From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>, Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
David Ahern <dsahern@gmail.com>,
lkml <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>,
Sandipan Das <sandipan@linux.vnet.ibm.com>
Subject: Re: [PATCH 9/9] perf tests: Use arch__compare_symbol_names to compare symbols
Date: Thu, 15 Feb 2018 20:18:51 +0530 [thread overview]
Message-ID: <1518705799.8kkjgp6cbr.naveen@linux.ibm.com> (raw)
In-Reply-To: <20180215142711.GH22818@kernel.org>
Arnaldo Carvalho de Melo wrote:
> Em Thu, Feb 15, 2018 at 01:26:35PM +0100, Jiri Olsa escreveu:
>> The symbol search called by machine__find_kernel_symbol_by_name
>> is using internally arch__compare_symbol_names function to compare
>> 2 symbol names, because different archs have different ways of
>> comparing symbols. Mostly for skipping '.' prefixes and similar.
>>
>> In test 1 when we try to find matching symbols in kallsyms and
>> vmlinux, by address and by symbol name. When either is found
>> we compare the pair symbol names by simple strcmp, which is not
>> good enough for reasons explained in previous paragraph.
>>
>> On powerpc this can cause lockup, because even thought we found
>> the pair, the compared names are different and don't match
>> simple strcmp. Following code path is executed, that leads
>> to lockup:
>
> Added a:
>
> Fixes: 031b84c407c3 ("perf probe ppc: Enable matching against dot symbols automatically")
>
> And CCed Naveen, the author of that patch, so that gets notified of this
> fix.
Thanks! This does fix the test on ppc64 BE. So:
Acked-and-Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
- Naveen
next prev parent reply other threads:[~2018-02-15 14:49 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-15 12:26 [PATCHv3 0/9] perf tool: Assorted fixes Jiri Olsa
2018-02-15 12:26 ` [PATCH 1/9] tools lib symbol: Skip non-address kallsyms line Jiri Olsa
2018-02-17 11:24 ` [tip:perf/core] " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 2/9] perf tools: Check if we read regular file in dso__load Jiri Olsa
2018-02-17 11:24 ` [tip:perf/core] perf symbols: Check if we read regular file in dso__load() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 3/9] perf tools: Free root_dir in machine__init error path Jiri Olsa
2018-02-17 11:25 ` [tip:perf/core] perf machine: Free root_dir in machine__init() " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 4/9] perf tools: Move kernel mmap name into struct machine Jiri Olsa
2018-02-17 11:25 ` [tip:perf/core] perf machine: " tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 5/9] perf tools: Generalize machine__set_kernel_mmap function Jiri Olsa
2018-02-17 11:26 ` [tip:perf/core] perf machine: Generalize machine__set_kernel_mmap() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 6/9] perf tools: Don't search for active kernel start in __machine__create_kernel_maps Jiri Olsa
2018-02-17 11:26 ` [tip:perf/core] perf machine: " tip-bot for Jiri Olsa
2018-02-19 2:20 ` [PATCH 6/9] perf tools: " Namhyung Kim
2018-02-19 10:01 ` Jiri Olsa
2018-02-19 10:19 ` Namhyung Kim
2018-02-19 10:49 ` Jiri Olsa
2018-02-19 12:18 ` Arnaldo Carvalho de Melo
2018-04-11 23:07 ` [PATCH] Revert "perf machine: Fix paranoid check in machine__set_kernel_mmap()" Kim Phillips
2018-04-11 23:31 ` Namhyung Kim
2018-04-12 0:29 ` Kim Phillips
2018-04-12 1:57 ` Namhyung Kim
2018-04-13 0:09 ` Kim Phillips
2018-04-13 7:36 ` Namhyung Kim
2018-02-21 10:25 ` [tip:perf/core] perf machine: Fix paranoid check in machine__set_kernel_mmap() tip-bot for Namhyung Kim
2018-02-19 12:21 ` [PATCH 6/9] perf tools: Don't search for active kernel start in __machine__create_kernel_maps Arnaldo Carvalho de Melo
2018-02-19 14:05 ` Namhyung Kim
2018-02-15 12:26 ` [PATCH 7/9] perf tools: Remove machine__load_kallsyms function Jiri Olsa
2018-02-17 11:27 ` [tip:perf/core] perf machine: Remove machine__load_kallsyms() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 8/9] perf tools: Do not create kernel maps in sample__resolve Jiri Olsa
2018-02-17 11:27 ` [tip:perf/core] perf tools: Do not create kernel maps in sample__resolve() tip-bot for Jiri Olsa
2018-02-15 12:26 ` [PATCH 9/9] perf tests: Use arch__compare_symbol_names to compare symbols Jiri Olsa
2018-02-15 14:27 ` Arnaldo Carvalho de Melo
2018-02-15 14:48 ` Naveen N. Rao [this message]
2018-02-15 15:10 ` Arnaldo Carvalho de Melo
2018-02-17 11:28 ` [tip:perf/core] " tip-bot for Jiri Olsa
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