From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Subject: Re: [PATCH v4 02/14] arm: add support for folded p4d page tables Date: Thu, 7 May 2020 19:11:55 +0300 Message-ID: <20200507161155.GE683243@linux.ibm.com> References: <20200414153455.21744-1-rppt@kernel.org> <20200414153455.21744-3-rppt@kernel.org> <39ba8a04-d6b5-649d-c289-0c8b27cb66c5@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <39ba8a04-d6b5-649d-c289-0c8b27cb66c5@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Marek Szyprowski Cc: Rich Felker , linux-ia64@vger.kernel.org, Geert Uytterhoeven , Fenghua Yu , Benjamin Herrenschmidt , linux-mm@kvack.org, Paul Mackerras , Michael Ellerman , Will Deacon , kvmarm@lists.cs.columbia.edu, Jonas Bonn , Brian Cain , linux-hexagon@vger.kernel.org, linux-sh@vger.kernel.org, Russell King , Ley Foon Tan , Catalin Marinas , uclinux-h8-devel@lists.sourceforge.jp, linux-arch@vger.kernel.org, Arnd Bergmann , Bartlomiej Zolnierkiewicz , =?utf-8?Q?=C5=81ukasz?= Stelmach , kvm-ppc@vger.kernel.org, Stefan Kristiansson List-Id: linux-arch.vger.kernel.org Hi, On Thu, May 07, 2020 at 02:16:56PM +0200, Marek Szyprowski wrote: > Hi > = > On 14.04.2020 17:34, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Implement primitives necessary for the 4th level folding, add walks of = p4d > > level where appropriate, and remove __ARCH_USE_5LEVEL_HACK. > > > > Signed-off-by: Mike Rapoport > = > Today I've noticed that kexec is broken on ARM 32bit. Bisecting between = > current linux-next and v5.7-rc1 pointed to this commit. I've tested this = > on Odroid XU4 and Raspberry Pi4 boards. Here is the relevant log: > = > # kexec --kexec-syscall -l zImage --append "$(cat /proc/cmdline)" > memory_range[0]:0x40000000..0xbe9fffff > memory_range[0]:0x40000000..0xbe9fffff > # kexec -e > kexec_core: Starting new kernel > 8<--- cut here --- > Unable to handle kernel paging request at virtual address c010f1f4 > pgd =3D c6817793 > [c010f1f4] *pgd=3D4000041e(bad) > Internal error: Oops: 80d [#1] PREEMPT ARM > Modules linked in: > CPU: 0 PID: 1329 Comm: kexec Tainted: G=A0=A0=A0=A0=A0=A0=A0 W = > 5.7.0-rc3-00127-g6cba81ed0f62 #611 > Hardware name: Samsung Exynos (Flattened Device Tree) > PC is at machine_kexec+0x40/0xfc Any chance you have the debug info in this kernel? scripts/faddr2line would come handy here. > LR is at 0xffffffff > pc : []=A0=A0=A0 lr : []=A0=A0=A0 psr: 60000013 > sp : ebc13e60=A0 ip : 40008000=A0 fp : 00000001 > r10: 00000058=A0 r9 : fee1dead=A0 r8 : 00000001 > r7 : c121387c=A0 r6 : 6c224000=A0 r5 : ece40c00=A0 r4 : ec222000 > r3 : c010f1f4=A0 r2 : c1100000=A0 r1 : c1100000=A0 r0 : 418d0000 > Flags: nZCv=A0 IRQs on=A0 FIQs on=A0 Mode SVC_32=A0 ISA ARM=A0 Segment no= ne > Control: 10c5387d=A0 Table: 6bc14059=A0 DAC: 00000051 > Process kexec (pid: 1329, stack limit =3D 0x366bb4dc) > Stack: (0xebc13e60 to 0xebc14000) > ... > [] (machine_kexec) from [] (kernel_kexec+0x74/0x7c) > [] (kernel_kexec) from [] (__do_sys_reboot+0x1f8/0x21= 0) > [] (__do_sys_reboot) from [] (ret_fast_syscall+0x0/0x= 28) > Exception stack(0xebc13fa8 to 0xebc13ff0) > ... > ---[ end trace 3e8d6c81723c778d ]--- > 1329 Segmentation fault=A0=A0=A0=A0=A0 ./kexec -e > = > > --- > > arch/arm/include/asm/pgtable.h | 1 - > > arch/arm/lib/uaccess_with_memcpy.c | 7 +++++- > > arch/arm/mach-sa1100/assabet.c | 2 +- > > arch/arm/mm/dump.c | 29 +++++++++++++++++----- > > arch/arm/mm/fault-armv.c | 7 +++++- > > arch/arm/mm/fault.c | 22 ++++++++++------ > > arch/arm/mm/idmap.c | 3 ++- > > arch/arm/mm/init.c | 2 +- > > arch/arm/mm/ioremap.c | 12 ++++++--- > > arch/arm/mm/mm.h | 2 +- > > arch/arm/mm/mmu.c | 35 +++++++++++++++++++++----- > > arch/arm/mm/pgd.c | 40 ++++++++++++++++++++++++------ > > 12 files changed, 125 insertions(+), 37 deletions(-) > > > > ... > = > Best regards > -- = > Marek Szyprowski, PhD > Samsung R&D Institute Poland > = -- = Sincerely yours, Mike.