├── LICENSE
├── Makefile
├── README.md
├── log.c
├── log.h
├── lsstack.c
└── unwind.c
/LICENSE:
--------------------------------------------------------------------------------
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583 |
584 | Later license versions may give you additional or different
585 | permissions. However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 |
589 | 15. Disclaimer of Warranty.
590 |
591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 |
600 | 16. Limitation of Liability.
601 |
602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 |
612 | 17. Interpretation of Sections 15 and 16.
613 |
614 | If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 |
621 | END OF TERMS AND CONDITIONS
622 |
623 | How to Apply These Terms to Your New Programs
624 |
625 | If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 |
629 | To do so, attach the following notices to the program. It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 |
634 | {one line to give the program's name and a brief idea of what it does.}
635 | Copyright (C) {year} {name of author}
636 |
637 | This program is free software: you can redistribute it and/or modify
638 | it under the terms of the GNU General Public License as published by
639 | the Free Software Foundation, either version 3 of the License, or
640 | (at your option) any later version.
641 |
642 | This program is distributed in the hope that it will be useful,
643 | but WITHOUT ANY WARRANTY; without even the implied warranty of
644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
645 | GNU General Public License for more details.
646 |
647 | You should have received a copy of the GNU General Public License
648 | along with this program. If not, see .
649 |
650 | Also add information on how to contact you by electronic and paper mail.
651 |
652 | If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 |
655 | {project} Copyright (C) {year} {fullname}
656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 | This is free software, and you are welcome to redistribute it
658 | under certain conditions; type `show c' for details.
659 |
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License. Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 |
664 | You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | .
668 |
669 | The GNU General Public License does not permit incorporating your program
670 | into proprietary programs. If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library. If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License. But first, please read
674 | .
675 |
676 |
--------------------------------------------------------------------------------
/Makefile:
--------------------------------------------------------------------------------
1 | CC = gcc
2 | CFLAGS = -Wall -Wextra -Werror -g
3 |
4 | logs = log.o
5 |
6 | objects = $(logs) unwind.o
7 |
8 | all: lsstack unwind
9 |
10 | lsstack: $(logs) lsstack.c
11 | gcc $(CFLAGS) -o lsstack64 lsstack.c $(logs) -lbfd -liberty
12 | strip lsstack64
13 |
14 | unwind: $(objects)
15 | gcc $(CFLAGS) -o unwind $(objects) -lunwind-x86_64 -lunwind-ptrace
16 | strip unwind
17 |
18 | .PHONY: clean
19 | clean:
20 | -rm -f lsstack64 unwind $(objects)
21 |
22 | distclean: clean
23 | rm -f *~
24 |
25 | # just for checkinstall
26 | install: lsstack
27 | install -d ${DESTDIR}/usr/bin/
28 | install -g staff -o root ${<} ${DESTDIR}/usr/bin/
29 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | # lsstack64
2 | Process execution stack tracer for x86_64 architecture. Per-thread tracing is possible.
3 | A fork of the pstack utility for Solaris which works only on x86 arch. Originally it's not even compilable on x86_64. The current project is an attempt to make it work on x86_64 Linux.
4 |
5 | [**Sample output**](http://paste.ubuntu.com/11886313/) with Leafpad editor that runs 2 threads.
6 |
7 | If you find `lsstack64` useful, please consider donating via PayPal.
8 | [](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=RMLTQ76JSXJ4Q)
9 |
10 | ## License
11 |
12 | While the original utility is GPLv2, the current project is licensed under **GPLv3**.
13 |
14 | ## Compilation
15 | Tested on Ubuntu 14.04.3 x86_64
16 |
17 | $ sudo apt-get install binutils-dev libiberty-dev libunwind8-dev
18 | $ git clone https://github.com/jarun/lsstack64
19 | $ cd lsstack64
20 | $ make
21 | $ sudo make install
22 |
23 | ## Usage
24 | LWP stands for `Light Weight Process`. In simpler terms it is the thread ID.
25 | It is shown in the fourth column in the output of
26 |
27 | $ ps -aeLf
28 | For the main thread of a process LWD == PID, for child threads they are different.
29 |
30 | $ unwind LWP
31 |
32 | You might need to use `sudo` if you are not the owner of the process.
33 | unwind is the test program on x86_64. The functionality will be merged to lsstack64.
34 |
35 | ## News
36 |
37 | 16 Jul 2015: Implemented thread tracing support.
38 |
39 | 03 Jun 2015: Merging unwind.c fnctionality to lsstack64 started. New logging mechanism incorporated into lsstack64.
40 |
41 | 25 Apr 2015: unwind.c is the new stub progam that uses libunwind to run through all the stack frames. The goal is to make unwind provide the information that pstack did.
42 |
43 | 23 Apr 2015: log.h and log.c demonstrate a tiny, easy to use and extensible logging frameowork with severity level and useful information for easy debugging.
44 |
45 | 15 Apr 2015: After some research, it turns out that x86_64 does NOT save the previous frame's frame pointer in RBP register (other than those compiled without -fomit-frame-pointer in GCC). The default optimization level in GCC is O2, which includes -fomit-frame-pointer. So the next strategy would be to use [libunwind] (http://www.nongnu.org/libunwind/).
46 |
47 | ## Important links
48 | #### General
49 | http://www.nongnu.org/libunwind/index.html
50 | http://www.nongnu.org/libunwind/man/libunwind(3).html#section_3
51 | http://www.nongnu.org/libunwind/man/libunwind-ptrace%283%29.html
52 | http://savannah.nongnu.org/git/?group=libunwind
53 | http://sourceforge.net/projects/lsstack/
54 | http://lxr.free-electrons.com/source/arch/powerpc/boot/elf.h#L12
55 | http://linux.die.net/man/2/ptrace
56 | http://linux.die.net/include/sys/user.h
57 | http://lxr.free-electrons.com/source/arch/x86/include/asm/ptrace.h?v=3.3
58 | http://manpages.ubuntu.com/manpages/trusty/en/man3/libunwind-ptrace.3.html
59 | http://stackoverflow.com/questions/3194479/relation-between-program-instruction-pointerrip-and-base-frame-pointerrbp-on
60 | http://stackoverflow.com/questions/8625352/x86-64-calling-conventions-and-stack-frames
61 | http://blog.bigpixel.ro/2010/09/stack-unwinding-stack-trace-with-gcc/
62 | http://stackoverflow.com/questions/7516273/using-libunwind-on-hp-ux-and-getting-stacktrace
63 | http://lists.nongnu.org/archive/html/libunwind-devel/2011-11/msg00002.html
64 |
65 | #### Threads
66 | http://stackoverflow.com/questions/6402160/getting-a-backtrace-of-other-thread
67 | http://comments.gmane.org/gmane.comp.lib.unwind.devel/696
68 | http://stackoverflow.com/questions/11468333/linux-threads-suspend-resume
69 | http://stackoverflow.com/questions/18577956/how-to-use-ptrace-to-get-a-consistent-view-of-multiple-threads
70 |
71 | ## Contributions
72 | [Ellié Computing](http://www.elliecomputing.com/) contributes to this project by giving free licences of ECMerge, comparison/merge tool.
73 |
--------------------------------------------------------------------------------
/log.c:
--------------------------------------------------------------------------------
1 | /*
2 | * A modular, level based log file implementation
3 | *
4 | * Author: Arun Prakash Jana
5 | * Copyright (C) 2014, 2015 by Arun Prakash Jana
6 | *
7 | * This program is free software: you can redistribute it and/or modify
8 | * it under the terms of the GNU General Public License as published by
9 | * the Free Software Foundation, either version 3 of the License, or
10 | * (at your option) any later version.
11 | *
12 | * This program is distributed in the hope that it will be useful,
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 | * GNU General Public License for more details.
16 | *
17 | * You should have received a copy of the GNU General Public License
18 | * along with lsstack64. If not, see .
19 | */
20 |
21 | #include "log.h"
22 |
23 | extern int current_log_level;
24 | char *logarr[] = {"ERROR", "INFO", "DEBUG"};
25 |
26 | void debug_log(const char *file,
27 | const char *func,
28 | int line,
29 | int level,
30 | const char *format,
31 | ...)
32 | {
33 | va_list ap;
34 |
35 | va_start(ap, format);
36 |
37 | if (level < 0 || level > DEBUG)
38 | return;
39 |
40 | if (level <= current_log_level) {
41 | fprintf(stderr, "[%s, %s(), ln %d] %s: ",
42 | file, func, line, logarr[level]);
43 | vfprintf(stderr, format, ap);
44 | }
45 |
46 | va_end(ap);
47 | }
48 |
--------------------------------------------------------------------------------
/log.h:
--------------------------------------------------------------------------------
1 | /*
2 | * A modular, level based log file implementation
3 | *
4 | * Author: Arun Prakash Jana
5 | * Copyright (C) 2014, 2015 by Arun Prakash Jana
6 | *
7 | * This program is free software: you can redistribute it and/or modify
8 | * it under the terms of the GNU General Public License as published by
9 | * the Free Software Foundation, either version 3 of the License, or
10 | * (at your option) any later version.
11 | *
12 | * This program is distributed in the hope that it will be useful,
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 | * GNU General Public License for more details.
16 | *
17 | * You should have received a copy of the GNU General Public License
18 | * along with lsstack64. If not, see .
19 | */
20 |
21 | #pragma once
22 |
23 | #include
24 | #include
25 |
26 | #define ERROR 0
27 | #define INFO 1
28 | #define DEBUG 2
29 |
30 | #define log(level, format, ...) \
31 | debug_log(__FILE__, __func__, __LINE__, level, format, ##__VA_ARGS__)
32 |
33 | void debug_log(const char *file,
34 | const char *func,
35 | int line,
36 | int level,
37 | const char *format,
38 | ...) __attribute__((__format__(printf, 5, 6)));
39 |
--------------------------------------------------------------------------------
/lsstack.c:
--------------------------------------------------------------------------------
1 | /*
2 | * A modified version of lsstack utility for x86_64 Linux
3 | *
4 | * This program is free software: you can redistribute it and/or modify
5 | * it under the terms of the GNU General Public License as published by
6 | * the Free Software Foundation, either version 3 of the License, or
7 | * (at your option) any later version.
8 | *
9 | * This program is distributed in the hope that it will be useful,
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 | * GNU General Public License for more details.
13 | *
14 | * You should have received a copy of the GNU General Public License
15 | * along with lsstack64. If not, see .
16 | */
17 |
18 | /*
19 | * Copyright (c) 2002 Bozeman Pass, Inc.
20 | * Written by: David Boreham
21 | * Modified by Arun Prakash Jana (2015-)
22 | */
23 |
24 |
25 | /*
26 | Todo:
27 | install signal handler so we detatch and free the target if someone interrupts us.
28 | Figure out what we should be free()'ing at the end.
29 | Implement file and line number identification.
30 | Correctly handle the case where the target is expecting a signal as we attach to it.
31 | Correctly handle relative paths (LD_LIBRARY_PATH) on shared objects.
32 | */
33 |
34 | #include
35 | #include
36 | #include
37 | #include
38 | #include
39 | #include
40 | #include
41 | #include
42 |
43 | #include
44 | #include
45 | #include
46 |
47 | #include
48 |
49 | #include
50 |
51 | #include
52 | #include
53 | #include
54 |
55 | /* Header for 64-bit registers */
56 | #include
57 |
58 | #include "log.h"
59 |
60 | #ifndef false
61 | #define false 0
62 | #define true !false
63 | #endif
64 |
65 | int current_log_level = DEBUG;
66 | static int debug_option = 1;
67 | static int execute_option = 0;
68 | static int period_option = 0;
69 |
70 | static int wait_loops = 20;
71 | static int wait_time = 1;
72 | static const char* append_file = NULL;
73 |
74 | static int pointer_size = sizeof(void*); /* DBDB there has to be an official place to get this from */
75 |
76 | typedef Elf64_Addr TARGET_ADDRESS;
77 |
78 | struct _symbol_entry {
79 | TARGET_ADDRESS value;
80 | struct _symbol_entry *next;
81 | char *name;
82 | };
83 |
84 | typedef struct _symbol_entry symbol_entry;
85 |
86 |
87 | typedef struct _process_info {
88 | int pid;
89 | int threads_present_flag;
90 | TARGET_ADDRESS link_map_head;
91 | TARGET_ADDRESS link_map_current; /* Used to iterate through the link map */
92 | symbol_entry *symbols;
93 | int *thread_pids;
94 | int initial_thread_id;
95 | int manager_thread_id;
96 | } process_info;
97 |
98 |
99 | static void msleep(int msecs)
100 | {
101 | usleep(msecs*1000);
102 | }
103 |
104 | static int attach_target(int thepid)
105 | {
106 | TARGET_ADDRESS ret;
107 | int waitstatus;
108 | int x;
109 |
110 | log(DEBUG, "Attaching to the target process...\n");
111 | ret = ptrace(PTRACE_ATTACH, thepid, NULL, NULL);
112 |
113 | if (0 != ret && 0 != errno) {
114 | ret = errno;
115 | return ret;
116 | }
117 | /* ptrace(PTRACE_ATTACH) does the equivalent of sending a SIG_STOP to the target.
118 | So we should wait for that signal to be handled before proceeding.
119 | */
120 | log(DEBUG, "Waiting for target process to stop...\n");
121 | x = 0;
122 | while (x < wait_loops) {
123 | ret = waitpid(thepid, &waitstatus, WUNTRACED | WNOHANG);
124 | if (debug_option) {
125 | log(DEBUG, "waitpid after attach returned: %ld, status=%d\n", ret, waitstatus);
126 | }
127 | if (WIFSTOPPED(waitstatus)) {
128 | return 0;
129 | }
130 | msleep(wait_time); /* Sleep for a bit so we don't busy wait */
131 | x++;
132 | }
133 | log(DEBUG, "Target process has stopped.\n");
134 |
135 | /* If we did attach, install a signal handler to allow us to detatch if we're interrupted */
136 | if (0 == errno) {
137 | /* DBDB implement this */
138 | /* Try to catch the following signals:
139 | SIGINT, SIGSEV,
140 | */
141 | }
142 |
143 | return errno;
144 | }
145 |
146 | static int attach_thread(int threadpid)
147 | {
148 | TARGET_ADDRESS ret;
149 | int waitstatus;
150 |
151 | log(DEBUG, "Attaching to the target thread %d...\n", threadpid);
152 | ret = ptrace(PTRACE_ATTACH, threadpid, NULL, NULL);
153 |
154 | if (0 != ret && 0 != errno) {
155 | perror("ptrace(PTRACE_ATTACH)");
156 | return errno;
157 | }
158 | while (1) {
159 | ret = waitpid(threadpid, &waitstatus, __WCLONE);
160 | if (ret > 0) {
161 | break;
162 | }
163 | }
164 |
165 | return errno;
166 | }
167 |
168 | static int detatch_target(process_info *pi)
169 | {
170 | TARGET_ADDRESS ret;
171 | if (pi->threads_present_flag) {
172 | int thread_pid = 0;
173 | int x = 0;
174 | log(DEBUG, "Detatching from threads...\n");
175 | for (x = 1; (pi->thread_pids)[x];x++) {
176 | thread_pid = (pi->thread_pids)[x];
177 | log(DEBUG, "Detatching from thread %d\n", thread_pid);
178 | ret = ptrace(PTRACE_CONT, thread_pid, 1, 0);
179 | log(DEBUG, "ptrace(PTRACE_CONT) returned: %ld\n", ret);
180 | }
181 | }
182 | log(DEBUG, "Detaching from target...\n");
183 | ret = ptrace(PTRACE_DETACH, pi->pid, 0, 0);
184 | log(DEBUG, "ptrace(PTRACE_DETACH) returned: %ld\n", ret);
185 | return ret;
186 | }
187 |
188 | process_info *pi_alloc(int pid)
189 | {
190 | process_info* ret = (process_info*)calloc(sizeof(process_info),1);
191 | if (NULL != ret) {
192 | ret->pid = pid;
193 | }
194 | return ret;
195 | }
196 |
197 | void pi_free(process_info *pi)
198 | {
199 | free(pi);
200 | }
201 |
202 | /* Symbol table helper functions */
203 |
204 | void add_new_symbol(process_info *pi, symbol_entry *symbol)
205 | {
206 | symbol_entry *temp = pi->symbols;
207 | pi->symbols = symbol;
208 | symbol->next = temp;
209 | }
210 |
211 | int symbol_entry_from_asymbol(symbol_entry **outsym, asymbol *insym, TARGET_ADDRESS base_address)
212 | {
213 | int ret = 0;
214 | int size = 0;
215 |
216 | size = sizeof(symbol_entry) + strlen(bfd_asymbol_name(insym)) + 1;
217 | *outsym = (symbol_entry*) malloc(size);
218 | if (NULL == *outsym) {
219 | log(ERROR, "Failed to allocate space for symbol\n");
220 | return ENOMEM;
221 | }
222 | (*outsym)->name = (char*)(*outsym) + sizeof(symbol_entry);
223 |
224 | (*outsym)->value = bfd_asymbol_value(insym) + base_address;
225 |
226 | strcpy( (*outsym)->name ,bfd_asymbol_name(insym));
227 |
228 | return ret;
229 | }
230 |
231 | int get_symbol_address(TARGET_ADDRESS *address, process_info *pi, char *symbol)
232 | {
233 | int found = 0;
234 | symbol_entry *sym = NULL;
235 | log(DEBUG, "Fetching address for symbol: %s\n", symbol);
236 | for (sym = pi->symbols; sym; sym = sym->next) {
237 | if (0 == strcmp(sym->name,symbol)) {
238 | log(DEBUG, "Found symbol, value: 0x%lx\n", sym->value);
239 | found = 1;
240 | *address = sym->value;
241 | }
242 | }
243 | return found;
244 | }
245 |
246 | static int max_symbol_distance = 1024 * 256; /* Addresses more than 256K from a symbol are in space */
247 |
248 | int get_symbol_for_address(char** symbol, process_info *pi, TARGET_ADDRESS address, int include_difference)
249 | {
250 | int ret = 0;
251 | int distance = max_symbol_distance;
252 | symbol_entry *hit = NULL;
253 | symbol_entry *sym = NULL;
254 | *symbol = NULL;
255 | /* Dumb implementation---linear scan through the symbols */
256 | for (sym = pi->symbols; sym; sym = sym->next) {
257 | int d = (address - sym->value);
258 | if ( (d > 0) && (d < distance)) {
259 | distance = d;
260 | hit = sym;
261 | }
262 | }
263 | if (distance < max_symbol_distance) {
264 | *symbol = malloc(strlen(hit->name) + 30);
265 | if (NULL == *symbol) {
266 | log(ERROR, "Failed to allocate symbol string\n");
267 | return ENOMEM;
268 | }
269 | if (distance && include_difference) {
270 | sprintf(*symbol,"%s + %d",hit->name,distance);
271 | } else {
272 | sprintf(*symbol,"%s",hit->name);
273 | }
274 | } else {
275 | *symbol = strdup("");
276 | ret = -1;
277 | }
278 | return ret;
279 | }
280 |
281 | /* End of symbol table helper functions */
282 |
283 | /* Target memory read helper functions */
284 |
285 | TARGET_ADDRESS read_target_pointer(TARGET_ADDRESS *value, process_info *pi, TARGET_ADDRESS address)
286 | {
287 | TARGET_ADDRESS ret = 0;
288 | ret = ptrace(PTRACE_PEEKDATA, pi->pid, address, 0);
289 | if (errno) {
290 | ret = errno;
291 | } else {
292 | *value = (TARGET_ADDRESS) ret;
293 | ret = 0;
294 | }
295 | return ret;
296 | }
297 |
298 | TARGET_ADDRESS read_target_word(TARGET_ADDRESS *value, process_info *pi, TARGET_ADDRESS address)
299 | {
300 | TARGET_ADDRESS ret = 0;
301 | ret = ptrace(PTRACE_PEEKDATA, pi->pid, address, 0);
302 | if (errno) {
303 | ret = errno;
304 | } else {
305 | *value = ret;
306 | ret = 0;
307 | }
308 | return ret;
309 | }
310 |
311 | TARGET_ADDRESS read_target_userpointer(TARGET_ADDRESS *value, int thepid, TARGET_ADDRESS address)
312 | {
313 | TARGET_ADDRESS ret = 0;
314 | ret = ptrace(PTRACE_PEEKUSER, thepid, address, 0);
315 | if (errno) {
316 | ret = errno;
317 | } else {
318 | *value = (TARGET_ADDRESS) ret;
319 | ret = 0;
320 | }
321 | return ret;
322 | }
323 |
324 | int read_target_byte(char *value, process_info *pi, TARGET_ADDRESS address)
325 | {
326 | TARGET_ADDRESS ret = 0;
327 | /* Read a word at the target address, word aligned */
328 | TARGET_ADDRESS aligned_address = address & ~(pointer_size - 1);
329 | int byte = address - aligned_address;
330 | ret = ptrace(PTRACE_PEEKDATA, pi->pid, aligned_address);
331 | if (errno) {
332 | ret = errno;
333 | } else {
334 | *value = (ret >> (byte*8)) & 0xff;
335 | ret = 0;
336 | }
337 | return ret;
338 | }
339 |
340 | int read_target_memory(char *value, size_t length, process_info *pi, TARGET_ADDRESS address)
341 | {
342 | /* We need to read word-aligned, otherwise ptrace blows up */
343 | int ret = 0;
344 | size_t offset = 0;
345 | for (offset = 0; offset < length; offset++ ) {
346 | ret = read_target_byte(value+offset, pi, address + offset);
347 | if (errno) {
348 | ret = errno;
349 | break;
350 | } else {
351 | ret = 0;
352 | }
353 | }
354 | return ret;
355 | }
356 |
357 | int read_target_string(char **value, process_info *pi, TARGET_ADDRESS address)
358 | {
359 | int ret = 0;
360 | int length = 0;
361 | char byte = 0;
362 | int offset = 0;
363 |
364 | /* First find out the string length */
365 | do {
366 | ret = read_target_byte(&byte,pi,address + length);
367 | if (ret) {
368 | log(ERROR, "Failed to read string length from target address 0x%lx : %s\n", address+length, strerror(ret));
369 | return ret;
370 | }
371 | if (byte) {
372 | length++;
373 | }
374 | } while (byte);
375 | log(DEBUG, "read_target_string from address 0x%lx, length=%d\n", address, length);
376 | /* Now allocate memory for the string and terminator */
377 | *value = malloc(length + 1);
378 | if (NULL == *value) {
379 | log(ERROR, "Failed to allocate string buffer in read_target_string\n");
380 | return ENOMEM;
381 | }
382 |
383 | for (offset = 0; offset < (length + 1); offset ++) {
384 | ret = read_target_byte((*value + offset),pi,address+offset);
385 | if (ret) {
386 | log(ERROR, "Failed to read string from target: %s\n", strerror(ret));
387 | break;
388 | }
389 | }
390 | return ret;
391 | }
392 |
393 | void grok_and_print_program_counter(TARGET_ADDRESS pc, process_info *pi)
394 | {
395 | char *symbol = NULL;
396 | int ret = 0;
397 | /* Get the symbol for this address */
398 | ret = get_symbol_for_address(&symbol,pi,pc,0);
399 | if (ret) {
400 | log(INFO, "0x%016lx \n", pc);
401 | } else {
402 | log(INFO, "0x%016lx in %s \n", pc, symbol);
403 | }
404 | }
405 |
406 | /* We should get argument information from the debug data, but in the meantime we
407 | have to make do with the frame pointers. The compiler seems to set the frame pointer
408 | to 32-byte boundaries, so even when there is one argument, it looks like there are 6.
409 | For now, let's set a maximum number of arguments we want to print.
410 | */
411 |
412 | static TARGET_ADDRESS maximum_number_of_arguments = 4;
413 |
414 | int grok_and_print_function_arguments(TARGET_ADDRESS previous_bp,TARGET_ADDRESS next_bp, process_info *pi)
415 | {
416 | TARGET_ADDRESS ret = 0;
417 | TARGET_ADDRESS x = 0;
418 | TARGET_ADDRESS number_of_arguments = ((next_bp - previous_bp) / pointer_size) - 2;
419 |
420 | log(DEBUG, "Found %ld arguments\n", number_of_arguments);
421 | if (number_of_arguments > maximum_number_of_arguments) {
422 | number_of_arguments = maximum_number_of_arguments;
423 | }
424 | log(INFO, "(\n");
425 | for (x = 2; x < (number_of_arguments + 2); x++) {
426 | TARGET_ADDRESS parameter = 0;
427 | TARGET_ADDRESS argument_pointer = previous_bp + (pointer_size * x);
428 | log(DEBUG, "Reading argument from address 0x%016lx:", argument_pointer);
429 | ret = read_target_word(¶meter, pi, argument_pointer);
430 | if (ret) {
431 | log(ERROR, "Failed to read parameter from target: %s\n", strerror(ret));
432 | return ret;
433 | } else {
434 | log(INFO, " 0x%016lx\n", parameter);
435 | }
436 | }
437 | log(INFO, ")\n");
438 | return ret;
439 | }
440 |
441 | TARGET_ADDRESS grok_and_print_thread_stack(process_info *pi, int thepid)
442 | {
443 | TARGET_ADDRESS ret = 0;
444 | TARGET_ADDRESS ip;
445 | TARGET_ADDRESS bp;
446 | TARGET_ADDRESS previous_bp;
447 | TARGET_ADDRESS previous_ip;
448 | log(DEBUG, "RIP: %d, RBP: %d, pi->pid: %d\n", RIP, RBP, pi->pid);
449 | /* Get the IP and the BP */
450 | ret = read_target_userpointer(&ip,thepid,RIP * pointer_size);
451 | if (ret) {
452 | log(DEBUG, "Failed to read RIP from target: %s\n", strerror(ret));
453 | return ret;
454 | } else {
455 | log(DEBUG, "Read RIP: 0x%lx\n", ip);
456 | }
457 | ret = read_target_userpointer(&bp,thepid,RBP * pointer_size);
458 | if (ret) {
459 | log(DEBUG, "Failed to read RBP from target: %s\n", strerror(ret));
460 | return ret;
461 | } else {
462 | log(DEBUG, "Read RBP: 0x%lx\n", bp);
463 | }
464 | /* walk up the stack */
465 | previous_bp = bp;
466 | previous_ip = ip;
467 | while (1) {
468 |
469 | TARGET_ADDRESS next_bp;
470 | TARGET_ADDRESS next_ip;
471 |
472 | ret = read_target_pointer(&next_bp,pi,previous_bp);
473 | if (ret) {
474 | log(ERROR, "Failed to read next BP from target: errno: %ld (%s)\n", ret, strerror(ret));
475 | return ret;
476 | } else {
477 | log(DEBUG, "Read next BP: 0x%lx\n", next_bp);
478 | }
479 |
480 | ret = read_target_pointer(&next_ip,pi,previous_bp + pointer_size);
481 | if (ret) {
482 | log(ERROR, "Failed to read next IP from target: %s\n", strerror(ret));
483 | return ret;
484 | } else {
485 | log(DEBUG, "Read next IP: 0x%lx\n", next_ip);
486 | }
487 |
488 | grok_and_print_program_counter(previous_ip, pi);
489 |
490 | if (NULL == (void*)next_bp) {
491 | log(DEBUG, "Reached the top of the stack\n");
492 | log(INFO, "\n");
493 | break;
494 | } else {
495 | ret = grok_and_print_function_arguments(previous_bp, next_bp, pi);
496 | if (ret) {
497 | return ret;
498 | }
499 | }
500 |
501 | previous_bp = next_bp;
502 | previous_ip = next_ip;
503 | }
504 | return ret;
505 | }
506 |
507 | int grok_and_print_stacks(process_info *pi)
508 | {
509 | int ret = 0;
510 | if (pi->threads_present_flag) {
511 | int thread_pid;
512 | int x;
513 | for (x = 0; (pi->thread_pids)[x] ; x++) {
514 | char *thread_name = "";
515 | thread_pid = (pi->thread_pids)[x];
516 | if (thread_pid == pi->initial_thread_id) {
517 | thread_name = " (initial thread)";
518 | } else {
519 | if (thread_pid == pi->manager_thread_id) {
520 | thread_name = " (manager thread)";
521 | }
522 | }
523 | log(INFO, "LWP %d%s:\n", thread_pid, thread_name);
524 | ret = grok_and_print_thread_stack(pi,thread_pid);
525 | if (ret) {
526 | break;
527 | }
528 | }
529 | } else {
530 | ret = grok_and_print_thread_stack(pi,pi->pid);
531 | }
532 | return ret;
533 | }
534 |
535 | /* End of target memory read helper functions */
536 |
537 | int grok_threads(process_info *pi)
538 | {
539 | TARGET_ADDRESS ret = 0;
540 | int thread_test_positive = 0;
541 | TARGET_ADDRESS loops = 0;
542 |
543 | /* Magic interaction with the pthread library here, copied from GDB */
544 |
545 | static char* magic_names[] = {
546 | "__pthread_threads_debug",
547 | "__pthread_handles",
548 | "__pthread_initial_thread",
549 | "__pthread_manager_thread",
550 | "__pthread_sizeof_handle",
551 | "__pthread_offsetof_descr",
552 | "__pthread_offsetof_pid",
553 | "__pthread_handles_num",
554 | NULL
555 | };
556 |
557 | static TARGET_ADDRESS magic_addresses[9] = {0};
558 |
559 | thread_test_positive = 1;
560 | for (loops = 0; NULL != magic_names[loops]; loops++) {
561 | ret = get_symbol_address(&magic_addresses[loops],pi,magic_names[loops]);
562 | if (!ret) {
563 | /* Failed to find one */
564 | thread_test_positive = 0;
565 | log(DEBUG, "Failed to find thread symbol %s\n", magic_names[loops]);
566 | break;
567 | } else {
568 | log(DEBUG, "Read thread symbol %s -> 0x%lx\n", magic_names[loops], magic_addresses[loops]);
569 | }
570 | }
571 |
572 |
573 | if (thread_test_positive) {
574 | /* we think that we have threads */
575 | TARGET_ADDRESS number_of_threads = 0;
576 | int *thread_pid_array = NULL;
577 |
578 | TARGET_ADDRESS handle_array = magic_addresses[1];
579 | TARGET_ADDRESS pid_offset = 0;
580 | TARGET_ADDRESS descriptor_offset = 0;
581 | TARGET_ADDRESS handle_size = 0;
582 | TARGET_ADDRESS initial_thread_descriptor, manager_thread_descriptor;
583 |
584 | /* How many ? */
585 | ret = read_target_word(&number_of_threads,pi,magic_addresses[7]);
586 | if (ret) {
587 | log(ERROR, "Failed to read number of threads from target: %s\n", strerror(ret));
588 | return ret;
589 | } else {
590 | log(DEBUG, "Found %ld threads\n", number_of_threads);
591 | }
592 |
593 | thread_pid_array = (int*) calloc(number_of_threads + 1, sizeof(int));
594 | if (NULL == thread_pid_array) {
595 | log(ERROR, "Failed to allocate thread pid array\n");
596 | return ENOMEM;
597 | }
598 |
599 | ret = read_target_pointer(&initial_thread_descriptor,pi,magic_addresses[2]);
600 | if (ret) {
601 | log(ERROR, "Failed to read initial thread descriptor from target: %s\n", strerror(ret));
602 | return ret;
603 | } else {
604 | log(DEBUG, "Initial thread descriptor: 0x%08lx\n", initial_thread_descriptor);
605 | }
606 | ret = read_target_pointer(&manager_thread_descriptor,pi,magic_addresses[3]);
607 | if (ret) {
608 | log(ERROR, "Failed to read manager thread descriptor from target: %s\n", strerror(ret));
609 | return ret;
610 | } else {
611 | log(DEBUG, "Manager thread descriptor: 0x%08lx\n", manager_thread_descriptor);
612 | }
613 | ret = read_target_word(&handle_size,pi,magic_addresses[4]);
614 | if (ret) {
615 | log(ERROR, "Failed to read handle size from target: %s\n", strerror(ret));
616 | return ret;
617 | } else {
618 | log(DEBUG, "Handle Size: %ld\n", handle_size);
619 | }
620 | ret = read_target_word(&pid_offset,pi,magic_addresses[6]);
621 | if (ret) {
622 | log(ERROR, "Failed to read pid offset from target: %s\n", strerror(ret));
623 | return ret;
624 | } else {
625 | log(DEBUG, "Pid offset: %ld\n", pid_offset);
626 | }
627 | ret = read_target_word(&descriptor_offset,pi,magic_addresses[5]);
628 | if (ret) {
629 | log(ERROR, "Failed to read descriptor offset from target: %s\n", strerror(ret));
630 | return ret;
631 | } else {
632 | log(DEBUG, "Descriptor offset: %ld\n", descriptor_offset);
633 | }
634 |
635 | /* Fill in the pid array, attaching as we go */
636 |
637 | for (loops = 0; loops < number_of_threads; loops++) {
638 | TARGET_ADDRESS descriptor_address;
639 | TARGET_ADDRESS thread_pid = 0;
640 | ret = read_target_pointer(&descriptor_address,pi,handle_array + descriptor_offset + (handle_size * loops));
641 | if (ret) {
642 | log(ERROR, "Failed to read descriptor address from target: %s\n", strerror(ret));
643 | return ret;
644 | } else {
645 | log(DEBUG, "Descriptor Address: 0x%lx\n", descriptor_address);
646 | }
647 | ret = read_target_word(&thread_pid,pi,descriptor_address + pid_offset);
648 | if (ret) {
649 | log(ERROR, "Failed to read thread pid from target: %s\n", strerror(ret));
650 | return ret;
651 | } else {
652 | log(DEBUG, "Thread PID: %ld\n", thread_pid);
653 | }
654 |
655 | if (descriptor_address == initial_thread_descriptor) {
656 | pi->initial_thread_id = thread_pid;
657 | } else {
658 | if (descriptor_address == manager_thread_descriptor) {
659 | pi->manager_thread_id = thread_pid;
660 | }
661 | }
662 |
663 | if ((int)thread_pid != pi->pid) {
664 | ret = attach_thread(thread_pid);
665 | if (ret) {
666 | log(ERROR, "Failed to attach to target thread %ld : %s\n", thread_pid, strerror(ret));
667 | return ret;
668 | }
669 | }
670 |
671 | thread_pid_array[loops] = thread_pid;
672 | }
673 |
674 | pi->thread_pids = thread_pid_array;
675 | pi->threads_present_flag = 1;
676 | }
677 |
678 | return ret;
679 | }
680 |
681 | int process_symbol(process_info *pi, asymbol *sym, TARGET_ADDRESS base_address)
682 | {
683 | int ret = 0;
684 | symbol_entry *outsym = NULL;
685 | log(DEBUG, "Groking symbol: %s -> 0x%lx\n", bfd_asymbol_name(sym), bfd_asymbol_value(sym) + base_address);
686 | ret = symbol_entry_from_asymbol(&outsym,sym, base_address);
687 | if (!ret) {
688 | add_new_symbol(pi,outsym);
689 | }
690 | return ret;
691 | }
692 |
693 |
694 | int get_file_symbols(process_info *pi, char* filename, TARGET_ADDRESS base_address)
695 | {
696 | int ret = 0;
697 | char *target = NULL;
698 | bfd *file;
699 |
700 | log(DEBUG, "get_file_symbols for %s\n", filename);
701 |
702 | file = bfd_openr (filename, target);
703 | if (NULL == file) {
704 | const char *errmsg = bfd_errmsg (bfd_get_error ());
705 | log(ERROR, "Failed to open file: %s (%s)\n", filename, errmsg);
706 | return -1;
707 | }
708 | log(DEBUG, "opened file ok\n");
709 | /* We have to do this otherwise bfd crashes */
710 | bfd_check_format(file,bfd_object);
711 | /* Now get the symbols */
712 |
713 | {
714 | long storage_needed;
715 | asymbol **symbol_table;
716 | long number_of_symbols;
717 | long i;
718 | int dynamic = 0;
719 |
720 | storage_needed = bfd_get_symtab_upper_bound (file);
721 |
722 | if (storage_needed == 0) {
723 | log(DEBUG, "storage needed == 0, trying dynamic\n");
724 | dynamic = 1;
725 | storage_needed = bfd_get_dynamic_symtab_upper_bound (file);
726 | if (storage_needed == 0) {
727 | log(DEBUG, "storage needed still == 0, give up\n");
728 | return -1;
729 | }
730 | }
731 | log(DEBUG, "storage needed = %ld\n", storage_needed);
732 | symbol_table = (asymbol **) malloc (storage_needed);
733 | if (NULL == symbol_table) {
734 | log(ERROR,"failed to allocate symbol table buffer\n");
735 | return ENOMEM;
736 | }
737 |
738 | number_of_symbols = dynamic ?
739 | bfd_canonicalize_dynamic_symtab (file, symbol_table) :
740 | bfd_canonicalize_symtab (file, symbol_table);
741 |
742 | log(DEBUG, "found %ld symbols\n", number_of_symbols);
743 |
744 | for (i = 0; i < number_of_symbols; i++) {
745 | process_symbol (pi,symbol_table[i],base_address);
746 | }
747 | }
748 |
749 | if (bfd_close (file) == false) {
750 | log(ERROR, "Error closing file: %s\n", filename);
751 | return -1;
752 | }
753 | return ret;
754 | }
755 |
756 | int dynamic_libs_present(process_info *pi)
757 | {
758 | int ret = 0;
759 | /* If the symbol "_DYNAMIC" is present in the executable, then we return true and set the link map head in the pi. */
760 | TARGET_ADDRESS dynamic;
761 |
762 | ret = get_symbol_address(&dynamic,pi,"_DYNAMIC");
763 | if (ret) {
764 | /* Find the entry in the DYNAMIC array which has the valid entry we need. */
765 | int keep_looking = 1;
766 | int found_it = 0;
767 | TARGET_ADDRESS r_debug_address;
768 | while (keep_looking) {
769 | ElfW(Dyn) thisdyn;
770 | ret = read_target_memory((char*)&thisdyn, sizeof( ElfW(Dyn)), pi, dynamic);
771 | if (ret) {
772 | log(ERROR, "Error %d (%s) reading from DYNAMIC array\n", ret, strerror(ret));
773 | return 0;
774 | } else {
775 | if (debug_option) {
776 | log(INFO, "Read ElfW(Dyn) from address 0x%lx, tag=%ld, value=0x%lx\n",
777 | dynamic, thisdyn.d_tag, thisdyn.d_un.d_ptr);
778 | }
779 | }
780 | if (DT_NULL == thisdyn.d_tag) {
781 | log(DEBUG, "Found a DT_NULL entry\n");
782 | keep_looking = 0;
783 | }
784 | if (DT_DEBUG == thisdyn.d_tag) {
785 | log(DEBUG, "Found r_debug in _DYNAMIC array.\n");
786 | r_debug_address = thisdyn.d_un.d_ptr;
787 | keep_looking = 0;
788 | found_it = 1;
789 | }
790 | dynamic += sizeof( ElfW(Dyn));
791 | }
792 | if (!found_it) {
793 | log(DEBUG, "Didn't find r_debug in _DYNAMIC array.\n");
794 | return 0;
795 | }
796 |
797 | {
798 | /* Get the link map head */
799 | TARGET_ADDRESS link_map_address;
800 | int r_map_offset = offsetof(struct r_debug, r_map);
801 | /* Now we've found the r_debug structure, get the link map from it. */
802 | ret = read_target_pointer(&link_map_address, pi, r_debug_address + r_map_offset );
803 | if (ret) {
804 | log(DEBUG, "Failed to read link map address.\n");
805 | } else {
806 | log(DEBUG, "Read r_map: 0x%lx\n", link_map_address);
807 | pi->link_map_head = link_map_address;
808 | pi->link_map_current = link_map_address;
809 | }
810 | }
811 | ret = 1;
812 | } else {
813 | log(DEBUG, "No _DYNAMIC symbol found in executable\n");
814 | ret = 0;
815 | }
816 | return ret;
817 | }
818 |
819 | int get_next_so_file_name(char** file_name, process_info *pi, TARGET_ADDRESS *base_address, int *more)
820 | {
821 | int ret = 0;
822 | struct link_map lm;
823 | /* Are we at the end of the list ? */
824 | if (NULL == (void*)pi->link_map_current) {
825 | *more = 0;
826 | return 0;
827 | } else {
828 | *more = 1;
829 | }
830 | /* Dereference the current pointer to get the filename */
831 | ret = read_target_memory((void*)&lm,sizeof(lm),pi,pi->link_map_current);
832 | if (ret) {
833 | log(ERROR, "Failed to read link map structure from target.\n");
834 | return ret;
835 | } else {
836 | log(DEBUG, "Read link_map entry from address 0x%lx, base=0x%lx, name=0x%lx, next=0x%lx\n",
837 | (TARGET_ADDRESS)lm.l_addr, pi->link_map_current, (TARGET_ADDRESS)lm.l_name, (TARGET_ADDRESS)lm.l_next);
838 | }
839 | ret = read_target_string(file_name,pi,(TARGET_ADDRESS)lm.l_name);
840 | if (ret) {
841 | log(ERROR, "Failed to copy filename from target.\n");
842 | return ret;
843 | } else {
844 | log(DEBUG, "Copied filename: '%s' from target\n", *file_name);
845 | }
846 | *base_address = (TARGET_ADDRESS)lm.l_addr;
847 | /* Advance down the linked list */
848 | pi->link_map_current = (TARGET_ADDRESS)lm.l_next;
849 | return ret;
850 | }
851 |
852 | int grok_symbols(process_info *pi)
853 | {
854 | int ret = 0;
855 | /* There are symbols in the executable, and also in any dynamic libraries it has loaded
856 | So we first get the executable's symbols, then look for dynamic libraries and get those too.
857 | */
858 | /* First fill in the process executable file */
859 | char *format_string = "/proc/%d/exe";
860 | char *exe_file_name = calloc(strlen(format_string) + 10 ,1);
861 |
862 | bfd_init();
863 |
864 | sprintf(exe_file_name,format_string,pi->pid);
865 | log(DEBUG, "Fetching symbols from executable: %s\n", exe_file_name);
866 | ret = get_file_symbols(pi,exe_file_name,0);
867 | if (!ret) {
868 | if (dynamic_libs_present(pi)) {
869 | int more_libs_to_check = 1;
870 | char *so_file_name = NULL;
871 | TARGET_ADDRESS base_address;
872 | while(more_libs_to_check) {
873 | ret = get_next_so_file_name(&so_file_name,pi,&base_address,&more_libs_to_check);
874 | if (ret) {
875 | return ret;
876 | }
877 | if (strlen(so_file_name) > 0) {
878 | log(DEBUG, "Fetching symbols from shared object: %s\n", so_file_name);
879 | get_file_symbols(pi,so_file_name, base_address);
880 | } else {
881 | log(DEBUG, "Skipping zero length so file name\n");
882 | }
883 | }
884 | }
885 | }
886 | return ret;
887 | }
888 |
889 | static void fatal(char* s)
890 | {
891 | log(ERROR, "lsstack: fatal error: %s\n", s);
892 | exit(0);
893 | }
894 |
895 | static void usage()
896 | {
897 | printf("lsstack: [-v] [-D] [-p peridod_in_ms] [-o file_to_append] { | -e program arguments}\n");
898 | exit(1);
899 | }
900 |
901 | int main(int argc, char** argv)
902 | {
903 | /* look for command line options */
904 | int pid = 0;
905 | int ret = 0;
906 | process_info *pi = NULL;
907 | int option_position = 1;
908 |
909 | struct utsname buf;
910 | memset(&buf, 0, sizeof(struct utsname));
911 |
912 | if (uname(&buf) == 0) {
913 | if (strcmp(buf.machine, "x86_64") == 0) {
914 | log(ERROR, "lsstack64 fails on x86_64 platform. Use unwind.");
915 | return -1;
916 | }
917 | } else
918 | log(ERROR, "uname() failed. Assuming 32-bit platform.");
919 |
920 | while ( option_position < (argc-1) && *argv[option_position] == '-') {
921 | switch (*(argv[option_position]+1)) {
922 | case 'v':
923 | current_log_level = DEBUG;
924 | break;
925 | case 'D':
926 | current_log_level = DEBUG;
927 | break;
928 | case 'e':
929 | execute_option = 1;
930 | break;
931 | case 'p':
932 | ++option_position;
933 | period_option = atoi(argv[option_position]);
934 | break;
935 | case 'o':
936 | ++option_position;
937 | append_file = argv[option_position];
938 | break;
939 | default:
940 | usage();
941 | break;
942 | }
943 | option_position++;
944 | if(execute_option) {
945 | break;
946 | }
947 | }
948 | if (execute_option) {
949 | pid = fork();
950 | if (pid) {
951 | execvp(argv[option_position], argv+option_position);
952 | return 1;
953 | } else {
954 | pid = getppid();
955 | msleep(1);
956 | }
957 | } else {
958 | if (option_position != (argc-1)) {
959 | usage();
960 | }
961 | pid = atoi(argv[option_position]);
962 | if (0 == pid) {
963 | usage();
964 | }
965 | }
966 |
967 | if (append_file) {
968 | close(1);
969 | int fd = open(append_file, O_WRONLY|O_APPEND|O_CREAT, 0666);
970 | dup2(fd, 1);
971 | }
972 |
973 | if (debug_option) {
974 | log(INFO, "pid: %d\n", pid);
975 | }
976 |
977 | /* check that the pesky user hasn't tried to lsstack himself */
978 | if (pid == getpid()) {
979 | log(ERROR, "Error: specified pid belongs to the lsstack process\n");
980 | exit(1);
981 | }
982 |
983 | here_we_go_in_polling_mode:
984 |
985 | /* See if we can attach to the target */
986 | ret = attach_target(pid);
987 |
988 | if (ret) {
989 | if(!period_option) {
990 | log(ERROR, "Failed to attach to the target process: %s\n", strerror(ret));
991 | }
992 | exit(1);
993 | }
994 |
995 | log(DEBUG, "Attached to target process\n");
996 |
997 | pi = pi_alloc(pid);
998 | if (NULL == pi) fatal("failed to allocate process info structure\n");
999 |
1000 | ret = grok_symbols(pi);
1001 |
1002 | ret = grok_threads(pi);
1003 |
1004 | ret = grok_and_print_stacks(pi);
1005 |
1006 | detatch_target(pi);
1007 |
1008 | pi_free(pi);
1009 |
1010 | log(DEBUG, "Detatched from target process\n");
1011 |
1012 | if(period_option) {
1013 | msleep(period_option);
1014 | goto here_we_go_in_polling_mode;
1015 | }
1016 |
1017 | return 0;
1018 | }
1019 |
1020 |
--------------------------------------------------------------------------------
/unwind.c:
--------------------------------------------------------------------------------
1 | /*
2 | * Program to unwind the stack frames of a x86_64 process using libunwind
3 | *
4 | * Author: Arun Prakash Jana
5 | * Copyright (C) 2014, 2015 by Arun Prakash Jana
6 | *
7 | * This program is free software: you can redistribute it and/or modify
8 | * it under the terms of the GNU General Public License as published by
9 | * the Free Software Foundation, either version 3 of the License, or
10 | * (at your option) any later version.
11 | *
12 | * This program is distributed in the hope that it will be useful,
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 | * GNU General Public License for more details.
16 | *
17 | * You should have received a copy of the GNU General Public License
18 | * along with lsstack64. If not, see .
19 | */
20 |
21 | #include
22 | #include
23 | #include
24 | #include
25 | #include
26 | #include
27 | #include
28 | #include
29 | #include
30 |
31 | #include "log.h"
32 |
33 | #define WAIT_TIME 1000
34 | #define MAX_STACK_DEPTH 32
35 |
36 | int current_log_level = DEBUG;
37 |
38 | int process_stack(pid_t PID)
39 | {
40 | unw_addr_space_t addrspace;
41 | struct UPT_info *uptinfo = NULL;
42 | unw_proc_info_t procinfo;
43 | unw_cursor_t cursor;
44 | unw_word_t RIP, RSP, RBP, offset;
45 |
46 | int ret = 0, step = 0;
47 | int wait_loops = 20;
48 | int waitstatus;
49 | int stopped = 0;
50 | char procname[512] = {0};
51 | size_t len;
52 |
53 | FILE* fp;
54 | char psbuf[64];
55 | pid_t MID = -1; /* Main thread ID */
56 |
57 | /* Create address space for little endian */
58 | addrspace = unw_create_addr_space(&_UPT_accessors, 0);
59 | if (!addrspace) {
60 | log(ERROR, "unw_create_addr_space failed\n");
61 | return -1;
62 | }
63 |
64 | /* Check if this is the main thread or a child thread.
65 | If child thread, we need to stop main thread as well. */
66 | sprintf(psbuf, "%s %d %s", "ps -aeLf | grep -w", PID, "| awk '{ print $2, $4 }'");
67 |
68 | fp = popen(psbuf, "r");
69 | if (fp) {
70 | char pid[16] = {0};
71 | char lwp[16] = {0}; /* LWP: Light Weight Process. LWP == PID for main thread. */
72 | int i, j;
73 | while (fgets(psbuf, sizeof(psbuf) - 1, fp) != NULL) {
74 | for (i = 0; psbuf[i] != '\n' && psbuf[i] != '\0'; i++) {
75 | if (psbuf[i] == ' ')
76 | break;
77 | else
78 | pid[i] = psbuf[i];
79 | }
80 |
81 | pid[++i] = '\0';
82 | j = 0;
83 |
84 | for (; psbuf[i] != '\n' && psbuf[i] != '\0'; i++)
85 | lwp[j++] = psbuf[i];
86 |
87 | lwp[j] = '\0';
88 |
89 | log(DEBUG, "From ps: pid [%s] lwp [%s]\n", pid, lwp);
90 |
91 | if (pid[0] && lwp[0]) {
92 | if (PID == atoi(lwp)) {
93 | if (strcmp(lwp, pid) == 0) {
94 | log(DEBUG, "This is the main thread.\n\n\n");
95 | break;
96 | } else {
97 | MID = atoi(pid);
98 | log(DEBUG, "This is a child thread of main thread %d.\n\n\n", MID);
99 | break;
100 | }
101 | }
102 | }
103 | }
104 |
105 | pclose(fp);
106 | } else {
107 | log(ERROR, "popen failed. errno: %d (%s)\n", errno, strerror(errno));
108 | }
109 |
110 | if (MID != -1) {
111 | ret = ptrace(PTRACE_ATTACH, MID, NULL, NULL);
112 | if (0 != ret && 0 != errno) {
113 | log(ERROR, "ptrace failed. errno: %d (%s)\n", errno, strerror(errno));
114 | unw_destroy_addr_space(addrspace);
115 | return -1;
116 | }
117 |
118 | while (wait_loops-- > 0) {
119 | ret = waitpid(MID, &waitstatus, WUNTRACED | WNOHANG);
120 | if (WIFSTOPPED(waitstatus)) {
121 | stopped = 1;
122 | break;
123 | }
124 | usleep(WAIT_TIME);
125 | }
126 |
127 | if (!stopped) {
128 | log(ERROR, "Main thread of process %d couldn't be stopped\n", MID);
129 | ret = -1;
130 | goto bail;
131 | }
132 | }
133 |
134 | ret = ptrace(PTRACE_ATTACH, PID, NULL, NULL);
135 | if (0 != ret && 0 != errno) {
136 | log(ERROR, "ptrace failed. errno: %d (%s)\n", errno, strerror(errno));
137 | if (MID != -1)
138 | ptrace(PTRACE_DETACH, MID, NULL, NULL);
139 | unw_destroy_addr_space(addrspace);
140 | return -1;
141 | }
142 |
143 | while (wait_loops-- > 0) {
144 | ret = waitpid(PID, &waitstatus, WUNTRACED | WNOHANG);
145 | if (WIFSTOPPED(waitstatus)) {
146 | stopped = 1;
147 | break;
148 | }
149 | usleep(WAIT_TIME);
150 | }
151 |
152 | if (!stopped) {
153 | log(ERROR, "Process %d couldn't be stopped\n", PID);
154 | ret = -1;
155 | goto bail;
156 | }
157 |
158 | uptinfo = (struct UPT_info *)_UPT_create(PID);
159 | if (!uptinfo) {
160 | log(ERROR, "_UPT_create failed\n");
161 | ret = -1;
162 | goto bail;
163 | }
164 |
165 | ret = unw_init_remote(&cursor, addrspace, (void *)uptinfo);
166 | if (ret < 0) {
167 | log(ERROR, "unw_init_remote failed\n");
168 | goto bail;
169 | }
170 |
171 | do {
172 | log(INFO, "STACK FRAME %d\n", step);
173 |
174 | if (unw_get_reg(&cursor, UNW_X86_64_RIP, &RIP) < 0 || unw_get_reg(&cursor, UNW_X86_64_RSP, &RSP) < 0
175 | || unw_get_reg(&cursor, UNW_X86_64_RBP, &RBP) < 0) {
176 | log(ERROR, "unw_get_reg RIP/RSP/RBP failed\n");
177 | ret = -1;
178 | goto bail;
179 | }
180 |
181 | procname[0] = '\0';
182 | unw_get_proc_name (&cursor, procname, sizeof(procname), &offset);
183 | if (offset) {
184 | len = strlen(procname);
185 | if (len >= sizeof(procname) - 32)
186 | len = sizeof(procname) - 32;
187 | sprintf((char *)(procname + len), "+0x%016lx", (unsigned long)offset);
188 | }
189 | log(INFO, "RIP = 0x%016lx %-32s\n", RIP, procname);
190 | log(INFO, "RSP = 0x%016lx RBP = 0x%016lx\n", RSP, RBP);
191 |
192 | ret = unw_get_proc_info (&cursor, &procinfo);
193 | if (ret < 0) {
194 | log(ERROR, "unw_get_proc_info failed. ret: %d\n", ret);
195 | goto bail;
196 | }
197 |
198 | log(INFO, "frame range = (0x%016lx <-> 0x%016lx)\n", procinfo.start_ip, procinfo.end_ip);
199 | log(INFO, "handler = %0lx lsda = %0lx\n\n\n", procinfo.handler, procinfo.lsda);
200 |
201 | ret = unw_step(&cursor);
202 | if (ret == 0) {
203 | log(DEBUG, "Last frame reached\n");
204 | goto bail;
205 | } else if (ret < 0) {
206 | log(ERROR, "unw_step failed. ret: %d\n", ret);
207 | goto bail;
208 | } else if (++step > MAX_STACK_DEPTH) {
209 | log(ERROR, "Too deeply nested. Breaking out.\n");
210 | ret = -1;
211 | goto bail;
212 | }
213 | } while (ret > 0);
214 |
215 | ret = 0;
216 |
217 | bail:
218 | if (uptinfo)
219 | _UPT_destroy(uptinfo);
220 | ptrace(PTRACE_DETACH, PID, NULL, NULL);
221 | if (MID != -1)
222 | ptrace(PTRACE_DETACH, MID, NULL, NULL);
223 | unw_destroy_addr_space(addrspace);
224 |
225 | return ret;
226 | }
227 |
228 | int main(int argc, char **argv)
229 | {
230 | pid_t PID = 1;
231 |
232 | if (argc !=2) {
233 | fprintf(stderr, "Usage: unwind PID\n");
234 | return -1;
235 | }
236 |
237 | if ((PID = atoi(argv[1])) <= 0) {
238 | fprintf(stderr, "Valid PID please!\n");
239 | return -1;
240 | }
241 |
242 | if (kill(PID, 0) == 0)
243 | log(INFO, "Tracing PID: %d\n\n", PID);
244 | else {
245 | log(ERROR, "kill failed. errno: %d (%s)\n", errno, strerror(errno));
246 | return -1;
247 | }
248 |
249 | if (process_stack(PID) != 0)
250 | log(ERROR, "Process stack printing failed\n");
251 |
252 | return 0;
253 | }
254 |
--------------------------------------------------------------------------------