[cgl_discussion] Announcing Non-intrusive Kernel Monitor Project
Steven Dake
sdake at mvista.com
Thu Jun 10 15:28:26 PDT 2004
patch looks acceptable.. Although character drivers that implement
ioctls are poorly received... Have you thought of a sysfs mechanism to
plug this into the kernel?
Thanks
-steve
On Thu, 2004-06-10 at 15:19, Rusty Lynch wrote:
> On Wed, Jun 09, 2004 at 10:19:03AM -0700, Sabharwal, Atul wrote:
> > I have been experimenting with the CGL 2.0 AVL 8.2 requirement on
> > Non-intrusive kernel
> > based monitoring of processes and threads. For your reference, the
> > requirement is
> > quoted below :
>
> Looks like outlook ate the patch. Here is the patch again (without the
> help of outlook)
>
> BTW, is this how everyone is interpreting the requirement? There isn't much
> to this and the performance/scalability is basically what ever real-time
> signals can do.
>
> I would at least like to hear if this is on or off target for the requirement
> before Atul takes this to LKML. We have played with this on various ia32 and
> IPF systems with hardly noticeable impact while monitoring a significant load,
> and no measurable impact while not monitoring anything.
>
> --rusty
>
> diff -Nru a/Documentation/ioctl-number.txt b/Documentation/ioctl-number.txt
> --- a/Documentation/ioctl-number.txt Wed Jun 9 10:37:42 2004
> +++ b/Documentation/ioctl-number.txt Wed Jun 9 10:37:42 2004
> @@ -189,3 +189,4 @@
> <mailto:michael.klein at puffin.lb.shuttle.de>
> 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
> <mailto:aherrman at de.ibm.com>
> +0xDE all drivers/char/kmonitor <mailto:atul.sabharwal at intel.com>
> diff -Nru a/Documentation/kmonitor.txt b/Documentation/kmonitor.txt
> --- /dev/null Wed Dec 31 16:00:00 1969
> +++ b/Documentation/kmonitor.txt Wed Jun 9 10:37:42 2004
> @@ -0,0 +1,119 @@
> +Enabling Non-intrusive Application Monitoring with kmonitor
> +-----------------------------------------------------------
> +The kmonitor driver implements a kernel level non-intrusive
> +mechanism for rapidly notifying a monitoring user space process
> +of key (process/thread creation/exit) kernel events.
> +
> +The monitoring user space process registers and deregisters for events via
> +a new misc char device using two new ioctl's. The kernel notifies the
> +monitoring process(es) of the events via a signal that the monitor specifies
> +during registration.
> +
> +An example of how this would be used in an minimal command line utility
> +to wait for an arbitrary process to exit:
> +
> +<snip>rest of required headers...</snip>
> +#include <linux/kmonitor.h>
> +
> +void target_exit_handler (int signum , struct siginfo * info, void * buf)
> +{
> + /*
> + * Since we only registered for one type of event,
> + * KMONITOR_PROCESS_EXIT, on one process, then we already
> + * know our target process has exited
> + *
> + * If we were doing something more complex, then the data in
> + * info might be usefull:
> + * 1. info->si_pid: process id of target process
> + * 2. info->si_gid: group id of target process
> + * 3. info->si_int: event that triggered this signal
> + * (See include/linux/kmonitor.h for the list of events)
> + *
> + * The target process has exited, so we are done. Kmonitor
> + * will do cleanup when we close the file descriptor for
> + * /dev/kmonitor (which will happen automatically when we
> + * exit.)
> + */
> + exit(0);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +<snip>...</snip>
> +
> + /*
> + * kmonitor will notify us that the target process has exited
> + * by sending us a real-time signal with the payload containing
> + * the event that triggered the notification.
> + */
> + action.sa_sigaction = target_exit_handler;
> + action.sa_flags = SA_SIGINFO;
> + if (-1 == sigaction(SIGRTMIN, &action, NULL)) {
> + perror("sigaction");
> + exit(-1);
> + }
> +
> + /*
> + * The kmonitor is implemented as misc char device, so the
> + * file that needs to be opened (assumed to be /dev/kmonitor
> + * in this example) is a char device with a major number of 10
> + * and a minor number of 221.
> + *
> + * mknod /dev/kmonitor c 10 221
> + */
> + fd = open("/dev/kmonitor", O_WRONLY);
> + if (-1 == fd) {
> + perror("open /dev/kmonitor");
> + exit(-1);
> + }
> +
> + /*
> + * To sign up for notification of an arbitrary event on an
> + * arbitrary process then we send the KMONITOR_IOW_REGISTER
> + * command to the device via the ioctl system call.
> + *
> + * We indicate the target process and event by sending a
> + * kmonitor_cmd structure.
> + *
> + * NOTE: The 'type' field in the structure is actually
> + * a bitmask, so it is possible to register for
> + * multiple events on a given target process in one
> + * ioctl call. The possible events are...
> + * #define KMONITOR_THREAD_CREATE 0x01
> + * #define KMONITOR_THREAD_ABORT 0x02
> + * #define KMONITOR_THREAD_EXIT 0x04
> + * #define KMONITOR_PROCESS_FORK 0x08
> + * #define KMONITOR_PROCESS_ABORT 0x10
> + * #define KMONITOR_PROCESS_EXEC 0x20
> + * #define KMONITOR_PROCESS_EXIT 0x40
> + */
> + hdr.signal = SIGRTMIN;
> + hdr.pid = args.pid;
> + hdr.type = KMONITOR_PROCESS_EXIT;
> + if (-1 == ioctl(fd, KMONITOR_IOW_REGISTER, &hdr)) {
> + perror("ioctl");
> + exit(-1);
> + }
> +
> + /*
> + * In this very simple example all we need to do is wait
> + * for a signal to be sent. The signal handler will exit
> + * when it is notified of the target process exiting.
> + */
> + sigemptyset(&empty_mask);
> + sigsuspend(&empty_mask);
> +
> + /*
> + * kmonitor will perform a cleanup of all request a given
> + * monitoring process has made, so it is required to deregister
> + * each of the specific request.
> + *
> + * If for some reason a monitoring process wanted to deregister
> + * a specific request, then the procedure is just like registering,
> + * other then the ioctl command is KMONITOR_IOW_DEREGISTER.
> + */
> + close(fd);
> + exit (0);
> +}
> +
> +
> diff -Nru a/drivers/char/Kconfig b/drivers/char/Kconfig
> --- a/drivers/char/Kconfig Wed Jun 9 10:37:42 2004
> +++ b/drivers/char/Kconfig Wed Jun 9 10:37:42 2004
> @@ -974,5 +974,15 @@
> out to lunch past a certain margin. It can reboot the system
> or merely print a warning.
>
> +config KMONITOR
> + bool "Kmonitor driver"
> + help
> + The kmonitor driver implements a kernel level non-intrusive
> + mechanism for rapidly notifying a monitoring user space process
> + of key (process/thread creation/exit) kernel events. For more
> + info see Documentation/kmonitor.txt
> +
> + If in doubt, say 'N'.
> +
> endmenu
>
> diff -Nru a/drivers/char/Makefile b/drivers/char/Makefile
> --- a/drivers/char/Makefile Wed Jun 9 10:37:42 2004
> +++ b/drivers/char/Makefile Wed Jun 9 10:37:42 2004
> @@ -79,6 +79,7 @@
> obj-$(CONFIG_DRM) += drm/
> obj-$(CONFIG_PCMCIA) += pcmcia/
> obj-$(CONFIG_IPMI_HANDLER) += ipmi/
> +obj-$(CONFIG_KMONITOR) += kmonitor.o
>
> obj-$(CONFIG_HANGCHECK_TIMER) += hangcheck-timer.o
>
> diff -Nru a/drivers/char/kmonitor.c b/drivers/char/kmonitor.c
> --- /dev/null Wed Dec 31 16:00:00 1969
> +++ b/drivers/char/kmonitor.c Wed Jun 9 10:37:42 2004
> @@ -0,0 +1,336 @@
> +/*
> + * linux/kmonitor.c
> + *
> + * Copyright (C) 2004 Intel Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public
> + * License v2.0 as published by the Free Software Foundation;
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public
> + * License along with this program; if not, write to the
> + * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
> + * Boston, MA 021110-1307, USA.
> + *
> + * Authors: Atul Sabharwal <atul.sabharwal at intel.com>
> + *
> + * The kmonitor driver implements a kernel level non-intrusive
> + * mechanism for rapidly notifying a monitoring user space process
> + * of key (process/thread creation/exit) kernel events.
> + *
> + * See Documentation/kmonitor.txt for more details
> + */
> +
> +#include <linux/config.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/fs.h>
> +#include <linux/hash.h>
> +#include <linux/init.h>
> +#include <linux/kmonitor.h>
> +#include <linux/miscdevice.h>
> +#include <linux/proc_fs.h>
> +#include <linux/sched.h>
> +#include <linux/types.h>
> +#include <linux/timer.h>
> +#include <asm/uaccess.h>
> +#include <asm/atomic.h>
> +
> +/*
> + * kmonitor maintains a database of resources containing:
> + * - the pid of the process being monitored (target)
> + * - the pid of process that should be notified (monitor)
> + * - an event mask
> + * - a signal number to notify the monitor with
> + * - a list_head
> + *
> + * To improve scalability, a hash of linked listed is maintained
> + * with a per bucket read-write lock. KMONITOR_BITS defines the
> + * order of the list size, so setting KMONITOR_BITS to 8 would translate
> + * to 265 buckets. Using a hash of linked list improves the order of the
> + * search from an O(n) to O(n/m) where n is the number of resources and
> + * m is the number of buckets.
> + *
> + * Note that since we are using a per bucket read-write lock, the number
> + * of buckets also as an effect on SMP performance since the smaller the
> + * list of resources in each bucket, the less likely a processor will
> + * spin waiting for another processor to finish writing to the same list.
> + */
> +
> +struct kmonitor_bucket
> +{
> + struct list_head list;
> + rwlock_t lock;
> +};
> +
> +#define KMONITOR_BITS 0x8
> +
> +struct kmonitor_bucket kmonitor_resources[1<<KMONITOR_BITS];
> +
> +static inline unsigned long khash(pid_t target)
> +{
> + return hash_long((unsigned long)target, KMONITOR_BITS);
> +}
> +
> +struct kmonitor_res
> +{
> + struct list_head rlist;
> + pid_t target;
> + pid_t monitor;
> + int signal;
> + __u32 event_mask;
> +};
> +
> +#define to_kmonitor_res(r) \
> + container_of(r, struct kmonitor_res, rlist);
> +
> +kmem_cache_t *kmonitor_cache;
> +
> +/*
> + * kmonitor_active is used to improve the performance of searching
> + * an empty resource database
> + */
> +atomic_t kmonitor_active = { .counter = 0};
> +
> +/* #define DEBUG */
> +#ifdef DEBUG
> +#define DBG(format, arg...) printk("%s: " format "\n", __FUNCTION__ , ## arg)
> +#define TRACE(format, arg...) printk("%s(" format ")\n", __FUNCTION__, ## arg)
> +#else
> +#define DBG(format, arg...) do {} while(0);
> +#define TRACE(arg...) do {} while(0);
> +#endif
> +
> +static int kmonitor_add(pid_t target, int type, int signal)
> +{
> + struct kmonitor_res *r;
> + struct list_head *tmp;
> + unsigned long bucket = khash(target);
> +
> + TRACE("%i, %i, %i", target, type, signal);
> + read_lock(&kmonitor_resources[bucket].lock);
> + list_for_each(tmp, &kmonitor_resources[bucket].list) {
> + r = to_kmonitor_res(tmp);
> + if (r->monitor == current->pid && r->target == target) {
> + /*
> + * There is an existing resource for this
> + * target/monitor combination so just flip
> + * a bit in the event mask indicating that
> + * this monitor also wants to be notified
> + * for this type of event.
> + */
> + r->event_mask |= type;
> + r->signal = signal;
> + DBG("Added %i to existing res", type);
> + read_unlock(&kmonitor_resources[bucket].lock);
> + return 0;
> + }
> + }
> + read_unlock(&kmonitor_resources[bucket].lock);
> +
> + /*
> + * This is the first event registered for this target
> + * on this monitor. Allocate a new resource from our
> + * cache and add the resource to the global list.
> + *
> + * Note: There is no race condition between the top half & the
> + * bottom part of this function as if multiple monitors are active,
> + * each will have a unique resource for itself. So, the function
> + * is SMP safe.
> + */
> + r = kmem_cache_alloc(kmonitor_cache, SLAB_KERNEL);
> + if (!r)
> + return -ENOMEM;
> +
> + r->target = target;
> + r->monitor = current->pid;
> + r->event_mask = type;
> + r->signal = signal;
> + write_lock(&kmonitor_resources[bucket].lock);
> + list_add(&r->rlist, &kmonitor_resources[bucket].list);
> + write_unlock(&kmonitor_resources[bucket].lock);
> + return 0;
> +}
> +
> +static int kmonitor_remove(pid_t target, int type)
> +{
> + struct list_head *tmp, *next;
> + int ret = -EINVAL;
> + int bucket = khash(target);
> +
> + TRACE("%i, %i", target, type);
> +
> + write_lock(&kmonitor_resources[bucket].lock);
> + list_for_each_safe(tmp, next, &kmonitor_resources[bucket].list) {
> + struct kmonitor_res *r = to_kmonitor_res(tmp);
> + if (r->monitor == current->pid && r->target == target) {
> + r->event_mask &= ~type;
> + if (!r->event_mask) {
> + /* No more events so go ahead and cleanup */
> + list_del(tmp);
> + kmem_cache_free(kmonitor_cache, r);
> + }
> + ret = 0;
> + break;
> + }
> + }
> +
> + write_unlock(&kmonitor_resources[bucket].lock);
> + return ret;
> +}
> +
> +void __kmonitor_notify_event(struct task_struct *tsk, int type)
> +{
> + struct siginfo info;
> + struct list_head *tmp, *next;
> + int bucket = khash(current->pid);
> +
> + read_lock(&kmonitor_resources[bucket].lock);
> + list_for_each_safe(tmp,next,&kmonitor_resources[bucket].list) {
> + struct kmonitor_res *r = to_kmonitor_res(tmp);
> + if (r->target == current->pid && type & r->event_mask) {
> + info.si_signo = r->signal;
> + info.si_code = SI_QUEUE;
> + info.si_int = type;
> + info.si_pid = tsk->pid;
> + info.si_uid = tsk->uid;
> + kill_proc_info(r->signal, &info, r->monitor);
> + }
> + }
> + read_unlock(&kmonitor_resources[bucket].lock);
> +}
> +
> +static int kmonitor_open(struct inode *inode, struct file *file)
> +{
> + atomic_inc(&kmonitor_active);
> + return 0;
> +}
> +
> +static int kmonitor_release(struct inode *inode, struct file *file)
> +{
> + struct list_head *tmp, *next;
> + int i;
> +
> + TRACE("%p, %p", inode, file);
> + atomic_dec(&kmonitor_active);
> +
> + /*
> + * Remove any resources associated with this monitor
> + */
> + for (i=0; i<(1<<KMONITOR_BITS); i++) {
> + write_lock(&kmonitor_resources[i].lock);
> + list_for_each_safe(tmp, next, &kmonitor_resources[i].list) {
> + struct kmonitor_res *r = to_kmonitor_res(tmp);
> + if (r->monitor == current->pid) {
> + list_del(tmp);
> + kmem_cache_free(kmonitor_cache, r);
> + }
> + }
> + write_unlock(&kmonitor_resources[i].lock);
> + }
> +
> + return 0;
> +}
> +
> +static int kmonitor_ioctl(struct inode *inode, struct file *file,
> + unsigned int cmd, unsigned long arg)
> +{
> + struct kmonitor_cmd hdr;
> +
> + TRACE("%p, %p, %i, %i", inode, file, (int)cmd, (int)arg);
> + if (copy_from_user((struct kmonitor_cmd *)&hdr,
> + (struct kmonitor_cmd *)arg,
> + sizeof(struct kmonitor_cmd)))
> + return -EFAULT;
> +
> + switch (cmd) {
> + case KMONITOR_IOW_REGISTER:
> + return kmonitor_add(hdr.pid, hdr.type, hdr.signal);
> + case KMONITOR_IOW_DEREGISTER:
> + return kmonitor_remove(hdr.pid, hdr.type);
> + }
> +
> + DBG("Unexpected ioctl, %i", cmd);
> + return -EINVAL;
> +}
> +
> +static struct file_operations kmonitor_fops = {
> + .owner = THIS_MODULE,
> + .llseek = no_llseek,
> + .open = kmonitor_open,
> + .release = kmonitor_release,
> + .ioctl = kmonitor_ioctl,
> +};
> +
> +static struct miscdevice kmonitor_miscdev = {
> + .minor = KMONITOR_MINOR,
> + .name = "kmonitor",
> + .fops = &kmonitor_fops,
> +};
> +
> +static int __init kmonitor_init(void)
> +{
> + int ret, i;
> +
> + TRACE("void");
> +
> + for (i=0; i<(1<<KMONITOR_BITS); i++) {
> + INIT_LIST_HEAD(&kmonitor_resources[i].list);
> + kmonitor_resources[i].lock = RW_LOCK_UNLOCKED;
> + }
> +
> + ret = misc_register(&kmonitor_miscdev);
> + if (ret) {
> + printk(KERN_ERR "unable to register kmonitor misc device\n");
> + goto error_misc_drvr_register;
> + }
> +
> + kmonitor_cache = kmem_cache_create("kmonitor_res",
> + sizeof(struct kmonitor_res), 0,
> + SLAB_HWCACHE_ALIGN,
> + NULL, NULL);
> + if (!kmonitor_cache) {
> + printk(KERN_ERR "unable to allocate kmonitor_cache\n");
> + ret = -EINVAL;
> + goto error_in_kmonitor_cache;
> + }
> +
> + return 0;
> +
> + error_in_kmonitor_cache:
> + misc_deregister(&kmonitor_miscdev);
> + error_misc_drvr_register:
> + return ret;
> +}
> +
> +static void __exit kmonitor_exit(void)
> +{
> + struct list_head *tmp, *next;
> + int i;
> +
> + TRACE("void");
> + misc_deregister(&kmonitor_miscdev);
> + for (i=0; i<(1<<KMONITOR_BITS); i++) {
> + write_lock(&kmonitor_resources[i].lock);
> + list_for_each_safe(tmp, next, &kmonitor_resources[i].list) {
> + struct kmonitor_res *r = to_kmonitor_res(tmp);
> + list_del(tmp);
> + kmem_cache_free(kmonitor_cache, r);
> + }
> + write_unlock(&kmonitor_resources[i].lock);
> + }
> + kmem_cache_destroy(kmonitor_cache);
> +}
> +
> +module_init(kmonitor_init);
> +module_exit(kmonitor_exit);
> +
> +MODULE_AUTHOR("Atul Sabharwal");
> +MODULE_DESCRIPTION("Kmonitor Char Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS_MISCDEV(KMONITOR_MINOR);
> diff -Nru a/fs/exec.c b/fs/exec.c
> --- a/fs/exec.c Wed Jun 9 10:37:42 2004
> +++ b/fs/exec.c Wed Jun 9 10:37:42 2004
> @@ -46,6 +46,7 @@
> #include <linux/security.h>
> #include <linux/syscalls.h>
> #include <linux/rmap.h>
> +#include <linux/kmonitor.h>
>
> #include <asm/uaccess.h>
> #include <asm/pgalloc.h>
> @@ -1144,6 +1145,7 @@
> free_arg_pages(&bprm);
>
> /* execve success */
> + kmonitor_notify_event(current, KMONITOR_PROCESS_EXEC);
> security_bprm_free(&bprm);
> return retval;
> }
> diff -Nru a/include/linux/kmonitor.h b/include/linux/kmonitor.h
> --- /dev/null Wed Dec 31 16:00:00 1969
> +++ b/include/linux/kmonitor.h Wed Jun 9 10:37:42 2004
> @@ -0,0 +1,62 @@
> +/*
> + *
> + * linux/kmonitor.h
> + *
> + * Copyright (C) 2004 Intel Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public
> + * License v2.0 as published by the Free Software Foundation;
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public
> + * License along with this program; if not, write to the
> + * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
> + * Boston, MA 021110-1307, USA.
> + *
> + * Authors: Atul Sabharwal <atul.sabharwal at intel.com>
> + *
> + */
> +#ifndef _LINUX_KMONITOR_H_
> +#define _LINUX_KMONITOR_H_
> +
> +#include <asm/atomic.h>
> +
> +#define KMONITOR_THREAD_CREATE 0x01
> +#define KMONITOR_THREAD_ABORT 0x02
> +#define KMONITOR_THREAD_EXIT 0x04
> +#define KMONITOR_PROCESS_FORK 0x08
> +#define KMONITOR_PROCESS_ABORT 0x10
> +#define KMONITOR_PROCESS_EXEC 0x20
> +#define KMONITOR_PROCESS_EXIT 0x40
> +
> +struct kmonitor_cmd
> +{
> + pid_t pid;
> + int type;
> + int signal;
> +};
> +
> +#define KMONITOR_IOW_REGISTER _IOW(0xDE, 1, struct kmonitor_cmd)
> +#define KMONITOR_IOW_DEREGISTER _IOW(0xDE, 2, struct kmonitor_cmd)
> +
> +#ifdef __KERNEL__
> +#include <linux/sysctl.h>
> +
> +extern atomic_t kmonitor_active;
> +extern void __kmonitor_notify_event(struct task_struct *tsk, int type);
> +
> +static inline void kmonitor_notify_event( struct task_struct *tsk, int type)
> +{
> +#ifdef CONFIG_KMONITOR
> + if (atomic_read(&kmonitor_active))
> + __kmonitor_notify_event(tsk, type);
> +#endif /* CONFIG_KMONITOR */
> +}
> +#endif /* __KERNEL__ */
> +#endif /* _LINUX_KMONITOR_H_ */
> +
> diff -Nru a/include/linux/miscdevice.h b/include/linux/miscdevice.h
> --- a/include/linux/miscdevice.h Wed Jun 9 10:37:42 2004
> +++ b/include/linux/miscdevice.h Wed Jun 9 10:37:42 2004
> @@ -35,6 +35,7 @@
> #define SGI_USEMACLONE 151
>
> #define TUN_MINOR 200
> +#define KMONITOR_MINOR 221
>
> struct device;
>
> diff -Nru a/kernel/exit.c b/kernel/exit.c
> --- a/kernel/exit.c Wed Jun 9 10:37:42 2004
> +++ b/kernel/exit.c Wed Jun 9 10:37:42 2004
> @@ -22,6 +22,7 @@
> #include <linux/profile.h>
> #include <linux/mount.h>
> #include <linux/proc_fs.h>
> +#include <linux/kmonitor.h>
>
> #include <asm/uaccess.h>
> #include <asm/pgtable.h>
> @@ -748,6 +749,11 @@
> */
> _raw_write_unlock(&tasklist_lock);
> local_irq_enable();
> +
> + if (tsk->pid == tsk->tgid)
> + kmonitor_notify_event(tsk, KMONITOR_PROCESS_EXIT);
> + else
> + kmonitor_notify_event(tsk, KMONITOR_THREAD_EXIT);
>
> /* If the process is dead, release it - nobody will wait for it */
> if (state == TASK_DEAD)
> diff -Nru a/kernel/fork.c b/kernel/fork.c
> --- a/kernel/fork.c Wed Jun 9 10:37:42 2004
> +++ b/kernel/fork.c Wed Jun 9 10:37:42 2004
> @@ -41,6 +41,7 @@
> #include <asm/mmu_context.h>
> #include <asm/cacheflush.h>
> #include <asm/tlbflush.h>
> +#include <linux/kmonitor.h>
>
> /* The idle threads do not count..
> * Protected by write_lock_irq(&tasklist_lock)
> @@ -1165,6 +1166,7 @@
> */
> pid = IS_ERR(p) ? PTR_ERR(p) : p->pid;
>
> +
> if (!IS_ERR(p)) {
> struct completion vfork;
>
> @@ -1223,6 +1225,11 @@
> * COW overhead when the child exec()s afterwards.
> */
> set_need_resched();
> +
> + if (p->pid == p->tgid)
> + kmonitor_notify_event(p, KMONITOR_PROCESS_FORK);
> + else
> + kmonitor_notify_event(p, KMONITOR_THREAD_CREATE);
> }
> return pid;
> }
>
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