From: Joerg Roedel <jroedel@xxxxxxx> Hi, here is my current WIP code to enable PTI on x86-32. It is still in a pretty early state, but it successfully boots my KVM guest with PAE and with legacy paging. The existing PTI code for x86-64 already prepares a lot of the stuff needed for 32 bit too, thanks for that to all the people involved in its development :) The patches are split as follows: - 1-3 contain the entry-code changes to enter and exit the kernel via the sysenter trampoline stack. - 4-7 are fixes to get the code compile on 32 bit with CONFIG_PAGE_TABLE_ISOLATION=y. - 8-14 adapt the existing PTI code to work properly on 32 bit and add the needed parts to 32 bit page-table code. - 15 switches PTI on by adding the CR3 switches to kernel entry/exit. - 16 enables the Kconfig for all of X86 The code has not run on bare-metal yet, I'll test that in the next days once I setup a 32 bit box again. I also havn't tested Wine and DosEMU yet, so this might also be broken. With that post I'd like to ask for all kinds of constructive feedback on the approaches I have taken and of course the many things I broke with it :) One of the things that are surely broken is XEN_PV support. I'd appreciate any help with testing and bugfixing on that front. So please review and let me know your thoughts. Thanks, Joerg Joerg Roedel (16): x86/entry/32: Rename TSS_sysenter_sp0 to TSS_sysenter_stack x86/entry/32: Enter the kernel via trampoline stack x86/entry/32: Leave the kernel via the trampoline stack x86/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h x86/mm/ldt: Reserve high address-space range for the LDT x86/mm: Move two more functions from pgtable_64.h to pgtable.h x86/pgtable/32: Allocate 8k page-tables when PTI is enabled x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level on x86_32 x86/mm/pti: Populate valid user pud entries x86/mm/pgtable: Move pti_set_user_pgd() to pgtable.h x86/mm/pae: Populate the user page-table with user pgd's x86/mm/pti: Add an overflow check to pti_clone_pmds() x86/mm/legacy: Populate the user page-table with user pgd's x86/entry/32: Switch between kernel and user cr3 on entry/exit x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 arch/x86/entry/entry_32.S | 170 +++++++++++++++++++++++++++++--- arch/x86/include/asm/pgtable-2level.h | 3 + arch/x86/include/asm/pgtable-3level.h | 3 + arch/x86/include/asm/pgtable.h | 88 +++++++++++++++++ arch/x86/include/asm/pgtable_32_types.h | 5 +- arch/x86/include/asm/pgtable_64.h | 85 ---------------- arch/x86/include/asm/processor-flags.h | 8 +- arch/x86/include/asm/switch_to.h | 6 +- arch/x86/kernel/asm-offsets_32.c | 5 +- arch/x86/kernel/cpu/common.c | 5 +- arch/x86/kernel/head_32.S | 23 ++++- arch/x86/kernel/process.c | 2 - arch/x86/kernel/process_32.c | 6 ++ arch/x86/mm/pgtable.c | 11 ++- arch/x86/mm/pti.c | 34 ++++++- security/Kconfig | 2 +- 16 files changed, 333 insertions(+), 123 deletions(-) -- 2.13.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
