#include <linux/config.h>
#include <linux/module.h>
-#define __KERNEL_SYSCALLS__
-
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched.h>
-#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/errno.h>
-#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
-
/* ======================== HCI interface ======================== */
#define FW_LOADER "/sbin/bluefw"
-static int errno;
-
-
-static int bt3c_fw_loader_exec(void *dev)
-{
- char *argv[] = { FW_LOADER, "pccard", dev, NULL };
- char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
- int err;
-
- err = exec_usermodehelper(FW_LOADER, argv, envp);
- if (err)
- printk(KERN_WARNING "bt3c_cs: Failed to exec \"%s pccard %s\".\n", FW_LOADER, (char *)dev);
-
- return err;
-}
static int bt3c_firmware_load(bt3c_info_t *info)
{
- sigset_t tmpsig;
char dev[16];
- pid_t pid;
- int result;
+ int err;
- /* Check if root fs is mounted */
- if (!current->fs->root) {
- printk(KERN_WARNING "bt3c_cs: Root filesystem is not mounted.\n");
- return -EPERM;
- }
+ char *argv[] = { FW_LOADER, "pccard", dev, NULL };
+ char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
sprintf(dev, "%04x", info->link.io.BasePort1);
- pid = kernel_thread(bt3c_fw_loader_exec, (void *)dev, 0);
- if (pid < 0) {
- printk(KERN_WARNING "bt3c_cs: Forking of kernel thread failed (errno=%d).\n", -pid);
- return pid;
- }
-
- /* Block signals, everything but SIGKILL/SIGSTOP */
- spin_lock_irq(¤t->sighand->siglock);
- tmpsig = current->blocked;
- siginitsetinv(¤t->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP));
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- result = waitpid(pid, NULL, __WCLONE);
-
- /* Allow signals again */
- spin_lock_irq(¤t->sighand->siglock);
- current->blocked = tmpsig;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- if (result != pid) {
- printk(KERN_WARNING "bt3c_cs: Waiting for pid %d failed (errno=%d).\n", pid, -result);
- return -result;
- }
+ err = call_usermodehelper(FW_LOADER, argv, envp, 1);
+ if (err)
+ printk(KERN_WARNING "bt3c_cs: Failed to run \"%s pccard %s\" (errno=%d).\n", FW_LOADER, dev, err);
- return 0;
+ return err;
}
Unblock all signals when we exec a usermode process.
Shuu Yamaguchi <shuu@wondernetworkresources.com> December 2000
-*/
+ call_usermodehelper wait flag, and remove exec_usermodehelper.
+ Rusty Russell <rusty@rustcorp.com.au> Jan 2003
+*/
#define __KERNEL_SYSCALLS__
#include <linux/config.h>
#include <linux/workqueue.h>
#include <linux/security.h>
#include <linux/mount.h>
+#include <linux/kernel.h>
#include <asm/uaccess.h>
extern int max_threads, system_running;
-static inline void
-use_init_fs_context(void)
-{
- struct fs_struct *our_fs, *init_fs;
- struct dentry *root, *pwd;
- struct vfsmount *rootmnt, *pwdmnt;
- struct namespace *our_ns, *init_ns;
-
- /*
- * Make modprobe's fs context be a copy of init's.
- *
- * We cannot use the user's fs context, because it
- * may have a different root than init.
- * Since init was created with CLONE_FS, we can grab
- * its fs context from "init_task".
- *
- * The fs context has to be a copy. If it is shared
- * with init, then any chdir() call in modprobe will
- * also affect init and the other threads sharing
- * init_task's fs context.
- *
- * We created the exec_modprobe thread without CLONE_FS,
- * so we can update the fields in our fs context freely.
- */
-
- init_fs = init_task.fs;
- init_ns = init_task.namespace;
- get_namespace(init_ns);
- our_ns = current->namespace;
- current->namespace = init_ns;
- put_namespace(our_ns);
- read_lock(&init_fs->lock);
- rootmnt = mntget(init_fs->rootmnt);
- root = dget(init_fs->root);
- pwdmnt = mntget(init_fs->pwdmnt);
- pwd = dget(init_fs->pwd);
- read_unlock(&init_fs->lock);
-
- /* FIXME - unsafe ->fs access */
- our_fs = current->fs;
- our_fs->umask = init_fs->umask;
- set_fs_root(our_fs, rootmnt, root);
- set_fs_pwd(our_fs, pwdmnt, pwd);
- write_lock(&our_fs->lock);
- if (our_fs->altroot) {
- struct vfsmount *mnt = our_fs->altrootmnt;
- struct dentry *dentry = our_fs->altroot;
- our_fs->altrootmnt = NULL;
- our_fs->altroot = NULL;
- write_unlock(&our_fs->lock);
- dput(dentry);
- mntput(mnt);
- } else
- write_unlock(&our_fs->lock);
- dput(root);
- mntput(rootmnt);
- dput(pwd);
- mntput(pwdmnt);
-}
-
-int exec_usermodehelper(char *program_path, char *argv[], char *envp[])
-{
- int i;
- struct task_struct *curtask = current;
-
- set_special_pids(1, 1);
-
- use_init_fs_context();
-
- /* Prevent parent user process from sending signals to child.
- Otherwise, if the modprobe program does not exist, it might
- be possible to get a user defined signal handler to execute
- as the super user right after the execve fails if you time
- the signal just right.
- */
- flush_signals(curtask);
- flush_signal_handlers(curtask);
- spin_lock_irq(&curtask->sighand->siglock);
- sigemptyset(&curtask->blocked);
- recalc_sigpending();
- spin_unlock_irq(&curtask->sighand->siglock);
-
- for (i = 0; i < curtask->files->max_fds; i++ ) {
- if (curtask->files->fd[i]) close(i);
- }
-
- switch_uid(INIT_USER);
-
- /* Give kmod all effective privileges.. */
- curtask->euid = curtask->fsuid = 0;
- curtask->egid = curtask->fsgid = 0;
- security_task_kmod_set_label();
-
- /* Allow execve args to be in kernel space. */
- set_fs(KERNEL_DS);
-
- /* Go, go, go... */
- if (execve(program_path, argv, envp) < 0)
- return -errno;
- return 0;
-}
-
#ifdef CONFIG_KMOD
/*
*/
char modprobe_path[256] = "/sbin/modprobe";
-static int exec_modprobe(void * module_name)
-{
- static char * envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
- char *argv[] = { modprobe_path, "--", (char*)module_name, NULL };
- int ret;
-
- if (!system_running)
- return -EBUSY;
-
- ret = exec_usermodehelper(modprobe_path, argv, envp);
- if (ret) {
- static unsigned long last;
- unsigned long now = jiffies;
- if (now - last > HZ) {
- last = now;
- printk(KERN_DEBUG
- "kmod: failed to exec %s -s -k %s, errno = %d\n",
- modprobe_path, (char*) module_name, errno);
- }
- }
- return ret;
-}
-
/**
* request_module - try to load a kernel module
* @module_name: Name of module
* If module auto-loading support is disabled then this function
* becomes a no-operation.
*/
-int request_module(const char * module_name)
+int request_module(const char *module_name)
{
- pid_t pid;
- int waitpid_result;
- sigset_t tmpsig;
- int i, ret;
+ unsigned int max_modprobes;
+ int ret;
+ char *argv[] = { modprobe_path, "--", (char*)module_name, NULL };
+ static char *envp[] = { "HOME=/",
+ "TERM=linux",
+ "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+ NULL };
static atomic_t kmod_concurrent = ATOMIC_INIT(0);
#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
static int kmod_loop_msg;
- unsigned long saved_policy = current->policy;
-
- current->policy = SCHED_NORMAL;
- /* Don't allow request_module() when the system isn't set up */
- if ( ! system_running ) {
- printk(KERN_ERR "request_module[%s]: not ready\n", module_name);
- ret = -EPERM;
- goto out;
- }
/* If modprobe needs a service that is in a module, we get a recursive
* loop. Limit the number of running kmod threads to max_threads/2 or
* process tables to get the command line, proc_pid_cmdline is static
* and it is not worth changing the proc code just to handle this case.
* KAO.
+ *
+
+ * "trace the ppid" is simple, but will fail if someone's
+ * parent exits. I think this is as good as it gets. --RR
*/
- i = max_threads/2;
- if (i > MAX_KMOD_CONCURRENT)
- i = MAX_KMOD_CONCURRENT;
+ max_modprobes = min(max_threads/2, MAX_KMOD_CONCURRENT);
atomic_inc(&kmod_concurrent);
- if (atomic_read(&kmod_concurrent) > i) {
+ if (atomic_read(&kmod_concurrent) > max_modprobes) {
+ /* We may be blaming an innocent here, but unlikely */
if (kmod_loop_msg++ < 5)
printk(KERN_ERR
- "kmod: runaway modprobe loop assumed and stopped\n");
+ "request_module: runaway loop modprobe %s\n",
+ module_name);
atomic_dec(&kmod_concurrent);
- ret = -ENOMEM;
- goto out;
+ return -ENOMEM;
}
- pid = kernel_thread(exec_modprobe, (void*) module_name, 0);
- if (pid < 0) {
- printk(KERN_ERR "request_module[%s]: fork failed, errno %d\n", module_name, -pid);
- atomic_dec(&kmod_concurrent);
- ret = pid;
- goto out;
+ ret = call_usermodehelper(modprobe_path, argv, envp, 1);
+ if (ret != 0) {
+ static unsigned long last;
+ unsigned long now = jiffies;
+ if (now - last > HZ) {
+ last = now;
+ printk(KERN_DEBUG
+ "request_module: failed %s -- %s. error = %d\n",
+ modprobe_path, module_name, ret);
+ }
}
-
- /* Block everything but SIGKILL/SIGSTOP */
- spin_lock_irq(¤t->sighand->siglock);
- tmpsig = current->blocked;
- siginitsetinv(¤t->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP));
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- waitpid_result = waitpid(pid, NULL, __WCLONE);
atomic_dec(&kmod_concurrent);
-
- /* Allow signals again.. */
- spin_lock_irq(¤t->sighand->siglock);
- current->blocked = tmpsig;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
-
- if (waitpid_result != pid) {
- printk(KERN_ERR "request_module[%s]: waitpid(%d,...) failed, errno %d\n",
- module_name, pid, -waitpid_result);
- }
- ret = 0;
-out:
- current->policy = saved_policy;
return ret;
}
#endif /* CONFIG_KMOD */
-
#ifdef CONFIG_HOTPLUG
/*
hotplug path is set via /proc/sys
invoked by hotplug-aware bus drivers,
- with exec_usermodehelper and some thread-spawner
+ with call_usermodehelper
argv [0] = hotplug_path;
argv [1] = "usb", "scsi", "pci", "network", etc;
char *path;
char **argv;
char **envp;
- pid_t retval;
+ int wait;
+ int retval;
};
/*
retval = -EPERM;
if (current->fs->root)
- retval = exec_usermodehelper(sub_info->path, sub_info->argv, sub_info->envp);
+ retval = execve(sub_info->path, sub_info->argv,sub_info->envp);
/* Exec failed? */
- sub_info->retval = (pid_t)retval;
+ sub_info->retval = retval;
do_exit(0);
}
+/* Keventd can't block, but this (a child) can. */
+static int wait_for_helper(void *data)
+{
+ struct subprocess_info *sub_info = data;
+ pid_t pid;
+
+ pid = kernel_thread(____call_usermodehelper, sub_info,
+ CLONE_VFORK | SIGCHLD);
+ if (pid < 0)
+ sub_info->retval = pid;
+ else
+ sys_wait4(pid, (unsigned int *)&sub_info->retval, 0, NULL);
+
+ complete(sub_info->complete);
+ return 0;
+}
+
/*
* This is run by keventd.
*/
struct subprocess_info *sub_info = data;
pid_t pid;
- /*
- * CLONE_VFORK: wait until the usermode helper has execve'd successfully
- * We need the data structures to stay around until that is done.
- */
- pid = kernel_thread(____call_usermodehelper, sub_info, CLONE_VFORK | SIGCHLD);
- if (pid < 0)
+ /* CLONE_VFORK: wait until the usermode helper has execve'd
+ * successfully We need the data structures to stay around
+ * until that is done. */
+ if (sub_info->wait)
+ pid = kernel_thread(wait_for_helper, sub_info,
+ CLONE_KERNEL | SIGCHLD);
+ else
+ pid = kernel_thread(____call_usermodehelper, sub_info,
+ CLONE_VFORK | SIGCHLD);
+
+ if (pid < 0) {
sub_info->retval = pid;
- complete(sub_info->complete);
+ complete(sub_info->complete);
+ } else if (!sub_info->wait)
+ complete(sub_info->complete);
}
/**
* @path: pathname for the application
* @argv: null-terminated argument list
* @envp: null-terminated environment list
+ * @wait: wait for the application to finish and return status.
*
- * Runs a user-space application. The application is started asynchronously. It
- * runs as a child of keventd. It runs with full root capabilities. keventd silently
- * reaps the child when it exits.
+ * 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 zero on success, else a negative
- * error code.
+ * Must be called from process context. Returns a negative error code
+ * if program was not execed successfully, or (exitcode << 8 + signal)
+ * of the application (0 if wait is not set).
*/
-int call_usermodehelper(char *path, char **argv, char **envp)
+int call_usermodehelper(char *path, char **argv, char **envp, int wait)
{
DECLARE_COMPLETION(done);
struct subprocess_info sub_info = {
.path = path,
.argv = argv,
.envp = envp,
+ .wait = wait,
.retval = 0,
};
DECLARE_WORK(work, __call_usermodehelper, &sub_info);
up(&dev_probe_sem);
}
-EXPORT_SYMBOL(exec_usermodehelper);
EXPORT_SYMBOL(call_usermodehelper);
#ifdef CONFIG_KMOD
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