[RFC] Some useless cleanup

[RFC] Some useless cleanup

[Paul P Komkoff Jr]

Look at this very funny cleanup changeset for 2.4
avaliable at linux-stingr.bkbits.net/comm

For those who don't have bk I including it here below.

Please give your comments. Maybe it is completely useless and anything
should stay as before, or maybe it is somewhat useful and this abstraction
will decrease possibility of bugs such as akpm worked around in 8139too

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.417   -> 1.422  
#	drivers/net/8139too.c	1.26    -> 1.27   
#	drivers/scsi/scsi_error.c	1.7     -> 1.8    
#	fs/jffs2/background.c	1.3     -> 1.4    
#	    fs/nfsd/nfssvc.c	1.8     -> 1.9    
#	         fs/buffer.c	1.62    -> 1.64   
#	   net/khttpd/main.c	1.3     -> 1.4    
#	drivers/mtd/devices/blkmtd.c	1.3     -> 1.4    
#	fs/reiserfs/journal.c	1.21    -> 1.22   
#	include/linux/sched.h	1.29    -> 1.31   
#	         mm/vmscan.c	1.59    -> 1.60   
#	    fs/jbd/journal.c	1.4     -> 1.5    
#	    kernel/softirq.c	1.8     -> 1.9    
#	drivers/usb/storage/usb.c	1.9     -> 1.10   
#	     drivers/md/md.c	1.30    -> 1.31   
#	drivers/mtd/mtdblock.c	1.8     -> 1.9    
#	           fs/exec.c	1.20    -> 1.22   
#	 fs/lockd/clntlock.c	1.3     -> 1.4    
#	    kernel/context.c	1.4     -> 1.5    
#	   drivers/acpi/os.c	1.8     -> 1.9    
#	   drivers/usb/hub.c	1.15    -> 1.16   
#	  net/sunrpc/sched.c	1.8     -> 1.9    
#	    fs/jffs/intrep.c	1.7     -> 1.8    
#	      fs/lockd/svc.c	1.6     -> 1.7    
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/05/06	stingray@proxy.sgu.ru	1.418
# task_t->comm cleanup: pilot
# --------------------------------------------
# 02/05/07	stingray@proxy.sgu.ru	1.419
# cut down the tails
# --------------------------------------------
# 02/05/07	stingray@boxster.stingr.net	1.420
# task_t->comm cleanup part 1: replace sprintfs in fs/*
# --------------------------------------------
# 02/05/07	stingray@boxster.stingr.net	1.421
# task_t->comm cleanup: less redundant dependencies
# --------------------------------------------
# 02/05/08	stingray@boxster.stingr.net	1.422
# task_t->comm cleanup part 2: drivers, net, and mm
# --------------------------------------------
#
diff -Nru a/drivers/acpi/os.c b/drivers/acpi/os.c
--- a/drivers/acpi/os.c	Thu May  9 14:18:32 2002
+++ b/drivers/acpi/os.c	Thu May  9 14:18:32 2002
@@ -568,7 +568,7 @@
 	PROC_NAME("acpi_os_queue_exec");
 
 	daemonize();
-	strcpy(current->comm, "kacpidpc");
+	set_current_title("kacpidpc");
     
 	if (!dpc || !dpc->function)
 		return AE_BAD_PARAMETER;
diff -Nru a/drivers/md/md.c b/drivers/md/md.c
--- a/drivers/md/md.c	Thu May  9 14:18:32 2002
+++ b/drivers/md/md.c	Thu May  9 14:18:32 2002
@@ -2920,7 +2920,7 @@
 
 	daemonize();
 
-	sprintf(current->comm, thread->name);
+	set_current_title(thread->name);
 	md_init_signals();
 	md_flush_signals();
 	thread->tsk = current;
diff -Nru a/drivers/mtd/devices/blkmtd.c b/drivers/mtd/devices/blkmtd.c
--- a/drivers/mtd/devices/blkmtd.c	Thu May  9 14:18:32 2002
+++ b/drivers/mtd/devices/blkmtd.c	Thu May  9 14:18:32 2002
@@ -307,7 +307,7 @@
   DECLARE_WAITQUEUE(wait, tsk);
   DEBUG(1, "blkmtd: writetask: starting (pid = %d)\n", tsk->pid);
   daemonize();
-  strcpy(tsk->comm, "blkmtdd");
+  set_task_title(tsk, "blkmtdd");
   tsk->tty = NULL;
   spin_lock_irq(&tsk->sigmask_lock);
   sigfillset(&tsk->blocked);
diff -Nru a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
--- a/drivers/mtd/mtdblock.c	Thu May  9 14:18:32 2002
+++ b/drivers/mtd/mtdblock.c	Thu May  9 14:18:32 2002
@@ -487,7 +487,7 @@
 	tsk->pgrp = 1;
 	/* we might get involved when memory gets low, so use PF_MEMALLOC */
 	tsk->flags |= PF_MEMALLOC;
-	strcpy(tsk->comm, "mtdblockd");
+	set_task_title(tsk, "mtdblockd");
 	tsk->tty = NULL;
 	spin_lock_irq(&tsk->sigmask_lock);
 	sigfillset(&tsk->blocked);
diff -Nru a/drivers/net/8139too.c b/drivers/net/8139too.c
--- a/drivers/net/8139too.c	Thu May  9 14:18:32 2002
+++ b/drivers/net/8139too.c	Thu May  9 14:18:32 2002
@@ -1563,8 +1563,7 @@
 	recalc_sigpending(current);
 	spin_unlock_irq(&current->sigmask_lock);
 
-	strncpy (current->comm, dev->name, sizeof(current->comm) - 1);
-	current->comm[sizeof(current->comm) - 1] = '\0';
+	set_current_title(dev->name);
 
 	while (1) {
 		timeout = next_tick;
diff -Nru a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
--- a/drivers/scsi/scsi_error.c	Thu May  9 14:18:32 2002
+++ b/drivers/scsi/scsi_error.c	Thu May  9 14:18:32 2002
@@ -1873,7 +1873,7 @@
 	 * Set the name of this process.
 	 */
 
-	sprintf(current->comm, "scsi_eh_%d", host->host_no);
+	set_current_title("scsi_eh_%d", host->host_no);
 
 	host->eh_wait = &sem;
 	host->ehandler = current;
diff -Nru a/drivers/usb/hub.c b/drivers/usb/hub.c
--- a/drivers/usb/hub.c	Thu May  9 14:18:32 2002
+++ b/drivers/usb/hub.c	Thu May  9 14:18:32 2002
@@ -907,7 +907,7 @@
 	reparent_to_init();
 
 	/* Setup a nice name */
-	strcpy(current->comm, "khubd");
+	set_current_title("khubd");
 
 	/* Send me a signal to get me die (for debugging) */
 	do {
diff -Nru a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
--- a/drivers/usb/storage/usb.c	Thu May  9 14:18:32 2002
+++ b/drivers/usb/storage/usb.c	Thu May  9 14:18:32 2002
@@ -328,7 +328,7 @@
 	spin_unlock_irq(&current->sigmask_lock);
 
 	/* set our name for identification purposes */
-	sprintf(current->comm, "usb-storage-%d", us->host_number);
+	set_current_title("usb-storage-%d", us->host_number);
 
 	unlock_kernel();
 
diff -Nru a/fs/buffer.c b/fs/buffer.c
--- a/fs/buffer.c	Thu May  9 14:18:32 2002
+++ b/fs/buffer.c	Thu May  9 14:18:32 2002
@@ -2978,7 +2978,7 @@
 
 	tsk->session = 1;
 	tsk->pgrp = 1;
-	strcpy(tsk->comm, "bdflush");
+	set_task_title(tsk, "bdflush");
 
 	/* avoid getting signals */
 	spin_lock_irq(&tsk->sigmask_lock);
@@ -3028,7 +3028,7 @@
 
 	tsk->session = 1;
 	tsk->pgrp = 1;
-	strcpy(tsk->comm, "kupdated");
+	set_task_title(tsk, "kupdated");
 
 	/* sigstop and sigcont will stop and wakeup kupdate */
 	spin_lock_irq(&tsk->sigmask_lock);
diff -Nru a/fs/exec.c b/fs/exec.c
--- a/fs/exec.c	Thu May  9 14:18:32 2002
+++ b/fs/exec.c	Thu May  9 14:18:32 2002
@@ -35,6 +35,7 @@
 #include <linux/highmem.h>
 #include <linux/spinlock.h>
 #include <linux/personality.h>
+#include <linux/compiler.h>
 #define __NO_VERSION__
 #include <linux/module.h>
 
@@ -554,15 +555,13 @@
 
 	if (current->euid == current->uid && current->egid == current->gid)
 		current->mm->dumpable = 1;
-	name = bprm->filename;
-	for (i=0; (ch = *(name++)) != '\0';) {
-		if (ch == '/')
-			i = 0;
-		else
-			if (i < 15)
-				current->comm[i++] = ch;
-	}
-	current->comm[i] = '\0';
+
+	if (likely(name = strrchr(bprm->filename, '/')))
+		name++;
+	else
+		name = bprm->filename;
+
+	set_current_title(name);
 
 	flush_thread();
 
diff -Nru a/fs/jbd/journal.c b/fs/jbd/journal.c
--- a/fs/jbd/journal.c	Thu May  9 14:18:32 2002
+++ b/fs/jbd/journal.c	Thu May  9 14:18:32 2002
@@ -210,7 +210,7 @@
 	recalc_sigpending(current);
 	spin_unlock_irq(&current->sigmask_lock);
 
-	sprintf(current->comm, "kjournald");
+	set_current_title("kjournald");
 
 	/* Set up an interval timer which can be used to trigger a
            commit wakeup after the commit interval expires */
diff -Nru a/fs/jffs/intrep.c b/fs/jffs/intrep.c
--- a/fs/jffs/intrep.c	Thu May  9 14:18:32 2002
+++ b/fs/jffs/intrep.c	Thu May  9 14:18:32 2002
@@ -3354,7 +3354,7 @@
 	siginitsetinv (&current->blocked, sigmask(SIGHUP) | sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT));
 	recalc_sigpending(current);
 	spin_unlock_irq(&current->sigmask_lock);
-	strcpy(current->comm, "jffs_gcd");
+	set_current_title("jffs_gcd");
 
 	D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): Starting infinite loop.\n"));
 
diff -Nru a/fs/jffs2/background.c b/fs/jffs2/background.c
--- a/fs/jffs2/background.c	Thu May  9 14:18:32 2002
+++ b/fs/jffs2/background.c	Thu May  9 14:18:32 2002
@@ -104,7 +104,7 @@
 	c->gc_task = current;
 	up(&c->gc_thread_start);
 
-        sprintf(current->comm, "jffs2_gcd_mtd%d", c->mtd->index);
+        set_current_title("jffs2_gcd_mtd%d", c->mtd->index);
 
 	/* FIXME in the 2.2 backport */
 	current->nice = 10;
diff -Nru a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
--- a/fs/lockd/clntlock.c	Thu May  9 14:18:32 2002
+++ b/fs/lockd/clntlock.c	Thu May  9 14:18:32 2002
@@ -203,9 +203,7 @@
 
 	daemonize();
 	reparent_to_init();
-	snprintf(current->comm, sizeof(current->comm),
-		 "%s-reclaim",
-		 host->h_name);
+	set_current_title("%s-reclaim", host->h_name);
 
 	/* This one ensures that our parent doesn't terminate while the
 	 * reclaim is in progress */
diff -Nru a/fs/lockd/svc.c b/fs/lockd/svc.c
--- a/fs/lockd/svc.c	Thu May  9 14:18:32 2002
+++ b/fs/lockd/svc.c	Thu May  9 14:18:32 2002
@@ -99,7 +99,7 @@
 
 	daemonize();
 	reparent_to_init();
-	sprintf(current->comm, "lockd");
+	set_current_title("lockd");
 
 	/* Process request with signals blocked.  */
 	spin_lock_irq(&current->sigmask_lock);
diff -Nru a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
--- a/fs/nfsd/nfssvc.c	Thu May  9 14:18:32 2002
+++ b/fs/nfsd/nfssvc.c	Thu May  9 14:18:32 2002
@@ -161,7 +161,7 @@
 	MOD_INC_USE_COUNT;
 	lock_kernel();
 	daemonize();
-	sprintf(current->comm, "nfsd");
+	set_current_title("nfsd");
 	current->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
 
 	nfsdstats.th_cnt++;
diff -Nru a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
--- a/fs/reiserfs/journal.c	Thu May  9 14:18:32 2002
+++ b/fs/reiserfs/journal.c	Thu May  9 14:18:32 2002
@@ -1872,7 +1872,7 @@
   recalc_sigpending(current);
   spin_unlock_irq(&current->sigmask_lock);
 
-  sprintf(current->comm, "kreiserfsd") ;
+  set_current_title("kreiserfsd") ;
   lock_kernel() ;
   while(1) {
 
diff -Nru a/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h	Thu May  9 14:18:32 2002
+++ b/include/linux/sched.h	Thu May  9 14:18:32 2002
@@ -110,6 +110,15 @@
 	__set_current_state(state_value)
 #endif
 
+#define TASK_TITLE_MAX	15
+#define __TASK_TITLE_SZ	(TASK_TITLE_MAX + 1)
+
+#define set_task_title(tsk, arg...) \
+	snprintf(tsk->comm, sizeof(tsk->comm), ##arg)
+
+#define set_current_title(arg...) \
+	snprintf(current->comm, sizeof(current->comm), ##arg)
+
 /*
  * Scheduling policies
  */
@@ -379,7 +388,7 @@
 /* limits */
 	struct rlimit rlim[RLIM_NLIMITS];
 	unsigned short used_math;
-	char comm[16];
+	char comm[__TASK_TITLE_SZ];
 /* file system info */
 	int link_count, total_link_count;
 	struct tty_struct *tty; /* NULL if no tty */
diff -Nru a/kernel/context.c b/kernel/context.c
--- a/kernel/context.c	Thu May  9 14:18:32 2002
+++ b/kernel/context.c	Thu May  9 14:18:32 2002
@@ -71,7 +71,7 @@
 	struct k_sigaction sa;
 
 	daemonize();
-	strcpy(curtask->comm, "keventd");
+	set_task_title(curtask, "keventd");
 	keventd_running = 1;
 	keventd_task = curtask;
 
diff -Nru a/kernel/softirq.c b/kernel/softirq.c
--- a/kernel/softirq.c	Thu May  9 14:18:32 2002
+++ b/kernel/softirq.c	Thu May  9 14:18:32 2002
@@ -373,7 +373,7 @@
 	while (smp_processor_id() != cpu)
 		schedule();
 
-	sprintf(current->comm, "ksoftirqd_CPU%d", bind_cpu);
+	set_current_title("ksoftirqd_CPU%d", bind_cpu);
 
 	__set_current_state(TASK_INTERRUPTIBLE);
 	mb();
diff -Nru a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c	Thu May  9 14:18:32 2002
+++ b/mm/vmscan.c	Thu May  9 14:18:32 2002
@@ -704,7 +704,7 @@
 	DECLARE_WAITQUEUE(wait, tsk);
 
 	daemonize();
-	strcpy(tsk->comm, "kswapd");
+	set_task_title(tsk, "kswapd");
 	sigfillset(&tsk->blocked);
 	
 	/*
diff -Nru a/net/khttpd/main.c b/net/khttpd/main.c
--- a/net/khttpd/main.c	Thu May  9 14:18:32 2002
+++ b/net/khttpd/main.c	Thu May  9 14:18:32 2002
@@ -105,7 +105,7 @@
 	if (cpu_pointer!=NULL)
 	CPUNR=(int)*(int*)cpu_pointer;
 
-	sprintf(current->comm,"khttpd - %i",CPUNR);
+	set_current_title("khttpd - %i", CPUNR);
 	daemonize();
 	
 	init_waitqueue_head(&(DummyWQ[CPUNR]));
@@ -195,7 +195,7 @@
 	DECLARE_WAIT_QUEUE_HEAD(WQ);
 	
 	
-	sprintf(current->comm,"khttpd manager");
+	set_current_title("khttpd manager");
 	daemonize();
 	
 
diff -Nru a/net/sunrpc/sched.c b/net/sunrpc/sched.c
--- a/net/sunrpc/sched.c	Thu May  9 14:18:32 2002
+++ b/net/sunrpc/sched.c	Thu May  9 14:18:32 2002
@@ -1067,7 +1067,7 @@
 	recalc_sigpending(current);
 	spin_unlock_irq(&current->sigmask_lock);
 
-	strcpy(current->comm, "rpciod");
+	set_current_title("rpciod");
 
 	dprintk("RPC: rpciod starting (pid %d)\n", rpciod_pid);
 	while (rpciod_users) {



-- 
Paul P 'Stingray' Komkoff 'Greatest' Jr // (icq)23200764 // (irc)Spacebar
  PPKJ1-RIPE // (smtp)i@stingr.net // (http)stingr.net // (pgp)0xA4B4ECA4

Re: [RFC] Some useless cleanup

[Paul P Komkoff Jr]

Replying to Denis Vlasenko:
> Well, it isn't bad, but what's the point in multiple
> set_xxxxxx(char *dst, char *src) functions?
> 
> Maybe it makes more sense to have a generic macro
> which copies string into char[N] buffer, avoiding overflow.
> 

Generic plan. I has something in mind when asked, but not this ...

Actually in task_t.comm we have 2 cases
1. strncpy(a, b, sz)
2. snprintf(a, n, blah-blah...)

I thought somebody will beat me for completely eliminating strcpyn and
replacing it with snprintf in ALL CASES which is more expensive.

> A macro:
> 
> #define STRNCPY(dst,src) \
> 	do { \
> 		/* todo: put clever check that dst is char[] here */ \
> 		strncpy((dst), (src), sizeof(dst)-1); \
> 		dst[sizeof(dst)-1] = '\0'; \
> 	} while(0)

Abstracting .comm access can result in, finally, replacing comm[16] with,
for example, *comm

Or if we require to do match_comm (netfilter match, connections belong to
process specified by name) job we can patchhook somewhere in set_xxx to
avoid excessive for_each_tasked strcmps.

... more?

-- 
Paul P 'Stingray' Komkoff 'Greatest' Jr // (icq)23200764 // (irc)Spacebar
  PPKJ1-RIPE // (smtp)i@stingr.net // (http)stingr.net // (pgp)0xA4B4ECA4

Re: [RFC] Some useless cleanup

[Rusty Russell]

On Thu, 9 May 2002 14:28:41 +0400
Paul P Komkoff Jr <i@stingr.net> wrote:

> Look at this very funny cleanup changeset for 2.4
> avaliable at linux-stingr.bkbits.net/comm

Um, why not simply:

static inline void set_name(struct task_struct *tsk, const char *name)
{
	/* comm is always nul-terminated already */
	strncpy(tsk->comm, name, sizeof(tsk->comm)-1);
}

Your implementation using snprintf is (wasteful and) dangerous,
Rusty.
-- 
   there are those who do and those who hang on and you don't see too
   many doers quoting their contemporaries.  -- Larry McVoy

Re: [RFC] Some useless cleanup

[Denis Vlasenko]

On 9 May 2002 08:28, Paul P Komkoff Jr wrote:
> Look at this very funny cleanup changeset for 2.4
> avaliable at linux-stingr.bkbits.net/comm
>
> For those who don't have bk I including it here below.
>
> Please give your comments. Maybe it is completely useless and anything
> should stay as before, or maybe it is somewhat useful and this abstraction
> will decrease possibility of bugs such as akpm worked around in 8139too

Well, it isn't bad, but what's the point in multiple
set_xxxxxx(char *dst, char *src) functions?

Maybe it makes more sense to have a generic macro
which copies string into char[N] buffer, avoiding overflow.

Actually, there is similar code in your mail:
> -       strncpy (current->comm, dev->name, sizeof(current->comm) - 1);
> -       current->comm[sizeof(current->comm) - 1] = '\0';
> +       set_current_title(dev->name);

A macro:

#define STRNCPY(dst,src) \
	do { \
		/* todo: put clever check that dst is char[] here */ \
		strncpy((dst), (src), sizeof(dst)-1); \
		dst[sizeof(dst)-1] = '\0'; \
	} while(0)

--
vda

Re: [RFC] Some useless cleanup

[Erik Andersen]

On Thu May 09, 2002 at 10:36:50PM +1000, Rusty Russell wrote:
> Um, why not simply:
> 
> static inline void set_name(struct task_struct *tsk, const char *name)
> {
> 	/* comm is always nul-terminated already */
> 	strncpy(tsk->comm, name, sizeof(tsk->comm)-1);
> }
> 
> Your implementation using snprintf is (wasteful and) dangerous,
> Rusty.

And both implementations suffer from the fact that if tsk->comm
were to change from a fixed length array to a char*, allowing
arbitrarily sized names, you would end up copying very little
indeed.  :)  What not something more general like:

char * safe_strncpy(char *dst, const char *src, size_t size)
{
    dst[size-1] = '\0';
    strncpy(dst, src, size-1);
}

 -Erik

--
Erik B. Andersen             http://codepoet-consulting.com/
--This message was written using 73% post-consumer electrons--

Re: [RFC] Some useless cleanup

[Bernd Petrovitsch]

Erik Andersen <andersen@codepoet.org> wrote:
>char * safe_strncpy(char *dst, const char *src, size_t size)
>{
>    dst[size-1] = '\0';
>    strncpy(dst, src, size-1);
>}

Maybe just call it strlcpy() similar to others :
e.g. http://www.tac.eu.org/cgi-bin/man-cgi?strlcpy+3

	bernd
-- 
Bernd Petrovitsch                              Email : bernd@gams.at
g.a.m.s gmbh                                  Fax : +43 1 205255-900
Prinz-Eugen-Straße 8                    A-1040 Vienna/Austria/Europe
                     LUGA : http://www.luga.at

Re: [RFC] Some useless cleanup

[Paul P Komkoff Jr]

Replying to Rusty Russell:
> Your implementation using snprintf is (wasteful and) dangerous,

Some pieces inside kernel using formatted titles
for example softirqd_CPU%d
or scsi_eh_%d

(But if we eliminate them then it can end with strncpy)

-- 
Paul P 'Stingray' Komkoff 'Greatest' Jr // (icq)23200764 // (irc)Spacebar
  PPKJ1-RIPE // (smtp)i@stingr.net // (http)stingr.net // (pgp)0xA4B4ECA4

Re: [RFC] Some useless cleanup

[Oliver Xymoron]

On Thu, 9 May 2002, Erik Andersen wrote:

> On Thu May 09, 2002 at 10:36:50PM +1000, Rusty Russell wrote:
> > Um, why not simply:
> >
> > static inline void set_name(struct task_struct *tsk, const char *name)
> > {
> > 	/* comm is always nul-terminated already */
> > 	strncpy(tsk->comm, name, sizeof(tsk->comm)-1);
> > }
> >
> > Your implementation using snprintf is (wasteful and) dangerous,
> > Rusty.
>
> And both implementations suffer from the fact that if tsk->comm
> were to change from a fixed length array to a char*, allowing
> arbitrarily sized names, you would end up copying very little
> indeed.  :)  What not something more general like:
>
> char * safe_strncpy(char *dst, const char *src, size_t size)
> {
>     dst[size-1] = '\0';
>     strncpy(dst, src, size-1);
> }

If we're gonna do that, we might as well adopt OpenBSD-style strlcpy and
strlcat:

http://www.courtesan.com/todd/papers/strlcpy.html

-- 
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.."

Re: [RFC] Some useless cleanup

[Rusty Russell]

In message <20020509222358.GB8651@codepoet.org> you write:
> On Thu May 09, 2002 at 10:36:50PM +1000, Rusty Russell wrote:
> > Um, why not simply:
> > 
> > static inline void set_name(struct task_struct *tsk, const char *name)
> > {
> > 	/* comm is always nul-terminated already */
> > 	strncpy(tsk->comm, name, sizeof(tsk->comm)-1);
> > }
> > 
> > Your implementation using snprintf is (wasteful and) dangerous,
> > Rusty.
> 
> And both implementations suffer from the fact that if tsk->comm
> were to change from a fixed length array to a char*, allowing
> arbitrarily sized names, you would end up copying very little
> indeed.  :)

Um, yes, if someone were to make a random change to the kernel without
looking at what it would effect, the kernel would likely break.

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.