“目标记录已满"在 gdb 中生成“n"；printf 命令失败，“进程记录不支持地址 0x7ffff7dee6e7 处的指令 0xc5"? [英] "target record-full" in gdb makes "n" command fail on printf with "Process record does not support instruction 0xc5 at address 0x7ffff7dee6e7"?

问题描述

我想在 gdb 中使用reverse-step"和reverse-next"命令.堆栈溢出告诉我应该在我希望rn"和rs"的执行上下文中运行target record-full".但是发生了一些奇怪的错误:

I was tring to use "reverse-step" and "reverse-next" command inside gdb. Stack overflow tells me that I should run "target record-full" in the execution context where I wish to "rn" and "rs". But some weird error happened:

  1 
  2 #include<stdio.h>
  3 int i=0;
  4 void fa()
  5 { 
  6   ++i;
  7   printf("%d
",i);
  8   ++i;
  9 }
 10 int main(){
 11   fa();
 12   return 0;
 13 } 

我编译并运行这个程序:

I compile and run this program:

(gdb) b 4
Breakpoint 1 at 0x40052a: file test02.c, line 4.
(gdb) r
Starting program: /home/Troskyvs/a.out 

Breakpoint 1, fa () at test02.c:6
6     ++i;
(gdb) target record-full
(gdb) n
7     printf("%d
",i);
(gdb) n                      # Error happens here!
Process record does not support instruction 0xc5 at address 0x7ffff7dee6e7.
Process record: failed to record execution log.

Program stopped.
_dl_runtime_resolve_avx () at ../sysdeps/x86_64/dl-trampoline.h:81
81  ../sysdeps/x86_64/dl-trampoline.h: No such file or directory.

好吧，如果我不运行target record-full"，那么第二个n"就可以并运行到下一行.我不太了解这里的错误信息.

Well if I don't run "target record-full", then the 2nd "n" will be OK and run to next line. I don't quite get the error information here.

是否与目标记录已满"有关?我该如何征服它?

Is it related to "target record-full"? How can I conquor it?

我尝试了另一种方法:

(gdb) set exec-direction reverse
(gdb) n

No more reverse-execution history.
fa () at test02.c:7
7     printf("%d
",i);
(gdb) n

No more reverse-execution history.
fa () at test02.c:7
7     printf("%d
",i);
(gdb) n

这样不行

推荐答案

从 GDB 7.11.1 开始不支持 AVX

根本问题似乎是当前不支持 AVX 指令，但 glibc 在 Ubuntu 16.04 64 位上使用它们:

The underlying problem seems to be that AVX instructions are not currently supported, but glibc uses them on Ubuntu 16.04 64-bit:

• gdb反向调试avx2
• https://sourceware.org/ml/gdb/2016-08/msg00028.html

rr 是一个很棒的替代方案:https://github.com/mozilla/rr 这是一个最小的工作示例:在函数返回的GDB中设置断点

rr is an awesome working alternative: https://github.com/mozilla/rr Here is a minimal working example: Setting breakpoint in GDB where the function returns

这篇关于“目标记录已满"在 gdb 中生成“n"；printf 命令失败，“进程记录不支持地址 0x7ffff7dee6e7 处的指令 0xc5"?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！