/** * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 2008 International Business Machines Corp. * Author(s): Michael A. Halcrow * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA * 02111-1307, USA. */ #include #include #include #include #include #include "ecryptfs_kernel.h" struct ecryptfs_open_req { struct file **lower_file; struct path path; struct completion done; struct list_head kthread_ctl_list; }; static struct ecryptfs_kthread_ctl { #define ECRYPTFS_KTHREAD_ZOMBIE 0x00000001 u32 flags; struct mutex mux; struct list_head req_list; wait_queue_head_t wait; } ecryptfs_kthread_ctl; static struct task_struct *ecryptfs_kthread; /** * ecryptfs_threadfn * @ignored: ignored * * The eCryptfs kernel thread that has the responsibility of getting * the lower file with RW permissions. * * Returns zero on success; non-zero otherwise */ static int ecryptfs_threadfn(void *ignored) { set_freezable(); while (1) { struct ecryptfs_open_req *req; wait_event_freezable( ecryptfs_kthread_ctl.wait, (!list_empty(&ecryptfs_kthread_ctl.req_list) || kthread_should_stop())); mutex_lock(&ecryptfs_kthread_ctl.mux); if (ecryptfs_kthread_ctl.flags & ECRYPTFS_KTHREAD_ZOMBIE) { mutex_unlock(&ecryptfs_kthread_ctl.mux); goto out; } while (!list_empty(&ecryptfs_kthread_ctl.req_list)) { req = list_first_entry(&ecryptfs_kthread_ctl.req_list, struct ecryptfs_open_req, kthread_ctl_list); list_del(&req->kthread_ctl_list); *req->lower_file = dentry_open(&req->path, (O_RDWR | O_LARGEFILE), current_cred()); complete(&req->done); } mutex_unlock(&ecryptfs_kthread_ctl.mux); } out: return 0; } int __init ecryptfs_init_kthread(void) { int rc = 0; mutex_init(&ecryptfs_kthread_ctl.mux); init_waitqueue_head(&ecryptfs_kthread_ctl.wait); INIT_LIST_HEAD(&ecryptfs_kthread_ctl.req_list); ecryptfs_kthread = kthread_run(&ecryptfs_threadfn, NULL, "ecryptfs-kthread"); if (IS_ERR(ecryptfs_kthread)) { rc = PTR_ERR(ecryptfs_kthread); printk(KERN_ERR "%s: Failed to create kernel thread; rc = [%d]" "\n", __func__, rc); } return rc; } void ecryptfs_destroy_kthread(void) { struct ecryptfs_open_req *req, *tmp; mutex_lock(&ecryptfs_kthread_ctl.mux); ecryptfs_kthread_ctl.flags |= ECRYPTFS_KTHREAD_ZOMBIE; list_for_each_entry_safe(req, tmp, &ecryptfs_kthread_ctl.req_list, kthread_ctl_list) { list_del(&req->kthread_ctl_list); *req->lower_file = ERR_PTR(-EIO); complete(&req->done); } mutex_unlock(&ecryptfs_kthread_ctl.mux); kthread_stop(ecryptfs_kthread); wake_up(&ecryptfs_kthread_ctl.wait); } /** * ecryptfs_privileged_open * @lower_file: Result of dentry_open by root on lower dentry * @lower_dentry: Lower dentry for file to open * @lower_mnt: Lower vfsmount for file to open * * This function gets a r/w file opened againt the lower dentry. * * Returns zero on success; non-zero otherwise */ int ecryptfs_privileged_open(struct file **lower_file, struct dentry *lower_dentry, struct vfsmount *lower_mnt, const struct cred *cred) { struct ecryptfs_open_req req; int flags = O_LARGEFILE; int rc = 0; init_completion(&req.done); req.lower_file = lower_file; req.path.dentry = lower_dentry; req.path.mnt = lower_mnt; /* Corresponding dput() and mntput() are done when the * lower file is fput() when all eCryptfs files for the inode are * released. */ flags |= IS_RDONLY(d_inode(lower_dentry)) ? O_RDONLY : O_RDWR; (*lower_file) = dentry_open(&req.path, flags, cred); if (!IS_ERR(*lower_file)) goto out; if ((flags & O_ACCMODE) == O_RDONLY) { rc = PTR_ERR((*lower_file)); goto out; } mutex_lock(&ecryptfs_kthread_ctl.mux); if (ecryptfs_kthread_ctl.flags & ECRYPTFS_KTHREAD_ZOMBIE) { rc = -EIO; mutex_unlock(&ecryptfs_kthread_ctl.mux); printk(KERN_ERR "%s: We are in the middle of shutting down; " "aborting privileged request to open lower file\n", __func__); goto out; } list_add_tail(&req.kthread_ctl_list, &ecryptfs_kthread_ctl.req_list); mutex_unlock(&ecryptfs_kthread_ctl.mux); wake_up(&ecryptfs_kthread_ctl.wait); wait_for_completion(&req.done); if (IS_ERR(*lower_file)) rc = PTR_ERR(*lower_file); out: return rc; } class='ctrl'>
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-18 11:13:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-18 11:13:41 -0800
commitca92e6c7e6329029d7188487a5c32e86ef471977 (patch)
tree704fb5c2ca533cdb569826522eed0dbbcf31f316 /sound/soc/sunxi/sun4i-i2s.c
parent0b75f821ec8be459dd4dec77be39595d989d77ac (diff)
parent4205e4786d0b9fc3b4fec7b1910cf645a0468307 (diff)
Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP hotplug update from Thomas Gleixner: "This contains a trivial typo fix and an extension to the core code for dynamically allocating states in the prepare stage. The extension is necessary right now because we need a proper way to unbreak LTTNG, which iscurrently non functional due to the removal of the notifiers. Surely it's out of tree, but it's widely used by distros. The simple solution would have been to reserve a state for LTTNG, but I'm not fond about unused crap in the kernel and the dynamic range, which we admittedly should have done right away, allows us to remove quite some of the hardcoded states, i.e. those which have no ordering requirements. So doing the right thing now is better than having an smaller intermediate solution which needs to be reworked anyway" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Provide dynamic range for prepare stage perf/x86/amd/ibs: Fix typo after cleanup state names in cpu/hotplug
Diffstat (limited to 'sound/soc/sunxi/sun4i-i2s.c')