Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750739AbVJ1X03 (ORCPT ); Fri, 28 Oct 2005 19:26:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750750AbVJ1X03 (ORCPT ); Fri, 28 Oct 2005 19:26:29 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:42675 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1750739AbVJ1X02 (ORCPT ); Fri, 28 Oct 2005 19:26:28 -0400 Subject: Re: [PATCH] Process Events Connector From: Matt Helsley To: Andrew Morton Cc: LKML , Evgeniy Polyakov , Jean-Pierre Dion , Guillaume Thouvenin , Badari Pulavarty , Ram Pai , CKRM-Tech , Erich Focht , elsa-devel , Gerrit Huizenga , Adrian Bunk , "Chandra S. Seetharaman" , Jay Lan , Erik Jacobson , Jack Steiner In-Reply-To: <1130489713.10680.685.camel@stark> References: <1130489713.10680.685.camel@stark> Content-Type: text/plain Date: Fri, 28 Oct 2005 16:19:45 -0700 Message-Id: <1130541585.10680.846.camel@stark> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 22628 Lines: 721 On Fri, 2005-10-28 at 01:55 -0700, Matt Helsley wrote: > Andrew, > > This patch adds a connector that reports fork, exec, id change, > and exit events for all processes to userspace. It replaces the > fork_advisor patch that ELSA is currently using. Applications that may > find these events useful include accounting/auditing (e.g. ELSA), > system activity monitoring (e.g. top), security, and resource management > (e.g. CKRM). > > Please consider for -mm. Andrew, Although it's not a change I did look into the possibility that the event structure would be laid out differently between a 64-bit kernel and 32-bit userspace. The layouts appear to match. Here's what I did to confirm this: I looked at header files and pid_t is an int on all platforms. All of the ABI suppliments (linked from LSB pages) I've looked at list int as 4 bytes and aligned to 4-byte boundaries. I reviewed ABIs for: i386 / x86_64 / ia64 ppc / ppc64 Since all the types in the struct are 4 bytes in size (__u32 and pid_t members only) there should be no internal padding, no tail padding, and no difference in structure alignment. http://gcc.fyxm.net/summit/2003/Porting%20to%2064%20bit.pdf suggests that many other platforms whose ABI I did not look at are also LP64. If anything would present a problem it would be the pid_t's. So I looked for 32-bit syscall translations of sys_getpid in 2.6.14-rc4 and did not see any that suggested an alternate size (I did see some that appeared to be for running binaries of alternate OSes). This further suggests that the pid_t fields would not change in size and hence would not alter the layout. Cheers, -Matt Helsley > Changes since 10/25/2005: > Fixed header include-once convention > Removed sparse idioms > Removed typedefs > Switched ints to __u32 for userspace > Gave proc_event struct's union a name: event_data > Removed useless module-isms > Removed space between function names and open paren > Removed unnecessary use of cn_already_initialized > Added initializer for per-cpu proc_event_counts > Made per-cpu proc_event_counts static > Fixed switch body indentation > Switched from __initcall to module_init() > Removed __exit function > Added comment describing IDX and VAL > Placed linux includes before asm includes in fs/exec.c, > kernel/fork.c, and kernel/sys.c > Moved cn_proc_ack closer to usage > Fixed sequence number in proc_id_connector > > Changes since 9/29/2005: > Changed signatures to take only task struct in anticipation of > task_notif(y|iers). As a consequence: > Lots of new little functions -- one per id that can > change > No more "from" and "to" ids -- just "to" ruid and euid > - Will anyone need the former id? > Adjusted structure passed to userspace to remove "from" > id > Moved exit notification past the point where the > struct's exit_code gets assigned > Adjusted callers to only pass a task struct > Moved fork notification above wake_up_new_task() so it takes > place before adding the child to a runqueue and after > parent/child linking has taken place > Use new gfp_t type > Prevent building as a module (task_notify or similar > infrastructure would enable building this connector as a > module) > Simpler and fewer calls in sys_set[res][u|g]id > Added exit signal to exit event information > > Signed-off-by: Matt Helsley > > --- > > drivers/connector/Kconfig | 8 + > drivers/connector/Makefile | 1 > drivers/connector/cn_proc.c | 222 ++++++++++++++++++++++++++++++++++++ > fs/exec.c | 2 > include/linux/cn_proc.h | 127 ++++++++++++++++++++ > include/linux/connector.h | 6 > kernel/exit.c | 3 > kernel/fork.c | 2 > kernel/sys.c | 9 + > 9 files changed, 380 insertions(+) > > Index: linux-2.6.14/include/linux/cn_proc.h > =================================================================== > --- /dev/null > +++ linux-2.6.14/include/linux/cn_proc.h > @@ -0,0 +1,127 @@ > +/* > + * cn_proc.h - process events connector > + * > + * Copyright (C) Matt Helsley, IBM Corp. 2005 > + * Based on cn_fork.h by Nguyen Anh Quynh and Guillaume Thouvenin > + * Original copyright notice follows: > + * Copyright (C) 2005 Nguyen Anh Quynh > + * Copyright (C) 2005 Guillaume Thouvenin > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * 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 02111-1307 USA > + */ > + > +#ifndef CN_PROC_H > +#define CN_PROC_H > + > +#include > +#include > + > +/* > + * Userspace sends this enum to register with the kernel that it is listening > + * for events on the connector. > + */ > +enum proc_cn_mcast_op { > + PROC_CN_MCAST_LISTEN = 1, > + PROC_CN_MCAST_IGNORE = 2 > +}; > + > +/* > + * From the user's point of view, the process > + * ID is the thread group ID and thread ID is the internal > + * kernel "pid". So, fields are assigned as follow: > + * > + * In user space - In kernel space > + * > + * parent process ID = parent->tgid > + * parent thread ID = parent->pid > + * child process ID = child->tgid > + * child thread ID = child->pid > + */ > + > +struct proc_event { > + enum what { > + /* Use successive bits so the enums can be used to record > + * sets of events as well > + */ > + PROC_EVENT_NONE = 0x00000000, > + PROC_EVENT_FORK = 0x00000001, > + PROC_EVENT_EXEC = 0x00000002, > + PROC_EVENT_UID = 0x00000004, > + PROC_EVENT_GID = 0x00000040, > + /* "next" should be 0x00000400 */ > + /* "last" is the last process event: exit */ > + PROC_EVENT_EXIT = 0x80000000 > + } what; > + __u32 cpu; > + union { /* must be last field of proc_event struct */ > + struct { > + __u32 err; > + } ack; > + > + struct fork_proc_event { > + pid_t parent_pid; > + pid_t parent_tgid; > + pid_t child_pid; > + pid_t child_tgid; > + } fork; > + > + struct exec_proc_event { > + pid_t process_pid; > + pid_t process_tgid; > + } exec; > + > + struct id_proc_event { > + pid_t process_pid; > + pid_t process_tgid; > + union { > + uid_t ruid; /* current->uid */ > + gid_t rgid; /* current->gid */ > + }; > + union { > + uid_t euid; > + gid_t egid; > + }; > + } id; > + > + struct exit_proc_event { > + pid_t process_pid; > + pid_t process_tgid; > + __u32 exit_code, exit_signal; > + } exit; > + } event_data; > +}; > + > +#ifdef __KERNEL__ > +#ifdef CONFIG_PROC_EVENTS > +void proc_fork_connector(struct task_struct *task); > +void proc_exec_connector(struct task_struct *task); > +void proc_id_connector(struct task_struct *task, int which_id); > +void proc_exit_connector(struct task_struct *task); > +#else > +static inline void proc_fork_connector(struct task_struct *task) > +{} > + > +static inline void proc_exec_connector(struct task_struct *task) > +{} > + > +static inline void proc_id_connector(struct task_struct *task, > + int which_id) > +{} > + > +static inline void proc_exit_connector(struct task_struct *task) > +{} > +#endif /* CONFIG_PROC_EVENTS */ > +#endif /* __KERNEL__ */ > +#endif /* CN_PROC_H */ > Index: linux-2.6.14/drivers/connector/cn_proc.c > =================================================================== > --- /dev/null > +++ linux-2.6.14/drivers/connector/cn_proc.c > @@ -0,0 +1,222 @@ > +/* > + * cn_proc.c - process events connector > + * > + * Copyright (C) Matt Helsley, IBM Corp. 2005 > + * Based on cn_fork.c by Guillaume Thouvenin > + * Original copyright notice follows: > + * Copyright (C) 2005 BULL SA. > + * > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * 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 02111-1307 USA > + */ > + > +#include > +#include > +#include > +#include > + > +#include > + > +#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event)) > + > +static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); > +static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; > + > +/* proc_counts is used as the sequence number of the netlink message */ > +static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; > + > +static inline void get_seq(__u32 *ts, int *cpu) > +{ > + *ts = get_cpu_var(proc_event_counts)++; > + *cpu = smp_processor_id(); > + put_cpu_var(proc_counts); > +} > + > +void proc_fork_connector(struct task_struct *task) > +{ > + struct cn_msg *msg; > + struct proc_event *ev; > + __u8 buffer[CN_PROC_MSG_SIZE]; > + > + if (atomic_read(&proc_event_num_listeners) < 1) > + return; > + > + msg = (struct cn_msg*)buffer; > + ev = (struct proc_event*)msg->data; > + get_seq(&msg->seq, &ev->cpu); > + ev->what = PROC_EVENT_FORK; > + ev->event_data.fork.parent_pid = task->real_parent->pid; > + ev->event_data.fork.parent_tgid = task->real_parent->tgid; > + ev->event_data.fork.child_pid = task->pid; > + ev->event_data.fork.child_tgid = task->tgid; > + > + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); > + msg->ack = 0; /* not used */ > + msg->len = sizeof(*ev); > + /* If cn_netlink_send() failed, the data is not sent */ > + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); > +} > + > +void proc_exec_connector(struct task_struct *task) > +{ > + struct cn_msg *msg; > + struct proc_event *ev; > + __u8 buffer[CN_PROC_MSG_SIZE]; > + > + if (atomic_read(&proc_event_num_listeners) < 1) > + return; > + > + msg = (struct cn_msg*)buffer; > + ev = (struct proc_event*)msg->data; > + get_seq(&msg->seq, &ev->cpu); > + ev->what = PROC_EVENT_EXEC; > + ev->event_data.exec.process_pid = task->pid; > + ev->event_data.exec.process_tgid = task->tgid; > + > + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); > + msg->ack = 0; /* not used */ > + msg->len = sizeof(*ev); > + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); > +} > + > +void proc_id_connector(struct task_struct *task, int which_id) > +{ > + struct cn_msg *msg; > + struct proc_event *ev; > + __u8 buffer[CN_PROC_MSG_SIZE]; > + > + if (atomic_read(&proc_event_num_listeners) < 1) > + return; > + > + msg = (struct cn_msg*)buffer; > + ev = (struct proc_event*)msg->data; > + ev->what = which_id; > + ev->event_data.id.process_pid = task->pid; > + ev->event_data.id.process_tgid = task->tgid; > + if (which_id == PROC_EVENT_UID) { > + ev->event_data.id.ruid = task->uid; > + ev->event_data.id.euid = task->euid; > + } else if (which_id == PROC_EVENT_GID) { > + ev->event_data.id.rgid = task->gid; > + ev->event_data.id.egid = task->egid; > + } else > + return; > + get_seq(&msg->seq, &ev->cpu); > + > + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); > + msg->ack = 0; /* not used */ > + msg->len = sizeof(*ev); > + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); > +} > + > +void proc_exit_connector(struct task_struct *task) > +{ > + struct cn_msg *msg; > + struct proc_event *ev; > + __u8 buffer[CN_PROC_MSG_SIZE]; > + > + if (atomic_read(&proc_event_num_listeners) < 1) > + return; > + > + msg = (struct cn_msg*)buffer; > + ev = (struct proc_event*)msg->data; > + get_seq(&msg->seq, &ev->cpu); > + ev->what = PROC_EVENT_EXIT; > + ev->event_data.exit.process_pid = task->pid; > + ev->event_data.exit.process_tgid = task->tgid; > + ev->event_data.exit.exit_code = task->exit_code; > + ev->event_data.exit.exit_signal = task->exit_signal; > + > + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); > + msg->ack = 0; /* not used */ > + msg->len = sizeof(*ev); > + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); > +} > + > +/* > + * Send an acknowledgement message to userspace > + * > + * Use 0 for success, EFOO otherwise. > + * Note: this is the negative of conventional kernel error > + * values because it's not being returned via syscall return > + * mechanisms. > + */ > +static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) > +{ > + struct cn_msg *msg; > + struct proc_event *ev; > + __u8 buffer[CN_PROC_MSG_SIZE]; > + > + if (atomic_read(&proc_event_num_listeners) < 1) > + return; > + > + msg = (struct cn_msg*)buffer; > + ev = (struct proc_event*)msg->data; > + msg->seq = rcvd_seq; > + ev->cpu = -1; > + ev->what = PROC_EVENT_NONE; > + ev->event_data.ack.err = err; > + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); > + msg->ack = rcvd_ack + 1; > + msg->len = sizeof(*ev); > + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); > +} > + > +/** > + * cn_proc_mcast_ctl > + * @data: message sent from userspace via the connector > + */ > +static void cn_proc_mcast_ctl(void *data) > +{ > + struct cn_msg *msg = data; > + enum proc_cn_mcast_op *mc_op = NULL; > + int err = 0; > + > + if (msg->len != sizeof(*mc_op)) > + return; > + > + mc_op = (enum proc_cn_mcast_op*)msg->data; > + switch (*mc_op) { > + case PROC_CN_MCAST_LISTEN: > + atomic_inc(&proc_event_num_listeners); > + break; > + case PROC_CN_MCAST_IGNORE: > + atomic_dec(&proc_event_num_listeners); > + break; > + default: > + err = EINVAL; > + break; > + } > + cn_proc_ack(err, msg->seq, msg->ack); > +} > + > +/* > + * cn_proc_init - initialization entry point > + * > + * Adds the connector callback to the connector driver. > + */ > +static int __init cn_proc_init(void) > +{ > + int err; > + > + if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc", > + &cn_proc_mcast_ctl))) { > + printk(KERN_WARNING "cn_proc failed to register\n"); > + return err; > + } > + return 0; > +} > + > +module_init(cn_proc_init); > Index: linux-2.6.14/include/linux/connector.h > =================================================================== > --- linux-2.6.14.orig/include/linux/connector.h > +++ linux-2.6.14/include/linux/connector.h > @@ -25,10 +25,16 @@ > #include > > #define CN_IDX_CONNECTOR 0xffffffff > #define CN_VAL_CONNECTOR 0xffffffff > > +/* > + * Process Events connector unique ids -- used for message routing > + */ > +#define CN_IDX_PROC 0x1 > +#define CN_VAL_PROC 0x1 > + > #define CN_NETLINK_USERS 1 > > /* > * Maximum connector's message size. > */ > Index: linux-2.6.14/drivers/connector/Kconfig > =================================================================== > --- linux-2.6.14.orig/drivers/connector/Kconfig > +++ linux-2.6.14/drivers/connector/Kconfig > @@ -8,6 +8,14 @@ config CONNECTOR > of the netlink socket protocol. > > Connector support can also be built as a module. If so, the module > will be called cn.ko. > > +config PROC_EVENTS > + boolean "Report process events to userspace" > + depends on CONNECTOR=y > + default y > + ---help--- > + Provide a connector that reports process events to userspace. Send > + events such as fork, exec, id change (uid, gid, suid, etc), and exit. > + > endmenu > Index: linux-2.6.14/drivers/connector/Makefile > =================================================================== > --- linux-2.6.14.orig/drivers/connector/Makefile > +++ linux-2.6.14/drivers/connector/Makefile > @@ -1,3 +1,4 @@ > obj-$(CONFIG_CONNECTOR) += cn.o > +obj-$(CONFIG_PROC_EVENTS) += cn_proc.o > > cn-y += cn_queue.o connector.o > Index: linux-2.6.14/fs/exec.c > =================================================================== > --- linux-2.6.14.orig/fs/exec.c > +++ linux-2.6.14/fs/exec.c > @@ -46,10 +46,11 @@ > #include > #include > #include > #include > #include > +#include > > #include > #include > > #ifdef CONFIG_KMOD > @@ -1098,10 +1099,11 @@ int search_binary_handler(struct linux_b > allow_write_access(bprm->file); > if (bprm->file) > fput(bprm->file); > bprm->file = NULL; > current->did_exec = 1; > + proc_exec_connector(current); > return retval; > } > read_lock(&binfmt_lock); > put_binfmt(fmt); > if (retval != -ENOEXEC || bprm->mm == NULL) > Index: linux-2.6.14/kernel/exit.c > =================================================================== > --- linux-2.6.14.orig/kernel/exit.c > +++ linux-2.6.14/kernel/exit.c > @@ -32,10 +32,12 @@ > #include > #include > #include > #include > > +#include > + > extern void sem_exit (void); > extern struct task_struct *child_reaper; > > int getrusage(struct task_struct *, int, struct rusage __user *); > > @@ -862,10 +864,11 @@ fastcall NORET_TYPE void do_exit(long co > module_put(tsk->thread_info->exec_domain->module); > if (tsk->binfmt) > module_put(tsk->binfmt->module); > > tsk->exit_code = code; > + proc_exit_connector(tsk); > exit_notify(tsk); > #ifdef CONFIG_NUMA > mpol_free(tsk->mempolicy); > tsk->mempolicy = NULL; > #endif > Index: linux-2.6.14/kernel/fork.c > =================================================================== > --- linux-2.6.14.orig/kernel/fork.c > +++ linux-2.6.14/kernel/fork.c > @@ -40,10 +40,11 @@ > #include > #include > #include > #include > #include > +#include > > #include > #include > #include > #include > @@ -1144,10 +1145,11 @@ static task_t *copy_process(unsigned lon > attach_pid(p, PIDTYPE_SID, p->signal->session); > if (p->pid) > __get_cpu_var(process_counts)++; > } > > + proc_fork_connector(p); > if (!current->signal->tty && p->signal->tty) > p->signal->tty = NULL; > > nr_threads++; > total_forks++; > Index: linux-2.6.14/kernel/sys.c > =================================================================== > --- linux-2.6.14.orig/kernel/sys.c > +++ linux-2.6.14/kernel/sys.c > @@ -26,10 +26,11 @@ > #include > #include > #include > #include > #include > +#include > > #include > #include > > #include > @@ -621,10 +622,11 @@ asmlinkage long sys_setregid(gid_t rgid, > current->sgid = new_egid; > current->fsgid = new_egid; > current->egid = new_egid; > current->gid = new_rgid; > key_fsgid_changed(current); > + proc_id_connector(current, PROC_EVENT_GID); > return 0; > } > > /* > * setgid() is implemented like SysV w/ SAVED_IDS > @@ -660,10 +662,11 @@ asmlinkage long sys_setgid(gid_t gid) > } > else > return -EPERM; > > key_fsgid_changed(current); > + proc_id_connector(current, PROC_EVENT_GID); > return 0; > } > > static int set_user(uid_t new_ruid, int dumpclear) > { > @@ -749,10 +752,11 @@ asmlinkage long sys_setreuid(uid_t ruid, > (euid != (uid_t) -1 && euid != old_ruid)) > current->suid = current->euid; > current->fsuid = current->euid; > > key_fsuid_changed(current); > + proc_id_connector(current, PROC_EVENT_UID); > > return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); > } > > > @@ -796,10 +800,11 @@ asmlinkage long sys_setuid(uid_t uid) > } > current->fsuid = current->euid = uid; > current->suid = new_suid; > > key_fsuid_changed(current); > + proc_id_connector(current, PROC_EVENT_UID); > > return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); > } > > > @@ -844,10 +849,11 @@ asmlinkage long sys_setresuid(uid_t ruid > current->fsuid = current->euid; > if (suid != (uid_t) -1) > current->suid = suid; > > key_fsuid_changed(current); > + proc_id_connector(current, PROC_EVENT_UID); > > return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); > } > > asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) > @@ -896,10 +902,11 @@ asmlinkage long sys_setresgid(gid_t rgid > current->gid = rgid; > if (sgid != (gid_t) -1) > current->sgid = sgid; > > key_fsgid_changed(current); > + proc_id_connector(current, PROC_EVENT_GID); > return 0; > } > > asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) > { > @@ -938,10 +945,11 @@ asmlinkage long sys_setfsuid(uid_t uid) > } > current->fsuid = uid; > } > > key_fsuid_changed(current); > + proc_id_connector(current, PROC_EVENT_UID); > > security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); > > return old_fsuid; > } > @@ -966,10 +974,11 @@ asmlinkage long sys_setfsgid(gid_t gid) > current->mm->dumpable = suid_dumpable; > smp_wmb(); > } > current->fsgid = gid; > key_fsgid_changed(current); > + proc_id_connector(current, PROC_EVENT_GID); > } > return old_fsgid; > } > > asmlinkage long sys_times(struct tms __user * tbuf) > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/