Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761774AbcJ1UP6 (ORCPT ); Fri, 28 Oct 2016 16:15:58 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:57909 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761712AbcJ1UPz (ORCPT ); Fri, 28 Oct 2016 16:15:55 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Date: Fri, 28 Oct 2016 21:15:48 +0100 From: Chris Wilson To: Guenter Roeck Cc: linux-kernel@vger.kernel.org, Andrew Morton , sparclinux@vger.kernel.org, linux-mm@kvack.org Subject: Re: Crash in -next due to 'mm/vmalloc: replace opencoded 4-level page walkers' Message-ID: <20161028201548.GA16450@nuc-i3427.alporthouse.com> References: <20161028171825.GA15116@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161028171825.GA15116@roeck-us.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2990 Lines: 51 On Fri, Oct 28, 2016 at 10:18:25AM -0700, Guenter Roeck wrote: > Hi, > > when running sparc64 images in qemu, I see the following crash. > This is with next-20161028. > > [ 2.530785] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff,max_idle_ns: 19112604462750000 ns > [ 2.532359] kernel BUG at mm/memory.c:1881! > [ 2.532798] \|/ ____ \|/ > [ 2.532798] "@'/ .. \`@" > [ 2.532798] /_| \__/ |_\ > [ 2.532798] \__U_/ > [ 2.533250] swapper(1): Kernel bad sw trap 5 [#1] > [ 2.533705] CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc2+ #1 > [ 2.534129] task: fffff8001f0af620 task.stack: fffff8001f0b0000 > [ 2.534505] TSTATE: 0000004480001605 TPC: 00000000005124d8 TNPC: 00000000005124dc Y: 00000035 Not tainted > [ 2.535112] TPC: > [ 2.535469] g0: 00000000009b1548 g1: 0000000000a4a990 g2: 0000000000a4a990 g3: 0000000000b37694 > [ 2.535857] g4: fffff8001f0af620 g5: 0000000000000000 g6: fffff8001f0b0000 g7: 0000000000000000 > [ 2.536236] o0: 000000000000001f o1: 00000000009ac2c0 o2: 0000000000000759 o3: 0000000000122000 > [ 2.536695] o4: 0000000000000000 o5: 00000000009ac2c0 sp: fffff8001f0b2d61 ret_pc: 00000000005124d0 > [ 2.537086] RPC: > [ 2.537454] l0: 0000000000000000 l1: 0000000000002000 l2: fffff8001f10b000 l3: 0000000100002000 > [ 2.537843] l4: 0000000000aef910 l5: 0000000000a5e7e8 l6: 0000000100001fff l7: ffffffffff800000 > [ 2.538229] i0: 0000000000a5e7e8 i1: 0000000100000000 i2: 0000000100002000 i3: 000000000051e5e0 > [ 2.538613] i4: fffff8001f0b3708 i5: fffff8001f10c000 i6: fffff8001f0b2e51 i7: 000000000051e8e0 > [ 2.539007] I7: > [ 2.539387] Call Trace: > [ 2.539765] [000000000051e8e0] vmap_page_range_noflush+0x40/0x80 > [ 2.540139] [000000000051e970] map_vm_area+0x50/0x80 > [ 2.540492] [000000000051f84c] __vmalloc_node_range+0x14c/0x260 > [ 2.540848] [000000000051f98c] __vmalloc_node+0x2c/0x40 > [ 2.541198] [00000000004d39cc] bpf_prog_alloc+0x2c/0xa0 > [ 2.541554] [00000000008129bc] bpf_prog_create+0x3c/0xa0 > [ 2.541916] [0000000000adb21c] ptp_classifier_init+0x20/0x4c > [ 2.542271] [0000000000ad9808] sock_init+0x90/0xa0 > [ 2.542622] [0000000000426cb0] do_one_initcall+0x30/0x160 > [ 2.542978] [0000000000aaeaec] kernel_init_freeable+0x10c/0x1b0 > [ 2.543332] [00000000008e3324] kernel_init+0x4/0x100 > [ 2.543681] [0000000000405f04] ret_from_fork+0x1c/0x2c > > Bisect points to commit 0c79e3331f08 ("mm/vmalloc: replace opencoded 4-level > page walkers"). Reverting this patch fixes the problem. Hmm, apply_to_pte_range() has a BUG_ON(pmd_huge(*pmd)) but the old vmap_pte_range() does not and neither has the code to handle that case. Presuming that the BUG_ON() there is actually meaningful. -Chris -- Chris Wilson, Intel Open Source Technology Centre