/*
* Copyright (c) 2013 Luca Clementi <luca.clementi@gmail.com>
- * Copyright (c) 2013-2017 The strace developers.
+ * 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
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
-#include <limits.h>
-#include <libunwind-ptrace.h>
-
-#ifdef _LARGEFILE64_SOURCE
-# ifdef HAVE_FOPEN64
-# define fopen_for_input fopen64
-# else
-# define fopen_for_input fopen
+#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
-#else
-# define fopen_for_input fopen
#endif
-/*
- * Keep a sorted array of cache entries,
- * so that we can binary search through it.
- */
-struct mmap_cache_t {
- /**
- * example entry:
- * 7fabbb09b000-7fabbb09f000 r-xp 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;
-};
-
-/*
- * Type used in stacktrace walker
- */
-typedef void (*call_action_fn)(void *data,
- const char *binary_filename,
- const char *symbol_name,
- unw_word_t function_offset,
- unsigned long true_offset);
-typedef void (*error_action_fn)(void *data,
- const char *error,
- unsigned long true_offset);
-
/*
* Type used in stacktrace capturing
*/
char *output_line;
};
-struct queue_t {
+struct unwind_queue_t {
struct call_t *tail;
struct call_t *head;
};
-static void queue_print(struct queue_t *queue);
-static void delete_mmap_cache(struct tcb *tcp, const char *caller);
-
-static unw_addr_space_t libunwind_as;
-static unsigned int mmap_cache_generation;
+static void queue_print(struct unwind_queue_t *queue);
static const char asprintf_error_str[] = "???";
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");
- unw_set_caching_policy(libunwind_as, UNW_CACHE_GLOBAL);
+ if (unwinder.init)
+ unwinder.init();
}
void
unwind_tcb_init(struct tcb *tcp)
{
- if (tcp->libunwind_ui)
+ if (tcp->unwind_queue)
return;
- tcp->libunwind_ui = _UPT_create(tcp->pid);
- if (!tcp->libunwind_ui)
- perror_msg_and_die("_UPT_create");
+ tcp->unwind_queue = xmalloc(sizeof(*tcp->unwind_queue));
+ tcp->unwind_queue->head = NULL;
+ tcp->unwind_queue->tail = NULL;
- tcp->queue = xmalloc(sizeof(*tcp->queue));
- tcp->queue->head = NULL;
- tcp->queue->tail = NULL;
+ tcp->unwind_ctx = unwinder.tcb_init(tcp);
}
void
unwind_tcb_fin(struct tcb *tcp)
{
- queue_print(tcp->queue);
- free(tcp->queue);
- tcp->queue = NULL;
-
- 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 syscalls that affect memory mappings,
- * e.g. mmap, mprotect, munmap, execve.
- */
-static void
-build_mmap_cache(struct tcb *tcp)
-{
- 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;
- char filename[sizeof("/proc/4294967296/maps")];
- char buffer[PATH_MAX + 80];
-
- unw_flush_cache(libunwind_as, 0, 0);
-
- sprintf(filename, "/proc/%u/maps", tcp->pid);
- fp = fopen_for_input(filename, "r");
- if (!fp) {
- perror_msg("fopen: %s", filename);
+ if (!tcp->unwind_queue)
return;
- }
-
- cache_head = xcalloc(cur_array_size, sizeof(*cache_head));
-
- while (fgets(buffer, sizeof(buffer), fp) != NULL) {
- 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;
-
- /* ignore mappings that have no PROT_EXEC bit set */
- if (exec_bit != 'x')
- continue;
-
- 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) {
- 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;
- }
- }
-
- if (tcp->mmap_cache_size >= cur_array_size) {
- cur_array_size *= 2;
- 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;
- tcp->mmap_cache_generation = mmap_cache_generation;
-
- debug_func_msg("tgen=%u, ggen=%u, tcp=%p, cache=%p",
- tcp->mmap_cache_generation,
- mmap_cache_generation,
- tcp, tcp->mmap_cache);
-}
-
-/* deleting the cache */
-static void
-delete_mmap_cache(struct tcb *tcp, const char *caller)
-{
- unsigned int i;
-
- debug_func_msg("tgen=%u, ggen=%u, tcp=%p, cache=%p, caller=%s",
- tcp->mmap_cache_generation,
- mmap_cache_generation,
- tcp, tcp->mmap_cache, caller);
-
- for (i = 0; i < tcp->mmap_cache_size; i++) {
- free(tcp->mmap_cache[i].binary_filename);
- tcp->mmap_cache[i].binary_filename = NULL;
- }
- free(tcp->mmap_cache);
- tcp->mmap_cache = NULL;
- tcp->mmap_cache_size = 0;
-}
-static bool
-rebuild_cache_if_invalid(struct tcb *tcp, const char *caller)
-{
- if ((tcp->mmap_cache_generation != mmap_cache_generation)
- && tcp->mmap_cache)
- delete_mmap_cache(tcp, caller);
+ queue_print(tcp->unwind_queue);
+ free(tcp->unwind_queue);
+ tcp->unwind_queue = NULL;
- if (!tcp->mmap_cache)
- build_mmap_cache(tcp);
-
- return tcp->mmap_cache && tcp->mmap_cache_size;
-}
-
-void
-unwind_cache_invalidate(struct tcb *tcp)
-{
-#if SUPPORTED_PERSONALITIES > 1
- if (tcp->currpers != DEFAULT_PERSONALITY) {
- /* disable stack trace */
- return;
- }
-#endif
- mmap_cache_generation++;
- debug_func_msg("tgen=%u, ggen=%u, tcp=%p, cache=%p",
- tcp->mmap_cache_generation,
- mmap_cache_generation,
- tcp, tcp->mmap_cache);
-}
-
-static void
-get_symbol_name(unw_cursor_t *cursor, char **name,
- size_t *size, unw_word_t *offset)
-{
- for (;;) {
- int rc = unw_get_proc_name(cursor, *name, *size, offset);
- if (rc == 0)
- break;
- if (rc != -UNW_ENOMEM) {
- **name = '\0';
- *offset = 0;
- break;
- }
- *name = xreallocarray(*name, 2, *size);
- *size *= 2;
- }
-}
-
-static int
-print_stack_frame(struct tcb *tcp,
- call_action_fn call_action,
- error_action_fn error_action,
- void *data,
- unw_cursor_t *cursor,
- char **symbol_name,
- size_t *symbol_name_size)
-{
- unw_word_t ip;
- int lower = 0;
- int upper = (int) tcp->mmap_cache_size - 1;
-
- if (unw_get_reg(cursor, UNW_REG_IP, &ip) < 0) {
- perror_msg("Can't walk the stack of process %d", tcp->pid);
- return -1;
- }
-
- while (lower <= upper) {
- struct mmap_cache_t *cur_mmap_cache;
- int mid = (upper + lower) / 2;
-
- cur_mmap_cache = &tcp->mmap_cache[mid];
-
- if (ip >= cur_mmap_cache->start_addr &&
- ip < cur_mmap_cache->end_addr) {
- unsigned long true_offset;
- unw_word_t function_offset;
-
- get_symbol_name(cursor, symbol_name, symbol_name_size,
- &function_offset);
- true_offset = ip - cur_mmap_cache->start_addr +
- cur_mmap_cache->mmap_offset;
- call_action(data,
- cur_mmap_cache->binary_filename,
- *symbol_name,
- function_offset,
- true_offset);
- return 0;
- } else if (ip < cur_mmap_cache->start_addr)
- upper = mid - 1;
- else
- lower = mid + 1;
- }
-
- /*
- * there is a bug in libunwind >= 1.0
- * after a set_tid_address syscall
- * unw_get_reg returns IP == 0
- */
- if (ip)
- error_action(data, "unexpected_backtracing_error", ip);
- return -1;
-}
-
-/*
- * walking the stack
- */
-static void
-stacktrace_walk(struct tcb *tcp,
- call_action_fn call_action,
- error_action_fn error_action,
- void *data)
-{
- char *symbol_name;
- size_t symbol_name_size = 40;
- unw_cursor_t cursor;
- int stack_depth;
-
- if (!tcp->mmap_cache)
- error_msg_and_die("bug: mmap_cache is NULL");
- if (tcp->mmap_cache_size == 0)
- error_msg_and_die("bug: mmap_cache is empty");
-
- 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");
-
- for (stack_depth = 0; stack_depth < 256; ++stack_depth) {
- if (print_stack_frame(tcp, call_action, error_action, data,
- &cursor, &symbol_name, &symbol_name_size) < 0)
- break;
- if (unw_step(&cursor) <= 0)
- break;
- }
- if (stack_depth >= 256)
- error_action(data, "too many stack frames", 0);
-
- free(symbol_name);
+ unwinder.tcb_fin(tcp);
+ tcp->unwind_ctx = NULL;
}
/*
* /lib64/libc.so.6(__libc_start_main+0xed) [0x7fa2f8a5976d]
* ./a.out() [0x400569]
*/
-#define STACK_ENTRY_SYMBOL_FMT \
+#define STACK_ENTRY_SYMBOL_FMT(SYM) \
" > %s(%s+0x%lx) [0x%lx]\n", \
binary_filename, \
- symbol_name, \
+ (SYM), \
(unsigned long) function_offset, \
true_offset
#define STACK_ENTRY_NOSYMBOL_FMT \
print_call_cb(void *dummy,
const char *binary_filename,
const char *symbol_name,
- unw_word_t function_offset,
+ unwind_function_offset_t function_offset,
unsigned long true_offset)
{
- if (symbol_name && (symbol_name[0] != '\0'))
- tprintf(STACK_ENTRY_SYMBOL_FMT);
+ 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
static char *
sprint_call_or_error(const char *binary_filename,
const char *symbol_name,
- unw_word_t function_offset,
+ unwind_function_offset_t function_offset,
unsigned long true_offset,
const char *error)
{
char *output_line = NULL;
int n;
- if (symbol_name)
- n = asprintf(&output_line, STACK_ENTRY_SYMBOL_FMT);
+ 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
+ }
else if (binary_filename)
n = asprintf(&output_line, STACK_ENTRY_NOSYMBOL_FMT);
else if (error)
* queue manipulators
*/
static void
-queue_put(struct queue_t *queue,
+queue_put(struct unwind_queue_t *queue,
const char *binary_filename,
const char *symbol_name,
- unw_word_t function_offset,
+ unwind_function_offset_t function_offset,
unsigned long true_offset,
const char *error)
{
queue_put_call(void *queue,
const char *binary_filename,
const char *symbol_name,
- unw_word_t function_offset,
+ unwind_function_offset_t function_offset,
unsigned long true_offset)
{
queue_put(queue,
}
static void
-queue_print(struct queue_t *queue)
+queue_print(struct unwind_queue_t *queue)
{
struct call_t *call, *tmp;
* printing stack
*/
void
-unwind_print_stacktrace(struct tcb *tcp)
+unwind_tcb_print(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
return;
}
#endif
- if (tcp->queue->head) {
- debug_func_msg("head: tcp=%p, queue=%p", tcp, tcp->queue->head);
- queue_print(tcp->queue);
- } else if (rebuild_cache_if_invalid(tcp, __func__)) {
- debug_func_msg("walk: tcp=%p, queue=%p", tcp, tcp->queue->head);
- stacktrace_walk(tcp, print_call_cb, print_error_cb, NULL);
- }
+ if (tcp->unwind_queue->head) {
+ debug_func_msg("head: tcp=%p, queue=%p",
+ tcp, tcp->unwind_queue->head);
+ queue_print(tcp->unwind_queue);
+ } else
+ unwinder.tcb_walk(tcp, print_call_cb, print_error_cb, NULL);
}
/*
* capturing stack
*/
void
-unwind_capture_stacktrace(struct tcb *tcp)
+unwind_tcb_capture(struct tcb *tcp)
{
#if SUPPORTED_PERSONALITIES > 1
if (tcp->currpers != DEFAULT_PERSONALITY) {
return;
}
#endif
- if (tcp->queue->head)
+ if (tcp->unwind_queue->head)
error_msg_and_die("bug: unprinted entries in queue");
-
- if (rebuild_cache_if_invalid(tcp, __func__)) {
- stacktrace_walk(tcp, queue_put_call, queue_put_error,
- tcp->queue);
- debug_func_msg("tcp=%p, queue=%p", tcp, tcp->queue->head);
+ else {
+ debug_func_msg("walk: tcp=%p, queue=%p",
+ tcp, tcp->unwind_queue->head);
+ unwinder.tcb_walk(tcp, queue_put_call, queue_put_error,
+ tcp->unwind_queue);
}
}
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