Re: [PATCH] perf probe: Fix null pointer dereference in convert_variable_location()

[Arnaldo Carvalho de Melo]

Em Tue, Jun 01, 2021 at 05:27:50PM +0800, Li Huafei escreveu:
> If we just check whether the variable can be converted, 'tvar' should be
> a null pointer. However, the null pointer check is missing in the
> 'Constant value' execution path.
> 
> The following cases can trigger this problem:
> 
> 	$ cat test.c
> 	#include <stdio.h>

Thanks for providing the detailed analysis and test steps, I've
reproduced the problem before the patch and it now works with your
patch:

[acme@five tmp]$ sudo perf probe -x ./test main:6
Added new event:
  probe_test:main_L6   (on main:6 in /tmp/test)

You can now use it in all perf tools, such as:

	perf record -e probe_test:main_L6 -aR sleep 1

[acme@five tmp]$

Thanks, applied.

- Arnaldo