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Date: Tue, 6 Feb 2018 16:07:53 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Jiri Olsa <jolsa@kernel.org>
Cc: lkml <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>, David Ahern <dsahern@gmail.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 06/17] tools lib symbol: Skip non-address kallsyms line
Message-ID: <20180206190753.GD3451@kernel.org>
References: <20180206181813.10943-1-jolsa@kernel.org>
 <20180206181813.10943-7-jolsa@kernel.org>
 <20180206190649.GC3451@kernel.org>
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Em Tue, Feb 06, 2018 at 04:06:49PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Feb 06, 2018 at 07:18:02PM +0100, Jiri Olsa escreveu:
> > Adding check on failed attempt to parse the address
> > and skip the line parsing early in that case.
> 
> How did you stumble on that? Can you provide an example of a line or
> situation where this would happen?

Something like this:

[acme@jouet perf]$ cat /proc/kallsyms  | head
          (null) A irq_stack_union
          (null) A __per_cpu_start
          (null) A cpu_debug_store
          (null) A cpu_tss_rw
          (null) A gdt_page
          (null) A exception_stacks
          (null) A entry_stack_storage
          (null) A espfix_waddr
          (null) A espfix_stack
          (null) A cpu_llc_id
[acme@jouet perf]$ id
uid=1000(acme) gid=1000(acme) groups=1000(acme),10(wheel),18(dialout),54(lock) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
[acme@jouet perf]$

?

- Arnaldo