6 files changed, 240 insertions, 77 deletions

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index ce61f42354..1bf093dcff 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1210,8 +1210,8 @@ static inline int audit_add_rule(struct audit_entry *entry,
         struct audit_entry *e;
         struct audit_field *inode_f = entry->rule.inode_f;
         struct audit_watch *watch = entry->rule.watch;
-        struct nameidata *ndp, *ndw;
-        int h, err, putnd_needed = 0;
+        struct nameidata *ndp = NULL, *ndw = NULL;
+        int h, err;
 #ifdef CONFIG_AUDITSYSCALL
         int dont_count = 0;
 
@@ -1239,7 +1239,6 @@ static inline int audit_add_rule(struct audit_entry *entry,
                 err = audit_get_nd(watch->path, &ndp, &ndw);
                 if (err)
                         goto error;
-                putnd_needed = 1;
         }
 
         mutex_lock(&audit_filter_mutex);
@@ -1269,14 +1268,11 @@ static inline int audit_add_rule(struct audit_entry *entry,
 #endif
         mutex_unlock(&audit_filter_mutex);
 
-        if (putnd_needed)
-                audit_put_nd(ndp, ndw);
-
+        audit_put_nd(ndp, ndw);         /* NULL args OK */
         return 0;
 
 error:
-        if (putnd_needed)
-                audit_put_nd(ndp, ndw);
+        audit_put_nd(ndp, ndw);         /* NULL args OK */
         if (watch)
                 audit_put_watch(watch); /* tmp watch, matches initial get */
         return err;
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 208cf3497c..181ae70860 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -103,11 +103,19 @@ static inline void check_for_tasks(int cpu)
         write_unlock_irq(&tasklist_lock);
 }
 
+struct take_cpu_down_param {
+        unsigned long mod;
+        void *hcpu;
+};
+
 /* Take this CPU down. */
-static int take_cpu_down(void *unused)
+static int take_cpu_down(void *_param)
 {
+        struct take_cpu_down_param *param = _param;
         int err;
 
+        raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
+                                param->hcpu);
         /* Ensure this CPU doesn't handle any more interrupts. */
         err = __cpu_disable();
         if (err < 0)
@@ -127,6 +135,10 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
         cpumask_t old_allowed, tmp;
         void *hcpu = (void *)(long)cpu;
         unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
+        struct take_cpu_down_param tcd_param = {
+                .mod = mod,
+                .hcpu = hcpu,
+        };
 
         if (num_online_cpus() == 1)
                 return -EBUSY;
@@ -153,7 +165,7 @@ static int _cpu_down(unsigned int cpu, int tasks_frozen)
         set_cpus_allowed(current, tmp);
 
         mutex_lock(&cpu_bitmask_lock);
-        p = __stop_machine_run(take_cpu_down, NULL, cpu);
+        p = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
         mutex_unlock(&cpu_bitmask_lock);
 
         if (IS_ERR(p) || cpu_online(cpu)) {
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 824b1c01f4..57e6448b17 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -516,7 +516,7 @@ static void cpuset_release_agent(const char *pathbuf)
         envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
         envp[i] = NULL;
 
-        call_usermodehelper(argv[0], argv, envp, 0);
+        call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
         kfree(pathbuf);
 }
 
@@ -2138,6 +2138,9 @@ static void common_cpu_mem_hotplug_unplug(void)
 static int cpuset_handle_cpuhp(struct notifier_block *nb,
                                 unsigned long phase, void *cpu)
 {
+        if (phase == CPU_DYING || phase == CPU_DYING_FROZEN)
+                return NOTIFY_DONE;
+
         common_cpu_mem_hotplug_unplug();
         return 0;
 }
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 4d32eb0771..78d365c524 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -119,9 +119,10 @@ struct subprocess_info {
         char **argv;
         char **envp;
         struct key *ring;
-        int wait;
+        enum umh_wait wait;
         int retval;
         struct file *stdin;
+        void (*cleanup)(char **argv, char **envp);
 };
 
 /*
@@ -180,6 +181,14 @@ static int ____call_usermodehelper(void *data)
         do_exit(0);
 }
 
+void call_usermodehelper_freeinfo(struct subprocess_info *info)
+{
+        if (info->cleanup)
+                (*info->cleanup)(info->argv, info->envp);
+        kfree(info);
+}
+EXPORT_SYMBOL(call_usermodehelper_freeinfo);
+
 /* Keventd can't block, but this (a child) can. */
 static int wait_for_helper(void *data)
 {
@@ -216,8 +225,8 @@ static int wait_for_helper(void *data)
                         sub_info->retval = ret;
         }
 
-        if (sub_info->wait < 0)
-                kfree(sub_info);
+        if (sub_info->wait == UMH_NO_WAIT)
+                call_usermodehelper_freeinfo(sub_info);
         else
                 complete(sub_info->complete);
         return 0;
@@ -229,34 +238,122 @@ static void __call_usermodehelper(struct work_struct *work)
         struct subprocess_info *sub_info =
                 container_of(work, struct subprocess_info, work);
         pid_t pid;
-        int wait = sub_info->wait;
+        enum umh_wait wait = sub_info->wait;
 
         /* CLONE_VFORK: wait until the usermode helper has execve'd
          * successfully We need the data structures to stay around
          * until that is done.  */
-        if (wait)
+        if (wait == UMH_WAIT_PROC || wait == UMH_NO_WAIT)
                 pid = kernel_thread(wait_for_helper, sub_info,
                                     CLONE_FS | CLONE_FILES | SIGCHLD);
         else
                 pid = kernel_thread(____call_usermodehelper, sub_info,
                                     CLONE_VFORK | SIGCHLD);
 
-        if (wait < 0)
-                return;
+        switch (wait) {
+        case UMH_NO_WAIT:
+                break;
 
-        if (pid < 0) {
+        case UMH_WAIT_PROC:
+                if (pid > 0)
+                        break;
                 sub_info->retval = pid;
+                /* FALLTHROUGH */
+
+        case UMH_WAIT_EXEC:
                 complete(sub_info->complete);
-        } else if (!wait)
-                complete(sub_info->complete);
+        }
+}
+
+/**
+ * call_usermodehelper_setup - prepare to call a usermode helper
+ * @path - path to usermode executable
+ * @argv - arg vector for process
+ * @envp - environment for process
+ *
+ * Returns either NULL on allocation failure, or a subprocess_info
+ * structure.  This should be passed to call_usermodehelper_exec to
+ * exec the process and free the structure.
+ */
+struct subprocess_info *call_usermodehelper_setup(char *path,
+                                                  char **argv, char **envp)
+{
+        struct subprocess_info *sub_info;
+        sub_info = kzalloc(sizeof(struct subprocess_info),  GFP_ATOMIC);
+        if (!sub_info)
+                goto out;
+
+        INIT_WORK(&sub_info->work, __call_usermodehelper);
+        sub_info->path = path;
+        sub_info->argv = argv;
+        sub_info->envp = envp;
+
+  out:
+        return sub_info;
 }
+EXPORT_SYMBOL(call_usermodehelper_setup);
 
 /**
- * call_usermodehelper_keys - start a usermode application
- * @path: pathname for the application
- * @argv: null-terminated argument list
- * @envp: null-terminated environment list
- * @session_keyring: session keyring for process (NULL for an empty keyring)
+ * call_usermodehelper_setkeys - set the session keys for usermode helper
+ * @info: a subprocess_info returned by call_usermodehelper_setup
+ * @session_keyring: the session keyring for the process
+ */
+void call_usermodehelper_setkeys(struct subprocess_info *info,
+                                 struct key *session_keyring)
+{
+        info->ring = session_keyring;
+}
+EXPORT_SYMBOL(call_usermodehelper_setkeys);
+
+/**
+ * call_usermodehelper_setcleanup - set a cleanup function
+ * @info: a subprocess_info returned by call_usermodehelper_setup
+ * @cleanup: a cleanup function
+ *
+ * The cleanup function is just befor ethe subprocess_info is about to
+ * be freed.  This can be used for freeing the argv and envp.  The
+ * Function must be runnable in either a process context or the
+ * context in which call_usermodehelper_exec is called.
+ */
+void call_usermodehelper_setcleanup(struct subprocess_info *info,
+                                    void (*cleanup)(char **argv, char **envp))
+{
+        info->cleanup = cleanup;
+}
+EXPORT_SYMBOL(call_usermodehelper_setcleanup);
+
+/**
+ * call_usermodehelper_stdinpipe - set up a pipe to be used for stdin
+ * @sub_info: a subprocess_info returned by call_usermodehelper_setup
+ * @filp: set to the write-end of a pipe
+ *
+ * This constructs a pipe, and sets the read end to be the stdin of the
+ * subprocess, and returns the write-end in *@filp.
+ */
+int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
+                                  struct file **filp)
+{
+        struct file *f;
+
+        f = create_write_pipe();
+        if (IS_ERR(f))
+                return PTR_ERR(f);
+        *filp = f;
+
+        f = create_read_pipe(f);
+        if (IS_ERR(f)) {
+                free_write_pipe(*filp);
+                return PTR_ERR(f);
+        }
+        sub_info->stdin = f;
+
+        return 0;
+}
+EXPORT_SYMBOL(call_usermodehelper_stdinpipe);
+
+/**
+ * call_usermodehelper_exec - start a usermode application
+ * @sub_info: information about the subprocessa
  * @wait: wait for the application to finish and return status.
  *        when -1 don't wait at all, but you get no useful error back when
  *        the program couldn't be exec'ed. This makes it safe to call
@@ -265,81 +362,68 @@ static void __call_usermodehelper(struct work_struct *work)
  * Runs a user-space application.  The application is started
  * asynchronously if wait is not set, and runs as a child of keventd.
  * (ie. it runs with full root capabilities).
- *
- * Must be called from process context.  Returns a negative error code
- * if program was not execed successfully, or 0.
  */
-int call_usermodehelper_keys(char *path, char **argv, char **envp,
-                             struct key *session_keyring, int wait)
+int call_usermodehelper_exec(struct subprocess_info *sub_info,
+                             enum umh_wait wait)
 {
         DECLARE_COMPLETION_ONSTACK(done);
-        struct subprocess_info *sub_info;
         int retval;
 
-        if (!khelper_wq)
-                return -EBUSY;
-
-        if (path[0] == '\0')
-                return 0;
+        if (sub_info->path[0] == '\0') {
+                retval = 0;
+                goto out;
+        }
 
-        sub_info = kzalloc(sizeof(struct subprocess_info),  GFP_ATOMIC);
-        if (!sub_info)
-                return -ENOMEM;
+        if (!khelper_wq) {
+                retval = -EBUSY;
+                goto out;
+        }
 
-        INIT_WORK(&sub_info->work, __call_usermodehelper);
         sub_info->complete = &done;
-        sub_info->path = path;
-        sub_info->argv = argv;
-        sub_info->envp = envp;
-        sub_info->ring = session_keyring;
         sub_info->wait = wait;
 
         queue_work(khelper_wq, &sub_info->work);
-        if (wait < 0) /* task has freed sub_info */
+        if (wait == UMH_NO_WAIT) /* task has freed sub_info */
                 return 0;
         wait_for_completion(&done);
         retval = sub_info->retval;
-        kfree(sub_info);
+
+  out:
+        call_usermodehelper_freeinfo(sub_info);
         return retval;
 }
-EXPORT_SYMBOL(call_usermodehelper_keys);
+EXPORT_SYMBOL(call_usermodehelper_exec);
 
+/**
+ * call_usermodehelper_pipe - call a usermode helper process with a pipe stdin
+ * @path: path to usermode executable
+ * @argv: arg vector for process
+ * @envp: environment for process
+ * @filp: set to the write-end of a pipe
+ *
+ * This is a simple wrapper which executes a usermode-helper function
+ * with a pipe as stdin.  It is implemented entirely in terms of
+ * lower-level call_usermodehelper_* functions.
+ */
 int call_usermodehelper_pipe(char *path, char **argv, char **envp,
                              struct file **filp)
 {
-        DECLARE_COMPLETION(done);
-        struct subprocess_info sub_info = {
-                .work           = __WORK_INITIALIZER(sub_info.work,
-                                                     __call_usermodehelper),
-                .complete       = &done,
-                .path           = path,
-                .argv           = argv,
-                .envp           = envp,
-                .retval         = 0,
-        };
-        struct file *f;
+        struct subprocess_info *sub_info;
+        int ret;
 
-        if (!khelper_wq)
-                return -EBUSY;
+        sub_info = call_usermodehelper_setup(path, argv, envp);
+        if (sub_info == NULL)
+                return -ENOMEM;
 
-        if (path[0] == '\0')
-                return 0;
+        ret = call_usermodehelper_stdinpipe(sub_info, filp);
+        if (ret < 0)
+                goto out;
 
-        f = create_write_pipe();
-        if (IS_ERR(f))
-                return PTR_ERR(f);
-        *filp = f;
-
-        f = create_read_pipe(f);
-        if (IS_ERR(f)) {
-                free_write_pipe(*filp);
-                return PTR_ERR(f);
-        }
-        sub_info.stdin = f;
+        return call_usermodehelper_exec(sub_info, 1);
 
-        queue_work(khelper_wq, &sub_info.work);
-        wait_for_completion(&done);
-        return sub_info.retval;
+  out:
+        call_usermodehelper_freeinfo(sub_info);
+        return ret;
 }
 EXPORT_SYMBOL(call_usermodehelper_pipe);
 
diff --git a/kernel/sys.c b/kernel/sys.c
index 4d141ae3e8..18987c7f6a 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2286,3 +2286,61 @@ asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
         }
         return err ? -EFAULT : 0;
 }
+
+char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
+
+static void argv_cleanup(char **argv, char **envp)
+{
+        argv_free(argv);
+}
+
+/**
+ * orderly_poweroff - Trigger an orderly system poweroff
+ * @force: force poweroff if command execution fails
+ *
+ * This may be called from any context to trigger a system shutdown.
+ * If the orderly shutdown fails, it will force an immediate shutdown.
+ */
+int orderly_poweroff(bool force)
+{
+        int argc;
+        char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
+        static char *envp[] = {
+                "HOME=/",
+                "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
+                NULL
+        };
+        int ret = -ENOMEM;
+        struct subprocess_info *info;
+
+        if (argv == NULL) {
+                printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
+                       __func__, poweroff_cmd);
+                goto out;
+        }
+
+        info = call_usermodehelper_setup(argv[0], argv, envp);
+        if (info == NULL) {
+                argv_free(argv);
+                goto out;
+        }
+
+        call_usermodehelper_setcleanup(info, argv_cleanup);
+
+        ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
+
+  out:
+        if (ret && force) {
+                printk(KERN_WARNING "Failed to start orderly shutdown: "
+                       "forcing the issue\n");
+
+                /* I guess this should try to kick off some daemon to
+                   sync and poweroff asap.  Or not even bother syncing
+                   if we're doing an emergency shutdown? */
+                emergency_sync();
+                kernel_power_off();
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(orderly_poweroff);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7063ebc6db..44a1d699aa 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -46,6 +46,7 @@
 #include <linux/syscalls.h>
 #include <linux/nfs_fs.h>
 #include <linux/acpi.h>
+#include <linux/reboot.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -705,6 +706,15 @@ static ctl_table kern_table[] = {
                 .proc_handler   = &proc_dointvec,
         },
 #endif
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "poweroff_cmd",
+                .data           = &poweroff_cmd,
+                .maxlen         = POWEROFF_CMD_PATH_LEN,
+                .mode           = 0644,
+                .proc_handler   = &proc_dostring,
+                .strategy       = &sysctl_string,
+        },
 
         { .ctl_name = 0 }
 };