Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750902AbdIJD6T (ORCPT ); Sat, 9 Sep 2017 23:58:19 -0400 Received: from mail-pg0-f46.google.com ([74.125.83.46]:33222 "EHLO mail-pg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750775AbdIJD6S (ORCPT ); Sat, 9 Sep 2017 23:58:18 -0400 X-Google-Smtp-Source: ADKCNb56QdFXor42DIcT1oMJfgSvi/a7lziBvGNzA2qqCGfRorM5mdzcD+BiwniJkSbELWNQ3/EMEg== Date: Sat, 9 Sep 2017 20:58:15 -0700 From: Guenter Roeck To: Daniel Micay Cc: linux-kernel@vger.kernel.org, Ley Foon Tan , nios2-dev@lists.rocketboards.org, Laura Abbott , Kees Cook , Andrew Morton Subject: nios2 crash due to 'init/main.c: extract early boot entropy from the passed cmdline' Message-ID: <20170910035815.GA9834@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2622 Lines: 39 Hi, I noticed that nios2 images crash in mainline. Bisect points to commit 33d72f3822d7 ("init/main.c: extract early boot entropy from the passed cmdline"). Bisect log is attached. As far as I can see, the problem is seen because add_device_randomness() calls random_get_entropy(). However, the underlying timer function used by the nios2 architecture (nios2_timer_read) is not yet initialized, causing a NULL pointer access and crash. A sample crash log is at http://kerneltests.org/builders/qemu-nios2-master/builds/175/steps/qemubuildcommand/logs/stdio Guenter --- # bad: [4dfc2788033d30dfccfd4268e06dd73ce2c654ed] Merge tag 'iommu-updates-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu # good: [5969d1bb3082b41eba8fd2c826559abe38ccb6df] Merge branch 'gperf-removal' git bisect start 'HEAD' '5969d1bb3082' # bad: [fbd01410e89a66f346ba1b3c0161e1198449b746] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net git bisect bad fbd01410e89a66f346ba1b3c0161e1198449b746 # good: [0d519f2d1ed1f11e49abc88cfcf6cf13b83ba14c] Merge tag 'pci-v4.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci git bisect good 0d519f2d1ed1f11e49abc88cfcf6cf13b83ba14c # bad: [229cf16d3c8ac2e9b082c223fd0e619dc8f62cc1] sh: defconfig: cleanup from old Kconfig options git bisect bad 229cf16d3c8ac2e9b082c223fd0e619dc8f62cc1 # good: [1caffba9db4aa27c3e7ebc05668afca1f991ab8d] drivers/scsi/sym53c8xx_2/sym_hipd.c: convert to use memset32 git bisect good 1caffba9db4aa27c3e7ebc05668afca1f991ab8d # good: [7c61bd6983b185272315722787cceacf5f5d2e7d] lib/cmdline.c: remove meaningless comment git bisect good 7c61bd6983b185272315722787cceacf5f5d2e7d # bad: [718b303b49893d8f9dd469f710d76f77673bd35d] autofs: use AUTOFS_DEV_IOCTL_SIZE git bisect bad 718b303b49893d8f9dd469f710d76f77673bd35d # good: [9367bb730e4d9d85a8911a08a3542ec2aa873d37] binfmt_flat: delete two error messages for a failed memory allocation in decompress_exec() git bisect good 9367bb730e4d9d85a8911a08a3542ec2aa873d37 # bad: [e54c7bcbf14a25dc3a913b4c808b52121c522e9b] autofs: make disc device user accessible git bisect bad e54c7bcbf14a25dc3a913b4c808b52121c522e9b # bad: [33d72f3822d7ff8a9e45bd7413c811085cb87aa5] init/main.c: extract early boot entropy from the passed cmdline git bisect bad 33d72f3822d7ff8a9e45bd7413c811085cb87aa5 # good: [121388a31362b0d3176dc1190ac8064b98a61b20] init: move stack canary initialization after setup_arch git bisect good 121388a31362b0d3176dc1190ac8064b98a61b20 # first bad commit: [33d72f3822d7ff8a9e45bd7413c811085cb87aa5] init/main.c: extract early boot entropy from the passed cmdline