From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:39541) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqwlT-0001jt-Kq for qemu-devel@nongnu.org; Tue, 05 Feb 2019 04:11:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gqwlN-0004Cz-1A for qemu-devel@nongnu.org; Tue, 05 Feb 2019 04:11:31 -0500 Received: from mail-wm1-x342.google.com ([2a00:1450:4864:20::342]:38693) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gqwlH-00046t-IA for qemu-devel@nongnu.org; Tue, 05 Feb 2019 04:11:25 -0500 Received: by mail-wm1-x342.google.com with SMTP id m22so2753045wml.3 for ; Tue, 05 Feb 2019 01:11:20 -0800 (PST) Date: Tue, 5 Feb 2019 10:11:15 +0100 From: Corentin Labbe Message-ID: <20190205091115.GA27918@Red> References: <20190103154810.GB32032@Red> <3a375dc6-f0ba-c3f0-6e86-2fd5cdf3ee35@ilande.co.uk> <8c302745-5097-afed-5c7e-9a992da03cf6@ilande.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8c302745-5097-afed-5c7e-9a992da03cf6@ilande.co.uk> Subject: Re: [Qemu-devel] sparc: crash when using initrd > 5M List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark Cave-Ayland Cc: sparclinux@vger.kernel.org, qemu-devel@nongnu.org On Fri, Feb 01, 2019 at 02:15:15PM +0000, Mark Cave-Ayland wrote: > On 18/01/2019 13:33, Mark Cave-Ayland wrote: > > > On 03/01/2019 15:48, Corentin Labbe wrote: > > > >> Hello > >> > >> When using an initrd > 5M, I hit the following kernel crash: > >> qemu-system-sparc -kernel vmlinux -initrd rootfs.cpio.gz -nographic > >> Configuration device id QEMU version 1 machine id 32 > >> Probing SBus slot 0 offset 0 > >> Probing SBus slot 1 offset 0 > >> Probing SBus slot 2 offset 0 > >> Probing SBus slot 3 offset 0 > >> Probing SBus slot 4 offset 0 > >> Probing SBus slot 5 offset 0 > >> Invalid FCode start byte > >> CPUs: 1 x FMI,MB86904 > >> UUID: 00000000-0000-0000-0000-000000000000 > >> Welcome to OpenBIOS v1.1 built on Oct 5 2018 08:20 > >> Type 'help' for detailed information > >> [sparc] Kernel already loaded > >> switching to new context: > >> PROMLIB: obio_ranges 1 > >> [ 0.000000] PROMLIB: Sun Boot Prom Version 3 Revision 2 > >> [ 0.000000] Linux version 4.20.0-next-20190102+ (compile@Red) (gcc version 7.3.0 (Gentoo 7.3.0-r3 p1.4)) #148 Thu Jan 3 16:17:08 CET 2019 > >> [ 0.000000] printk: bootconsole [earlyprom0] enabled > >> [ 0.000000] ARCH: SUN4M > >> [ 0.000000] TYPE: SPARCstation 5 > >> [ 0.000000] Ethernet address: 52:54:00:12:34:56 > >> [ 0.000000] Unable to handle kernel NULL pointer dereference > >> [ 0.000000] tsk->{mm,active_mm}->context = ffffffff > >> [ 0.000000] tsk->{mm,active_mm}->pgd = 00000000 > >> [ 0.000000] \|/ ____ \|/ > >> [ 0.000000] "@'/ ,. \`@" > >> [ 0.000000] /_| \__/ |_\ > >> [ 0.000000] \__U_/ > >> [ 0.000000] swapper(0): Oops [#1] > >> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.20.0-next-20190102+ #148 > >> [ 0.000000] PSR: 04001fc0 PC: f0010ef0 NPC: f0010ef4 Y: 00000000 Not tainted > >> [ 0.000000] PC: > >> [ 0.000000] %G: 0000000a 000003c4 f05ece08 f05ecc00 00000000 00e00000 f05d4000 00000001 > >> [ 0.000000] %O: 00000000 00e00000 00800000 00e00000 00000000 00000002 f05d5bb8 f00bba58 > >> [ 0.000000] RPC: > >> [ 0.000000] %L: 00000040 f05dfaf8 f05d5c68 00000001 0003ffff 006951e0 f05ed014 f0674ab4 > >> [ 0.000000] %I: f05d5c80 00000000 00000002 f1000000 ffffffff 00000000 f05d5c20 f0007fd8 > >> [ 0.000000] Disabling lock debugging due to kernel taint > >> [ 0.000000] Caller[f0007fd8]: srmmu_fault+0x58/0x68 > >> [ 0.000000] Caller[f0618598]: memblock_alloc_try_nid+0xb8/0xc8 > >> [ 0.000000] Caller[f0611094]: srmmu_paging_init+0x174/0xaf8 > >> [ 0.000000] Caller[f06106a8]: paging_init+0x4/0x24 > >> [ 0.000000] Caller[f060e4f0]: setup_arch+0x3e8/0x480 > >> [ 0.000000] Caller[f060ab50]: start_kernel+0x48/0x460 > >> [ 0.000000] Caller[f060a43c]: continue_boot+0x324/0x334 > >> [ 0.000000] Caller[00000000]: (null) > >> [ 0.000000] Instruction DUMP: > >> [ 0.000000] c800a024 > >> [ 0.000000] 83286002 > >> [ 0.000000] 073c17b3 > >> [ 0.000000] > >> [ 0.000000] c600e22c > >> [ 0.000000] 8a08a003 > >> [ 0.000000] 80a16001 > >> [ 0.000000] 0280003b > >> [ 0.000000] c600c001 > >> [ 0.000000] > >> [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! > >> [ 0.000000] Press Stop-A (L1-A) from sun keyboard or send break > >> [ 0.000000] twice on console to return to the boot prom > >> [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- > >> qemu-system-sparc: terminating on signal 15 from pid 13043 (killall) > >> > >> The NULL ptr dereference is done by memset() in srmmu_nocache_init() and memblock_alloc_try_nid(). > >> If I comment both memset, the boot pass > >> > >> But since nothing explain the NULL ptr deref in memset(), I suspect something is overriden by the initrd > > > > Sorry about the delay in replying to this, I haven't been too well recently. > > > > Looking at the code I suspect the problem is that when loading a kernel directly, > > OpenBIOS isn't adding the kernel/initrd memory ranges to the DT properties, and so > > the kernel doesn't recreate its own mapping on boot. > > > > It shouldn't be too hard to make this happen, let me take and look and see how > > difficult this would be. > > I think I now have a fix for this, with changes needed in both QEMU and OpenBIOS. > > Firstly you'll need to apply the QEMU patch from > https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg06635.html and then you'll > need an updated OpenBIOS. > > I've uploaded a pre-compiled openbios-sparc32 with the patches from > https://mail.coreboot.org/hyperkitty/list/openbios@openbios.org/thread/E6IMJNUFRF7W6ALWSYBOOCEYLBFXXQEN/ > to https://www.ilande.co.uk/tmp/qemu/openbios-sparc32-initrdfix for testing. > > Please can you test and let me know if this solves the issue? If so, I'll see if I > can get them merged in time for the upcoming QEMU 4.0 release. > Hello Sorry even with the patch I still hit the issue. I have added some debug and at least qemu set initrd_size correctly now. I have tried to compile openbios-sparc32 for debugging but fail with arch/sparc32/context.c:116:5: error: PIC register clobbered by 'l7' in 'asm' asm __volatile__ ("\n\tcall __switch_context" ^~~ make[1]: *** [rules.mak:219: target/arch/sparc32/context.o] Error 1 (gcc 7.2 and gc 6.4 with binutils 2.30) Regards