Re: [PATCH 2/3] perf tests: Add dwarf unwind test on ARM

[Jiri Olsa <jolsa@redhat.com>]

On Wed, May 07, 2014 at 02:24:53PM +0200, Jean Pihet wrote:
> Hi Jiri,
> 
> On 7 May 2014 14:06, Jiri Olsa <jolsa@redhat.com> wrote:
> > On Tue, May 06, 2014 at 05:26:18PM +0200, Jean Pihet wrote:
> >
> SNIP
> >
> > there's a memory leak of 'buf' already fixed fox x86:
> >
> >   perf tests x86: Fix memory leak in sample_ustack()
> >   commit 763d7f5f2718f085bab5a9e63308349728f3ad12
> >   Author: Masanari Iida <standby24x7@gmail.com>
> >   Date:   Sun Apr 20 00:16:41 2014 +0900
> >
> > jirka
> 
> Ok
> 
> Here is the diff between the x86 and the ARM implementations:
> $ diff -urN tools/perf/arch/arm64/tests/dwarf-unwind.c
> tools/perf/arch/x86/tests/dwarf-unwind.c
> --- tools/perf/arch/arm64/tests/dwarf-unwind.c    2014-05-06
> 17:31:17.507961045 +0200
> +++ tools/perf/arch/x86/tests/dwarf-unwind.c    2014-05-06
> 16:52:00.589776839 +0200
> @@ -21,11 +21,12 @@
>          return -1;
>      }
> 
> -    sp = (unsigned long) regs[PERF_REG_ARM64_SP];
> +    sp = (unsigned long) regs[PERF_REG_X86_SP];
> 
> -    map = map_groups__find(&thread->mg, MAP__FUNCTION, (u64) sp);
> +    map = map_groups__find(thread->mg, MAP__VARIABLE, (u64) sp);
>      if (!map) {
>          pr_debug("failed to get stack map\n");
> +        free(buf);
>          return -1;
>      }
> 
> Which leads to a few questions:
> - the map_groups__find parameters need to be fixed too, right?

the reason for this is following commit:
  6392b4e perf x86: Fix perf to use non-executable stack, again

which also adds global link flags: -Wl,-z,noexecstack 
so I'm guessing arm is affected too

> - the free(buf) needs to be fixed,
> - given that the remaining difference in the file is just a register
> macro, it is worth to factor the code in a single file. Does that make
> sense? If worthwhile I can do that once the ARM and ARM64 support is
> merged in.

we can do the code factoring later here, np

thanks,
jirka