Re: [PATCH] connector: Some fixes for ia64 unaligned access errors

[Erik Jacobson]

Hi Andrew.

There was some discussion on this patch but I believe we've agreed
on the first version I sent.  This was ACKed by Matt Helsley.

Would you consider taking this in to -mm?

I've included my original patch email at the bottom.

On Mon, Dec 11, 2006 at 03:52:46PM -0800, Matt Helsley wrote:
(snipped up)
> On Thu, 2006-12-07 at 17:22 -0600, Erik Jacobson wrote:
> > Signed-off-by: Erik Jacobson <erikj@xxxxxxx>
> Acked-by: Matt Helsley <matthltc@xxxxxxxxxx>
> > ---
> >  cn_proc.c |   94 +++++++++++++++++++++++++++++++-------------------------------

Original patch email:

Date: Thu, 7 Dec 2006 17:22:13 -0600
From: Erik Jacobson <erikj@xxxxxxx>
To: linux-kernel@xxxxxxxxxxxxxxx
Cc: guillaume.thouvenin@xxxxxxxx, matthltc@xxxxxxxxxx
Subject: [PATCH] connector: Some fixes for ia64 unaligned access errors

On ia64, the various functions that make up cn_proc.c cause kernel
unaligned access errors.

If you are using these, for example, to get notification about
all tasks forking and exiting, you get multiple unaligned access errors
per process.

Here, we just adjust how the variables are declared and use memcopy to
avoid the error messages.

Signed-off-by: Erik Jacobson <erikj@xxxxxxx>
---

 cn_proc.c |   94 +++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 47 insertions(+), 47 deletions(-)
--- linux.orig/drivers/connector/cn_proc.c	2006-11-29 15:57:37.000000000 -0600
+++ linux/drivers/connector/cn_proc.c	2006-12-07 16:50:03.195035791 -0600
@@ -49,7 +49,7 @@
 void proc_fork_connector(struct task_struct *task)
 {
 	struct cn_msg *msg;
-	struct proc_event *ev;
+	struct proc_event ev;
 	__u8 buffer[CN_PROC_MSG_SIZE];
 	struct timespec ts;
 
@@ -57,19 +57,19 @@
 		return;
 
 	msg = (struct cn_msg*)buffer;
-	ev = (struct proc_event*)msg->data;
-	get_seq(&msg->seq, &ev->cpu);
+	get_seq(&msg->seq, &ev.cpu);
 	ktime_get_ts(&ts); /* get high res monotonic timestamp */
-	ev->timestamp_ns = timespec_to_ns(&ts);
-	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;
+	ev.timestamp_ns = timespec_to_ns(&ts);
+	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);
+	msg->len = sizeof(ev);
+	memcpy(msg->data, &ev, sizeof(ev));
 	/*  If cn_netlink_send() failed, the data is not sent */
 	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 }
@@ -77,7 +77,7 @@
 void proc_exec_connector(struct task_struct *task)
 {
 	struct cn_msg *msg;
-	struct proc_event *ev;
+	struct proc_event ev;
 	struct timespec ts;
 	__u8 buffer[CN_PROC_MSG_SIZE];
 
@@ -85,24 +85,24 @@
 		return;
 
 	msg = (struct cn_msg*)buffer;
-	ev = (struct proc_event*)msg->data;
-	get_seq(&msg->seq, &ev->cpu);
+	get_seq(&msg->seq, &ev.cpu);
 	ktime_get_ts(&ts); /* get high res monotonic timestamp */
-	ev->timestamp_ns = timespec_to_ns(&ts);
-	ev->what = PROC_EVENT_EXEC;
-	ev->event_data.exec.process_pid = task->pid;
-	ev->event_data.exec.process_tgid = task->tgid;
+	ev.timestamp_ns = timespec_to_ns(&ts);
+	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);
+	msg->len = sizeof(ev);
+	memcpy(msg->data, &ev, 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;
+	struct proc_event ev;
 	__u8 buffer[CN_PROC_MSG_SIZE];
 	struct timespec ts;
 
@@ -110,32 +110,32 @@
 		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;
+	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.r.ruid = task->uid;
-	 	ev->event_data.id.e.euid = task->euid;
+	 	ev.event_data.id.r.ruid = task->uid;
+	 	ev.event_data.id.e.euid = task->euid;
 	} else if (which_id == PROC_EVENT_GID) {
-	   	ev->event_data.id.r.rgid = task->gid;
-	   	ev->event_data.id.e.egid = task->egid;
+	   	ev.event_data.id.r.rgid = task->gid;
+	   	ev.event_data.id.e.egid = task->egid;
 	} else
 	     	return;
-	get_seq(&msg->seq, &ev->cpu);
+	get_seq(&msg->seq, &ev.cpu);
 	ktime_get_ts(&ts); /* get high res monotonic timestamp */
-	ev->timestamp_ns = timespec_to_ns(&ts);
+	ev.timestamp_ns = timespec_to_ns(&ts);
 
 	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 	msg->ack = 0; /* not used */
-	msg->len = sizeof(*ev);
+	msg->len = sizeof(ev);
+	memcpy(msg->data, &ev, 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;
+	struct proc_event ev;
 	__u8 buffer[CN_PROC_MSG_SIZE];
 	struct timespec ts;
 
@@ -143,19 +143,19 @@
 		return;
 
 	msg = (struct cn_msg*)buffer;
-	ev = (struct proc_event*)msg->data;
-	get_seq(&msg->seq, &ev->cpu);
+	get_seq(&msg->seq, &ev.cpu);
 	ktime_get_ts(&ts); /* get high res monotonic timestamp */
-	ev->timestamp_ns = timespec_to_ns(&ts);
-	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;
+	ev.timestamp_ns = timespec_to_ns(&ts);
+	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);
+	msg->len = sizeof(ev);
+	memcpy(msg->data, &ev, sizeof(ev));
 	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 }
 
@@ -170,7 +170,7 @@
 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
 {
 	struct cn_msg *msg;
-	struct proc_event *ev;
+	struct proc_event ev;
 	__u8 buffer[CN_PROC_MSG_SIZE];
 	struct timespec ts;
 
@@ -178,16 +178,16 @@
 		return;
 
 	msg = (struct cn_msg*)buffer;
-	ev = (struct proc_event*)msg->data;
 	msg->seq = rcvd_seq;
 	ktime_get_ts(&ts); /* get high res monotonic timestamp */
-	ev->timestamp_ns = timespec_to_ns(&ts);
-	ev->cpu = -1;
-	ev->what = PROC_EVENT_NONE;
-	ev->event_data.ack.err = err;
+	ev.timestamp_ns = timespec_to_ns(&ts);
+	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);
+	msg->len = sizeof(ev);
+	memcpy(msg->data, &ev, sizeof(ev));
 	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 }


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