From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anshuman Khandual Date: Tue, 15 Oct 2019 15:33:11 +0000 Subject: Re: [PATCH V6 0/2] mm/debug: Add tests validating architecture page table helpers Message-Id: List-Id: References: <1571131302-32290-1-git-send-email-anshuman.khandual@arm.com> <1571150502.5937.39.camel@lca.pw> In-Reply-To: <1571150502.5937.39.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Qian Cai , linux-mm@kvack.org Cc: Mark Rutland , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , James Hogan , Heiko Carstens , Michal Hocko , Dave Hansen , Paul Mackerras , sparclinux@vger.kernel.org, Thomas Gleixner , linux-s390@vger.kernel.org, Jason Gunthorpe , Michael Ellerman , x86@kernel.org, Russell King - ARM Linux , Matthew Wilcox , Steven Price , Tetsuo Handa , Gerald Schaefer , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Kees Cook , Masahiro Yamada , Mark Brown , "Kirill A . Shutemov" , Dan Williams , Vlastimil Babka , Christophe Leroy , Sri Krishna chowdary , Ard Biesheuvel , Greg Kroah-Hartman , linux-mips@vger.kernel.org, Ralf Baechle , linux-kernel@vger.kernel.org, Paul Burton , Mike Rapoport , Vineet Gupta , Martin Schwidefsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , Mike Kravetz 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=y. I am not sure if v6 would address > it. > > https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config > > [   33.862600][    T1] page:ffffea0009000000 is uninitialized and poisoned > [   33.862608][    T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff > ffffff871140][    T1]  ? _raw_spin_unlock_irq+0x27/0x40 > [   33.871140][    T1]  ? rest_init+0x307/0x307 > [   33.871140][    T1]  kernel_init+0x11/0x139 > [   33.871140][    T1]  ? rest_init+0x307/0x307 > [   33.871140][    T1]  ret_from_fork+0x27/0x50 > [   33.871140][    T1] Modules linked in: > [   33.871140][    T1] ---[ end trace e99d392b0f7befbd ]--- > [   33.871140][    T1] RIP: 0010:alloc_gigantic_page_order+0x3fe/0x490 Hmm, with defconfig (DEBUG_VM=y and DEBUG_VM_PGTABLE=y) it does not crash but with the config above, it does. Just wondering if it is possible that these pages might not been initialized yet because DEFERRED_STRUCT_PAGE_INIT=y ? [ 13.898549][ T1] page:ffffea0005000000 is uninitialized and poisoned [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff 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 KASAN PTI [ 13.898549][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-next-20191015+ #