/*
* Copyright (c) 2013 Luca Clementi <luca.clementi@gmail.com>
+ * Copyright (c) 2013-2018 The strace developers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
*/
#include "defs.h"
-#include <limits.h>
-#include <libunwind-ptrace.h>
+#include "mmap_cache.h"
+#include "unwind.h"
+
+#ifdef USE_DEMANGLE
+# if defined HAVE_DEMANGLE_H
+# include <demangle.h>
+# elif defined HAVE_LIBIBERTY_DEMANGLE_H
+# include <libiberty/demangle.h>
+# endif
+#endif
/*
- * Кeep a sorted array of cache entries,
- * so that we can binary search through it.
+ * Type used in stacktrace capturing
*/
-struct mmap_cache_t {
- /**
- * example entry:
- * 7fabbb09b000-7fabbb09f000 r--p 00179000 fc:00 1180246 /lib/libc-2.11.1.so
- *
- * start_addr is 0x7fabbb09b000
- * end_addr is 0x7fabbb09f000
- * mmap_offset is 0x179000
- * binary_filename is "/lib/libc-2.11.1.so"
- */
- unsigned long start_addr;
- unsigned long end_addr;
- unsigned long mmap_offset;
- char* binary_filename;
+struct call_t {
+ struct call_t *next;
+ char *output_line;
+};
+
+struct unwind_queue_t {
+ struct call_t *tail;
+ struct call_t *head;
};
-static unw_addr_space_t libunwind_as;
+static void queue_print(struct unwind_queue_t *queue);
+
+static const char asprintf_error_str[] = "???";
void
-init_unwind_addr_space(void)
+unwind_init(void)
{
- libunwind_as = unw_create_addr_space(&_UPT_accessors, 0);
- if (!libunwind_as)
- error_msg_and_die("failed to create address space for stack tracing");
+ if (unwinder.init)
+ unwinder.init();
+ mmap_cache_enable();
}
void
-init_libunwind_ui(struct tcb *tcp)
+unwind_tcb_init(struct tcb *tcp)
{
- tcp->libunwind_ui = _UPT_create(tcp->pid);
- if (!tcp->libunwind_ui)
- die_out_of_memory();
+ if (tcp->unwind_queue)
+ return;
+
+ tcp->unwind_queue = xmalloc(sizeof(*tcp->unwind_queue));
+ tcp->unwind_queue->head = NULL;
+ tcp->unwind_queue->tail = NULL;
+
+ tcp->unwind_ctx = unwinder.tcb_init(tcp);
}
void
-free_libunwind_ui(struct tcb *tcp)
+unwind_tcb_fin(struct tcb *tcp)
{
- _UPT_destroy(tcp->libunwind_ui);
- tcp->libunwind_ui = NULL;
+ if (!tcp->unwind_queue)
+ return;
+
+ queue_print(tcp->unwind_queue);
+ free(tcp->unwind_queue);
+ tcp->unwind_queue = NULL;
+
+ unwinder.tcb_fin(tcp);
+ tcp->unwind_ctx = NULL;
}
/*
- * caching of /proc/ID/maps for each process to speed up stack tracing
+ * printing an entry in stack to stream or buffer
+ */
+/*
+ * we want to keep the format used by backtrace_symbols from the glibc
*
- * The cache must be refreshed after some syscall: mmap, mprotect, munmap, execve
+ * ./a.out() [0x40063d]
+ * ./a.out() [0x4006bb]
+ * ./a.out() [0x4006c6]
+ * /lib64/libc.so.6(__libc_start_main+0xed) [0x7fa2f8a5976d]
+ * ./a.out() [0x400569]
*/
-void
-alloc_mmap_cache(struct tcb* tcp)
+#define STACK_ENTRY_SYMBOL_FMT(SYM) \
+ " > %s(%s+0x%lx) [0x%lx]\n", \
+ binary_filename, \
+ (SYM), \
+ (unsigned long) function_offset, \
+ true_offset
+#define STACK_ENTRY_NOSYMBOL_FMT \
+ " > %s() [0x%lx]\n", \
+ binary_filename, true_offset
+#define STACK_ENTRY_BUG_FMT \
+ " > BUG IN %s\n"
+#define STACK_ENTRY_ERROR_WITH_OFFSET_FMT \
+ " > %s [0x%lx]\n", error, true_offset
+#define STACK_ENTRY_ERROR_FMT \
+ " > %s\n", error
+
+static void
+print_call_cb(void *dummy,
+ const char *binary_filename,
+ const char *symbol_name,
+ unwind_function_offset_t function_offset,
+ unsigned long true_offset)
{
- unsigned long start_addr, end_addr, mmap_offset;
- char filename[sizeof ("/proc/0123456789/maps")];
- char buffer[PATH_MAX + 80];
- char binary_path[PATH_MAX];
- struct mmap_cache_t *cur_entry, *prev_entry;
- /* start with a small dynamically-allocated array and then expand it */
- size_t cur_array_size = 10;
- struct mmap_cache_t *cache_head;
- FILE *fp;
-
- sprintf(filename, "/proc/%d/maps", tcp->pid);
- fp = fopen(filename, "r");
- if (!fp) {
- perror_msg("fopen: %s", filename);
- return;
+ if (symbol_name && (symbol_name[0] != '\0')) {
+#ifdef USE_DEMANGLE
+ char *demangled_name =
+ cplus_demangle(symbol_name,
+ DMGL_AUTO | DMGL_PARAMS);
+#endif
+ tprintf(STACK_ENTRY_SYMBOL_FMT(
+#ifdef USE_DEMANGLE
+ demangled_name ? demangled_name :
+#endif
+ symbol_name));
+#ifdef USE_DEMANGLE
+ free(demangled_name);
+#endif
}
+ else if (binary_filename)
+ tprintf(STACK_ENTRY_NOSYMBOL_FMT);
+ else
+ tprintf(STACK_ENTRY_BUG_FMT, __func__);
- cache_head = calloc(cur_array_size, sizeof(*cache_head));
- if (!cache_head)
- die_out_of_memory();
-
- while (fgets(buffer, sizeof(buffer), fp) != NULL) {
- binary_path[0] = '\0'; // 'reset' it just to be paranoid
-
- sscanf(buffer, "%lx-%lx %*c%*c%*c%*c %lx %*x:%*x %*d %[^\n]",
- &start_addr, &end_addr, &mmap_offset, binary_path);
-
- /* ignore special 'fake files' like "[vdso]", "[heap]", "[stack]", */
- if (binary_path[0] == '[') {
- continue;
- }
-
- if (binary_path[0] == '\0') {
- continue;
- }
-
- if (end_addr < start_addr)
- perror_msg_and_die("%s: unrecognized maps file format",
- filename);
-
- cur_entry = &cache_head[tcp->mmap_cache_size];
- cur_entry->start_addr = start_addr;
- cur_entry->end_addr = end_addr;
- cur_entry->mmap_offset = mmap_offset;
- cur_entry->binary_filename = strdup(binary_path);
-
- /*
- * sanity check to make sure that we're storing
- * non-overlapping regions in ascending order
- */
- if (tcp->mmap_cache_size > 0) {
- prev_entry = &cache_head[tcp->mmap_cache_size - 1];
- if (prev_entry->start_addr >= cur_entry->start_addr)
- perror_msg_and_die("Overlaying memory region in %s",
- filename);
- if (prev_entry->end_addr > cur_entry->start_addr)
- perror_msg_and_die("Overlaying memory region in %s",
- filename);
- }
- tcp->mmap_cache_size++;
-
- /* resize doubling its size */
- if (tcp->mmap_cache_size >= cur_array_size) {
- cur_array_size *= 2;
- cache_head = realloc(cache_head, cur_array_size * sizeof(*cache_head));
- if (!cache_head)
- die_out_of_memory();
- }
+ line_ended();
+}
+
+static void
+print_error_cb(void *dummy,
+ const char *error,
+ unsigned long true_offset)
+{
+ if (true_offset)
+ tprintf(STACK_ENTRY_ERROR_WITH_OFFSET_FMT);
+ else
+ tprintf(STACK_ENTRY_ERROR_FMT);
+
+ line_ended();
+}
+
+static char *
+sprint_call_or_error(const char *binary_filename,
+ const char *symbol_name,
+ unwind_function_offset_t function_offset,
+ unsigned long true_offset,
+ const char *error)
+{
+ char *output_line = NULL;
+ int n;
+
+ if (symbol_name) {
+#ifdef USE_DEMANGLE
+ char *demangled_name =
+ cplus_demangle(symbol_name,
+ DMGL_AUTO | DMGL_PARAMS);
+#endif
+ n = asprintf(&output_line,
+ STACK_ENTRY_SYMBOL_FMT(
+#ifdef USE_DEMANGLE
+ demangled_name ? demangled_name :
+#endif
+ symbol_name));
+#ifdef USE_DEMANGLE
+ free(demangled_name);
+#endif
}
- fclose(fp);
- tcp->mmap_cache = cache_head;
+ else if (binary_filename)
+ n = asprintf(&output_line, STACK_ENTRY_NOSYMBOL_FMT);
+ else if (error)
+ n = true_offset
+ ? asprintf(&output_line, STACK_ENTRY_ERROR_WITH_OFFSET_FMT)
+ : asprintf(&output_line, STACK_ENTRY_ERROR_FMT);
+ else
+ n = asprintf(&output_line, STACK_ENTRY_BUG_FMT, __func__);
+
+ if (n < 0) {
+ perror_func_msg("asprintf");
+ output_line = (char *) asprintf_error_str;
+ }
+
+ return output_line;
}
-/* deleting the cache */
-void
-delete_mmap_cache(struct tcb* tcp)
+/*
+ * queue manipulators
+ */
+static void
+queue_put(struct unwind_queue_t *queue,
+ const char *binary_filename,
+ const char *symbol_name,
+ unwind_function_offset_t function_offset,
+ unsigned long true_offset,
+ const char *error)
{
- unsigned int i;
- for (i = 0; i < tcp->mmap_cache_size; i++) {
- free(tcp->mmap_cache[i].binary_filename);
- tcp->mmap_cache[i].binary_filename = NULL;
+ struct call_t *call;
+
+ call = xmalloc(sizeof(*call));
+ call->output_line = sprint_call_or_error(binary_filename,
+ symbol_name,
+ function_offset,
+ true_offset,
+ error);
+ call->next = NULL;
+
+ if (!queue->head) {
+ queue->head = call;
+ queue->tail = call;
+ } else {
+ queue->tail->next = call;
+ queue->tail = call;
}
- free(tcp->mmap_cache);
- tcp->mmap_cache = NULL;
- tcp->mmap_cache_size = 0;
}
-/* use libunwind to unwind the stack and print a backtrace */
-void
-print_stacktrace(struct tcb* tcp)
+static void
+queue_put_call(void *queue,
+ const char *binary_filename,
+ const char *symbol_name,
+ unwind_function_offset_t function_offset,
+ unsigned long true_offset)
{
- unw_word_t ip;
- unw_cursor_t cursor;
- unw_word_t function_off_set;
- int stack_depth = 0, ret_val;
- /* these are used for the binary search through the mmap_chace */
- unsigned int lower, upper, mid;
- size_t symbol_name_size = 40;
- char * symbol_name;
- struct mmap_cache_t* cur_mmap_cache;
- unsigned long true_offset;
-
- if (!tcp->mmap_cache)
- alloc_mmap_cache(tcp);
- if (!tcp->mmap_cache || !tcp->mmap_cache_size)
- return;
+ queue_put(queue,
+ binary_filename,
+ symbol_name,
+ function_offset,
+ true_offset,
+ NULL);
+}
+
+static void
+queue_put_error(void *queue,
+ const char *error,
+ unsigned long ip)
+{
+ queue_put(queue, NULL, NULL, 0, ip, error);
+}
- symbol_name = malloc(symbol_name_size);
- if (!symbol_name)
- die_out_of_memory();
+static void
+queue_print(struct unwind_queue_t *queue)
+{
+ struct call_t *call, *tmp;
- if (unw_init_remote(&cursor, libunwind_as, tcp->libunwind_ui) < 0)
- perror_msg_and_die("Can't initiate libunwind");
+ queue->tail = NULL;
+ call = queue->head;
+ queue->head = NULL;
+ while (call) {
+ tmp = call;
+ call = call->next;
- do {
- /* looping on the stack frame */
- if (unw_get_reg(&cursor, UNW_REG_IP, &ip) < 0) {
- perror_msg("Can't walk the stack of process %d", tcp->pid);
- break;
- }
-
- lower = 0;
- upper = tcp->mmap_cache_size - 1;
-
- while (lower <= upper) {
- /* find the mmap_cache and print the stack frame */
- mid = (upper + lower) / 2;
- cur_mmap_cache = &tcp->mmap_cache[mid];
-
- if (ip >= cur_mmap_cache->start_addr &&
- ip < cur_mmap_cache->end_addr) {
- for (;;) {
- symbol_name[0] = '\0';
- ret_val = unw_get_proc_name(&cursor, symbol_name,
- symbol_name_size, &function_off_set);
- if (ret_val != -UNW_ENOMEM)
- break;
- symbol_name_size *= 2;
- symbol_name = realloc(symbol_name, symbol_name_size);
- if (!symbol_name)
- die_out_of_memory();
- }
-
- true_offset = ip - cur_mmap_cache->start_addr +
- cur_mmap_cache->mmap_offset;
- if (symbol_name[0]) {
- /*
- * we want to keep the format used by backtrace_symbols from the glibc
- *
- * ./a.out() [0x40063d]
- * ./a.out() [0x4006bb]
- * ./a.out() [0x4006c6]
- * /lib64/libc.so.6(__libc_start_main+0xed) [0x7fa2f8a5976d]
- * ./a.out() [0x400569]
- */
- tprintf(" > %s(%s+0x%lx) [0x%lx]\n",
- cur_mmap_cache->binary_filename,
- symbol_name, function_off_set, true_offset);
- } else {
- tprintf(" > %s() [0x%lx]\n",
- cur_mmap_cache->binary_filename, true_offset);
- }
- line_ended();
- break; /* stack frame printed */
- }
- else if (mid == 0) {
- /*
- * there is a bug in libunwind >= 1.0
- * after a set_tid_address syscall
- * unw_get_reg returns IP == 0
- */
- if(ip)
- tprintf(" > backtracing_error\n");
- line_ended();
- goto ret;
- }
- else if (ip < cur_mmap_cache->start_addr)
- upper = mid;
- else
- lower = mid + 1;
-
- }
- if (lower > upper) {
- tprintf(" > backtracing_error [0x%lx]\n", ip);
- line_ended();
- goto ret;
- }
-
- ret_val = unw_step(&cursor);
-
- if (++stack_depth > 255) {
- tprintf("> too many stack frames\n");
- line_ended();
+ tprints(tmp->output_line);
+ line_ended();
+
+ if (tmp->output_line != asprintf_error_str)
+ free(tmp->output_line);
+
+ tmp->output_line = NULL;
+ tmp->next = NULL;
+ free(tmp);
+ }
+}
+
+/*
+ * printing stack
+ */
+void
+unwind_tcb_print(struct tcb *tcp)
+{
+#if SUPPORTED_PERSONALITIES > 1
+ if (tcp->currpers != DEFAULT_PERSONALITY) {
+ /* disable stack trace */
+ return;
+ }
+#endif
+ if (tcp->unwind_queue->head) {
+ debug_func_msg("head: tcp=%p, queue=%p",
+ tcp, tcp->unwind_queue->head);
+ queue_print(tcp->unwind_queue);
+ } else switch (mmap_cache_rebuild_if_invalid(tcp, __func__)) {
+ case MMAP_CACHE_REBUILD_RENEWED:
+ unwinder.tcb_flush_cache(tcp);
+ ATTRIBUTE_FALLTHROUGH;
+ case MMAP_CACHE_REBUILD_READY:
+ debug_func_msg("walk: tcp=%p, queue=%p",
+ tcp, tcp->unwind_queue->head);
+ unwinder.tcb_walk(tcp, print_call_cb, print_error_cb, NULL);
break;
- }
- } while (ret_val > 0);
-ret:
- free(symbol_name);
+ default:
+ /* Do nothing */
+ ;
+ }
+}
+
+/*
+ * capturing stack
+ */
+void
+unwind_tcb_capture(struct tcb *tcp)
+{
+#if SUPPORTED_PERSONALITIES > 1
+ if (tcp->currpers != DEFAULT_PERSONALITY) {
+ /* disable stack trace */
+ return;
+ }
+#endif
+ if (tcp->unwind_queue->head)
+ error_msg_and_die("bug: unprinted entries in queue");
+
+ switch (mmap_cache_rebuild_if_invalid(tcp, __func__)) {
+ case MMAP_CACHE_REBUILD_RENEWED:
+ unwinder.tcb_flush_cache(tcp);
+ ATTRIBUTE_FALLTHROUGH;
+ case MMAP_CACHE_REBUILD_READY:
+ unwinder.tcb_walk(tcp, queue_put_call, queue_put_error,
+ tcp->unwind_queue);
+ debug_func_msg("tcp=%p, queue=%p",
+ tcp, tcp->unwind_queue->head);
+ break;
+ default:
+ /* Do nothing */
+ ;
+ }
}
projects / strace / blobdiff