Process Events Connector

drivers/connector/cn_proc.c line 51

Quoted 5 lines · Matt Helsley

drivers/connector/cn_proc.c new file +5 -0

+void proc_fork_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	__u8 buffer[CN_PROC_MSG_SIZE];

do you really want to do this stack based?

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.

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 <[email protected]>

---

 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
===================================================================

include/linux/cn_proc.h new file +127 -0

@@ -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 <[email protected]>
+ * Copyright (C) 2005 Guillaume Thouvenin <[email protected]>
+ *
+ * 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 <linux/types.h>
+#include <linux/connector.h>
+
+/*
+ * 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
===================================================================

drivers/connector/cn_proc.c new file +222 -0

@@ -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 <[email protected]>
+ * 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 <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+
+#include <linux/cn_proc.h>
+
+#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
===================================================================

include/linux/connector.h +6 -0

@@ -25,10 +25,16 @@
 #include <asm/types.h>
 
 #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
===================================================================

drivers/connector/Kconfig +8 -0

@@ -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
===================================================================

drivers/connector/Makefile +1 -0

@@ -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
===================================================================

fs/exec.c +2 -0

@@ -46,10 +46,11 @@
 #include <linux/mount.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/rmap.h>
 #include <linux/acct.h>
+#include <linux/cn_proc.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
 
 #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
===================================================================

kernel/exit.c +3 -0

@@ -32,10 +32,12 @@
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
+#include <linux/cn_proc.h>
+
 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
===================================================================

kernel/fork.c +2 -0

@@ -40,10 +40,11 @@
 #include <linux/mount.h>
 #include <linux/audit.h>
 #include <linux/profile.h>
 #include <linux/rmap.h>
 #include <linux/acct.h>
+#include <linux/cn_proc.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>

@@ -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
===================================================================

kernel/sys.c +9 -1

@@ -26,10 +26,11 @@
 #include <linux/security.h>
 #include <linux/dcookies.h>
 #include <linux/suspend.h>
 #include <linux/tty.h>
 #include <linux/signal.h>
+#include <linux/cn_proc.h>
 
 #include <linux/compat.h>
 #include <linux/syscalls.h>
 
 #include <asm/uaccess.h>

@@ -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 [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

OK, I wasn't as thorough as I had hoped re: 64-bit kernel/32-bit userspace. The uid_t and gid_t types appear to present a problem to the following:

User <-> Kernel
i386 <-> x86_64/IA64
sparc <-> sparc64
s390 <-> s390x

:(

I'll look at this some more and see if I need to resubmit. Until then
I'll hold off on my request for inclusion in -mm.

Cheers,
-Matt Helsley

Quoted 9 lines · Matt Helsley

OK, I wasn't as thorough as I had hoped re: 64-bit kernel/32-bit userspace. The uid_t and gid_t types appear to present a problem to the following:

User <-> Kernel
i386 <-> x86_64/IA64
sparc <-> sparc64
s390 <-> s390x

Quoted 7 lines

:(

I'll look at this some more and see if I need to resubmit. Until then
I'll hold off on my request for inclusion in -mm.

Cheers,
-Matt Helsley

Userspace can include sys/types.h -- in which case uid_t and gid_t
match -- or linux/types.h -- in which case they are not guaranteed to match. To further complicate things translation is not possible because the connector broadcasts the events to multiple 'listener's. A mix of 32 and 64-bit userspace programs could be listening; guaranteeing incompatibility if the structure layouts do not match.

This patch addresses the problem by fixing the size to the largest size
found in the kernel (and likely the largest size needed). This preserves the total size of the event structure while ensuring that the event structure layouts match.

Are there better alternative solutions?

Signed-off-by Matt Helsley <[email protected]>

---

Index: linux-2.6.14/include/linux/cn_proc.h
===================================================================

include/linux/cn_proc.h +4 -4

@@ -84,16 +84,16 @@ struct proc_event {
 
 		struct id_proc_event {
 			pid_t process_pid;
 			pid_t process_tgid;
 			union {
-				uid_t ruid; /* current->uid */
-				gid_t rgid; /* current->gid */
+				__u32 ruid; /* task uid */
+				__u32 rgid; /* task gid */
 			};
 			union {
-				uid_t euid;
-				gid_t egid;
+				__u32 euid;
+				__u32 egid;
 			};
 		} id;
 
 		struct exit_proc_event {
 			pid_t process_pid;