├── LICENSE ├── Makefile ├── README.md ├── log.c ├── log.h ├── lsstack.c └── unwind.c /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. By contrast, 15 | the GNU General Public License is intended to guarantee your freedom to 16 | share and change all versions of a program--to make sure it remains free 17 | software for all its users. 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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 | [![Donate Button](https://img.shields.io/badge/paypal-donate-green.svg)](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 | --------------------------------------------------------------------------------