From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: dvyukov@google.com
Cc: bot+980f5e5fc060c37505bd65abb49a963518b269d9@syzkaller.appspotmail.com,
ak@linux.intel.com, akpm@linux-foundation.org, jack@suse.cz,
jlayton@redhat.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, mgorman@techsingularity.net,
mingo@kernel.org, npiggin@gmail.com, rgoldwyn@suse.com,
syzkaller-bugs@googlegroups.com, axboe@kernel.dk,
tom.leiming@gmail.com, hare@suse.de, osandov@fb.com, shli@fb.com
Subject: Re: INFO: task hung in filemap_fault
Date: Mon, 15 Jan 2018 23:38:26 +0900 [thread overview]
Message-ID: <201801152338.EBJ73933.FLSJHFVtOFOOQM@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <CACT4Y+abO438-ncA83M296BQUMi+Ya0ZZRzY35uMD9QfOobhAA@mail.gmail.com>
Dmitry Vyukov wrote:
> On Mon, Jan 15, 2018 at 3:25 PM, Tetsuo Handa
> <penguin-kernel@i-love.sakura.ne.jp> wrote:
> > Dmitry Vyukov wrote:
> >> >> I am not completely following. You previously mentioned raw.log, which
> >> >> is a collection of multiple programs, but now you seem to be talking
> >> >> about a single reproducer. When syzbot manages to reproduce the bug
> >> >> only with syzkaller program but not with a corresponding C program, it
> >> >> provides only syzkaller program. It such case it can sense to convert.
> >> >> But the case you pointed to actually contains C program. So there is
> >> >> no need to do the conversion at all... What am I missing?
> >> >>
> >> >
> >> > raw.log is not readable for me.
> >> > I want to see C program even if syzbot did not manage to reproduce the bug.
> >> > If C program is available, everyone can try reproducing the bug with manually
> >> > trimmed C program.
> >>
> >> If it did not manage to reproduce the bug, there is no C program.
> >> There is no program at all.
> >>
> >
> > What!? Then, what does raw.log contain? I want to read raw.log as C program.
>
>
> raw.log is not a _program_, it's hundreds of separate programs that
> were executed before the crash.
I want to know the hundreds of separate programs as C programs.
Even if there are hundreds, more recently ran programs tend to be
the culprit.
> It's also very compressed
> representation as compared to equivalent C programs. For example for
> this program:
>
> mmap(&(0x7f0000000000/0xfff000)=nil, 0xfff000, 0x3, 0x32,
> 0xffffffffffffffff, 0x0)
> r0 = socket$nl_generic(0x10, 0x3, 0x10)
> sendmsg$nl_generic(r0,
> &(0x7f0000b3e000-0x38)={&(0x7f0000d4a000-0xc)={0x10, 0x0, 0x0, 0x0},
> 0xc, &(0x7f0000007000)={&(0x7f0000f7c000-0x15c)={0x24, 0x1c, 0x109,
> 0xffffffffffffffff, 0xffffffffffffffff, {0x4, 0x0, 0x0},
> [@nested={0x10, 0x9, [@typed={0xc, 0x0, @u32=0x0}]}]}, 0x24}, 0x1,
> 0x0, 0x0, 0x0}, 0x0)
>
> you can get up to this amount of C code:
> https://gist.githubusercontent.com/dvyukov/eeaeb4e4ac45c3a251f72098c9295bf9/raw/700cd583507eca90711ba11b42e406f317553371/gistfile1.txt
>
> that is, 700 lines of C source for 3 line program. So instead of a 1MB
> file that will be 100MB, and then it probably should be a gzip archive
> with hundreds of separate C files. There are people on this list
> complaining even about 200K of attachments. I don't see that this will
> be better and well accepted.
>
I don't think attaching to mails is acceptable. Thus, I suggest e.g. CGI
service so that only those who want to try can obtain the C programs.
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next prev parent reply other threads:[~2018-01-15 14:38 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-18 8:43 INFO: task hung in filemap_fault syzbot
2017-12-18 14:52 ` Tetsuo Handa
2017-12-18 22:19 ` Tetsuo Handa
2017-12-28 14:09 ` Dmitry Vyukov
2018-01-01 15:27 ` Tetsuo Handa
2018-01-08 9:08 ` Dmitry Vyukov
2018-01-08 10:48 ` Tetsuo Handa
2018-01-15 9:40 ` Dmitry Vyukov
2018-01-15 10:44 ` Tetsuo Handa
2018-01-15 12:29 ` Dmitry Vyukov
2018-01-15 13:43 ` Dmitry Vyukov
2018-01-15 13:56 ` Tetsuo Handa
2018-01-15 14:00 ` Dmitry Vyukov
2018-01-15 14:25 ` Tetsuo Handa
2018-01-15 14:27 ` Dmitry Vyukov
2018-01-15 14:38 ` Tetsuo Handa [this message]
2018-01-08 9:17 ` Dmitry Vyukov
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