From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:32772 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726949AbfJPIU2 (ORCPT ); Wed, 16 Oct 2019 04:20:28 -0400 Date: Wed, 16 Oct 2019 10:20:22 +0200 From: Michal Hocko Subject: Re: [PATCH V6 0/2] mm/debug: Add tests validating architecture page table helpers Message-ID: <20191016082022.GN317@dhcp22.suse.cz> References: <1571131302-32290-1-git-send-email-anshuman.khandual@arm.com> <1571150502.5937.39.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: Sender: linux-s390-owner@vger.kernel.org List-ID: To: Anshuman Khandual Cc: Qian Cai , linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Greg Kroah-Hartman , Thomas Gleixner , Mike Rapoport , Jason Gunthorpe , Dan Williams , Peter Zijlstra , Mark Rutland , Mark Brown , Steven Price , Ard Biesheuvel , Masahiro Yamada , Kees Cook , Tetsuo Handa , Matthew Wilcox , Sri Krishna chowdary , Dave Hansen , Russell King - ARM Linux , Michael Ellerman , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , "David S. Miller" , Vineet Gupta , James Hogan , Paul Burton , Ralf Baechle , "Kirill A . Shutemov" , Gerald Schaefer , Christophe Leroy , Mike Kravetz , linux-snps-arc@lists.infradead.org, linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org On Tue 15-10-19 20:51:11, Anshuman Khandual wrote: >=20 >=20 > On 10/15/2019 08:11 PM, Qian Cai wrote: > > The x86 will crash with linux-next during boot due to this series (v5) = with the > > config below plus CONFIG_DEBUG_VM_PGTABLE=3Dy. I am not sure if v6 woul= d address > > it. > >=20 > > https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config > >=20 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.862600][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1] page:ffffea0009000000 is uninitialized and poisoned > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.862608][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff > > ffffff871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BDT1]=EF=BF=BD=EF=BF=BD= ? _raw_spin_unlock_irq+0x27/0x40 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1]=EF=BF=BD=EF=BF=BD? rest_init+0x307/0x307 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1]=EF=BF=BD=EF=BF=BDkernel_init+0x11/0x139 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1]=EF=BF=BD=EF=BF=BD? rest_init+0x307/0x307 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1]=EF=BF=BD=EF=BF=BDret_from_fork+0x27/0x50 > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1] Modules linked in: > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1] ---[ end trace e99d392b0f7befbd ]--- > > [=EF=BF=BD=EF=BF=BD=EF=BF=BD33.871140][=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BDT1] RIP: 0010:alloc_gigantic_page_order+0x3fe/0x490 >=20 > Hmm, with defconfig (DEBUG_VM=3Dy and DEBUG_VM_PGTABLE=3Dy) it does not c= rash but > with the config above, it does. Just wondering if it is possible that the= se > pages might not been initialized yet because DEFERRED_STRUCT_PAGE_INIT=3D= y ? Quite likely. You need to wait for page_alloc_init_late to finish. >=20 > [ 13.898549][ T1] page:ffffea0005000000 is uninitialized and poisoned > [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff fffffffffff= fffff ffffffffffffffff > [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff fffffffffff= fffff ffffffffffffffff > [ 13.898549][ T1] page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p= )) > [ 13.898549][ T1] ------------[ cut here ]------------ > [ 13.898549][ T1] kernel BUG at ./include/linux/mm.h:1107! > [ 13.898549][ T1] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASA= N PTI > [ 13.898549][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc= 3-next-20191015+ # --=20 Michal Hocko SUSE Labs