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Subject[PATCH] Remove exec_usermodehelper
Date
Linus, please apply.

Updated for 2.5.56, and retested (dumb compile error fixed). No word
from James, but Marcel and Thomas gave it the thumbs up.

Name: exec_usermodehelper sucks
Author: Rusty Russell, Marcel Holtmann
Status: Tested on 2.5.56

D: Urban Widmark points out that modprobe calls system() in many
D: configurations, which drops privs since request_module() doesn't
D: doesn't set ruid and rguid.
D:
D: This gets rid of exec_usermodehelper and makes everyone use
D: call_usermodehelper, which has a new "wait" flag.

diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/arch/i386/mach-voyager/voyager_thread.c working-2.5-bk-kmod-noclean/arch/i386/mach-voyager/voyager_thread.c
--- linux-2.5-bk/arch/i386/mach-voyager/voyager_thread.c Thu Jan 2 12:32:34 2003
+++ working-2.5-bk-kmod-noclean/arch/i386/mach-voyager/voyager_thread.c Sat Jan 11 17:57:13 2003
@@ -57,7 +57,7 @@ voyager_thread_start(void)
}

static int
-execute_helper(void *string)
+execute(const char *string)
{
int ret;

@@ -74,20 +74,11 @@ execute_helper(void *string)
NULL,
};

- if((ret = exec_usermodehelper(argv[0], argv, envp)) < 0) {
- printk(KERN_ERR "Voyager failed to execute \"%s\"\n",
- (char *)string);
+ if ((ret = call_usermodehelper(argv[0], argv, envp, 1)) != 0) {
+ printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
+ string, ret);
}
return ret;
-}
-
-static void
-execute(char *string)
-{
- if(kernel_thread(execute_helper, (void *)string, CLONE_VFORK | SIGCHLD) < 0) {
- printk(KERN_ERR "Voyager failed to fork before exec of \"%s\"\n",
- string);
- }
}

static void
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/acpi/thermal.c working-2.5-bk-kmod-noclean/drivers/acpi/thermal.c
--- linux-2.5-bk/drivers/acpi/thermal.c Sat Jan 11 14:44:41 2003
+++ working-2.5-bk-kmod-noclean/drivers/acpi/thermal.c Sat Jan 11 17:57:13 2003
@@ -431,7 +431,7 @@ acpi_thermal_call_usermode (
envp[0] = "HOME=/";
envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";

- call_usermodehelper(argv[0], argv, envp);
+ call_usermodehelper(argv[0], argv, envp, 0);

return_VALUE(0);
}
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/base/hotplug.c working-2.5-bk-kmod-noclean/drivers/base/hotplug.c
--- linux-2.5-bk/drivers/base/hotplug.c Thu Jan 2 12:46:16 2003
+++ working-2.5-bk-kmod-noclean/drivers/base/hotplug.c Sat Jan 11 17:57:13 2003
@@ -114,7 +114,7 @@ static int do_hotplug (struct device *de

pr_debug ("%s: %s %s %s %s %s %s\n", __FUNCTION__, argv [0], argv[1],
envp[0], envp[1], envp[2], envp[3]);
- retval = call_usermodehelper (argv [0], argv, envp);
+ retval = call_usermodehelper (argv [0], argv, envp, 0);
if (retval)
pr_debug ("%s - call_usermodehelper returned %d\n",
__FUNCTION__, retval);
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/bluetooth/bt3c_cs.c working-2.5-bk-kmod-noclean/drivers/bluetooth/bt3c_cs.c
--- linux-2.5-bk/drivers/bluetooth/bt3c_cs.c Thu Jan 2 12:35:09 2003
+++ working-2.5-bk-kmod-noclean/drivers/bluetooth/bt3c_cs.c Sat Jan 11 17:57:13 2003
@@ -24,18 +24,14 @@
#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>
@@ -405,7 +401,6 @@ void bt3c_interrupt(int irq, void *dev_i



-
/* ======================== HCI interface ======================== */


@@ -489,65 +484,23 @@ static int bt3c_hci_ioctl(struct hci_dev


#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(&current->sig->siglock);
- tmpsig = current->blocked;
- siginitsetinv(&current->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP));
- recalc_sigpending();
- spin_unlock_irq(&current->sig->siglock);
-
- result = waitpid(pid, NULL, __WCLONE);
-
- /* Allow signals again */
- spin_lock_irq(&current->sig->siglock);
- current->blocked = tmpsig;
- recalc_sigpending();
- spin_unlock_irq(&current->sig->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;
}


diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/ieee1394/nodemgr.c working-2.5-bk-kmod-noclean/drivers/ieee1394/nodemgr.c
--- linux-2.5-bk/drivers/ieee1394/nodemgr.c Thu Jan 2 12:46:17 2003
+++ working-2.5-bk-kmod-noclean/drivers/ieee1394/nodemgr.c Sat Jan 11 17:57:13 2003
@@ -786,7 +786,7 @@ static void nodemgr_call_policy(char *ve
#ifdef CONFIG_IEEE1394_VERBOSEDEBUG
HPSB_DEBUG("NodeMgr: %s %s %016Lx", argv[0], verb, (long long unsigned)ud->ne->guid);
#endif
- value = call_usermodehelper(argv[0], argv, envp);
+ value = call_usermodehelper(argv[0], argv, envp, 0);
kfree(buf);
kfree(envp);
if (value != 0)
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/input/input.c working-2.5-bk-kmod-noclean/drivers/input/input.c
--- linux-2.5-bk/drivers/input/input.c Thu Jan 2 12:30:27 2003
+++ working-2.5-bk-kmod-noclean/drivers/input/input.c Sat Jan 11 17:57:13 2003
@@ -383,7 +383,7 @@ static void input_call_hotplug(char *ver
argv[0], argv[1], envp[0], envp[1], envp[2], envp[3], envp[4]);
#endif

- value = call_usermodehelper(argv [0], argv, envp);
+ value = call_usermodehelper(argv [0], argv, envp, 0);

kfree(buf);
kfree(envp);
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/isdn/hardware/eicon/divasmain.c working-2.5-bk-kmod-noclean/drivers/isdn/hardware/eicon/divasmain.c
--- linux-2.5-bk/drivers/isdn/hardware/eicon/divasmain.c Thu Jan 2 12:45:18 2003
+++ working-2.5-bk-kmod-noclean/drivers/isdn/hardware/eicon/divasmain.c Sat Jan 11 17:57:13 2003
@@ -263,7 +263,7 @@ static void diva_adapter_trapped(void *c
pdpc->card_failed = 0;
argv[2] = &adapter[0];

- ret = call_usermodehelper(argv[0], argv, envp);
+ ret = call_usermodehelper(argv[0], argv, envp, 0);

if (ret) {
printk(KERN_ERR
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/net/hamradio/baycom_epp.c working-2.5-bk-kmod-noclean/drivers/net/hamradio/baycom_epp.c
--- linux-2.5-bk/drivers/net/hamradio/baycom_epp.c Thu Jan 2 14:47:58 2003
+++ working-2.5-bk-kmod-noclean/drivers/net/hamradio/baycom_epp.c Sat Jan 11 17:57:13 2003
@@ -369,15 +369,14 @@ static char eppconfig_path[256] = "/usr/

static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/usr/bin:/bin", NULL };

-static int errno;
-
-static int exec_eppfpga(void *b)
+/* eppconfig: called during ifconfig up to configure the modem */
+static int eppconfig(struct baycom_state *bc)
{
- struct baycom_state *bc = (struct baycom_state *)b;
char modearg[256];
char portarg[16];
- char *argv[] = { eppconfig_path, "-s", "-p", portarg, "-m", modearg, NULL};
- int i;
+ char *argv[] = { eppconfig_path, "-s", "-p", portarg, "-m", modearg,
+ NULL };
+ int ret;

/* set up arguments */
sprintf(modearg, "%sclk,%smodem,fclk=%d,bps=%d,divider=%d%s,extstat",
@@ -388,39 +387,7 @@ static int exec_eppfpga(void *b)
sprintf(portarg, "%ld", bc->pdev->port->base);
printk(KERN_DEBUG "%s: %s -s -p %s -m %s\n", bc_drvname, eppconfig_path, portarg, modearg);

- i = exec_usermodehelper(eppconfig_path, argv, envp);
- if (i < 0) {
- printk(KERN_ERR "%s: failed to exec %s -s -p %s -m %s, errno = %d\n",
- bc_drvname, eppconfig_path, portarg, modearg, i);
- return i;
- }
- return 0;
-}
-
-
-/* eppconfig: called during ifconfig up to configure the modem */
-
-static int eppconfig(struct baycom_state *bc)
-{
- int i, pid, r;
- mm_segment_t fs;
-
- pid = kernel_thread(exec_eppfpga, bc, CLONE_FS);
- if (pid < 0) {
- printk(KERN_ERR "%s: fork failed, errno %d\n", bc_drvname, -pid);
- return pid;
- }
- fs = get_fs();
- set_fs(KERNEL_DS); /* Allow i to be in kernel space. */
- r = waitpid(pid, &i, __WCLONE);
- set_fs(fs);
- if (r != pid) {
- printk(KERN_ERR "%s: waitpid(%d) failed, returning %d\n",
- bc_drvname, pid, r);
- return -1;
- }
- printk(KERN_DEBUG "%s: eppfpga returned %d\n", bc_drvname, i);
- return i;
+ return call_usermodehelper(eppconfig_path, argv, envp, 1);
}

/* ---------------------------------------------------------------------- */
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/drivers/pnp/pnpbios/core.c working-2.5-bk-kmod-noclean/drivers/pnp/pnpbios/core.c
--- linux-2.5-bk/drivers/pnp/pnpbios/core.c Thu Jan 2 14:47:59 2003
+++ working-2.5-bk-kmod-noclean/drivers/pnp/pnpbios/core.c Sat Jan 11 17:57:13 2003
@@ -602,7 +602,7 @@ static int pnp_dock_event(int dock, stru
info->location_id, info->serial, info->capabilities);
envp[i] = 0;

- value = call_usermodehelper (argv [0], argv, envp);
+ value = call_usermodehelper (argv [0], argv, envp, 0);
kfree (buf);
kfree (envp);
return 0;
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/include/linux/kmod.h working-2.5-bk-kmod-noclean/include/linux/kmod.h
--- linux-2.5-bk/include/linux/kmod.h Thu Jan 2 12:35:15 2003
+++ working-2.5-bk-kmod-noclean/include/linux/kmod.h Sat Jan 11 17:57:13 2003
@@ -21,6 +21,7 @@

#include <linux/config.h>
#include <linux/errno.h>
+#include <linux/compiler.h>

#ifdef CONFIG_KMOD
extern int request_module(const char * name);
@@ -29,8 +30,7 @@ static inline int request_module(const c
#endif

#define try_then_request_module(x, mod) ((x) ?: request_module(mod), (x))
-extern int exec_usermodehelper(char *program_path, char *argv[], char *envp[]);
-extern int call_usermodehelper(char *path, char *argv[], char *envp[]);
+extern int call_usermodehelper(char *path, char *argv[], char *envp[], int wait);

#ifdef CONFIG_HOTPLUG
extern char hotplug_path [];
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/kernel/futex.c working-2.5-bk-kmod-noclean/kernel/futex.c
--- linux-2.5-bk/kernel/futex.c Thu Jan 2 12:36:08 2003
+++ working-2.5-bk-kmod-noclean/kernel/futex.c Sat Jan 11 18:19:32 2003
@@ -34,6 +34,7 @@
#include <linux/futex.h>
#include <linux/vcache.h>
#include <linux/mount.h>
+#include <linux/kmod.h>

#define FUTEX_HASHBITS 8

@@ -453,6 +454,8 @@ asmlinkage int sys_futex(unsigned long u
ret = futex_wait_utime(uaddr, pos_in_page, val, utime);
break;
case FUTEX_WAKE:
+ ret = request_module("foo");
+ printk("request_module foo = %i\n", ret);
ret = futex_wake(uaddr, pos_in_page, val);
break;
case FUTEX_FD:
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/kernel/kmod.c working-2.5-bk-kmod-noclean/kernel/kmod.c
--- linux-2.5-bk/kernel/kmod.c Thu Jan 2 12:37:03 2003
+++ working-2.5-bk-kmod-noclean/kernel/kmod.c Sat Jan 11 18:08:36 2003
@@ -14,8 +14,10 @@

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>
@@ -31,121 +33,11 @@
#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;
-
- curtask->session = 1;
- curtask->pgrp = 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.
- */
- spin_lock_irq(&curtask->sig->siglock);
- sigemptyset(&curtask->blocked);
- flush_signals(curtask);
- flush_signal_handlers(curtask);
- recalc_sigpending();
- spin_unlock_irq(&curtask->sig->siglock);
-
- for (i = 0; i < curtask->files->max_fds; i++ ) {
- if (curtask->files->fd[i]) close(i);
- }
-
- /* Drop the "current user" thing */
- {
- struct user_struct *user = curtask->user;
- curtask->user = INIT_USER;
- atomic_inc(&INIT_USER->__count);
- atomic_inc(&INIT_USER->processes);
- atomic_dec(&user->processes);
- free_uid(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

/*
@@ -153,29 +45,6 @@ int exec_usermodehelper(char *program_pa
*/
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
@@ -189,24 +58,18 @@ static int exec_modprobe(void * module_n
* 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
@@ -216,61 +79,44 @@ int request_module(const char * module_n
* 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) { /* Exec failed, or fork failed or something bad */
+ 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(&current->sig->siglock);
- tmpsig = current->blocked;
- siginitsetinv(&current->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP));
- recalc_sigpending();
- spin_unlock_irq(&current->sig->siglock);
-
- waitpid_result = waitpid(pid, NULL, __WCLONE);
atomic_dec(&kmod_concurrent);
-
- /* Allow signals again.. */
- spin_lock_irq(&current->sig->siglock);
- current->blocked = tmpsig;
- recalc_sigpending();
- spin_unlock_irq(&current->sig->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;
+ return ret < 0 ? ret : 0;
}
#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;
@@ -294,7 +140,8 @@ struct subprocess_info {
char *path;
char **argv;
char **envp;
- pid_t retval;
+ int wait;
+ int retval;
};

/*
@@ -307,13 +154,30 @@ static int ____call_usermodehelper(void

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.
*/
@@ -322,14 +186,21 @@ static void __call_usermodehelper(void *
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);
}

/**
@@ -337,15 +208,17 @@ static void __call_usermodehelper(void *
* @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 = {
@@ -353,6 +226,7 @@ int call_usermodehelper(char *path, char
.path = path,
.argv = argv,
.envp = envp,
+ .wait = wait,
.retval = 0,
};
DECLARE_WORK(work, __call_usermodehelper, &sub_info);
@@ -390,7 +264,6 @@ void dev_probe_unlock(void)
up(&dev_probe_sem);
}

-EXPORT_SYMBOL(exec_usermodehelper);
EXPORT_SYMBOL(call_usermodehelper);

#ifdef CONFIG_KMOD
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/net/bluetooth/hci_core.c working-2.5-bk-kmod-noclean/net/bluetooth/hci_core.c
--- linux-2.5-bk/net/bluetooth/hci_core.c Thu Jan 2 12:33:56 2003
+++ working-2.5-bk-kmod-noclean/net/bluetooth/hci_core.c Sat Jan 11 17:57:13 2003
@@ -114,7 +114,7 @@ static int hci_run_hotplug(char *dev, ch
envp[3] = astr;
envp[4] = NULL;

- return call_usermodehelper(argv[0], argv, envp);
+ return call_usermodehelper(argv[0], argv, envp, 0);
}
#else
#define hci_run_hotplug(A...)
diff -urp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/net/core/dev.c working-2.5-bk-kmod-noclean/net/core/dev.c
--- linux-2.5-bk/net/core/dev.c Sat Jan 11 17:51:52 2003
+++ working-2.5-bk-kmod-noclean/net/core/dev.c Sat Jan 11 17:57:13 2003
@@ -2930,6 +2930,6 @@ static int net_run_sbin_hotplug(struct n
envp [i++] = action_str;
envp [i] = 0;

- return call_usermodehelper(argv [0], argv, envp);
+ return call_usermodehelper(argv [0], argv, envp, 0);
}
#endif
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
-
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