From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48D1419FA9E for ; Tue, 16 Jul 2024 14:36:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721140606; cv=none; b=rujT3RCiYUVRWwoE7y/pRXKimedSvx7lVubOb+wgapjGil+CtDhGblj+mVisyzN/Fjf1LsXFdkIDLuebWjqgRZuqAuxK0xKjmCHyEfkyAX8a5F/o60N1q13y+FPaIBIkcqSLMpCXBv0yR4rNXUqO3qf0AVzfrsb1uP6fFexY3Uo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721140606; c=relaxed/simple; bh=lr7MZBRMd/oIbF6gc3IKKOBclfJ43ES2oXaNTQ8yunQ=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=PQ5ycCU5F0vfxOkH3/LKuQKkUKn/LizTThB8PheRJjMy2JdBhqtY1V/pTM0GCW/0IUb398xRzP1x7UsbCT8aq1Cj/4KqTqC/JOHZgs1BH5MnEYvIH6Qb+fBT8M6FB6Un989SjuxtdRODJc9Qe0B4Ahf/nlx3wYdzQ65gxVC5gyU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SwmMoGDK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SwmMoGDK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A030CC4AF09; Tue, 16 Jul 2024 14:36:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721140605; bh=lr7MZBRMd/oIbF6gc3IKKOBclfJ43ES2oXaNTQ8yunQ=; h=Date:From:To:Cc:Subject:From; b=SwmMoGDK1QRCOwh2MinKnko6xbS2p9SbOFi5NqGrGhwntTlukvnK43Svcxi3sjuV/ 9fckbwtTbrjIqSumFH7s13qbY4vESpNJUM7vhAqQibSdCeuaim5qG5ks4Q+Vu76dii LITOaBaOXTh/uFGsUBNaaFD67fOU3eWbLR6u1UoHnankvgObv7SO8MC1cUHmiBFiTh Ezj0jH6jDwtkiFiTJ1aoYOxkEpS3kqd15YCdGqZ/uF5zQNAcxD8up3iHrgKFanL3EZ icbWb4heBwWFdupUeRofRcDhRBmCY8QSb7lh9p1VCnh3l73AeUrSS2cZXi/YqqZUov Rd/Z82rgoIjsQ== Date: Tue, 16 Jul 2024 07:36:44 -0700 From: Nathan Chancellor To: Linus Torvalds Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Crash when booting UML after e3c92e81711d14b46c3121d36bc8e152cb843923 Message-ID: <20240716143644.GA1827132@thelio-3990X> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Linus, Our continuous integration notices a crash when booting User Mode Linux after commit e3c92e81711d ("runtime constants: add x86 architecture support"), which I've distilled down to: $ make -skj"$(nproc)" ARCH=um CROSS_COMPILE=x86_64-linux- defconfig linux $ curl -LSs https://github.com/ClangBuiltLinux/boot-utils/releases/download/20230707-182910/x86_64-rootfs.ext4.zst | zstd -d >/tmp/rootfs.ext4 $ ./linux ubd0=/tmp/rootfs.ext4 Core dump limits : soft - NONE hard - NONE Checking that ptrace can change system call numbers...OK Checking syscall emulation for ptrace...OK Checking environment variables for a tempdir...none found Checking if /dev/shm is on tmpfs...OK Checking PROT_EXEC mmap in /dev/shm...OK Adding 945225728 bytes to physical memory to account for exec-shield gap kmsg_dump: <5>Linux version 6.10.0-rc4-00003-ge3c92e81711d (nathan@thelio-3990X) (x86_64-linux-gcc (GCC) 14.1.0, GNU ld (GNU Binutils) 2.42) #1 Tue Jul 16 07:14:46 MST 2024 <6>Zone ranges: <6> Normal [mem 0x0000000000000000-0x000000009c56ffff] <6>Movable zone start for each node <6>Early memory node ranges <6> node 0: [mem 0x0000000000000000-0x000000003c56ffff] <6>Initmem setup node 0 [mem 0x0000000000000000-0x000000003c56ffff] <5>random: crng init done <7>pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 <7>pcpu-alloc: [0] 0 <5>Kernel command line: ubd0=/tmp/rootfs.ext4 root=98:0 console=tty0 <6>Dentry cache hash table entries: 8192 (order: 4, 65536 bytes, linear) <4> <4>Modules linked in: <6>Pid: 0, comm: swapper Not tainted 6.10.0-rc4-00003-ge3c92e81711d <6>RIP: 0033:vfs_caches_init_early+0xa9/0xe4 <6>RSP: 00000000604ebf10 EFLAGS: 00010206 <6>RAX: 000000009b817000 RBX: 00000000605e3d68 RCX: 0000000000000013 <6>RDX: 00000000604a2d78 RSI: 00000000604a2d84 RDI: ffffffffffc6543b <6>RBP: 00000000604ebf10 R08: 0000000000000001 R09: 0000000000000001 <6>R10: 000000009b817000 R11: 0000000000000001 R12: 00000000604f0468 <6>R13: 0000000000000000 R14: 00000000600571bd R15: 00000000605d6000 <0>Kernel panic - not syncing: Segfault with no mm <4>CPU: 0 PID: 0 Comm: swapper Not tainted 6.10.0-rc4-00003-ge3c92e81711d #1 <4>Stack: <4> 604ebf80 60001ba4 00000000 6003328d <4> 0000002d 00000000 00000000 604e00c0 <4> 00000000 604ebfb8 604d71c8 00000000 <4>Call Trace: <4> [<60001ba4>] start_kernel+0x4de/0x79c <4> [<6003328d>] ? block_signals+0x0/0xf <4> [<60003c68>] start_kernel_proc+0x37/0x3b <4> [<60020847>] new_thread_handler+0x7f/0xb1 <4> [<600233ae>] uml_finishsetup+0x54/0x59 At commit e78298556ee5 ("runtime constants: add default dummy infrastructure"), everything starts up fine: $ ./linux ubd0=/tmp/rootfs.ext4 Core dump limits : soft - NONE hard - NONE Checking that ptrace can change system call numbers...OK Checking syscall emulation for ptrace...OK Checking environment variables for a tempdir...none found Checking if /dev/shm is on tmpfs...OK Checking PROT_EXEC mmap in /dev/shm...OK Adding 808370176 bytes to physical memory to account for exec-shield gap Linux version 6.10.0-rc4-00002-ge78298556ee5 (nathan@thelio-3990X) (x86_64-linux-gcc (GCC) 14.1.0, GNU ld (GNU Binutils) 2.42) #1 Tue Jul 16 07:29:04 MST 2024 Zone ranges: Normal [mem 0x0000000000000000-0x00000000942ebfff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000000000000-0x00000000342ebfff] Initmem setup node 0 [mem 0x0000000000000000-0x00000000342ebfff] random: crng init done Kernel command line: ubd0=/tmp/rootfs.ext4 root=98:0 console=tty0 Dentry cache hash table entries: 8192 (order: 4, 65536 bytes, linear) Inode-cache hash table entries: 4096 (order: 3, 32768 bytes, linear) Sorting __ex_table... Built 1 zonelists, mobility grouping on. Total pages: 213740 mem auto-init: stack:all(zero), heap alloc:off, heap free:off, mlocked free:off Memory: 47476K/854960K available (3575K kernel code, 974K rwdata, 1252K rodata, 153K init, 233K bss, 807484K reserved, 0K cma-reserved) ... If there is any other information I can provide or patches I can test, I am more than happy to do so. Cheers, Nathan # bad: [d67978318827d06f1c0fa4c31343a279e9df6fde] Merge tag 'x86_cpu_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip # good: [0c3836482481200ead7b416ca80c68a29cfdaabd] Linux 6.10 git bisect start 'd67978318827d06f1c0fa4c31343a279e9df6fde' 'v6.10' # bad: [bbb3556c014dc8ed1645b725ad84477603553743] Merge tag 'keys-next-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd git bisect bad bbb3556c014dc8ed1645b725ad84477603553743 # good: [3c1743a685b19bc17cf65af4a2eb149fd3b15c50] floppy: add missing MODULE_DESCRIPTION() macro git bisect good 3c1743a685b19bc17cf65af4a2eb149fd3b15c50 # bad: [4f5e249ec0ea8872e1644df23cffffbe28007188] Merge tag 'vfs-6.11.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs git bisect bad 4f5e249ec0ea8872e1644df23cffffbe28007188 # bad: [aff31330e037f75de7820bc7deb494eeaeaadd35] Merge tag 'vfs-6.11.pg_error' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs git bisect bad aff31330e037f75de7820bc7deb494eeaeaadd35 # bad: [2ffd45da0b06b26f30480584de7c660d84b2d7dc] Merge tag 'drm-fixes-2024-07-12' of https://gitlab.freedesktop.org/drm/kernel git bisect bad 2ffd45da0b06b26f30480584de7c660d84b2d7dc # bad: [5e0497553643b6c6acd16c389afb9cec210f4ea9] Merge branch 'link_path_walk' git bisect bad 5e0497553643b6c6acd16c389afb9cec210f4ea9 # bad: [6a31ffdfed10dc48e6fd1775d50c22429382ab98] Merge branch 'word-at-a-time' git bisect bad 6a31ffdfed10dc48e6fd1775d50c22429382ab98 # bad: [94a2bc0f611cd9fa4d26e4679bf7ea4b01b12d56] arm64: add 'runtime constant' support git bisect bad 94a2bc0f611cd9fa4d26e4679bf7ea4b01b12d56 # good: [e78298556ee5d881f6679effb2a6743969ea6e2d] runtime constants: add default dummy infrastructure git bisect good e78298556ee5d881f6679effb2a6743969ea6e2d # bad: [e3c92e81711d14b46c3121d36bc8e152cb843923] runtime constants: add x86 architecture support git bisect bad e3c92e81711d14b46c3121d36bc8e152cb843923 # first bad commit: [e3c92e81711d14b46c3121d36bc8e152cb843923] runtime constants: add x86 architecture support