ struct pid_namespace; #ifdef CONFIG_POSIX_MQUEUE extern void mq_clear_sbinfo(struct ipc_namespace *ns); -extern void mq_put_mnt(struct ipc_namespace *ns); #else static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } -static inline void mq_put_mnt(struct ipc_namespace *ns) { } #endif #ifdef CONFIG_SYSVIPC |