Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 14 Aug 2002 00:31:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 14 Aug 2002 00:31:14 -0400 Received: from to-velocet.redhat.com ([216.138.202.10]:26361 "EHLO touchme.toronto.redhat.com") by vger.kernel.org with ESMTP id ; Wed, 14 Aug 2002 00:31:13 -0400 Date: Wed, 14 Aug 2002 00:35:05 -0400 From: Benjamin LaHaise To: Linus Torvalds Cc: Alexander Viro , Andrew Morton , "H. Peter Anvin" , lkml Subject: Re: [patch] printk from userspace Message-ID: <20020814003505.A16322@redhat.com> References:

Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from torvalds@transmeta.com on Tue, Aug 13, 2002 at 09:26:45PM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2223 Lines: 71 On Tue, Aug 13, 2002 at 09:26:45PM -0700, Linus Torvalds wrote: > That said, I like the notion. I've always hated the fact that all the > boot-time messages get lost, simply because syslogd hadn't started, and > as a result things like fsck ran without any sign afterwards. The kernel > log approach saves it all in one place. > > But /dev/console just sounds potentially _too_ noisy. /dev/kmsg was another suggestion for the name. But please revert the yet-another-syscall variant -- having a duplicate way for logging that doesn't work with stdio just seems sick to me (sys_syslog should die). Something like the following untested code is much better. -ben -- "You will be reincarnated as a toad; and you will be much happier." diff -urN v2.5.31/drivers/char/mem.c foo/drivers/char/mem.c --- v2.5.31/drivers/char/mem.c Fri Aug 2 11:41:29 2002 +++ foo/drivers/char/mem.c Wed Aug 14 00:34:33 2002 @@ -579,6 +579,24 @@ write: write_full, }; +static ssize_t kmsg_write(struct file * file, const char * buf, + size_t count, loff_t *ppos) +{ + char tmp[1025]; + + if (count > 1024) + count = 1024; + if (copy_from_user(tmp, buf, count)) + return -EFAULT; + tmp[count] = 0; + printk("%s", tmp); + return count; +} + +static struct file_operations kmsg_fops = { + write: kmsg_write, +}; + static int memory_open(struct inode * inode, struct file * filp) { switch (minor(inode->i_rdev)) { @@ -608,6 +626,9 @@ case 9: filp->f_op = &urandom_fops; break; + case 11: + filp->f_op = &kmsg_fops; + break; default: return -ENXIO; } @@ -634,7 +655,8 @@ {5, "zero", S_IRUGO | S_IWUGO, &zero_fops}, {7, "full", S_IRUGO | S_IWUGO, &full_fops}, {8, "random", S_IRUGO | S_IWUSR, &random_fops}, - {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops} + {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops}, + {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops}, }; int i; - 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/