鸟哥，求助，写了个扩展，在执行完函数正确输出后segment fault了

[JihanZhuang]

(gdb) bt
#0 strlen () at ../sysdeps/x86_64/strlen.S:106
#1 0x00000000007be335 in format_converter (odp=0x7fff6e1d0f90, fmt=0xd5a491 "s(%d) : Freeing 0x%.8lX (%zu bytes), script=%s\n", ap=0x7fff6e1d0ff0)

at /home/jihanzhuang/Downloads/php-7.0.8/main/snprintf.c:993

#2 0x00000000007bedcf in strx_printv (ccp=0x7fff6e1d0fec,

buf=0x7fff6e1d1360 "[Sat Aug 13 21:02:14 2016]  Script:  '/home/jihanzhuang/code/Pinyin/tests/pinyin.php'\n", len=512, 
format=0xd5a490 "%s(%d) :  Freeing 0x%.8lX (%zu bytes), script=%s\n", ap=0x7fff6e1d0ff0) at /home/jihanzhuang/Downloads/php-7.0.8/main/snprintf.c:1248

#3 0x00000000007bf07a in ap_php_snprintf (buf=0x7fff6e1d1360 "[Sat Aug 13 21:02:14 2016] Script: '/home/jihanzhuang/code/Pinyin/tests/pinyin.php'\n", len=512,

format=0xd5a490 "%s(%d) :  Freeing 0x%.8lX (%zu bytes), script=%s\n") at /home/jihanzhuang/Downloads/php-7.0.8/main/snprintf.c:1293

#4 0x00000000007b9768 in php_message_handler_for_zend (message=4, data=0x7fff6e1d2410) at /home/jihanzhuang/Downloads/php-7.0.8/main/main.c:1444
#5 0x0000000000851cad in zend_message_dispatcher (message=4, data=0x7fff6e1d2410) at /home/jihanzhuang/Downloads/php-7.0.8/Zend/zend.c:998
#6 0x000000000081cf06 in zend_mm_check_leaks (heap=0x7f2a6c000040) at /home/jihanzhuang/Downloads/php-7.0.8/Zend/zend_alloc.c:2129
#7 0x000000000081d268 in zend_mm_shutdown (heap=0x7f2a6c000040, full=0, silent=0) at /home/jihanzhuang/Downloads/php-7.0.8/Zend/zend_alloc.c:2201
#8 0x000000000081e113 in shutdown_memory_manager (silent=0, full_shutdown=0) at /home/jihanzhuang/Downloads/php-7.0.8/Zend/zend_alloc.c:2637
#9 0x00000000007ba6e0 in php_request_shutdown (dummy=0x0) at /home/jihanzhuang/Downloads/php-7.0.8/main/main.c:1856
#10 0x000000000091b7ec in do_cli (argc=2, argv=0x1b55310) at /home/jihanzhuang/Downloads/php-7.0.8/sapi/cli/php_cli.c:1141
#11 0x000000000091c068 in main (argc=2, argv=0x1b55310) at /home/jihanzhuang/Downloads/php-7.0.8/sapi/cli/php_cli.c:1344

## core文件的信息，是在format_converter函数中，s是不能访问的地址，程序直接strlen导致的错误。
(gdb) list
case 's':
case 'v':
s = va_arg(ap, char *);
if (s != NULL) {
s_len = strlen(s);
if (adjust_precision && precision < s_len) {
s_len = precision;
}
}
请问有什么办法可以更好地排查问题。

[JihanZhuang]

一个一个方法进行测试，排查到问题了。sorry，我还以为是php7的bug。新手请原谅

[laruence]

;)