Hi Mike, On 08.05.2020 19:42, Mike Rapoport wrote: > On Fri, May 08, 2020 at 08:53:27AM +0200, Marek Szyprowski wrote: >> On 07.05.2020 18:11, Mike Rapoport wrote: >>> On Thu, May 07, 2020 at 02:16:56PM +0200, Marek Szyprowski wrote: >>>> On 14.04.2020 17:34, Mike Rapoport wrote: >>>>> From: Mike Rapoport <rppt****@linux*****> >>>>> >>>>> 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 <rppt****@linux*****> >>>> 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 = c6817793 >>>> [c010f1f4] *pgd=4000041e(bad) >>>> Internal error: Oops: 80d [#1] PREEMPT ARM >>>> Modules linked in: >>>> CPU: 0 PID: 1329 Comm: kexec Tainted: G 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. >> # ./scripts/faddr2line --list vmlinux machine_kexec+0x40 >> machine_kexec+0x40/0xf8: >> >> machine_kexec at arch/arm/kernel/machine_kexec.c:182 >> 177 reboot_code_buffer = >> page_address(image->control_code_page); >> 178 >> 179 /* Prepare parameters for reboot_code_buffer*/ >> 180 set_kernel_text_rw(); >> 181 kexec_start_address = image->start; >> >182< kexec_indirection_page = page_list; >> 183 kexec_mach_type = machine_arch_type; >> 184 kexec_boot_atags = image->arch.kernel_r2; >> 185 >> 186 /* copy our kernel relocation code to the control code >> page */ >> 187 reboot_entry = fncpy(reboot_code_buffer, > Can you please try the patch below: > > diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c > index 963b5284d284..f86b3d17928e 100644 > --- a/arch/arm/mm/init.c > +++ b/arch/arm/mm/init.c > @@ -571,7 +571,7 @@ static inline void section_update(unsigned long addr, pmdval_t mask, > { > pmd_t *pmd; > > - pmd = pmd_off_k(addr); > + pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, addr), addr), addr), addr); > > #ifdef CONFIG_ARM_LPAE > pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); This fixes kexec issue! Thanks! Feel free to add: Reported-by: Marek Szyprowski <m.szy****@samsu*****> Fixes: 218f1c390557 ("arm: add support for folded p4d page tables") Tested-by: Marek Szyprowski <m.szy****@samsu*****> Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
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