kernel.git/arch/x86/platform/efi, branch linux-5.12.y

Merge tag 'x86_fpu_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-02-21T04:07:44Z

Pull x86 FPU updates from Borislav Petkov: "x86 fpu usage optimization and cleanups: - make 64-bit kernel code which uses 387 insns request a x87 init (FNINIT) explicitly when using the FPU - misc cleanups" * tag 'x86_fpu_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu/xstate: Use sizeof() instead of a constant x86/fpu/64: Don't FNINIT in kernel_fpu_begin() x86/fpu: Make the EFI FPU calling convention explicit

Merge tag 'x86_mm_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-02-21T03:34:09Z

Pull x86 mm cleanups from Borislav Petkov: - PTRACE_GETREGS/PTRACE_PUTREGS regset selection cleanup - Another initial cleanup - more to follow - to the fault handling code. - Other minor cleanups and corrections. * tag 'x86_mm_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/{fault,efi}: Fix and rename efi_recover_from_page_fault() x86/fault: Don't run fixups for SMAP violations x86/fault: Don't look for extable entries for SMEP violations x86/fault: Rename no_context() to kernelmode_fixup_or_oops() x86/fault: Bypass no_context() for implicit kernel faults from usermode x86/fault: Split the OOPS code out from no_context() x86/fault: Improve kernel-executing-user-memory handling x86/fault: Correct a few user vs kernel checks wrt WRUSS x86/fault: Document the locking in the fault_signal_pending() path x86/fault/32: Move is_f00f_bug() to do_kern_addr_fault() x86/fault: Fold mm_fault_error() into do_user_addr_fault() x86/fault: Skip the AMD erratum #91 workaround on unaffected CPUs x86/fault: Fix AMD erratum #91 errata fixup for user code x86/Kconfig: Remove HPET_EMULATE_RTC depends on RTC x86/asm: Fixup TASK_SIZE_MAX comment x86/ptrace: Clean up PTRACE_GETREGS/PTRACE_PUTREGS regset selection x86/vm86/32: Remove VM86_SCREEN_BITMAP support x86: Remove definition of DEBUG x86/entry: Remove now unused do_IRQ() declaration x86/mm: Remove duplicate definition of _PAGE_PAT_LARGE ...

Merge tag 'efi-next-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-02-21T03:09:26Z

Pull EFI updates from Ard Biesheuvel via Borislav Petkov: "A few cleanups left and right, some of which were part of a initrd measured boot series that needs some more work, and so only the cleanup patches have been included for this release" * tag 'efi-next-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/arm64: Update debug prints to reflect other entropy sources efi: x86: clean up previous struct mm switching efi: x86: move mixed mode stack PA variable out of 'efi_scratch' efi/libstub: move TPM related prototypes into efistub.h efi/libstub: fix prototype of efi_tcg2_protocol::get_event_log() efi/libstub: whitespace cleanup efi: ia64: move IA64-only declarations to new asm/efi.h header

x86/{fault,efi}: Fix and rename efi_recover_from_page_fault()

2021-02-10T17:39:23Z

efi_recover_from_page_fault() doesn't recover -- it does a special EFI mini-oops. Rename it to make it clear that it crashes. While renaming it, I noticed a blatant bug: a page fault oops in a different thread happening concurrently with an EFI runtime service call would be misinterpreted as an EFI page fault. Fix that. This isn't quite exact. The situation could be improved by using a special CS for calls into EFI. [ bp: Massage commit message and simplify in interrupt check. ] Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/f43b1e80830dc78ed60ed8b0826f4f189254570c.1612924255.git.luto@kernel.org

x86/efi: Remove EFI PGD build time checks

2021-02-06T12:54:14Z

With CONFIG_X86_5LEVEL, CONFIG_UBSAN and CONFIG_UBSAN_UNSIGNED_OVERFLOW enabled, clang fails the build with x86_64-linux-ld: arch/x86/platform/efi/efi_64.o: in function `efi_sync_low_kernel_mappings': efi_64.c:(.text+0x22c): undefined reference to `__compiletime_assert_354' which happens due to -fsanitize=unsigned-integer-overflow being enabled: -fsanitize=unsigned-integer-overflow: Unsigned integer overflow, where the result of an unsigned integer computation cannot be represented in its type. Unlike signed integer overflow, this is not undefined behavior, but it is often unintentional. This sanitizer does not check for lossy implicit conversions performed before such a computation (see -fsanitize=implicit-conversion). and that fires when the (intentional) EFI_VA_START/END defines overflow an unsigned long, leading to the assertion expressions not getting optimized away (on GCC they do)... However, those checks are superfluous: the runtime services mapping code already makes sure the ranges don't overshoot EFI_VA_END as the EFI mapping range is hardcoded. On each runtime services call, it is switched to the EFI-specific PGD and even if mappings manage to escape that last PGD, this won't remain unnoticed for long. So rip them out. See https://github.com/ClangBuiltLinux/linux/issues/256 for more info. Reported-by: Arnd Bergmann Signed-off-by: Borislav Petkov Reviewed-by: Nathan Chancellor Acked-by: Ard Biesheuvel Tested-by: Nick Desaulniers Tested-by: Nathan Chancellor Link: http://lkml.kernel.org/r/20210107223424.4135538-1-arnd@kernel.org

x86/fpu: Make the EFI FPU calling convention explicit

2021-01-29T11:22:15Z

EFI uses kernel_fpu_begin() to conform to the UEFI calling convention. This specifically requires initializing FCW (FPU Control Word), whereas no sane 64-bit kernel code should use legacy 387 operations that reference FCW. This should allow to safely change the default semantics of kernel_fpu_begin() to stop initializing FCW on 64-bit kernels. [ bp: Massage commit message a little. ] Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/25d392fff64680e0f4bb8cf0b1003314dc29eafe.1611205691.git.luto@kernel.org

efi: x86: clean up previous struct mm switching

2021-01-19T16:57:15Z

EFI on x86_64 keeps track of the process's MM pointer by storing it in a global struct called 'efi_scratch', which also used to contain the mixed mode stack pointer. Let's clean this up a little bit, by getting rid of the struct, and pushing the mm handling into the callees entirely. Signed-off-by: Ard Biesheuvel

efi: x86: move mixed mode stack PA variable out of 'efi_scratch'

2021-01-19T16:57:16Z

As a first step to removing the awkward 'struct efi_scratch' definition that conveniently combines the storage of the mixed mode stack pointer with the MM pointer variable that records the task's MM pointer while it is being replaced with the EFI MM one, move the mixed mode stack pointer into a separate variable. Signed-off-by: Ard Biesheuvel

efi/x86: Free efi_pgd with free_pages()

2020-11-10T18:18:11Z

Commit d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD") changed the PGD allocation to allocate PGD_ALLOCATION_ORDER pages, so in the error path it should be freed using free_pages() rather than free_page(). Commit 06ace26f4e6f ("x86/efi: Free efi_pgd with free_pages()") fixed one instance of this, but missed another. Move the freeing out-of-line to avoid code duplication and fix this bug. Fixes: d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD") Link: https://lore.kernel.org/r/20201110163919.1134431-1-nivedita@alum.mit.edu Signed-off-by: Arvind Sankar Signed-off-by: Ard Biesheuvel

Merge tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-14T17:21:34Z

Pull x86 SEV-ES support from Borislav Petkov: "SEV-ES enhances the current guest memory encryption support called SEV by also encrypting the guest register state, making the registers inaccessible to the hypervisor by en-/decrypting them on world switches. Thus, it adds additional protection to Linux guests against exfiltration, control flow and rollback attacks. With SEV-ES, the guest is in full control of what registers the hypervisor can access. This is provided by a guest-host exchange mechanism based on a new exception vector called VMM Communication Exception (#VC), a new instruction called VMGEXIT and a shared Guest-Host Communication Block which is a decrypted page shared between the guest and the hypervisor. Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest so in order for that exception mechanism to work, the early x86 init code needed to be made able to handle exceptions, which, in itself, brings a bunch of very nice cleanups and improvements to the early boot code like an early page fault handler, allowing for on-demand building of the identity mapping. With that, !KASLR configurations do not use the EFI page table anymore but switch to a kernel-controlled one. The main part of this series adds the support for that new exchange mechanism. The goal has been to keep this as much as possibly separate from the core x86 code by concentrating the machinery in two SEV-ES-specific files: arch/x86/kernel/sev-es-shared.c arch/x86/kernel/sev-es.c Other interaction with core x86 code has been kept at minimum and behind static keys to minimize the performance impact on !SEV-ES setups. Work by Joerg Roedel and Thomas Lendacky and others" * tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits) x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer x86/sev-es: Check required CPU features for SEV-ES x86/efi: Add GHCB mappings when SEV-ES is active x86/sev-es: Handle NMI State x86/sev-es: Support CPU offline/online x86/head/64: Don't call verify_cpu() on starting APs x86/smpboot: Load TSS and getcpu GDT entry before loading IDT x86/realmode: Setup AP jump table x86/realmode: Add SEV-ES specific trampoline entry point x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES x86/sev-es: Handle #DB Events x86/sev-es: Handle #AC Events x86/sev-es: Handle VMMCALL Events x86/sev-es: Handle MWAIT/MWAITX Events x86/sev-es: Handle MONITOR/MONITORX Events x86/sev-es: Handle INVD Events x86/sev-es: Handle RDPMC Events x86/sev-es: Handle RDTSC(P) Events ...