把 c 编译成 arm 指令的可执行文件
/usr/bin/arm-linux-gnueabi-g++ hello.cpp
cat hello.cpp #include <stdio.h> void crash(){ char *a=0; *a=0; } int main() { printf("hello world\n"); crash(); printf("after crash\n"); }
直接运行报错,因为 host 是 linux x86
$ ./a.out
-bash: ./a.out: cannot execute binary file
需要用 qemu-arm 来运行, 结果是期望的
qemu-arm -L /usr/arm-linux-gnueabi/ a.out
hello world
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
Segmentation fault (core dumped)
进行远程调试(关键是增加 -g 参数,指定端口为1235)
qemu-arm -g 1235 -L /usr/arm-linux-gnueabi/ a.out
执行用 linux-x86 的 gdb 并不能打印 symbol
(gdb) target remote :1235 Remote debugging using :1235 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x00000000 in ?? () (gdb) bt #0 0x00000000 in ?? () Cannot access memory at address 0x0 (gdb) file /home/payne/hello/a.out A program is being debugged already. Are you sure you want to change the file? (y or n) y Reading symbols from /home/payne/hello/a.out...(no debugging symbols found)...done. (gdb) bt #0 0x00000000 in ?? () Cannot access memory at address 0x0 (gdb)
怀疑要使用 arm 的 gdb
参见 http://mazhijing.blog.51cto.com/215535/40759, 编译了 arm 的gdb, 执行后定位到 crash()
qemu-arm -L /usr/arm-linux-gnueabi/ ./gdb (gdb) target remote :1235 Remote debugging using :1235 warning: Can not parse XML target description; XML support was disabled at compile time 0x40801c40 in ?? () (gdb) file /home/payne/hello/a.out A program is being debugged already. Are you sure you want to change the file? (y or n) y Reading symbols from /home/payne/hello/a.out...(no debugging symbols found)...done. (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x0000841e in crash() () (gdb)
结论:
难道说 arm 的 gdbserver, 就只能用 arm 的 gdb?