From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f42.google.com (mail-pj1-f42.google.com [209.85.216.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B7C484C65 for ; Tue, 7 Jun 2022 23:52:07 +0000 (UTC) Received: by mail-pj1-f42.google.com with SMTP id l7-20020a17090aaa8700b001dd1a5b9965so16821682pjq.2 for ; Tue, 07 Jun 2022 16:52:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=b3NZKzwwnS36QL4ucaqxtIuHPEUyyTomuKdcLQyEKAY=; b=Gf7bKdJ2hUOr/LphELuKt2o2il5QdNDO4rPQYRQp+1RKXfjR13N6bKmp5cYllzWRT1 xhWgDv9jhC081rAPWRyoHtai4YiXoOEshYmG98xEi3wfEpFCM2PDCdIuy+YcJ0chYvKT atBYZkLGl8/N43pToDTwRSTpFzFaMaAypJvvAQf+dndtlcYidM4/cRGYnwFcXWEtFEWi Tcg9DoCiNNhHm/4hSnGnujiO9+rEPF9ieyuGMobYFn67e4mR2wStVhet3fN/z1EhPV1t aMmWf/7BmFv9yBtn8Iwp64KBjrIImavp8mV1C3jBkHuJyJPrwDy+v+PnhrbQjoGDC5sB 2t0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=b3NZKzwwnS36QL4ucaqxtIuHPEUyyTomuKdcLQyEKAY=; b=2/Gvprd8YtsciP3ISxrbkyVCgxgNDUChjWEpgTJ2fbIcXJhuDztJXH722WWtbDAmmf 7Qkr6gP0wwF+/WfZzo7RkX/bKvovbxuvzI79Tnvqr9PLpF7cDHpBgodE2xctx5guDpp8 wGUI4AFiYsytRYA12cS3de5oBEuQrS2wJgkNcCwV8UAbGwKkETiyapMR3E5H7I+v/jfn e8CvdS5nsUpc4KGxJtZS6iFFHPkeuB3Z0es9jVKL4xDvCrE062sTFtMxuwMt3YjRzOpr oaFVyvxonncMJ/hT6yyWVtPbGcCLBI/gFBhAmKw96zS1A5OrWd8vJ9MJWNWSK+vhZeps wI1g== X-Gm-Message-State: AOAM531IPJSrIHInGl+Z/uFW4H314buns12y96fDilZ5WpNckRBkwmcM saV3Tomb/GWl/zB7HXbS0l8= X-Google-Smtp-Source: ABdhPJxccdrile2mSoYxkExBirNwrH/WiEDWbZeQDdUwJ0Lkq9krO4qFXX5rn/DFlb/QY2Iq77CWPw== X-Received: by 2002:a17:902:ce11:b0:167:7d4a:964b with SMTP id k17-20020a170902ce1100b001677d4a964bmr12617889plg.37.1654645927119; Tue, 07 Jun 2022 16:52:07 -0700 (PDT) Received: from google.com ([2620:15c:211:201:f30f:4d03:66e6:b121]) by smtp.gmail.com with ESMTPSA id t9-20020a1709027fc900b00167863f0e68sm4026924plb.237.2022.06.07.16.52.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jun 2022 16:52:06 -0700 (PDT) Sender: Minchan Kim Date: Tue, 7 Jun 2022 16:52:04 -0700 From: Minchan Kim To: Naresh Kamboju Cc: open list , linux-fsdevel@vger.kernel.org, Linux ARM , "open list:KERNEL SELFTEST FRAMEWORK" , linux-block , regressions@lists.linux.dev, Jens Axboe , Sergey Senozhatsky , Nitin Gupta Subject: Re: qemu-arm: zram: mkfs.ext4 : Unable to handle kernel NULL pointer dereference at virtual address 00000140 Message-ID: References: Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jun 07, 2022 at 06:51:27AM +0530, Naresh Kamboju wrote: > On Mon, 6 Jun 2022 at 23:06, Minchan Kim wrote: > > > > On Thu, Jun 02, 2022 at 02:19:34PM +0530, Naresh Kamboju wrote: > > > The following kernel crash reported while running selftests: zram: zram.sh > > > test case on qemu-arm with Linux mainline v5.18.0 kernel version. > > > > > > Reported-by: Linux Kernel Functional Testing > > > > > > Started noticing from kernel crash from > > > BAD: git_sha: cdeffe87f790dfd1baa193020411ce9a538446d7 > > > GOOD: git_sha: babf0bb978e3c9fce6c4eba6b744c8754fd43d8e > > > > > > # git log --oneline > > > babf0bb978e3c9fce6c4eba6b744c8754fd43d8e..cdeffe87f790dfd1baa193020411ce9a538446d7 > > > -- drivers/block/ > > > 98931dd95fd4 Merge tag 'mm-stable-2022-05-25' of > > > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > > 6140ae41effe zram: fix Kconfig dependency warning > > > b3fbd58fcbb1 mm: Kconfig: simplify zswap configuration > > > e7be8d1dd983 zram: remove double compression logic > > > a2ad63daa88b VFS: add FMODE_CAN_ODIRECT file flag > > > 30226b69f876 zram: add a huge_idle writeback mode > > > > Hi Nalesh, > > > > Thanks for the reporting the bug! > > > > I locally ran the test in my x86 KVM machine but couldn't reproduce it. > > How is it easy to reproduce? Could you help to bisect it? > > It works on qemu_x86-64 > It is always reproducible in qemu arm32 environment. > > steps to reproduce: > # Please download and use this rootfs and kernel zImage > > rootfs: https://oebuilds.tuxbuild.com/29zhlbEc3EWq2wod9Uy964Bp27q/images/am57xx-evm/rpb-console-image-lkft-am57xx-evm-20220601222434.rootfs.ext4.gz > kernel: https://builds.tuxbuild.com/29zhqJJizU2Y7Ka7ArhryUOrNDC/zImage > > Boot command, > /usr/bin/qemu-system-aarch64 -cpu host,aarch64=off -machine > virt-2.10,accel=kvm -nographic -net > nic,model=virtio,maaacaddr=BA:DD:AD:CC:09:04 -net tap -m 2048 -monitor > none -kernel kernel/zImage --append "console=ttyAMA0 root=/dev/vda rw" > -hda rootfs/rpb-console-image-lkft-am57xx-evm-20220601222434.rootfs.ext4 > -m 4096 -smp 2 > > # cd /opt/kselftests/default-in-kernel/zram > # ./zram.sh > > Allow me sometime I will try to bisect this problem. Thanks for sharing the info. I managed to work your rootfs with my local arm build based on the problematic git tip. However, I couldn't suceed to reproduce it. I needed to build zsmalloc/zram built-in instead of modules Is it related? Hmm, Yeah, It would be very helpful if you could help to bisect it. Thanks! === &< ==== create '1' zram device(s) zram modules already loaded, kernel supports zram-control interface [ 936.188541] zram: Added device: zram1 all zram devices (/dev/zram1~1 successfully created set max_comp_streams to zram device(s) The device attribute max_comp_streams was deprecated in 4.7 set disk size to zram device(s) /sys/block/zram1/disksize = '1048576' zram set disksizes: OK set memory limit to zram device(s) [ 936.214438] zram1: detected capacity change from 0 to 2048 /sys/block/zram1/mem_limit = '1M' zram set memory limit: OK make swap with zram device(s) [ 936.608854] Adding 1020k swap on /dev/zram1. Priority:-2 extents:1 across:1020k SS done with /dev/zram1 zram making zram mkswap and swapon: OK zram swapoff: OK zram cleanup [ 937.063416] zram1: detected capacity change from 2048 to 0 [ 937.189223] zram: Removed device: zram1 zram02 : [PASS] root@am57xx-evm:/opt/kselftests/default-in-kernel/zram# uname -r 5.18.0-11934-g54eb8462f21f