[PATCH] Add debugging feature /proc/timer_list

[pandora-kernel.git] / kernel / kmod.c

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 842f801..7962761 100644 (file)
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -18,8 +18,6 @@
        call_usermodehelper wait flag, and remove exec_usermodehelper.
        Rusty Russell <rusty@rustcorp.com.au>  Jan 2003
 */
-#define __KERNEL_SYSCALLS__
-
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/syscalls.h>
@@ -27,7 +25,7 @@
 #include <linux/kmod.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>
-#include <linux/namespace.h>
+#include <linux/mnt_namespace.h>
 #include <linux/completion.h>
 #include <linux/file.h>
 #include <linux/workqueue.h>
@@ -35,6 +33,7 @@
 #include <linux/mount.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/resource.h>
 #include <asm/uaccess.h>
 
 extern int max_threads;
@@ -115,6 +114,7 @@ EXPORT_SYMBOL(request_module);
 #endif /* CONFIG_KMOD */
 
 struct subprocess_info {
+       struct work_struct work;
        struct completion *complete;
        char *path;
        char **argv;
@@ -122,6 +122,7 @@ struct subprocess_info {
        struct key *ring;
        int wait;
        int retval;
+       struct file *stdin;
 };
 
 /*
@@ -145,12 +146,30 @@ static int ____call_usermodehelper(void *data)
 
        key_put(old_session);
 
+       /* Install input pipe when needed */
+       if (sub_info->stdin) {
+               struct files_struct *f = current->files;
+               struct fdtable *fdt;
+               /* no races because files should be private here */
+               sys_close(0);
+               fd_install(0, sub_info->stdin);
+               spin_lock(&f->file_lock);
+               fdt = files_fdtable(f);
+               FD_SET(0, fdt->open_fds);
+               FD_CLR(0, fdt->close_on_exec);
+               spin_unlock(&f->file_lock);
+
+               /* and disallow core files too */
+               current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
+       }
+
        /* We can run anywhere, unlike our parent keventd(). */
        set_cpus_allowed(current, CPU_MASK_ALL);
 
        retval = -EPERM;
        if (current->fs->root)
-               retval = execve(sub_info->path, sub_info->argv,sub_info->envp);
+               retval = kernel_execve(sub_info->path,
+                               sub_info->argv, sub_info->envp);
 
        /* Exec failed? */
        sub_info->retval = retval;
@@ -198,14 +217,18 @@ static int wait_for_helper(void *data)
                        sub_info->retval = ret;
        }
 
-       complete(sub_info->complete);
+       if (sub_info->wait < 0)
+               kfree(sub_info);
+       else
+               complete(sub_info->complete);
        return 0;
 }
 
 /* This is run by khelper thread  */
-static void __call_usermodehelper(void *data)
+static void __call_usermodehelper(struct work_struct *work)
 {
-       struct subprocess_info *sub_info = data;
+       struct subprocess_info *sub_info =
+               container_of(work, struct subprocess_info, work);
        pid_t pid;
        int wait = sub_info->wait;
 
@@ -219,6 +242,9 @@ static void __call_usermodehelper(void *data)
                pid = kernel_thread(____call_usermodehelper, sub_info,
                                    CLONE_VFORK | SIGCHLD);
 
+       if (wait < 0)
+               return;
+
        if (pid < 0) {
                sub_info->retval = pid;
                complete(sub_info->complete);
@@ -233,6 +259,9 @@ static void __call_usermodehelper(void *data)
  * @envp: null-terminated environment list
  * @session_keyring: session keyring for process (NULL for an empty keyring)
  * @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
+ *        from interrupt context.
  *
  * Runs a user-space application.  The application is started
  * asynchronously if wait is not set, and runs as a child of keventd.
@@ -245,16 +274,51 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
                             struct key *session_keyring, int wait)
 {
        DECLARE_COMPLETION_ONSTACK(done);
+       struct subprocess_info *sub_info;
+       int retval;
+
+       if (!khelper_wq)
+               return -EBUSY;
+
+       if (path[0] == '\0')
+               return 0;
+
+       sub_info = kzalloc(sizeof(struct subprocess_info),  GFP_ATOMIC);
+       if (!sub_info)
+               return -ENOMEM;
+
+       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 */
+               return 0;
+       wait_for_completion(&done);
+       retval = sub_info->retval;
+       kfree(sub_info);
+       return retval;
+}
+EXPORT_SYMBOL(call_usermodehelper_keys);
+
+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,
-               .ring           = session_keyring,
-               .wait           = wait,
                .retval         = 0,
        };
-       DECLARE_WORK(work, __call_usermodehelper, &sub_info);
+       struct file *f;
 
        if (!khelper_wq)
                return -EBUSY;
@@ -262,11 +326,23 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
        if (path[0] == '\0')
                return 0;
 
-       queue_work(khelper_wq, &work);
+       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;
+
+       queue_work(khelper_wq, &sub_info.work);
        wait_for_completion(&done);
        return sub_info.retval;
 }
-EXPORT_SYMBOL(call_usermodehelper_keys);
+EXPORT_SYMBOL(call_usermodehelper_pipe);
 
 void __init usermodehelper_init(void)
 {