Hi, here is an updated version of my PTI enablement patches for the x86-32 architecture. I worked in the review comments for v3 and updated the patches here and there. The patch that re-organized RESTORE_REGS to load segments first is dropped now. A notable addition in this version is the last patch which adds debug-checks to the kernel entry/exit points that will cause a BUG if they find a wrong CR3. The checks can be enabled with a config-option and are for debugging only. I used them for testing this series, the checks did not trigger during my tests. I included the patch because I am not sure whether it is wanted upstream, if not, just tell me and I'll drop it. While at testing: I tested the patches again on a real machine (4C/8T, 16GB RAM) and ran 'perf top' for the NMI load, the x86 self-tests in a loop, and a -j16 kernel compile loop in parallel for a couple of hours. This didn't trigger any problems. I also boot-tested various combinations of PAE/non-PAE and HIGHMEM/no-HIGHMEM, also without any issues. In particular, the changes to v3 are: * Dropped the RESTORE_REGS splitting * Changed the cpu_current_top_of_stack to just point to tss.sp1, like it does on x86-64. * Simplified SAVE_ALL_NMI to just use SWITCH_TO_KERNEL_CR3 now that this macro returns the old cr3 * Added a debug Kconfig option which adds checks to the kernel entry/exit paths if the cpu is on the expected cr3 and which will BUG if not. * Explicitly clear the high word of the CS slot in pt_regs for hardware that doesn't do it for us. There is also a again branch with these patches on git.kernel.org: git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git pti-x32-v4 The previous version of this patch-set can be found at: * For v3: Post : https://marc.info/?l=linux-kernel&m=152024559419876&w=2 Git : git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git pti-x32-v3 * For v2: Post : https://marc.info/?l=linux-kernel&m=151816914932088&w=2 Git : git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git pti-x32-v2 Please review. Thanks, Joerg Joerg Roedel (35): x86/asm-offsets: Move TSS_sp0 and TSS_sp1 to asm-offsets.c x86/entry/32: Rename TSS_sysenter_sp0 to TSS_entry_stack x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler x86/entry/32: Put ESPFIX code into a macro x86/entry/32: Unshare NMI return path x86/entry/32: Split off return-to-kernel path x86/entry/32: Enter the kernel via trampoline stack x86/entry/32: Leave the kernel via trampoline stack x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack x86/entry/32: Simplify debug entry point x86/32: Use tss.sp1 as cpu_current_top_of_stack x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points x86/entry/32: Add PTI cr3 switches to NMI handler code x86/pgtable: Rename pti_set_user_pgd to pti_set_user_pgtbl x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled x86/pgtable/32: Allocate 8k page-tables when PTI is enabled x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h x86/pgtable: Move pti_set_user_pgtbl() to pgtable.h x86/pgtable: Move two more functions from pgtable_64.h to pgtable.h x86/mm/pae: Populate valid user PGD entries x86/mm/pae: Populate the user page-table with user pgd's x86/mm/legacy: Populate the user page-table with user pgd's x86/mm/pti: Add an overflow check to pti_clone_pmds() x86/mm/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level on x86_32 x86/mm/dump_pagetables: Define INIT_PGD x86/pgtable/pae: Use separate kernel PMDs for user page-table x86/ldt: Reserve address-space range on 32 bit for the LDT x86/ldt: Define LDT_END_ADDR x86/ldt: Split out sanity check in map_ldt_struct() x86/ldt: Enable LDT user-mapping for PAE x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 x86/mm/pti: Add Warning when booting on a PCID capable CPU x86/entry/32: Add debug code to check entry/exit cr3 arch/x86/Kconfig.debug | 12 + arch/x86/entry/entry_32.S | 640 +++++++++++++++++++++++----- arch/x86/include/asm/mmu_context.h | 4 - arch/x86/include/asm/pgtable-2level.h | 9 + arch/x86/include/asm/pgtable-2level_types.h | 3 + arch/x86/include/asm/pgtable-3level.h | 7 + arch/x86/include/asm/pgtable-3level_types.h | 6 +- arch/x86/include/asm/pgtable.h | 88 ++++ arch/x86/include/asm/pgtable_32_types.h | 9 +- arch/x86/include/asm/pgtable_64.h | 89 +--- arch/x86/include/asm/pgtable_64_types.h | 4 + arch/x86/include/asm/pgtable_types.h | 28 +- arch/x86/include/asm/processor-flags.h | 8 +- arch/x86/include/asm/processor.h | 4 - arch/x86/include/asm/switch_to.h | 6 +- arch/x86/include/asm/thread_info.h | 2 - arch/x86/kernel/asm-offsets.c | 5 + arch/x86/kernel/asm-offsets_32.c | 2 +- arch/x86/kernel/asm-offsets_64.c | 2 - arch/x86/kernel/cpu/common.c | 9 +- arch/x86/kernel/head_32.S | 20 +- arch/x86/kernel/ldt.c | 137 ++++-- arch/x86/kernel/process.c | 2 - arch/x86/kernel/process_32.c | 4 +- arch/x86/mm/dump_pagetables.c | 21 +- arch/x86/mm/pgtable.c | 105 ++++- arch/x86/mm/pti.c | 42 +- security/Kconfig | 2 +- 28 files changed, 969 insertions(+), 301 deletions(-) -- 2.7.4
