The patch titled Subject: x86/kaslr: take CONFIG_RANDOMIZE_MEMORY into account in kaslr_enabled() has been added to the -mm tree. Its filename is x86-mm-simplify-init_trampoline-and-surrounding-logic-fix.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/x86-mm-simplify-init_trampoline-and-surrounding-logic-fix.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/x86-mm-simplify-init_trampoline-and-surrounding-logic-fix.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: x86/kaslr: take CONFIG_RANDOMIZE_MEMORY into account in kaslr_enabled() Until refactoring of the init_trampoline(), kaslr_enabled() was used only inside '#ifdef CONFIG_RANDOMIZE_MEMORY' and reported only the state of the command line override. The simplification of init_trampoline() made kaslr_enabled() visible for builds with CONFIG_RANDOMIZE_MEMORY=n and in this case it will return true if the randomization was not disabled on the command line. This in turn will call a dummy init_trampoline_kaslr() instead of setting trampline_pgd_entry directly. As the result, the kernel reboots while starting the secondary CPUs, e.g. kernel test bot reported: ... [ 0.244628] Performance Events: unsupported p6 CPU model 60 no PMU driver, software events only. [ 0.244993] rcu: Hierarchical SRCU implementation. [ 0.245617] smp: Bringing up secondary CPUs ... [ 0.247388] x86: Booting SMP configuration: BUG: kernel reboot-without-warning in boot stage Adding a check for IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) to kaslr_enabled() resolves the issue. Link: http://lkml.kernel.org/r/20200525104045.GB13212@xxxxxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Reported-by: kbuild test robot <lkp@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/setup.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/setup.h~x86-mm-simplify-init_trampoline-and-surrounding-logic-fix +++ a/arch/x86/include/asm/setup.h @@ -75,7 +75,8 @@ extern char _text[]; static inline bool kaslr_enabled(void) { - return !!(boot_params.hdr.loadflags & KASLR_FLAG); + return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) && + !!(boot_params.hdr.loadflags & KASLR_FLAG); } /* _ Patches currently in -mm which might be from rppt@xxxxxxxxxxxxx are mm-memblock-replace-dereferences-of-memblock_regionnid-with-api-calls.patch mm-make-early_pfn_to_nid-and-related-defintions-close-to-each-other.patch mm-remove-config_have_memblock_node_map-option.patch mm-free_area_init-use-maximal-zone-pfns-rather-than-zone-sizes.patch mm-use-free_area_init-instead-of-free_area_init_nodes.patch alpha-simplify-detection-of-memory-zone-boundaries.patch arm-simplify-detection-of-memory-zone-boundaries.patch arm64-simplify-detection-of-memory-zone-boundaries-for-uma-configs.patch csky-simplify-detection-of-memory-zone-boundaries.patch m68k-mm-simplify-detection-of-memory-zone-boundaries.patch parisc-simplify-detection-of-memory-zone-boundaries.patch sparc32-simplify-detection-of-memory-zone-boundaries.patch unicore32-simplify-detection-of-memory-zone-boundaries.patch xtensa-simplify-detection-of-memory-zone-boundaries.patch mm-remove-early_pfn_in_nid-and-config_nodes_span_other_nodes.patch mm-free_area_init-allow-defining-max_zone_pfn-in-descending-order.patch mm-free_area_init-allow-defining-max_zone_pfn-in-descending-order-fix-2.patch mm-rename-free_area_init_node-to-free_area_init_memoryless_node.patch mm-clean-up-free_area_init_node-and-its-helpers.patch mm-simplify-find_min_pfn_with_active_regions.patch docs-vm-update-memory-models-documentation.patch h8300-remove-usage-of-__arch_use_5level_hack.patch arm-add-support-for-folded-p4d-page-tables.patch arm-add-support-for-folded-p4d-page-tables-fix.patch arm64-add-support-for-folded-p4d-page-tables.patch hexagon-remove-__arch_use_5level_hack.patch ia64-add-support-for-folded-p4d-page-tables.patch nios2-add-support-for-folded-p4d-page-tables.patch openrisc-add-support-for-folded-p4d-page-tables.patch powerpc-add-support-for-folded-p4d-page-tables.patch powerpc-add-support-for-folded-p4d-page-tables-fix.patch powerpc-add-support-for-folded-p4d-page-tables-fix-2.patch sh-drop-__pxd_offset-macros-that-duplicate-pxd_index-ones.patch sh-add-support-for-folded-p4d-page-tables.patch unicore32-remove-__arch_use_5level_hack.patch asm-generic-remove-pgtable-nop4d-hackh.patch mm-remove-__arch_has_5level_hack-and-include-asm-generic-5level-fixuph.patch mm-dont-include-asm-pgtableh-if-linux-mmh-is-already-included.patch mm-introduce-include-linux-pgtableh.patch mm-reorder-includes-after-introduction-of-linux-pgtableh.patch csky-replace-definitions-of-__pxd_offset-with-pxd_index.patch m68k-mm-motorola-move-comment-about-page-table-allocation-funcitons.patch m68k-mm-move-cachenocahe_page-definitions-close-to-their-user.patch x86-mm-simplify-init_trampoline-and-surrounding-logic.patch x86-mm-simplify-init_trampoline-and-surrounding-logic-fix.patch mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte.patch mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte-fix.patch mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte-fix-2.patch mm-consolidate-pte_index-and-pte_offset_-definitions.patch mm-consolidate-pmd_index-and-pmd_offset-definitions.patch mm-consolidate-pud_index-and-pud_offset-definitions.patch mm-consolidate-pgd_index-and-pgd_offset_k-definitions.patch