If BusyBox was compiled with -DCONFIG_FEATURE_CLEAN_UP dmesg command
    segfaults if invoked with the "-n" option. (Due to a free() of an
    uninitialized pointer).
		
	
		
			
				
	
	
		
			100 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* vi: set sw=4 ts=4: */
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/* dmesg.c -- Print out the contents of the kernel ring buffer
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 * Created: Sat Oct  9 16:19:47 1993
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 * Revised: Thu Oct 28 21:52:17 1993 by faith@cs.unc.edu
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 * Copyright 1993 Theodore Ts'o (tytso@athena.mit.edu)
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 * This program comes with ABSOLUTELY NO WARRANTY.
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 * Modifications by Rick Sladkey (jrs@world.std.com)
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 * Larger buffersize 3 June 1998 by Nicolai Langfeldt, based on a patch
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 * by Peeter Joot.  This was also suggested by John Hudson.
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 * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org>
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 * - added Native Language Support
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 *
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 * from util-linux -- adapted for busybox by 
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 * Erik Andersen <andersen@codepoet.org>. I ripped out Native Language 
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 * Support, replaced getopt, added some gotos for redundant stuff.
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 *
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 * Audited and cleaned up on 7 March 2003 to reduce size of
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 * check error handling by Erik Andersen <andersen@codepoet.org>
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include <getopt.h>
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#include <errno.h>
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#include <sys/klog.h>
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#include "busybox.h"
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int dmesg_main(int argc, char **argv)
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{
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	char *buf
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#ifdef CONFIG_FEATURE_CLEAN_UP
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		= NULL
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#endif
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		;
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	int bufsize = 8196;
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	int i, n;
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	int level = 0;
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	int lastc;
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	int cmd = 3;
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	while ((i = getopt(argc, argv, "cn:s:")) > 0) {
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		switch (i) {
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			case 'c':
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				cmd = 4;
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				break;
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			case 'n':
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				cmd = 8;
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				level = bb_xgetlarg(optarg, 10, 0, 10);
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				break;
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			case 's':
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				/* I think a 512k max kernel ring buffer is big enough for
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				 * anybody, as the default is 16k...  Could be wrong though.
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				 * If so I'm sure I'll hear about it by the enraged masses*/
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				bufsize = bb_xgetlarg(optarg, 10, 4096, 512*1024);
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				break;
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			default:
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				bb_show_usage();
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		}
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	}
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	if (optind < argc) {
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		bb_show_usage();
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	}
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	if (cmd == 8) {
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		if (klogctl(cmd, NULL, level) < 0)
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			goto die_the_death;
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		goto all_done;
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	}
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	buf = xmalloc(bufsize);
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	if ((n = klogctl(cmd, buf, bufsize)) < 0)
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		goto die_the_death;
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	lastc = '\n';
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	for (i = 0; i < n; i++) {
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		if (lastc == '\n' && buf[i] == '<') {
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			i++;
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			while (buf[i] >= '0' && buf[i] <= '9')
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				i++;
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			if (buf[i] == '>')
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				i++;
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		}
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		lastc = buf[i];
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		putchar(lastc);
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	}
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	if (lastc != '\n')
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		putchar('\n');
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all_done:
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#ifdef CONFIG_FEATURE_CLEAN_UP
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	if (buf) {
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		free(buf);
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	}
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#endif
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	return EXIT_SUCCESS;
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die_the_death:
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	bb_perror_nomsg_and_die();
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}
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