Re: [PATCH] perf: top: fix a segfault when kernel map is restricted.

[Arnaldo Carvalho de Melo]

Em Fri, Apr 24, 2015 at 11:35:29PM +0000, Wang Nan escreveu:
> Perf top raise a warning if a kernel sample is collected but kernel map
> is restricted. The warning message needs to dereference al.map->dso...
> However, previous perf_event__preprocess_sample() doesn't always
> guarantee al.map != NULL, for example, when kernel map is restricted.
> 
> This patch validates al.map before dereferencing, avoid the segfault.
> 
> Before this patch:
> 
>  $ cat /proc/sys/kernel/kptr_restrict
>  1
>  $ perf top -p  120183

Thanks, applied.

- Arnaldo
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