2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
kmod, the new module loader (replaces kerneld)
|
|
|
|
Kirk Petersen
|
|
|
|
|
|
|
|
Reorganized not to be a daemon by Adam Richter, with guidance
|
|
|
|
from Greg Zornetzer.
|
|
|
|
|
|
|
|
Modified to avoid chroot and file sharing problems.
|
|
|
|
Mikael Pettersson
|
|
|
|
|
|
|
|
Limit the concurrent number of kmod modprobes to catch loops from
|
|
|
|
"modprobe needs a service that is in a module".
|
|
|
|
Keith Owens <kaos@ocs.com.au> December 1999
|
|
|
|
|
|
|
|
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
|
|
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#include <linux/syscalls.h>
|
|
|
|
#include <linux/unistd.h>
|
|
|
|
#include <linux/kmod.h>
|
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/completion.h>
|
|
|
|
#include <linux/file.h>
|
2008-04-24 05:44:08 -06:00
|
|
|
#include <linux/fdtable.h>
|
2005-04-16 16:20:36 -06:00
|
|
|
#include <linux/workqueue.h>
|
|
|
|
#include <linux/security.h>
|
|
|
|
#include <linux/mount.h>
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/init.h>
|
2006-10-01 00:29:28 -06:00
|
|
|
#include <linux/resource.h>
|
2007-07-19 02:47:36 -06:00
|
|
|
#include <linux/notifier.h>
|
|
|
|
#include <linux/suspend.h>
|
2005-04-16 16:20:36 -06:00
|
|
|
#include <asm/uaccess.h>
|
|
|
|
|
2009-08-17 02:56:28 -06:00
|
|
|
#include <trace/events/module.h>
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
extern int max_threads;
|
|
|
|
|
|
|
|
static struct workqueue_struct *khelper_wq;
|
|
|
|
|
2008-07-08 11:00:17 -06:00
|
|
|
#ifdef CONFIG_MODULES
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
modprobe_path is set via /proc/sys.
|
|
|
|
*/
|
|
|
|
char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
|
|
|
|
|
|
|
|
/**
|
2009-02-08 11:42:01 -07:00
|
|
|
* __request_module - try to load a kernel module
|
|
|
|
* @wait: wait (or not) for the operation to complete
|
2009-01-06 15:42:39 -07:00
|
|
|
* @fmt: printf style format string for the name of the module
|
|
|
|
* @...: arguments as specified in the format string
|
2005-04-16 16:20:36 -06:00
|
|
|
*
|
|
|
|
* Load a module using the user mode module loader. The function returns
|
|
|
|
* zero on success or a negative errno code on failure. Note that a
|
|
|
|
* successful module load does not mean the module did not then unload
|
|
|
|
* and exit on an error of its own. Callers must check that the service
|
|
|
|
* they requested is now available not blindly invoke it.
|
|
|
|
*
|
|
|
|
* If module auto-loading support is disabled then this function
|
|
|
|
* becomes a no-operation.
|
|
|
|
*/
|
2009-02-08 11:42:01 -07:00
|
|
|
int __request_module(bool wait, const char *fmt, ...)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
va_list args;
|
|
|
|
char module_name[MODULE_NAME_LEN];
|
|
|
|
unsigned int max_modprobes;
|
|
|
|
int ret;
|
|
|
|
char *argv[] = { modprobe_path, "-q", "--", 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;
|
|
|
|
|
|
|
|
va_start(args, fmt);
|
|
|
|
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
|
|
|
|
va_end(args);
|
|
|
|
if (ret >= MODULE_NAME_LEN)
|
|
|
|
return -ENAMETOOLONG;
|
|
|
|
|
2009-11-02 22:35:32 -07:00
|
|
|
ret = security_kernel_module_request(module_name);
|
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/* 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
|
|
|
|
* MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
|
|
|
|
* would be to run the parents of this process, counting how many times
|
|
|
|
* kmod was invoked. That would mean accessing the internals of the
|
|
|
|
* 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
|
|
|
|
*/
|
|
|
|
max_modprobes = min(max_threads/2, MAX_KMOD_CONCURRENT);
|
|
|
|
atomic_inc(&kmod_concurrent);
|
|
|
|
if (atomic_read(&kmod_concurrent) > max_modprobes) {
|
|
|
|
/* We may be blaming an innocent here, but unlikely */
|
|
|
|
if (kmod_loop_msg++ < 5)
|
|
|
|
printk(KERN_ERR
|
|
|
|
"request_module: runaway loop modprobe %s\n",
|
|
|
|
module_name);
|
|
|
|
atomic_dec(&kmod_concurrent);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
2009-08-17 02:56:28 -06:00
|
|
|
trace_module_request(module_name, wait, _RET_IP_);
|
|
|
|
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
ret = call_usermodehelper_fns(modprobe_path, argv, envp,
|
|
|
|
wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC,
|
|
|
|
NULL, NULL, NULL);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
atomic_dec(&kmod_concurrent);
|
|
|
|
return ret;
|
|
|
|
}
|
2009-02-08 11:42:01 -07:00
|
|
|
EXPORT_SYMBOL(__request_module);
|
2008-10-17 01:38:36 -06:00
|
|
|
#endif /* CONFIG_MODULES */
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* This is the task which runs the usermode application
|
|
|
|
*/
|
|
|
|
static int ____call_usermodehelper(void *data)
|
|
|
|
{
|
|
|
|
struct subprocess_info *sub_info = data;
|
|
|
|
int retval;
|
|
|
|
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
|
|
flush_signal_handlers(current, 1);
|
|
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
|
|
|
|
/* We can run anywhere, unlike our parent keventd(). */
|
2009-03-30 22:05:10 -06:00
|
|
|
set_cpus_allowed_ptr(current, cpu_all_mask);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2007-05-08 01:28:24 -06:00
|
|
|
/*
|
|
|
|
* Our parent is keventd, which runs with elevated scheduling priority.
|
|
|
|
* Avoid propagating that into the userspace child.
|
|
|
|
*/
|
|
|
|
set_user_nice(current, 0);
|
|
|
|
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
if (sub_info->init) {
|
|
|
|
retval = sub_info->init(sub_info);
|
|
|
|
if (retval)
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
|
2008-02-14 20:34:29 -07:00
|
|
|
retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* Exec failed? */
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
fail:
|
2005-04-16 16:20:36 -06:00
|
|
|
sub_info->retval = retval;
|
|
|
|
do_exit(0);
|
|
|
|
}
|
|
|
|
|
2007-07-17 19:37:02 -06:00
|
|
|
void call_usermodehelper_freeinfo(struct subprocess_info *info)
|
|
|
|
{
|
|
|
|
if (info->cleanup)
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
(*info->cleanup)(info);
|
2007-07-17 19:37:02 -06:00
|
|
|
kfree(info);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(call_usermodehelper_freeinfo);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/* 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;
|
|
|
|
|
2010-05-26 15:43:03 -06:00
|
|
|
/* If SIGCLD is ignored sys_wait4 won't populate the status. */
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
|
|
current->sighand->action[SIGCHLD-1].sa.sa_handler = SIG_DFL;
|
|
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
|
|
|
|
if (pid < 0) {
|
|
|
|
sub_info->retval = pid;
|
|
|
|
} else {
|
2010-05-26 15:43:03 -06:00
|
|
|
int ret = -ECHILD;
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Normally it is bogus to call wait4() from in-kernel because
|
|
|
|
* wait4() wants to write the exit code to a userspace address.
|
|
|
|
* But wait_for_helper() always runs as keventd, and put_user()
|
|
|
|
* to a kernel address works OK for kernel threads, due to their
|
|
|
|
* having an mm_segment_t which spans the entire address space.
|
|
|
|
*
|
|
|
|
* Thus the __user pointer cast is valid here.
|
|
|
|
*/
|
2006-09-29 03:00:46 -06:00
|
|
|
sys_wait4(pid, (int __user *)&ret, 0, NULL);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If ret is 0, either ____call_usermodehelper failed and the
|
|
|
|
* real error code is already in sub_info->retval or
|
|
|
|
* sub_info->retval is 0 anyway, so don't mess with it then.
|
|
|
|
*/
|
|
|
|
if (ret)
|
|
|
|
sub_info->retval = ret;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2010-05-26 15:43:04 -06:00
|
|
|
complete(sub_info->complete);
|
2005-04-16 16:20:36 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* This is run by khelper thread */
|
2006-11-22 07:55:48 -07:00
|
|
|
static void __call_usermodehelper(struct work_struct *work)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2006-11-22 07:55:48 -07:00
|
|
|
struct subprocess_info *sub_info =
|
|
|
|
container_of(work, struct subprocess_info, work);
|
2007-07-17 19:37:03 -06:00
|
|
|
enum umh_wait wait = sub_info->wait;
|
2010-05-26 15:43:04 -06:00
|
|
|
pid_t pid;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* CLONE_VFORK: wait until the usermode helper has execve'd
|
|
|
|
* successfully We need the data structures to stay around
|
|
|
|
* until that is done. */
|
2010-05-26 15:43:04 -06:00
|
|
|
if (wait == UMH_WAIT_PROC)
|
2005-04-16 16:20:36 -06:00
|
|
|
pid = kernel_thread(wait_for_helper, sub_info,
|
|
|
|
CLONE_FS | CLONE_FILES | SIGCHLD);
|
|
|
|
else
|
|
|
|
pid = kernel_thread(____call_usermodehelper, sub_info,
|
|
|
|
CLONE_VFORK | SIGCHLD);
|
|
|
|
|
2007-07-17 19:37:03 -06:00
|
|
|
switch (wait) {
|
|
|
|
case UMH_NO_WAIT:
|
2010-05-26 15:43:04 -06:00
|
|
|
call_usermodehelper_freeinfo(sub_info);
|
2007-07-17 19:37:03 -06:00
|
|
|
break;
|
2007-02-13 05:26:23 -07:00
|
|
|
|
2007-07-17 19:37:03 -06:00
|
|
|
case UMH_WAIT_PROC:
|
|
|
|
if (pid > 0)
|
|
|
|
break;
|
|
|
|
/* FALLTHROUGH */
|
|
|
|
case UMH_WAIT_EXEC:
|
2010-05-26 15:43:05 -06:00
|
|
|
if (pid < 0)
|
|
|
|
sub_info->retval = pid;
|
2005-04-16 16:20:36 -06:00
|
|
|
complete(sub_info->complete);
|
2007-07-17 19:37:03 -06:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2008-10-15 23:01:21 -06:00
|
|
|
#ifdef CONFIG_PM_SLEEP
|
2007-07-19 02:47:37 -06:00
|
|
|
/*
|
|
|
|
* If set, call_usermodehelper_exec() will exit immediately returning -EBUSY
|
|
|
|
* (used for preventing user land processes from being created after the user
|
|
|
|
* land has been frozen during a system-wide hibernation or suspend operation).
|
|
|
|
*/
|
|
|
|
static int usermodehelper_disabled;
|
|
|
|
|
|
|
|
/* Number of helpers running */
|
|
|
|
static atomic_t running_helpers = ATOMIC_INIT(0);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Wait queue head used by usermodehelper_pm_callback() to wait for all running
|
|
|
|
* helpers to finish.
|
|
|
|
*/
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Time to wait for running_helpers to become zero before the setting of
|
|
|
|
* usermodehelper_disabled in usermodehelper_pm_callback() fails
|
|
|
|
*/
|
|
|
|
#define RUNNING_HELPERS_TIMEOUT (5 * HZ)
|
|
|
|
|
2008-10-15 23:01:21 -06:00
|
|
|
/**
|
|
|
|
* usermodehelper_disable - prevent new helpers from being started
|
|
|
|
*/
|
|
|
|
int usermodehelper_disable(void)
|
2007-07-19 02:47:36 -06:00
|
|
|
{
|
2007-07-19 02:47:37 -06:00
|
|
|
long retval;
|
|
|
|
|
2008-10-15 23:01:21 -06:00
|
|
|
usermodehelper_disabled = 1;
|
|
|
|
smp_mb();
|
|
|
|
/*
|
|
|
|
* From now on call_usermodehelper_exec() won't start any new
|
|
|
|
* helpers, so it is sufficient if running_helpers turns out to
|
|
|
|
* be zero at one point (it may be increased later, but that
|
|
|
|
* doesn't matter).
|
|
|
|
*/
|
|
|
|
retval = wait_event_timeout(running_helpers_waitq,
|
2007-07-19 02:47:37 -06:00
|
|
|
atomic_read(&running_helpers) == 0,
|
|
|
|
RUNNING_HELPERS_TIMEOUT);
|
2008-10-15 23:01:21 -06:00
|
|
|
if (retval)
|
|
|
|
return 0;
|
2007-07-19 02:47:36 -06:00
|
|
|
|
2008-10-15 23:01:21 -06:00
|
|
|
usermodehelper_disabled = 0;
|
|
|
|
return -EAGAIN;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* usermodehelper_enable - allow new helpers to be started again
|
|
|
|
*/
|
|
|
|
void usermodehelper_enable(void)
|
|
|
|
{
|
|
|
|
usermodehelper_disabled = 0;
|
2007-07-19 02:47:36 -06:00
|
|
|
}
|
|
|
|
|
2007-07-19 02:47:37 -06:00
|
|
|
static void helper_lock(void)
|
|
|
|
{
|
|
|
|
atomic_inc(&running_helpers);
|
|
|
|
smp_mb__after_atomic_inc();
|
|
|
|
}
|
|
|
|
|
|
|
|
static void helper_unlock(void)
|
|
|
|
{
|
|
|
|
if (atomic_dec_and_test(&running_helpers))
|
|
|
|
wake_up(&running_helpers_waitq);
|
|
|
|
}
|
2008-10-15 23:01:21 -06:00
|
|
|
#else /* CONFIG_PM_SLEEP */
|
2007-07-19 02:47:37 -06:00
|
|
|
#define usermodehelper_disabled 0
|
|
|
|
|
|
|
|
static inline void helper_lock(void) {}
|
|
|
|
static inline void helper_unlock(void) {}
|
2008-10-15 23:01:21 -06:00
|
|
|
#endif /* CONFIG_PM_SLEEP */
|
2007-07-19 02:47:37 -06:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/**
|
2007-07-17 19:37:02 -06:00
|
|
|
* call_usermodehelper_setup - prepare to call a usermode helper
|
2007-07-26 11:40:56 -06:00
|
|
|
* @path: path to usermode executable
|
|
|
|
* @argv: arg vector for process
|
|
|
|
* @envp: environment for process
|
2008-07-25 02:45:38 -06:00
|
|
|
* @gfp_mask: gfp mask for memory allocation
|
2007-07-17 19:37:02 -06:00
|
|
|
*
|
2007-07-26 11:40:56 -06:00
|
|
|
* Returns either %NULL on allocation failure, or a subprocess_info
|
2007-07-17 19:37:02 -06:00
|
|
|
* structure. This should be passed to call_usermodehelper_exec to
|
|
|
|
* exec the process and free the structure.
|
|
|
|
*/
|
2008-07-25 02:45:38 -06:00
|
|
|
struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
|
|
|
|
char **envp, gfp_t gfp_mask)
|
2007-07-17 19:37:02 -06:00
|
|
|
{
|
|
|
|
struct subprocess_info *sub_info;
|
2008-07-25 02:45:38 -06:00
|
|
|
sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask);
|
2007-07-17 19:37:02 -06:00
|
|
|
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);
|
|
|
|
|
|
|
|
/**
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
* call_usermodehelper_setfns - set a cleanup/init function
|
2007-07-17 19:37:02 -06:00
|
|
|
* @info: a subprocess_info returned by call_usermodehelper_setup
|
|
|
|
* @cleanup: a cleanup function
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
* @init: an init function
|
|
|
|
* @data: arbitrary context sensitive data
|
|
|
|
*
|
|
|
|
* The init function is used to customize the helper process prior to
|
|
|
|
* exec. A non-zero return code causes the process to error out, exit,
|
|
|
|
* and return the failure to the calling process
|
2007-07-17 19:37:02 -06:00
|
|
|
*
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
* The cleanup function is just before ethe subprocess_info is about to
|
2007-07-17 19:37:02 -06:00
|
|
|
* 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.
|
|
|
|
*/
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
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void call_usermodehelper_setfns(struct subprocess_info *info,
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int (*init)(struct subprocess_info *info),
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void (*cleanup)(struct subprocess_info *info),
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void *data)
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2007-07-17 19:37:02 -06:00
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{
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info->cleanup = cleanup;
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kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
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info->init = init;
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|
info->data = data;
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2007-07-17 19:37:02 -06:00
|
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|
}
|
kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 15:42:58 -06:00
|
|
|
EXPORT_SYMBOL(call_usermodehelper_setfns);
|
2007-07-17 19:37:02 -06:00
|
|
|
|
|
|
|
/**
|
|
|
|
* call_usermodehelper_exec - start a usermode application
|
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|
|
* @sub_info: information about the subprocessa
|
2005-04-16 16:20:36 -06:00
|
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|
* @wait: wait for the application to finish and return status.
|
2007-02-13 05:26:23 -07:00
|
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* when -1 don't wait at all, but you get no useful error back when
|
|
|
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* the program couldn't be exec'ed. This makes it safe to call
|
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* from interrupt context.
|
2005-04-16 16:20:36 -06:00
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*
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* Runs a user-space application. The application is started
|
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* asynchronously if wait is not set, and runs as a child of keventd.
|
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* (ie. it runs with full root capabilities).
|
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|
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*/
|
2007-07-17 19:37:02 -06:00
|
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int call_usermodehelper_exec(struct subprocess_info *sub_info,
|
2007-07-17 19:37:03 -06:00
|
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enum umh_wait wait)
|
2005-04-16 16:20:36 -06:00
|
|
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{
|
2006-07-03 01:25:26 -06:00
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DECLARE_COMPLETION_ONSTACK(done);
|
2008-01-17 16:21:21 -07:00
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int retval = 0;
|
2005-04-16 16:20:36 -06:00
|
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|
2007-07-19 02:47:37 -06:00
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helper_lock();
|
2008-01-17 16:21:21 -07:00
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if (sub_info->path[0] == '\0')
|
2007-07-17 19:37:02 -06:00
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goto out;
|
2005-04-16 16:20:36 -06:00
|
|
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|
2007-07-19 02:47:36 -06:00
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|
if (!khelper_wq || usermodehelper_disabled) {
|
2007-07-17 19:37:02 -06:00
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|
retval = -EBUSY;
|
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|
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goto out;
|
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|
|
}
|
2007-02-13 05:26:23 -07:00
|
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|
sub_info->complete = &done;
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|
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sub_info->wait = wait;
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|
queue_work(khelper_wq, &sub_info->work);
|
2008-01-17 16:21:21 -07:00
|
|
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if (wait == UMH_NO_WAIT) /* task has freed sub_info */
|
|
|
|
goto unlock;
|
2005-04-16 16:20:36 -06:00
|
|
|
wait_for_completion(&done);
|
2007-02-13 05:26:23 -07:00
|
|
|
retval = sub_info->retval;
|
2007-07-17 19:37:02 -06:00
|
|
|
|
2008-01-17 16:21:21 -07:00
|
|
|
out:
|
2007-07-17 19:37:02 -06:00
|
|
|
call_usermodehelper_freeinfo(sub_info);
|
2008-01-17 16:21:21 -07:00
|
|
|
unlock:
|
2007-07-19 02:47:37 -06:00
|
|
|
helper_unlock();
|
2007-02-13 05:26:23 -07:00
|
|
|
return retval;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2007-07-17 19:37:02 -06:00
|
|
|
EXPORT_SYMBOL(call_usermodehelper_exec);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
void __init usermodehelper_init(void)
|
|
|
|
{
|
|
|
|
khelper_wq = create_singlethread_workqueue("khelper");
|
|
|
|
BUG_ON(!khelper_wq);
|
|
|
|
}
|