/*
* Copyright (c) 2013 Luca Clementi <luca.clementi@gmail.com>
+ * Copyright (c) 2013-2017 The strace developers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
# define fopen_for_input fopen
#endif
-#define DPRINTF(F, A, ...) if (debug_flag) fprintf(stderr, " [unwind(" A ")] " F "\n", __VA_ARGS__)
+#define DPRINTF(F, A, ...) \
+ do { \
+ if (debug_flag) \
+ error_msg("[unwind(" A ")] " F, __VA_ARGS__); \
+ } while (0)
/*
- * Кeep a sorted array of cache entries,
+ * Keep a sorted array of cache entries,
* so that we can binary search through it.
*/
struct mmap_cache_t {
/**
* example entry:
- * 7fabbb09b000-7fabbb09f000 r--p 00179000 fc:00 1180246 /lib/libc-2.11.1.so
+ * 7fabbb09b000-7fabbb09f000 r-xp 00179000 fc:00 1180246 /lib/libc-2.11.1.so
*
* start_addr is 0x7fabbb09b000
* end_addr is 0x7fabbb09f000
unsigned long end_addr;
unsigned long mmap_offset;
char *binary_filename;
- bool deleted;
};
/*
* Type used in stacktrace capturing
*/
struct call_t {
- struct call_t* next;
- char *output_line;
+ struct call_t *next;
+ char *output_line;
};
struct queue_t {
- struct call_t *tail;
- struct call_t *head;
+ struct call_t *tail;
+ struct call_t *head;
};
static void queue_print(struct queue_t *queue);
void
unwind_tcb_init(struct tcb *tcp)
{
+ if (tcp->libunwind_ui)
+ return;
+
tcp->libunwind_ui = _UPT_create(tcp->pid);
if (!tcp->libunwind_ui)
- die_out_of_memory();
+ perror_msg_and_die("_UPT_create");
- tcp->queue = malloc(sizeof(*tcp->queue));
- if (!tcp->queue)
- die_out_of_memory();
+ tcp->queue = xmalloc(sizeof(*tcp->queue));
tcp->queue->head = NULL;
tcp->queue->tail = NULL;
}
free(tcp->queue);
tcp->queue = NULL;
- delete_mmap_cache(tcp, __FUNCTION__);
+ delete_mmap_cache(tcp, __func__);
_UPT_destroy(tcp->libunwind_ui);
tcp->libunwind_ui = NULL;
/*
* caching of /proc/ID/maps for each process to speed up stack tracing
*
- * The cache must be refreshed after some syscall: mmap, mprotect, munmap, execve
+ * The cache must be refreshed after syscalls that affect memory mappings,
+ * e.g. mmap, mprotect, munmap, execve.
*/
static void
-build_mmap_cache(struct tcb* tcp)
+build_mmap_cache(struct tcb *tcp)
{
- 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;
+ FILE *fp;
+ struct mmap_cache_t *cache_head;
/* 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;
-
- const char *deleted = " (deleted)";
- size_t blen;
- size_t dlen;
+ char filename[sizeof("/proc/4294967296/maps")];
+ char buffer[PATH_MAX + 80];
- unw_flush_cache (libunwind_as, 0, 0);
+ unw_flush_cache(libunwind_as, 0, 0);
- sprintf(filename, "/proc/%d/maps", tcp->pid);
+ sprintf(filename, "/proc/%u/maps", tcp->pid);
fp = fopen_for_input(filename, "r");
if (!fp) {
perror_msg("fopen: %s", filename);
return;
}
- cache_head = calloc(cur_array_size, sizeof(*cache_head));
- if (!cache_head)
- die_out_of_memory();
+ cache_head = xcalloc(cur_array_size, sizeof(*cache_head));
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] == '[') {
+ struct mmap_cache_t *entry;
+ unsigned long start_addr, end_addr, mmap_offset;
+ char exec_bit;
+ char binary_path[sizeof(buffer)];
+
+ if (sscanf(buffer, "%lx-%lx %*c%*c%c%*c %lx %*x:%*x %*d %[^\n]",
+ &start_addr, &end_addr, &exec_bit,
+ &mmap_offset, binary_path) != 5)
continue;
- }
- if (binary_path[0] == '\0') {
+ /* ignore mappings that have no PROT_EXEC bit set */
+ if (exec_bit != 'x')
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);
-
- dlen = strlen(deleted);
- blen = strlen(binary_path);
- if (blen >= dlen && strcmp(binary_path + blen - dlen, deleted) == 0)
- cur_entry->deleted = true;
- else
- cur_entry->deleted = false;
+ if (end_addr < start_addr) {
+ error_msg("%s: unrecognized file format", filename);
+ break;
+ }
/*
* 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);
+ entry = &cache_head[tcp->mmap_cache_size - 1];
+ if (entry->start_addr == start_addr &&
+ entry->end_addr == end_addr) {
+ /* duplicate entry, e.g. [vsyscall] */
+ continue;
+ }
+ if (start_addr <= entry->start_addr ||
+ start_addr < entry->end_addr) {
+ error_msg("%s: overlapping memory region",
+ filename);
+ continue;
+ }
}
- 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();
+ cache_head = xreallocarray(cache_head, cur_array_size,
+ sizeof(*cache_head));
}
+
+ entry = &cache_head[tcp->mmap_cache_size];
+ entry->start_addr = start_addr;
+ entry->end_addr = end_addr;
+ entry->mmap_offset = mmap_offset;
+ entry->binary_filename = xstrdup(binary_path);
+ tcp->mmap_cache_size++;
}
fclose(fp);
tcp->mmap_cache = cache_head;
}
void
-unwind_cache_invalidate(struct tcb* tcp)
+unwind_cache_invalidate(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
*offset = 0;
break;
}
+ *name = xreallocarray(*name, 2, *size);
*size *= 2;
- *name = realloc(*name, *size);
- if (!*name)
- die_out_of_memory();
}
}
function_offset,
true_offset);
return 0;
- }
- else if (ip < cur_mmap_cache->start_addr)
+ } else if (ip < cur_mmap_cache->start_addr)
upper = mid - 1;
else
lower = mid + 1;
* after a set_tid_address syscall
* unw_get_reg returns IP == 0
*/
- if(ip)
+ if (ip)
error_action(data, "unexpected_backtracing_error", ip);
return -1;
}
if (tcp->mmap_cache_size == 0)
error_msg_and_die("bug: mmap_cache is empty");
- symbol_name = malloc(symbol_name_size);
- if (!symbol_name)
- die_out_of_memory();
+ symbol_name = xmalloc(symbol_name_size);
if (unw_init_remote(&cursor, libunwind_as, tcp->libunwind_ui) < 0)
perror_msg_and_die("Can't initiate libunwind");
unw_word_t function_offset,
unsigned long true_offset)
{
- if (symbol_name)
+ if (symbol_name && (symbol_name[0] != '\0'))
tprintf(STACK_ENTRY_SYMBOL_FMT);
else if (binary_filename)
tprintf(STACK_ENTRY_NOSYMBOL_FMT);
else
- tprintf(STACK_ENTRY_BUG_FMT, __FUNCTION__);
+ tprintf(STACK_ENTRY_BUG_FMT, __func__);
line_ended();
}
unsigned long true_offset,
const char *error)
{
- char *output_line = NULL;
- int n;
-
- if (symbol_name)
- n = asprintf(&output_line, STACK_ENTRY_SYMBOL_FMT);
- 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, __FUNCTION__);
-
- if (n < 0)
- error_msg_and_die("error in asprintf");
-
- return output_line;
+ char *output_line = NULL;
+ int n;
+
+ if (symbol_name)
+ n = asprintf(&output_line, STACK_ENTRY_SYMBOL_FMT);
+ 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)
+ error_msg_and_die("error in asprintf");
+
+ return output_line;
}
/*
{
struct call_t *call;
- call = malloc(sizeof(*call));
- if (!call)
- die_out_of_memory();
-
+ call = xmalloc(sizeof(*call));
call->output_line = sprint_call_or_error(binary_filename,
symbol_name,
function_offset,
* printing stack
*/
void
-unwind_print_stacktrace(struct tcb* tcp)
+unwind_print_stacktrace(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
return;
}
#endif
- if (tcp->queue->head) {
- DPRINTF("tcp=%p, queue=%p", "queueprint", tcp, tcp->queue->head);
- queue_print(tcp->queue);
- }
- else if (rebuild_cache_if_invalid(tcp, __FUNCTION__)) {
- DPRINTF("tcp=%p, queue=%p", "stackprint", tcp, tcp->queue->head);
- stacktrace_walk(tcp, print_call_cb, print_error_cb, NULL);
- }
+ if (tcp->queue->head) {
+ DPRINTF("tcp=%p, queue=%p", "queueprint", tcp, tcp->queue->head);
+ queue_print(tcp->queue);
+ } else if (rebuild_cache_if_invalid(tcp, __func__)) {
+ DPRINTF("tcp=%p, queue=%p", "stackprint", tcp, tcp->queue->head);
+ stacktrace_walk(tcp, print_call_cb, print_error_cb, NULL);
+ }
}
/*
if (tcp->queue->head)
error_msg_and_die("bug: unprinted entries in queue");
- if (rebuild_cache_if_invalid(tcp, __FUNCTION__)) {
+ if (rebuild_cache_if_invalid(tcp, __func__)) {
stacktrace_walk(tcp, queue_put_call, queue_put_error,
tcp->queue);
DPRINTF("tcp=%p, queue=%p", "captured", tcp, tcp->queue->head);