From: Ingo Molnar <mingo@kernel.org>
To: Wang Nan <wangnan0@huawei.com>
Cc: jolsa@redhat.com, namhyung@kernel.org, jolsa@kernel.org,
acme@redhat.com, linux-kernel@vger.kernel.org, pi3orama@163.com
Subject: Re: [PATCH v2] perf: report/annotate: fix segfault problem.
Date: Fri, 3 Apr 2015 08:48:22 +0200 [thread overview]
Message-ID: <20150403064822.GB29383@gmail.com> (raw)
In-Reply-To: <1428040585-52586-1-git-send-email-wangnan0@huawei.com>
* Wang Nan <wangnan0@huawei.com> wrote:
> perf report and perf annotate are easy to trigger segfault if trace data
> contain kernel module information like this:
>
> # perf report -D -i ./perf.data
> ...
> 0 0 0x188 [0x50]: PERF_RECORD_MMAP -1/0: [0xffffffbff1018000(0xf068000) @ 0]: x [test_module]
> ...
>
> # perf report -i ./perf.data --objdump=/path/to/objdump --kallsyms=/path/to/kallsyms
>
> perf: Segmentation fault
> -------- backtrace --------
> /path/to/perf[0x503478]
> /lib64/libc.so.6(+0x3545f)[0x7fb201f3745f]
> /path/to/perf[0x499b56]
> /path/to/perf(dso__load_kallsyms+0x13c)[0x49b56c]
> /path/to/perf(dso__load+0x72e)[0x49c21e]
> /path/to/perf(map__load+0x6e)[0x4ae9ee]
> /path/to/perf(thread__find_addr_map+0x24c)[0x47deec]
> /path/to/perf(perf_event__preprocess_sample+0x88)[0x47e238]
> /path/to/perf[0x43ad02]
> /path/to/perf[0x4b55bc]
> /path/to/perf(ordered_events__flush+0xca)[0x4b57ea]
> /path/to/perf[0x4b1a01]
> /path/to/perf(perf_session__process_events+0x3be)[0x4b428e]
> /path/to/perf(cmd_report+0xf11)[0x43bfc1]
> /path/to/perf[0x474702]
> /path/to/perf(main+0x5f5)[0x42de95]
> /lib64/libc.so.6(__libc_start_main+0xf4)[0x7fb201f23bd4]
> /path/to/perf[0x42dfc4]
>
> This is because __kmod_path__parse regard '[' leading name as kernel
> instead of kernel module. The DSO will then be passed to
> dso__load_kernel_sym() then dso__load_kcore() because of --kallsyms
> argument. The segfault is triggered because the kmap structure is not
> initialized.
Could we also make the place that generated the segfault more robust,
to protect against future mishaps of this type? I suppose the
non-initialized value was NULL?
Thanks,
Ingo
next prev parent reply other threads:[~2015-04-03 6:48 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-03 5:56 [PATCH v2] perf: report/annotate: fix segfault problem Wang Nan
2015-04-03 6:48 ` Ingo Molnar [this message]
2015-04-03 8:47 ` [PATCH] perf: kmaps: enforce usage of kmaps to protect futher bugs Wang Nan
2015-04-03 8:49 ` Ingo Molnar
2015-04-03 11:11 ` Jiri Olsa
2015-04-07 10:42 ` Adrian Hunter
2015-04-08 10:50 ` [PATCH v4] " Wang Nan
2015-04-03 9:07 ` [PATCH v2] perf: report/annotate: fix segfault problem Jiri Olsa
2015-04-03 10:57 ` Jiri Olsa
2015-04-06 12:52 ` Arnaldo Carvalho de Melo
2015-04-07 8:22 ` [PATCH v3 0/2] " Wang Nan
2015-04-07 8:22 ` [PATCH v3 1/2] perf: kmaps: enforce usage of kmaps to protect futher bugs Wang Nan
2015-04-08 15:10 ` [tip:perf/core] perf kmaps: Check kmaps to make code more robust tip-bot for Wang Nan
2015-04-07 8:22 ` [PATCH v3 2/2] perf: report/annotate: fix segfault problem Wang Nan
2015-04-07 15:13 ` Arnaldo Carvalho de Melo
2015-04-08 3:49 ` Wang Nan
2015-04-08 3:52 ` [PATCH v4 " Wang Nan
2015-04-08 13:59 ` Jiri Olsa
2015-04-09 7:05 ` Wang Nan
2015-04-09 11:40 ` Jiri Olsa
2015-04-09 11:52 ` Jiri Olsa
2015-04-10 1:57 ` Wang Nan
2015-04-10 2:49 ` Wang Nan
2015-04-10 3:53 ` [PATCH v5 " Wang Nan
2015-04-15 1:27 ` Wang Nan
2015-04-20 1:18 ` Wang Nan
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