From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from so254-9.mailgun.net ([198.61.254.9]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2K5K-004ARc-51 for linux-um@lists.infradead.org; Sat, 10 Jul 2021 21:00:27 +0000 MIME-Version: 1.0 Date: Sat, 10 Jul 2021 15:00:19 -0600 From: subashab@codeaurora.org Subject: UML kernel panic on initialization Message-ID: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com, linux-um@lists.infradead.org, johannes.berg@intel.com Hi I am seeing a panic on init when using Linux 5.13.1. Following is the panic call stack- Run /sbin/init as init process init[1]: segfault at 0 ip 0000000040000af0 sp 0000007fbfb0be40 error 0 in ld-2.13.so[40000000+20000] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b CPU: 0 PID: 1 Comm: init Not tainted 5.13.1 #10 Stack: 60462043 60462043 62037bc0 6202a000 60537f9b 60462043 62045b01 6004191f 62037bd0 6046f12c 62037cf0 60461d67 Call Trace: [<60462043>] ? printk+0x0/0x94 [<600251ee>] show_stack+0x101/0x14e [<60462043>] ? printk+0x0/0x94 [<60462043>] ? printk+0x0/0x94 [<60462043>] ? printk+0x0/0x94 [<6004191f>] ? exit_mm+0x0/0x2b0 [<6046f12c>] dump_stack+0x34/0x36 [<60461d67>] panic+0x18c/0x3d3 [<60037322>] ? set_signals+0x28/0x40 [<60461bdb>] ? panic+0x0/0x3d3 [<60098bba>] ? acct_collect+0x0/0x1ff [<60037322>] ? set_signals+0x28/0x40 [<6047651b>] ? _raw_spin_unlock_irq+0x1c/0x1e [<600372fa>] ? set_signals+0x0/0x40 [<60037322>] ? set_signals+0x28/0x40 [<6004aba1>] ? percpu_up_read.constprop.46+0x74/0x79 [<6004ab2d>] ? percpu_up_read.constprop.46+0x0/0x79 [<6004d59e>] ? exit_signals+0xa2/0x180 [<6004191f>] ? exit_mm+0x0/0x2b0 [<6004259c>] do_exit+0x27c/0x99a [<60043c8f>] do_group_exit+0x94/0x127 [<6004e8e0>] get_signal+0x8cf/0x8fe [<60476406>] ? _raw_spin_lock_irq+0x0/0x2a [<6004dc20>] ? force_sig_info_to_task+0xd7/0xe9 [<60024f9c>] do_signal+0x21/0x109 [<6004e00f>] ? force_sig_fault+0x21/0x23 [<600241ba>] interrupt_end+0x5c/0xc7 [<6003a18c>] userspace+0x546/0x554 [<6002415e>] ? interrupt_end+0x0/0xc7 [<6003c6d5>] ? get_fp_registers+0x0/0x12 [<60462043>] ? printk+0x0/0x94 [<600223b8>] ? run_init_process+0xc2/0xca [<600223c0>] ? try_to_run_init_process+0x0/0x44 [<600223d6>] ? try_to_run_init_process+0x16/0x44 [<600223c0>] ? try_to_run_init_process+0x0/0x44 [<60023ec6>] new_thread_handler+0xb0/0xb2 Aborted (core dumped) After doing a git bisect, the first bad commit is listed as- commit 84b2789d61156db0224724806b20110c0d34b07c Author: Johannes Berg Date: Wed Jan 13 22:09:42 2021 +0100 um: separate child and parent errors in clone stub If the two are mixed up, then it looks as though the parent returned an error if the child failed (before) the mmap(), and then the resulting process never gets killed. Fix this by splitting the child and parent errors, reporting and using them appropriately. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger I have reverted the following patches (to allow for a clean revert) and I don't see the panic anymore - bfc58e2b98e99737409cd9f4d86a79677c5b887c dc01a3b9db43abf95b801c9694980777a329e303 9f0b4807a44ff81cf59421c8a86641efec586610 84b2789d61156db0224724806b20110c0d34b07c Let me know if more information is needed to debug this. The startup arguments I have been using are the following and is working upto Linux 5.11 - ./linux ubda= mem=512M eth0=daemon,00:18:8b:75:1d:e1 UML is compiled using the following arguments - make -j32 linux ARCH=um SUBARCH=x86_64 CROSS_COMPILE= _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um