debug.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdarg.h>
#include <dlfcn.h>
#include <unistd.h>
#include <string.h>
#include <thread.h>
#include <debug.h>
#include "_rtld.h"
#include "_elf.h"
#include "msg.h"
static int dbg_fd; /* debugging output file descriptor */
static dev_t dbg_dev;
static ino_t dbg_ino;
static pid_t pid;
/*
* Enable diagnostic output. All debugging functions reside in the linker
* debugging library liblddbg.so which is lazy loaded when required.
*/
uintptr_t
dbg_setup(const char *options, Dbg_desc *dbp)
{
uintptr_t ret;
struct stat status;
/*
* If we're running secure, only allow debugging if ld.so.1 itself is
* owned by root and has its mode setuid. Fail silently.
*/
if (rtld_flags & RT_FL_SECURE) {
struct stat status;
if (stat(NAME(lml_rtld.lm_head), &status) == 0) {
if ((status.st_uid != 0) ||
(!(status.st_mode & S_ISUID)))
return (0);
} else
return (0);
}
/*
* As Dbg_setup() will effectively lazy load the necessary support
* libraries, make sure ld.so.1 is initialized for plt relocations.
*/
if (elf_rtld_load() == 0)
return (0);
/*
* Call the debugging setup routine. This function verifies the
* debugging tokens provided and returns a mask indicating the debugging
* categories selected. The mask effectively enables calls to the
* debugging library.
*/
if ((ret = Dbg_setup(options, dbp)) != (uintptr_t)1)
return (ret);
/*
* If an LD_DEBUG_OUTPUT file was specified then we need to direct all
* diagnostics to the specified file. Add the process id as a file
* suffix so that multiple processes that inherit the same debugging
* environment variable don't fight over the same file.
*/
if (dbg_file) {
char file[MAXPATHLEN];
(void) snprintf(file, MAXPATHLEN, MSG_ORIG(MSG_DBG_FILE),
dbg_file, getpid());
if ((dbg_fd = open(file, (O_RDWR | O_CREAT), 0666)) == -1) {
int err = errno;
eprintf(&lml_rtld, ERR_FATAL, MSG_INTL(MSG_SYS_OPEN),
file, strerror(err));
dbp->d_class = 0;
return (0);
}
} else {
/*
* The default is to direct debugging to the stderr.
*/
dbg_fd = 2;
}
/*
* Initialize the dev/inode pair to enable us to determine if
* the debugging file descriptor is still available once the
* application has been entered.
*/
(void) fstat(dbg_fd, &status);
dbg_dev = status.st_dev;
dbg_ino = status.st_ino;
pid = getpid();
return (ret);
}
static int
dbg_lmid(Lm_list *lml)
{
const char *str;
Aliste idx;
for (APLIST_TRAVERSE(dbg_desc->d_list, idx, str)) {
if (strcmp(lml->lm_lmidstr, str) == 0)
return (1);
}
return (0);
}
/*
* All diagnostic requests are funneled to this routine.
*/
/* PRINTFLIKE2 */
void
dbg_print(Lm_list *lml, const char *format, ...)
{
va_list args;
char buffer[ERRSIZE + 1];
pid_t _pid;
struct stat status;
Prfbuf prf;
/*
* Knock off any newline indicator to signify that a diagnostic has
* been processed.
*/
dbg_desc->d_extra &= ~DBG_E_STDNL;
/*
* If debugging has been isolated to individual link-map lists,
* determine whether this request originates from a link-map list that
* is being monitored. Otherwise, process all link-map list diagnostics
* except those that originate from ld.so.1 processing its own
* dependencies.
*/
if (dbg_desc->d_list && lml && lml->lm_lmidstr) {
if (dbg_lmid(lml) == 0)
return;
} else if (lml && (lml->lm_flags & LML_FLG_RTLDLM))
return;
/*
* If we're in the application make sure the debugging file descriptor
* is still available (ie, the user hasn't closed and/or reused the
* same descriptor).
*/
if (rtld_flags & RT_FL_APPLIC) {
if ((fstat(dbg_fd, &status) == -1) ||
(status.st_dev != dbg_dev) ||
(status.st_ino != dbg_ino)) {
if (dbg_file) {
/*
* If the user specified output file has been
* disconnected try and reconnect to it.
*/
char file[MAXPATHLEN];
(void) snprintf(file, MAXPATHLEN,
MSG_ORIG(MSG_DBG_FILE), dbg_file, pid);
if ((dbg_fd = open(file, (O_RDWR | O_APPEND),
0)) == -1) {
dbg_desc->d_class = 0;
return;
}
(void) fstat(dbg_fd, &status);
dbg_dev = status.st_dev;
dbg_ino = status.st_ino;
} else {
/*
* If stderr has been stolen from us simply
* turn debugging off.
*/
dbg_desc->d_class = 0;
return;
}
}
}
prf.pr_buf = prf.pr_cur = buffer;
prf.pr_len = ERRSIZE;
prf.pr_fd = dbg_fd;
/*
* The getpid() call is a 'special' interface between ld.so.1 and dbx,
* because of this getpid() can't be called freely until after control
* has been given to the user program. Once the control has been given
* to the user program we know that the r_debug structure has been
* properly initialized for the debugger.
*/
if (rtld_flags & RT_FL_APPLIC)
_pid = getpid();
else
_pid = pid;
if (lml)
(void) bufprint(&prf, MSG_ORIG(MSG_DBG_PID), _pid);
else
(void) bufprint(&prf, MSG_ORIG(MSG_DBG_UNDEF));
prf.pr_cur--;
if (DBG_ISLMID() && lml && lml->lm_lmidstr) {
(void) bufprint(&prf, MSG_ORIG(MSG_DBG_LMID), lml->lm_lmidstr);
prf.pr_cur--;
}
if (rtld_flags & RT_FL_THREADS) {
(void) bufprint(&prf, MSG_ORIG(MSG_DBG_THREAD), rt_thr_self());
prf.pr_cur--;
}
/*
* Format the message and print it.
*/
va_start(args, format);
(void) doprf(format, args, &prf);
*(prf.pr_cur - 1) = '\n';
(void) dowrite(&prf);
va_end(args);
}