# 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, ...) if (debug_flag) error_msg("[unwind(" A ")] " F, __VA_ARGS__)
/*
* Кeep a sorted array of cache entries,
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
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();
- 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;
}
/*
* 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)
{
- 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;
+ 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[PATH_MAX];
+
+ 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);
+ 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;
*offset = 0;
break;
}
+ *name = xreallocarray(*name, 2, *size);
*size *= 2;
- *name = realloc(*name, *size);
- if (!*name)
- die_out_of_memory();
}
}
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);
{
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,
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