xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/debug.c (revision 69112edd)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
55aefb655Srie  * Common Development and Distribution License (the "License").
65aefb655Srie  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
227c478bd9Sstevel@tonic-gate /*
23*69112eddSAli Bahrami  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
277c478bd9Sstevel@tonic-gate #include	<sys/types.h>
287c478bd9Sstevel@tonic-gate #include	<sys/stat.h>
297c478bd9Sstevel@tonic-gate #include	<sys/param.h>
307c478bd9Sstevel@tonic-gate #include	<stdio.h>
317c478bd9Sstevel@tonic-gate #include	<fcntl.h>
327c478bd9Sstevel@tonic-gate #include	<stdarg.h>
337c478bd9Sstevel@tonic-gate #include	<dlfcn.h>
347c478bd9Sstevel@tonic-gate #include	<unistd.h>
357c478bd9Sstevel@tonic-gate #include	<string.h>
367c478bd9Sstevel@tonic-gate #include	<thread.h>
375aefb655Srie #include	<debug.h>
382017c965SRod Evans #include	<conv.h>
397c478bd9Sstevel@tonic-gate #include	"_rtld.h"
407c478bd9Sstevel@tonic-gate #include	"_elf.h"
417c478bd9Sstevel@tonic-gate #include	"msg.h"
44cb511613SAli Bahrami static int		dbg_fd;		/* debugging output file descriptor */
45cb511613SAli Bahrami static dev_t		dbg_dev;
46cb511613SAli Bahrami static rtld_ino_t	dbg_ino;
47e23c41c9SAli Bahrami static int		dbg_add_pid;	/* True to add pid to debug file name */
48cb511613SAli Bahrami static pid_t		pid;
507c478bd9Sstevel@tonic-gate /*
517c478bd9Sstevel@tonic-gate  * Enable diagnostic output.  All debugging functions reside in the linker
527c478bd9Sstevel@tonic-gate  * debugging library liblddbg.so which is lazy loaded when required.
537c478bd9Sstevel@tonic-gate  */
54e23c41c9SAli Bahrami int
dbg_setup(const char * options,Dbg_desc * dbp)555aefb655Srie dbg_setup(const char *options, Dbg_desc *dbp)
567c478bd9Sstevel@tonic-gate {
57cb511613SAli Bahrami 	rtld_stat_t	status;
58e23c41c9SAli Bahrami 	const char	*ofile;
607c478bd9Sstevel@tonic-gate 	/*
617c478bd9Sstevel@tonic-gate 	 * If we're running secure, only allow debugging if ld.so.1 itself is
627c478bd9Sstevel@tonic-gate 	 * owned by root and has its mode setuid.  Fail silently.
637c478bd9Sstevel@tonic-gate 	 */
643dbfc803SRod Evans 	if ((rtld_flags & RT_FL_SECURE) && (is_rtld_setuid() == 0))
65e23c41c9SAli Bahrami 		return (1);
677c478bd9Sstevel@tonic-gate 	/*
687c478bd9Sstevel@tonic-gate 	 * As Dbg_setup() will effectively lazy load the necessary support
697c478bd9Sstevel@tonic-gate 	 * libraries, make sure ld.so.1 is initialized for plt relocations.
707c478bd9Sstevel@tonic-gate 	 */
717c478bd9Sstevel@tonic-gate 	if (elf_rtld_load() == 0)
72e23c41c9SAli Bahrami 		return (1);
747c478bd9Sstevel@tonic-gate 	/*
757c478bd9Sstevel@tonic-gate 	 * Call the debugging setup routine.  This function verifies the
767c478bd9Sstevel@tonic-gate 	 * debugging tokens provided and returns a mask indicating the debugging
777c478bd9Sstevel@tonic-gate 	 * categories selected.  The mask effectively enables calls to the
787c478bd9Sstevel@tonic-gate 	 * debugging library.
797c478bd9Sstevel@tonic-gate 	 */
80e23c41c9SAli Bahrami 	if (Dbg_setup(DBG_CALLER_RTLD, options, dbp, &ofile) == 0)
81e23c41c9SAli Bahrami 		return (0);
83dde769a2SRod Evans 	/*
84dde769a2SRod Evans 	 * Obtain the process id.
85dde769a2SRod Evans 	 */
86dde769a2SRod Evans 	pid = getpid();
87dde769a2SRod Evans 
887c478bd9Sstevel@tonic-gate 	/*
897c478bd9Sstevel@tonic-gate 	 * If an LD_DEBUG_OUTPUT file was specified then we need to direct all
907c478bd9Sstevel@tonic-gate 	 * diagnostics to the specified file.  Add the process id as a file
917c478bd9Sstevel@tonic-gate 	 * suffix so that multiple processes that inherit the same debugging
927c478bd9Sstevel@tonic-gate 	 * environment variable don't fight over the same file.
93e23c41c9SAli Bahrami 	 *
94e23c41c9SAli Bahrami 	 * If LD_DEBUG_OUTPUT is not specified, and the output=file token
95e23c41c9SAli Bahrami 	 * was, then we direct all diagnostics to that file. Unlike
96e23c41c9SAli Bahrami 	 * LD_DEBUG_OUTPUT, we do not add the process id suffix. This
97e23c41c9SAli Bahrami 	 * is more convenient for interactive use.
98e23c41c9SAli Bahrami 	 *
99e23c41c9SAli Bahrami 	 * If neither redirection option is present, we send debugging
100e23c41c9SAli Bahrami 	 * output to stderr. Note that the caller will not be able
101e23c41c9SAli Bahrami 	 * to pipe or redirect this output at the shell level. libc
102e23c41c9SAli Bahrami 	 * has not yet initialized things to make that possible.
1037c478bd9Sstevel@tonic-gate 	 */
104e23c41c9SAli Bahrami 	if (dbg_file == NULL) {
105e23c41c9SAli Bahrami 		if (ofile && (*ofile != '\0'))
106e23c41c9SAli Bahrami 			dbg_file = ofile;
107e23c41c9SAli Bahrami 	} else {
108e23c41c9SAli Bahrami 		dbg_add_pid = 1;
109e23c41c9SAli Bahrami 	}
110e23c41c9SAli Bahrami 
1117c478bd9Sstevel@tonic-gate 	if (dbg_file) {
112e23c41c9SAli Bahrami 		char 		_file[MAXPATHLEN];
113e23c41c9SAli Bahrami 		const char	*file;
115e23c41c9SAli Bahrami 		if (dbg_add_pid) {
116e23c41c9SAli Bahrami 			file = _file;
117e23c41c9SAli Bahrami 			(void) snprintf(_file, MAXPATHLEN,
118e23c41c9SAli Bahrami 			    MSG_ORIG(MSG_DBG_FILE), dbg_file, pid);
119e23c41c9SAli Bahrami 		} else {
120e23c41c9SAli Bahrami 			file = dbg_file;
121e23c41c9SAli Bahrami 		}
122e23c41c9SAli Bahrami 		dbg_fd = open(file, O_RDWR | O_CREAT | O_TRUNC, 0666);
123e23c41c9SAli Bahrami 		if (dbg_fd == -1) {
1247c478bd9Sstevel@tonic-gate 			int	err = errno;
1265aefb655Srie 			eprintf(&lml_rtld, ERR_FATAL, MSG_INTL(MSG_SYS_OPEN),
1275aefb655Srie 			    file, strerror(err));
1285aefb655Srie 			dbp->d_class = 0;
1297c478bd9Sstevel@tonic-gate 			return (0);
1307c478bd9Sstevel@tonic-gate 		}
1317c478bd9Sstevel@tonic-gate 	} else {
1327c478bd9Sstevel@tonic-gate 		/*
1337c478bd9Sstevel@tonic-gate 		 * The default is to direct debugging to the stderr.
1347c478bd9Sstevel@tonic-gate 		 */
1357c478bd9Sstevel@tonic-gate 		dbg_fd = 2;
1367c478bd9Sstevel@tonic-gate 	}
1387c478bd9Sstevel@tonic-gate 	/*
1397c478bd9Sstevel@tonic-gate 	 * Initialize the dev/inode pair to enable us to determine if
1407c478bd9Sstevel@tonic-gate 	 * the debugging file descriptor is still available once the
1417c478bd9Sstevel@tonic-gate 	 * application has been entered.
1427c478bd9Sstevel@tonic-gate 	 */
143cb511613SAli Bahrami 	(void) rtld_fstat(dbg_fd, &status);
1447c478bd9Sstevel@tonic-gate 	dbg_dev = status.st_dev;
1457c478bd9Sstevel@tonic-gate 	dbg_ino = status.st_ino;
147e23c41c9SAli Bahrami 	/*
148*69112eddSAli Bahrami 	 * Now that the output file is established, identify the linker
149*69112eddSAli Bahrami 	 * package, and generate help output if the user specified the
150*69112eddSAli Bahrami 	 * debug help token.
151e23c41c9SAli Bahrami 	 */
152*69112eddSAli Bahrami 	Dbg_version();
153e23c41c9SAli Bahrami 	if (dbp->d_extra & DBG_E_HELP)
154e23c41c9SAli Bahrami 		Dbg_help();
155e23c41c9SAli Bahrami 
156e23c41c9SAli Bahrami 	return (1);
1575aefb655Srie }
159e23c41c9SAli Bahrami /*
160e23c41c9SAli Bahrami  * Return True (1) if dbg_print() should produce output for the
161e23c41c9SAli Bahrami  * specified link-map list, and False (0) otherwise.
162e23c41c9SAli Bahrami  */
1635aefb655Srie static int
dbg_lmid_validate(Lm_list * lml)164e23c41c9SAli Bahrami dbg_lmid_validate(Lm_list *lml)
1655aefb655Srie {
166cce0e03bSab 	const char	*str;
167cce0e03bSab 	Aliste		idx;
169e23c41c9SAli Bahrami 	/*
170e23c41c9SAli Bahrami 	 * The LDSO link-map list is a special case, requiring
171e23c41c9SAli Bahrami 	 * an explicit user request.
172e23c41c9SAli Bahrami 	 */
173e23c41c9SAli Bahrami 	if (lml->lm_flags & LML_FLG_RTLDLM)
174e23c41c9SAli Bahrami 		return ((dbg_desc->d_extra & DBG_E_LMID_LDSO) != 0);
175e23c41c9SAli Bahrami 
176e23c41c9SAli Bahrami 	/*
177e23c41c9SAli Bahrami 	 * Approve special cases:
178e23c41c9SAli Bahrami 	 * -	The link-map list has no name
179e23c41c9SAli Bahrami 	 * -	lmid=all was set
180e23c41c9SAli Bahrami 	 * -	lmid=alt was set, and this is not the BASE linkmap
181e23c41c9SAli Bahrami 	 */
182e23c41c9SAli Bahrami 	if ((lml->lm_lmidstr == NULL) ||
183e23c41c9SAli Bahrami 	    ((dbg_desc->d_extra & DBG_E_LMID_ALL) != 0) ||
184e23c41c9SAli Bahrami 	    (((dbg_desc->d_extra & DBG_E_LMID_ALT) != 0) &&
185e23c41c9SAli Bahrami 	    ((lml->lm_flags & LML_FLG_BASELM) == 0)))
186e23c41c9SAli Bahrami 		return (1);
187e23c41c9SAli Bahrami 
188e23c41c9SAli Bahrami 	/*
189e23c41c9SAli Bahrami 	 * If there is no list of specific link-map list names to check,
190e23c41c9SAli Bahrami 	 * then approval depends on lmid={ldso|alt} not being specified.
191e23c41c9SAli Bahrami 	 */
192e23c41c9SAli Bahrami 	if (aplist_nitems(dbg_desc->d_list) == 0)
193e23c41c9SAli Bahrami 		return ((dbg_desc->d_extra &
194e23c41c9SAli Bahrami 		    (DBG_E_LMID_LDSO | DBG_E_LMID_ALT)) == 0);
195e23c41c9SAli Bahrami 
196e23c41c9SAli Bahrami 	/*
197e23c41c9SAli Bahrami 	 * Compare the link-map list name against the list of approved names
198e23c41c9SAli Bahrami 	 */
199e23c41c9SAli Bahrami 	for (APLIST_TRAVERSE(dbg_desc->d_list, idx, str))
200cce0e03bSab 		if (strcmp(lml->lm_lmidstr, str) == 0)
2015aefb655Srie 			return (1);
202e23c41c9SAli Bahrami 
203e23c41c9SAli Bahrami 	/* Output for this linkmap is denied */
2045aefb655Srie 	return (0);
2057c478bd9Sstevel@tonic-gate }
2077c478bd9Sstevel@tonic-gate /*
2087c478bd9Sstevel@tonic-gate  * All diagnostic requests are funneled to this routine.
2097c478bd9Sstevel@tonic-gate  */
2105aefb655Srie /* PRINTFLIKE2 */
2117c478bd9Sstevel@tonic-gate void
dbg_print(Lm_list * lml,const char * format,...)2125aefb655Srie dbg_print(Lm_list *lml, const char *format, ...)
2137c478bd9Sstevel@tonic-gate {
2145aefb655Srie 	va_list		args;
2155aefb655Srie 	char		buffer[ERRSIZE + 1];
2165aefb655Srie 	pid_t		_pid;
217cb511613SAli Bahrami 	rtld_stat_t	status;
2185aefb655Srie 	Prfbuf		prf;
2205aefb655Srie 	/*
2215aefb655Srie 	 * Knock off any newline indicator to signify that a diagnostic has
2225aefb655Srie 	 * been processed.
2235aefb655Srie 	 */
2245aefb655Srie 	dbg_desc->d_extra &= ~DBG_E_STDNL;
2265aefb655Srie 	/*
2275aefb655Srie 	 * If debugging has been isolated to individual link-map lists,
2285aefb655Srie 	 * determine whether this request originates from a link-map list that
229e23c41c9SAli Bahrami 	 * is being monitored.
2305aefb655Srie 	 */
231e23c41c9SAli Bahrami 	if (lml && (dbg_lmid_validate(lml) == 0))
2325aefb655Srie 		return;
2347c478bd9Sstevel@tonic-gate 	/*
2357c478bd9Sstevel@tonic-gate 	 * If we're in the application make sure the debugging file descriptor
2367c478bd9Sstevel@tonic-gate 	 * is still available (ie, the user hasn't closed and/or reused the
2377c478bd9Sstevel@tonic-gate 	 * same descriptor).
2387c478bd9Sstevel@tonic-gate 	 */
2397c478bd9Sstevel@tonic-gate 	if (rtld_flags & RT_FL_APPLIC) {
240cb511613SAli Bahrami 		if ((rtld_fstat(dbg_fd, &status) == -1) ||
2417c478bd9Sstevel@tonic-gate 		    (status.st_dev != dbg_dev) ||
2427c478bd9Sstevel@tonic-gate 		    (status.st_ino != dbg_ino)) {
2437c478bd9Sstevel@tonic-gate 			if (dbg_file) {
2447c478bd9Sstevel@tonic-gate 				/*
2457c478bd9Sstevel@tonic-gate 				 * If the user specified output file has been
2467c478bd9Sstevel@tonic-gate 				 * disconnected try and reconnect to it.
2477c478bd9Sstevel@tonic-gate 				 */
248e23c41c9SAli Bahrami 				char 		_file[MAXPATHLEN];
249e23c41c9SAli Bahrami 				const char	*file;
251e23c41c9SAli Bahrami 				if (dbg_add_pid) {
252e23c41c9SAli Bahrami 					file = _file;
253e23c41c9SAli Bahrami 					(void) snprintf(_file, MAXPATHLEN,
254e23c41c9SAli Bahrami 					    MSG_ORIG(MSG_DBG_FILE), dbg_file,
255e23c41c9SAli Bahrami 					    pid);
256e23c41c9SAli Bahrami 				} else {
257e23c41c9SAli Bahrami 					file = dbg_file;
258e23c41c9SAli Bahrami 				}
2597c478bd9Sstevel@tonic-gate 				if ((dbg_fd = open(file, (O_RDWR | O_APPEND),
2607c478bd9Sstevel@tonic-gate 				    0)) == -1) {
2615aefb655Srie 					dbg_desc->d_class = 0;
2627c478bd9Sstevel@tonic-gate 					return;
2637c478bd9Sstevel@tonic-gate 				}
264cb511613SAli Bahrami 				(void) rtld_fstat(dbg_fd, &status);
2657c478bd9Sstevel@tonic-gate 				dbg_dev = status.st_dev;
2667c478bd9Sstevel@tonic-gate 				dbg_ino = status.st_ino;
2677c478bd9Sstevel@tonic-gate 			} else {
2687c478bd9Sstevel@tonic-gate 				/*
2697c478bd9Sstevel@tonic-gate 				 * If stderr has been stolen from us simply
2707c478bd9Sstevel@tonic-gate 				 * turn debugging off.
2717c478bd9Sstevel@tonic-gate 				 */
2725aefb655Srie 				dbg_desc->d_class = 0;
2737c478bd9Sstevel@tonic-gate 				return;
2747c478bd9Sstevel@tonic-gate 			}
2757c478bd9Sstevel@tonic-gate 		}
2767c478bd9Sstevel@tonic-gate 	}
2785aefb655Srie 	prf.pr_fd = dbg_fd;
2807c478bd9Sstevel@tonic-gate 	/*
281dde769a2SRod Evans 	 * Obtain the process id.
2827c478bd9Sstevel@tonic-gate 	 */
283dde769a2SRod Evans 	_pid = getpid();
2852017c965SRod Evans 	/*
2862017c965SRod Evans 	 * Each time ld.so.1 is entered, the diagnostic times are reset.  It is
2872017c965SRod Evans 	 * useful to convey this reset as part of our diagnostics, but only if
2882017c965SRod Evans 	 * other diagnostics will follow.  If a reset has preceded this
2892017c965SRod Evans 	 * diagnostic, print a division line.
2902017c965SRod Evans 	 */
2912017c965SRod Evans 	if (DBG_ISRESET()) {
2922017c965SRod Evans 		DBG_OFFRESET();
2932017c965SRod Evans 
2942017c965SRod Evans 		prf.pr_buf = prf.pr_cur = buffer;
2952017c965SRod Evans 		prf.pr_len = ERRSIZE;
2962017c965SRod Evans 
2972017c965SRod Evans 		if (lml)
2982017c965SRod Evans 			(void) bufprint(&prf, MSG_ORIG(MSG_DBG_PID), _pid);
2992017c965SRod Evans 		else
3002017c965SRod Evans 			(void) bufprint(&prf, MSG_ORIG(MSG_DBG_UNDEF));
3012017c965SRod Evans 		prf.pr_cur--;
3022017c965SRod Evans 
3032017c965SRod Evans 		(void) bufprint(&prf, MSG_ORIG(MSG_DBG_RESET));
3042017c965SRod Evans 		(void) dowrite(&prf);
3052017c965SRod Evans 	}
3062017c965SRod Evans 
3072017c965SRod Evans 	/*
3082017c965SRod Evans 	 * Reestablish the buffer for standard printing.
3092017c965SRod Evans 	 */
3102017c965SRod Evans 	prf.pr_buf = prf.pr_cur = buffer;
3112017c965SRod Evans 	prf.pr_len = ERRSIZE;
3122017c965SRod Evans 
3132017c965SRod Evans 	/*
3142017c965SRod Evans 	 * Establish any diagnostic prefix strings.
3152017c965SRod Evans 	 */
3165aefb655Srie 	if (lml)
3175aefb655Srie 		(void) bufprint(&prf, MSG_ORIG(MSG_DBG_PID), _pid);
3187c478bd9Sstevel@tonic-gate 	else
3195aefb655Srie 		(void) bufprint(&prf, MSG_ORIG(MSG_DBG_UNDEF));
3205aefb655Srie 	prf.pr_cur--;
3225aefb655Srie 	if (DBG_ISLMID() && lml && lml->lm_lmidstr) {
3235aefb655Srie 		(void) bufprint(&prf, MSG_ORIG(MSG_DBG_LMID), lml->lm_lmidstr);
3245aefb655Srie 		prf.pr_cur--;
3255aefb655Srie 	}
3262017c965SRod Evans 	if (DBG_ISTIME()) {
3272017c965SRod Evans 		struct timeval	new;
3282017c965SRod Evans 
3292017c965SRod Evans 		if (gettimeofday(&new, NULL) == 0) {
3302017c965SRod Evans 			Conv_time_buf_t	buf;
3312017c965SRod Evans 
3322017c965SRod Evans 			if (DBG_ISTTIME()) {
3332017c965SRod Evans 				(void) bufprint(&prf,
3342017c965SRod Evans 				    conv_time(&DBG_TOTALTIME, &new, &buf));
3352017c965SRod Evans 				prf.pr_cur--;
3362017c965SRod Evans 			}
3372017c965SRod Evans 			if (DBG_ISDTIME()) {
3382017c965SRod Evans 				(void) bufprint(&prf,
3392017c965SRod Evans 				    conv_time(&DBG_DELTATIME, &new, &buf));
3402017c965SRod Evans 				prf.pr_cur--;
3412017c965SRod Evans 			}
3422017c965SRod Evans 			DBG_DELTATIME = new;
3432017c965SRod Evans 		}
3442017c965SRod Evans 	}
3455aefb655Srie 	if (rtld_flags & RT_FL_THREADS) {
3465aefb655Srie 		(void) bufprint(&prf, MSG_ORIG(MSG_DBG_THREAD), rt_thr_self());
3475aefb655Srie 		prf.pr_cur--;
3485aefb655Srie 	}
3507c478bd9Sstevel@tonic-gate 	/*
3517c478bd9Sstevel@tonic-gate 	 * Format the message and print it.
3527c478bd9Sstevel@tonic-gate 	 */
3537c478bd9Sstevel@tonic-gate 	va_start(args, format);
3547c478bd9Sstevel@tonic-gate 	(void) doprf(format, args, &prf);
3557c478bd9Sstevel@tonic-gate 	*(prf.pr_cur - 1) = '\n';
3567c478bd9Sstevel@tonic-gate 	(void) dowrite(&prf);
3577c478bd9Sstevel@tonic-gate 	va_end(args);
3587c478bd9Sstevel@tonic-gate }