From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 2DA1E6B025E for ; Mon, 15 Jan 2018 09:28:21 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id y13so3188265pfl.16 for ; Mon, 15 Jan 2018 06:28:21 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id w24sor806628plq.51.2018.01.15.06.28.20 for (Google Transport Security); Mon, 15 Jan 2018 06:28:20 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <201801152325.FGE87548.tSLMFOVHFJOFQO@I-love.SAKURA.ne.jp> References: <201801151944.FII09821.FMVQFJtHOOOSLF@I-love.SAKURA.ne.jp> <201801152256.HDH17623.tSJHFLFOFMVOQO@I-love.SAKURA.ne.jp> <201801152325.FGE87548.tSLMFOVHFJOFQO@I-love.SAKURA.ne.jp> From: Dmitry Vyukov Date: Mon, 15 Jan 2018 15:27:58 +0100 Message-ID: Subject: Re: INFO: task hung in filemap_fault Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: syzbot , Andi Kleen , Andrew Morton , Jan Kara , jlayton@redhat.com, LKML , Linux-MM , Mel Gorman , Ingo Molnar , npiggin@gmail.com, rgoldwyn@suse.com, syzkaller-bugs@googlegroups.com, Jens Axboe , Ming Lei , Hannes Reinecke , Omar Sandoval , shli@fb.com On Mon, Jan 15, 2018 at 3:25 PM, Tetsuo Handa 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. 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org