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2021-05-12x86/boot/compressed: Enable -WundefNick Desaulniers3-2/+3
A discussion around -Wundef showed that there were still a few boolean Kconfigs where #if was used rather than #ifdef to guard different code. Kconfig doesn't define boolean configs, which can result in -Wundef warnings. arch/x86/boot/compressed/Makefile resets the CFLAGS used for this directory, and doesn't re-enable -Wundef as the top level Makefile does. If re-added, with RANDOMIZE_BASE and X86_NEED_RELOCS disabled, the following warnings are visible. arch/x86/boot/compressed/misc.h:82:5: warning: 'CONFIG_RANDOMIZE_BASE' is not defined, evaluates to 0 [-Wundef] ^ arch/x86/boot/compressed/misc.c:175:5: warning: 'CONFIG_X86_NEED_RELOCS' is not defined, evaluates to 0 [-Wundef] ^ Simply fix these and re-enable this warning for this directory. Suggested-by: Nathan Chancellor <nathan@kernel.org> Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20210422190450.3903999-1-ndesaulniers@google.com
2021-05-10x86/sev-es: Rename sev-es.{ch} to sev.{ch}Brijesh Singh2-5/+5
SEV-SNP builds upon the SEV-ES functionality while adding new hardware protection. Version 2 of the GHCB specification adds new NAE events that are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all SEV* functionality can be consolidated in one place. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com
2021-04-28Merge tag 'x86_core_for_v5.13' of ↵Linus Torvalds1-6/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates from Borislav Petkov: - Turn the stack canary into a normal __percpu variable on 32-bit which gets rid of the LAZY_GS stuff and a lot of code. - Add an insn_decode() API which all users of the instruction decoder should preferrably use. Its goal is to keep the details of the instruction decoder away from its users and simplify and streamline how one decodes insns in the kernel. Convert its users to it. - kprobes improvements and fixes - Set the maximum DIE per package variable on Hygon - Rip out the dynamic NOP selection and simplify all the machinery around selecting NOPs. Use the simplified NOPs in objtool now too. - Add Xeon Sapphire Rapids to list of CPUs that support PPIN - Simplify the retpolines by folding the entire thing into an alternative now that objtool can handle alternatives with stack ops. Then, have objtool rewrite the call to the retpoline with the alternative which then will get patched at boot time. - Document Intel uarch per models in intel-family.h - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the exception on Intel. * tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) x86, sched: Treat Intel SNC topology as default, COD as exception x86/cpu: Comment Skylake server stepping too x86/cpu: Resort and comment Intel models objtool/x86: Rewrite retpoline thunk calls objtool: Skip magical retpoline .altinstr_replacement objtool: Cache instruction relocs objtool: Keep track of retpoline call sites objtool: Add elf_create_undef_symbol() objtool: Extract elf_symbol_add() objtool: Extract elf_strtab_concat() objtool: Create reloc sections implicitly objtool: Add elf_create_reloc() helper objtool: Rework the elf_rebuild_reloc_section() logic objtool: Fix static_call list generation objtool: Handle per arch retpoline naming objtool: Correctly handle retpoline thunk calls x86/retpoline: Simplify retpolines x86/alternatives: Optimize optimize_nops() x86: Add insn_decode_kernel() x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration ...
2021-04-26Merge tag 'x86_build_for_v5.13' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build updates from Borislav Petkov: "A bunch of clang build fixes and a Kconfig highmem selection fix for 486SX" * tag 'x86_build_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Disable HIGHMEM64G selection for M486SX efi/libstub: Add $(CLANG_FLAGS) to x86 flags x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
2021-04-26Merge tag 'x86_cleanups_for_v5.13' of ↵Linus Torvalds3-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 cleanups from Borislav Petkov: "Trivial cleanups and fixes all over the place" * tag 'x86_cleanups_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Remove me from IDE/ATAPI section x86/pat: Do not compile stubbed functions when X86_PAT is off x86/asm: Ensure asm/proto.h can be included stand-alone x86/platform/intel/quark: Fix incorrect kernel-doc comment syntax in files x86/msr: Make locally used functions static x86/cacheinfo: Remove unneeded dead-store initialization x86/process/64: Move cpu_current_top_of_stack out of TSS tools/turbostat: Unmark non-kernel-doc comment x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL() x86/fpu/math-emu: Fix function cast warning x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes x86: Fix various typos in comments, take #2 x86: Remove unusual Unicode characters from comments x86/kaslr: Return boolean values from a function returning bool x86: Fix various typos in comments x86/setup: Remove unused RESERVE_BRK_ARRAY() stacktrace: Move documentation for arch_stack_walk_reliable() to header x86: Remove duplicate TSC DEADLINE MSR definitions
2021-04-26Merge tag 'x86_boot_for_v5.13' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Borislav Petkov: "Consolidation and cleanup of the early memory reservations, along with a couple of gcc11 warning fixes" * tag 'x86_boot_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/setup: Move trim_snb_memory() later in setup_arch() to fix boot hangs x86/setup: Merge several reservations of start of memory x86/setup: Consolidate early memory reservations x86/boot/compressed: Avoid gcc-11 -Wstringop-overread warning x86/boot/tboot: Avoid Wstringop-overread-warning
2021-03-26x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGSNathan Chancellor1-0/+1
When cross compiling x86 on an ARM machine with clang, there are several errors along the lines of: arch/x86/include/asm/string_64.h:27:10: error: invalid output constraint '=&c' in asm This happens because the compressed boot Makefile reassigns KBUILD_CFLAGS and drops the clang flags that set the target architecture ('--target=') and the path to the GNU cross tools ('--prefix='), meaning that the host architecture is targeted. These flags are available as $(CLANG_FLAGS) from the main Makefile so add them to the compressed boot folder's KBUILD_CFLAGS so that cross compiling works as expected. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lkml.kernel.org/r/20210326000435.4785-3-nathan@kernel.org
2021-03-23x86/boot/compressed: Avoid gcc-11 -Wstringop-overread warningArnd Bergmann1-2/+0
GCC gets confused by the comparison of a pointer to an integer literal, with the assumption that this is an offset from a NULL pointer and that dereferencing it is invalid: In file included from arch/x86/boot/compressed/misc.c:18: In function ‘parse_elf’, inlined from ‘extract_kernel’ at arch/x86/boot/compressed/misc.c:442:2: arch/x86/boot/compressed/../string.h:15:23: error: ‘__builtin_memcpy’ reading 64 bytes from a region of size 0 [-Werror=stringop-overread] 15 | #define memcpy(d,s,l) __builtin_memcpy(d,s,l) | ^~~~~~~~~~~~~~~~~~~~~~~ arch/x86/boot/compressed/misc.c:283:9: note: in expansion of macro ‘memcpy’ 283 | memcpy(&ehdr, output, sizeof(ehdr)); | ^~~~~~ I could not find any good workaround for this, but as this is only a warning for a failure during early boot, removing the line entirely works around the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Sebor <msebor@gmail.com> Link: https://lore.kernel.org/r/20210322160253.4032422-2-arnd@kernel.org
2021-03-22x86: Fix various typos in comments, take #2Ingo Molnar2-2/+2
Fix another ~42 single-word typos in arch/x86/ code comments, missed a few in the first pass, in particular in .S files. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
2021-03-19x86/kaslr: Return boolean values from a function returning boolJiapeng Chong1-2/+2
Fix the following coccicheck warnings: ./arch/x86/boot/compressed/kaslr.c:642:10-11: WARNING: return of 0/1 in function 'process_mem_region' with return type bool. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/1615283963-67277-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-03-19x86/sev-es: Replace open-coded hlt-loops with sev_es_terminate()Joerg Roedel1-9/+3
There are a few places left in the SEV-ES C code where hlt loops and/or terminate requests are implemented. Replace them all with calls to sev_es_terminate(). Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-9-joro@8bytes.org
2021-03-19x86/boot/compressed/64: Check SEV encryption in the 32-bit boot-pathJoerg Roedel1-0/+83
Check whether the hypervisor reported the correct C-bit when running as an SEV guest. Using a wrong C-bit position could be used to leak sensitive data from the guest to the hypervisor. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-8-joro@8bytes.org
2021-03-19x86/boot/compressed/64: Add CPUID sanity check to 32-bit boot-pathJoerg Roedel1-0/+28
The 32-bit #VC handler has no GHCB and can only handle CPUID exit codes. It is needed by the early boot code to handle #VC exceptions raised in verify_cpu() and to get the position of the C-bit. But the CPUID information comes from the hypervisor which is untrusted and might return results which trick the guest into the no-SEV boot path with no C-bit set in the page-tables. All data written to memory would then be unencrypted and could leak sensitive data to the hypervisor. Add sanity checks to the 32-bit boot #VC handler to make sure the hypervisor does not pretend that SEV is not enabled. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-7-joro@8bytes.org
2021-03-19x86/boot/compressed/64: Add 32-bit boot #VC handlerJoerg Roedel2-1/+101
Add a #VC exception handler which is used when the kernel still executes in protected mode. This boot-path already uses CPUID, which will cause #VC exceptions in an SEV-ES guest. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-6-joro@8bytes.org
2021-03-18x86/boot/compressed/64: Setup IDT in startup_32 boot pathJoerg Roedel1-0/+72
This boot path needs exception handling when it is used with SEV-ES. Setup an IDT and provide a helper function to write IDT entries for use in 32-bit protected mode. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-5-joro@8bytes.org
2021-03-18x86/boot/compressed/64: Reload CS in startup_32Joerg Roedel1-1/+8
Exception handling in the startup_32 boot path requires the CS selector to be correctly set up. Reload it from the current GDT. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-4-joro@8bytes.org
2021-03-18x86/sev: Do not require Hypervisor CPUID bit for SEV guestsJoerg Roedel1-6/+0
A malicious hypervisor could disable the CPUID intercept for an SEV or SEV-ES guest and trick it into the no-SEV boot path, where it could potentially reveal secrets. This is not an issue for SEV-SNP guests, as the CPUID intercept can't be disabled for those. Remove the Hypervisor CPUID bit check from the SEV detection code to protect against this kind of attack and add a Hypervisor bit equals zero check to the SME detection path to prevent non-encrypted guests from trying to enable SME. This handles the following cases: 1) SEV(-ES) guest where CPUID intercept is disabled. The guest will still see leaf 0x8000001f and the SEV bit. It can retrieve the C-bit and boot normally. 2) Non-encrypted guests with intercepted CPUID will check the SEV_STATUS MSR and find it 0 and will try to enable SME. This will fail when the guest finds MSR_K8_SYSCFG to be zero, as it is emulated by KVM. But we can't rely on that, as there might be other hypervisors which return this MSR with bit 23 set. The Hypervisor bit check will prevent that the guest tries to enable SME in this case. 3) Non-encrypted guests on SEV capable hosts with CPUID intercept disabled (by a malicious hypervisor) will try to boot into the SME path. This will fail, but it is also not considered a problem because non-encrypted guests have no protection against the hypervisor anyway. [ bp: s/non-SEV/non-encrypted/g ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20210312123824.306-3-joro@8bytes.org
2021-03-18x86/boot/compressed/64: Cleanup exception handling before booting kernelJoerg Roedel3-5/+22
Disable the exception handling before booting the kernel to make sure any exceptions that happen during early kernel boot are not directed to the pre-decompression code. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210312123824.306-2-joro@8bytes.org
2021-03-15x86/boot/compressed/sev-es: Convert to insn_decode()Borislav Petkov1-6/+5
Other than simplifying the code there should be no functional changes resulting from this. Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210304174237.31945-7-bp@alien8.de
2020-12-24Merge tag 'efi_updates_for_v5.11' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Borislav Petkov: "These got delayed due to a last minute ia64 build issue which got fixed in the meantime. EFI updates collected by Ard Biesheuvel: - Don't move BSS section around pointlessly in the x86 decompressor - Refactor helper for discovering the EFI secure boot mode - Wire up EFI secure boot to IMA for arm64 - Some fixes for the capsule loader - Expose the RT_PROP table via the EFI test module - Relax DT and kernel placement restrictions on ARM with a few followup fixes: - fix the build breakage on IA64 caused by recent capsule loader changes - suppress a type mismatch build warning in the expansion of EFI_PHYS_ALIGN on ARM" * tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: arm: force use of unsigned type for EFI_PHYS_ALIGN efi: ia64: disable the capsule loader efi: stub: get rid of efi_get_max_fdt_addr() efi/efi_test: read RuntimeServicesSupported efi: arm: reduce minimum alignment of uncompressed kernel efi: capsule: clean scatter-gather entries from the D-cache efi: capsule: use atomic kmap for transient sglist mappings efi: x86/xen: switch to efi_get_secureboot_mode helper arm64/ima: add ima_arch support ima: generalize x86/EFI arch glue for other EFI architectures efi: generalize efi_get_secureboot efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes efi/x86: Only copy the compressed kernel image in efi_relocate_kernel() efi/libstub/x86: simplify efi_is_native()
2020-12-22kasan, x86, s390: update undef CONFIG_KASANAndrey Konovalov1-0/+1
With the intoduction of hardware tag-based KASAN some kernel checks of this kind: ifdef CONFIG_KASAN will be updated to: if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code that isn't linked with KASAN runtime and shouldn't have any KASAN annotations. Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN. Link: https://lkml.kernel.org/r/9d84bfaaf8fabe0fc89f913c9e420a30bd31a260.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15Merge tag 'x86_build_for_v5.11' of ↵Linus Torvalds1-12/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build updates from Borislav Petkov: "Two x86 build fixes: - Fix the vmlinux size check on 64-bit along with adding useful clarifications on the topic (Arvind Sankar) - Remove -m16 workaround now that the GCC versions that need it are unsupported (Nick Desaulniers)" * tag 'x86_build_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Remove -m16 workaround for unsupported versions of GCC x86/build: Fix vmlinux size check on 64-bit
2020-12-15Merge tag 'x86_cleanups_for_v5.11' of ↵Linus Torvalds2-14/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "Another branch with a nicely negative diffstat, just the way I like 'em: - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end (Gabriel Krisman Bertazi) - All kinds of minor cleanups all over the tree" * tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/ia32_signal: Propagate __user annotation properly x86/alternative: Update text_poke_bp() kernel-doc comment x86/PCI: Make a kernel-doc comment a normal one x86/asm: Drop unused RDPID macro x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg x86/head64: Remove duplicate include x86/mm: Declare 'start' variable where it is used x86/head/64: Remove unused GET_CR2_INTO() macro x86/boot: Remove unused finalize_identity_maps() x86/uaccess: Document copy_from_user_nmi() x86/dumpstack: Make show_trace_log_lvl() static x86/mtrr: Fix a kernel-doc markup x86/setup: Remove unused MCA variables x86, libnvdimm/test: Remove COPY_MC_TEST x86: Reclaim TIF_IA32 and TIF_X32 x86/mm: Convert mmu context ia32_compat into a proper flags field x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() elf: Expose ELF header on arch_setup_additional_pages() x86/elf: Use e_machine to select start_thread for x32 elf: Expose ELF header in compat_start_thread() ...
2020-12-06Merge tag 'x86-urgent-2020-12-06' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of fixes for x86: - Make the AMD L3 QoS code and data priorization enable/disable mechanism work correctly. The control bit was only set/cleared on one of the CPUs in a L3 domain, but it has to be modified on all CPUs in the domain. The initial documentation was not clear about this, but the updated one from Oct 2020 spells it out. - Fix an off by one in the UV platform detection code which causes the UV hubs to be identified wrongly. The chip revisions start at 1 not at 0. - Fix a long standing bug in the evaluation of prefixes in the uprobes code which fails to handle repeated prefixes properly. The aggregate size of the prefixes can be larger than the bytes array but the code blindly iterated over the aggregate size beyond the array boundary. Add a macro to handle this case properly and use it at the affected places" * tag 'x86-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Use new for_each_insn_prefix() macro to loop over prefixes bytes x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytes x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes x86/platform/uv: Fix UV4 hub revision adjustment x86/resctrl: Fix AMD L3 QOS CDP enable/disable
2020-12-06x86/sev-es: Use new for_each_insn_prefix() macro to loop over prefixes bytesMasami Hiramatsu1-3/+2
Since insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a prefix is repeated, the proper check must be: insn.prefixes.bytes[i] != 0 and i < 4 instead of using insn.prefixes.nbytes. Use the new for_each_insn_prefix() macro which does it correctly. Debugged by Kees Cook <keescook@chromium.org>. [ bp: Massage commit message. ] Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/160697106089.3146288.2052422845039649176.stgit@devnote2
2020-12-01x86/build: Remove -m16 workaround for unsupported versions of GCCNick Desaulniers1-12/+0
Revert the following two commits: de3accdaec88 ("x86, build: Build 16-bit code with -m16 where possible") a9cfccee6604 ("x86, build: Change code16gcc.h from a C header to an assembly header") Since 0bddd227f3dc ("Documentation: update for gcc 4.9 requirement") the minimum supported version of GCC is gcc-4.9. It's now safe to remove this code. Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20201201011307.3676986-1-ndesaulniers@google.com
2020-12-01kbuild: Hoist '--orphan-handling' into KconfigNathan Chancellor1-1/+3
Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-11-21x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%regUros Bizjak1-4/+4
Use TEST %reg,%reg which sets the zero flag in the same way as CMP $0,%reg, but the encoding uses one byte less. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20201029160258.139216-1-ubizjak@gmail.com
2020-11-18x86/boot: Remove unused finalize_identity_maps()Arvind Sankar1-10/+0
Commit 8570978ea030 ("x86/boot/compressed/64: Don't pre-map memory in KASLR code") removed all the references to finalize_identity_maps(), but neglected to delete the actual function. Remove it. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201005151208.2212886-2-nivedita@alum.mit.edu
2020-11-05efi: generalize efi_get_securebootChester Lin1-1/+1
Generalize the efi_get_secureboot() function so not only efistub but also other subsystems can use it. Note that the MokSbState handling is not factored out: the variable is boot time only, and so it cannot be parameterized as easily. Also, the IMA code will switch to this version in a future patch, and it does not incorporate the MokSbState exception in the first place. Note that the new efi_get_secureboot_mode() helper treats any failures to read SetupMode as setup mode being disabled. Co-developed-by: Chester Lin <clin@suse.com> Signed-off-by: Chester Lin <clin@suse.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-10-29x86/boot/compressed/64: Check SEV encryption in 64-bit boot-pathJoerg Roedel3-0/+7
Check whether the hypervisor reported the correct C-bit when running as an SEV guest. Using a wrong C-bit position could be used to leak sensitive data from the guest to the hypervisor. The check function is in a separate file: arch/x86/kernel/sev_verify_cbit.S so that it can be re-used in the running kernel image. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-4-joro@8bytes.org
2020-10-29x86/boot/compressed/64: Introduce sev_statusJoerg Roedel1-1/+15
Introduce sev_status and initialize it together with sme_me_mask to have an indicator which SEV features are enabled. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-2-joro@8bytes.org
2020-10-26treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches3-9/+9
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-19x86/boot/64: Explicitly map boot_params and command lineArvind Sankar2-3/+23
Commits ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") 8570978ea030 ("x86/boot/compressed/64: Don't pre-map memory in KASLR code") set up a new page table in the decompressor stub, but without explicit mappings for boot_params and the kernel command line, relying on the #PF handler instead. This is fragile, as boot_params and the command line mappings are required for the main kernel. If EARLY_PRINTK and RANDOMIZE_BASE are disabled, a QEMU/OVMF boot never accesses the command line in the decompressor stub, and so it never gets mapped. The main kernel accesses it from the identity mapping if AMD_MEM_ENCRYPT is enabled, and will crash. Fix this by adding back the explicit mapping of boot_params and the command line. Note: the changes also removed the explicit mapping of the main kernel, with the result that .bss and .brk may not be in the identity mapping, but those don't get accessed by the main kernel before it switches to its own page tables. [ bp: Pass boot_params with a MOV %rsp... instead of PUSH/POP. Use block formatting for the comment. ] Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/20201016200404.1615994-1-nivedita@alum.mit.edu
2020-10-19x86/boot/64: Initialize 5-level paging variables earlierArvind Sankar3-14/+16
Commit ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") started using a new set of pagetables even without KASLR. After that commit, initialize_identity_maps() is called before the 5-level paging variables are setup in choose_random_location(), which will not work if 5-level paging is actually enabled. Fix this by moving the initialization of __pgtable_l5_enabled, pgdir_shift and ptrs_per_p4d into cleanup_trampoline(), which is called immediately after the finalization of whether the kernel is executing with 4- or 5-level paging. This will be earlier than anything that might require those variables, and keeps the 4- vs 5-level paging code all in one place. Fixes: ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Joerg Roedel <jroedel@suse.de> Tested-by: Joerg Roedel <jroedel@suse.de> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20201010191110.4060905-1-nivedita@alum.mit.edu
2020-10-14Merge tag 'x86_seves_for_v5.10' of ↵Linus Torvalds11-207/+781
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2020-10-13Merge tag 'x86_asm_for_v5.10' of ↵Linus Torvalds1-9/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Borislav Petkov: "Two asm wrapper fixes: - Use XORL instead of XORQ to avoid a REX prefix and save some bytes in the .fixup section, by Uros Bizjak. - Replace __force_order dummy variable with a memory clobber to fix LLVM requiring a definition for former and to prevent memory accesses from still being cached/reordered, by Arvind Sankar" * tag 'x86_asm_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Replace __force_order with a memory clobber x86/uaccess: Use XORL %0,%0 in __get_user_asm()
2020-10-13Merge tag 'x86-build-2020-10-12' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build update from Ingo Molnar: "Remove a couple of ancient and distracting printouts from the x86 build, such as the CRC sum or limited size data - most of which can be gained via tools" * tag 'x86-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Declutter the build output
2020-10-13Merge tag 'x86-kaslr-2020-10-12' of ↵Linus Torvalds2-135/+107
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 kaslr updates from Ingo Molnar: "This cleans up and simplifies the x86 KASLR code, and also fixes some corner case bugs" * tag 'x86-kaslr-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86/kaslr: Replace strlen() with strnlen() x86/kaslr: Add a check that the random address is in range x86/kaslr: Make local variables 64-bit x86/kaslr: Replace 'unsigned long long' with 'u64' x86/kaslr: Make minimum/image_size 'unsigned long' x86/kaslr: Small cleanup of find_random_phys_addr() x86/kaslr: Drop unnecessary alignment in find_random_virt_addr() x86/kaslr: Drop redundant check in store_slot_info() x86/kaslr: Make the type of number of slots/slot areas consistent x86/kaslr: Drop test for command-line parameters before parsing x86/kaslr: Simplify process_gb_huge_pages() x86/kaslr: Short-circuit gb_huge_pages on x86-32 x86/kaslr: Fix off-by-one error in process_gb_huge_pages() x86/kaslr: Drop some redundant checks from __process_mem_region() x86/kaslr: Drop redundant variable in __process_mem_region() x86/kaslr: Eliminate 'start_orig' local variable from __process_mem_region() x86/kaslr: Drop redundant cur_entry from __process_mem_region() x86/kaslr: Fix off-by-one error in __process_mem_region() x86/kaslr: Initialize mem_limit to the real maximum address x86/kaslr: Fix process_efi_entries comment ...
2020-10-12Merge tag 'core-build-2020-10-12' of ↵Linus Torvalds6-204/+159
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull orphan section checking from Ingo Molnar: "Orphan link sections were a long-standing source of obscure bugs, because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms" * tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/boot/compressed: Warn on orphan section placement x86/build: Warn on orphan section placement arm/boot: Warn on orphan section placement arm/build: Warn on orphan section placement arm64/build: Warn on orphan section placement x86/boot/compressed: Add missing debugging sections to output x86/boot/compressed: Remove, discard, or assert for unwanted sections x86/boot/compressed: Reorganize zero-size section asserts x86/build: Add asserts for unwanted sections x86/build: Enforce an empty .got.plt section x86/asm: Avoid generating unused kprobe sections arm/boot: Handle all sections explicitly arm/build: Assert for unwanted sections arm/build: Add missing sections arm/build: Explicitly keep .ARM.attributes sections arm/build: Refactor linker script headers arm64/build: Assert for unwanted sections arm64/build: Add missing DWARF sections arm64/build: Use common DISCARDS in linker script arm64/build: Remove .eh_frame* sections due to unwind tables ...
2020-10-01x86/asm: Replace __force_order with a memory clobberArvind Sankar1-9/+0
The CRn accessor functions use __force_order as a dummy operand to prevent the compiler from reordering CRn reads/writes with respect to each other. The fact that the asm is volatile should be enough to prevent this: volatile asm statements should be executed in program order. However GCC 4.9.x and 5.x have a bug that might result in reordering. This was fixed in 8.1, 7.3 and 6.5. Versions prior to these, including 5.x and 4.9.x, may reorder volatile asm statements with respect to each other. There are some issues with __force_order as implemented: - It is used only as an input operand for the write functions, and hence doesn't do anything additional to prevent reordering writes. - It allows memory accesses to be cached/reordered across write functions, but CRn writes affect the semantics of memory accesses, so this could be dangerous. - __force_order is not actually defined in the kernel proper, but the LLVM toolchain can in some cases require a definition: LLVM (as well as GCC 4.9) requires it for PIE code, which is why the compressed kernel has a definition, but also the clang integrated assembler may consider the address of __force_order to be significant, resulting in a reference that requires a definition. Fix this by: - Using a memory clobber for the write functions to additionally prevent caching/reordering memory accesses across CRn writes. - Using a dummy input operand with an arbitrary constant address for the read functions, instead of a global variable. This will prevent reads from being reordered across writes, while allowing memory loads to be cached/reordered across CRn reads, which should be safe. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82602 Link: https://lore.kernel.org/lkml/20200527135329.1172644-1-arnd@arndb.de/ Link: https://lkml.kernel.org/r/20200902232152.3709896-1-nivedita@alum.mit.edu
2020-09-14x86/boot/compressed: Disable relocation relaxationArvind Sankar1-0/+2
The x86-64 psABI [0] specifies special relocation types (R_X86_64_[REX_]GOTPCRELX) for indirection through the Global Offset Table, semantically equivalent to R_X86_64_GOTPCREL, which the linker can take advantage of for optimization (relaxation) at link time. This is supported by LLD and binutils versions 2.26 onwards. The compressed kernel is position-independent code, however, when using LLD or binutils versions before 2.27, it must be linked without the -pie option. In this case, the linker may optimize certain instructions into a non-position-independent form, by converting foo@GOTPCREL(%rip) to $foo. This potential issue has been present with LLD and binutils-2.26 for a long time, but it has never manifested itself before now: - LLD and binutils-2.26 only relax movq foo@GOTPCREL(%rip), %reg to leaq foo(%rip), %reg which is still position-independent, rather than mov $foo, %reg which is permitted by the psABI when -pie is not enabled. - GCC happens to only generate GOTPCREL relocations on mov instructions. - CLang does generate GOTPCREL relocations on non-mov instructions, but when building the compressed kernel, it uses its integrated assembler (due to the redefinition of KBUILD_CFLAGS dropping -no-integrated-as), which has so far defaulted to not generating the GOTPCRELX relocations. Nick Desaulniers reports [1,2]: "A recent change [3] to a default value of configuration variable (ENABLE_X86_RELAX_RELOCATIONS OFF -> ON) in LLVM now causes Clang's integrated assembler to emit R_X86_64_GOTPCRELX/R_X86_64_REX_GOTPCRELX relocations. LLD will relax instructions with these relocations based on whether the image is being linked as position independent or not. When not, then LLD will relax these instructions to use absolute addressing mode (R_RELAX_GOT_PC_NOPIC). This causes kernels built with Clang and linked with LLD to fail to boot." Patch series [4] is a solution to allow the compressed kernel to be linked with -pie unconditionally, but even if merged is unlikely to be backported. As a simple solution that can be applied to stable as well, prevent the assembler from generating the relaxed relocation types using the -mrelax-relocations=no option. For ease of backporting, do this unconditionally. [0] https://gitlab.com/x86-psABIs/x86-64-ABI/-/blob/master/x86-64-ABI/linker-optimization.tex#L65 [1] https://lore.kernel.org/lkml/20200807194100.3570838-1-ndesaulniers@google.com/ [2] https://github.com/ClangBuiltLinux/linux/issues/1121 [3] https://reviews.llvm.org/rGc41a18cf61790fc898dcda1055c3efbf442c14c0 [4] https://lore.kernel.org/lkml/20200731202738.2577854-1-nivedita@alum.mit.edu/ Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200812004308.1448603-1-nivedita@alum.mit.edu
2020-09-10x86/sev-es: Check required CPU features for SEV-ESMartin Radev3-6/+6
Make sure the machine supports RDRAND, otherwise there is no trusted source of randomness in the system. To also check this in the pre-decompression stage, make has_cpuflag() not depend on CONFIG_RANDOMIZE_BASE anymore. Signed-off-by: Martin Radev <martin.b.radev@gmail.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200907131613.12703-73-joro@8bytes.org
2020-09-10x86/efi: Add GHCB mappings when SEV-ES is activeTom Lendacky1-0/+1
Calling down to EFI runtime services can result in the firmware performing VMGEXIT calls. The firmware is likely to use the GHCB of the OS (e.g., for setting EFI variables), so each GHCB in the system needs to be identity-mapped in the EFI page tables, as unencrypted, to avoid page faults. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Moved GHCB mapping loop to sev-es.c ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lkml.kernel.org/r/20200907131613.12703-72-joro@8bytes.org
2020-09-09x86/sev-es: Handle RDTSC(P) EventsTom Lendacky1-0/+4
Implement a handler for #VC exceptions caused by RDTSC and RDTSCP instructions. Also make it available in the pre-decompression stage because the KASLR code uses RDTSC/RDTSCP to gather entropy and some hypervisors intercept these instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: - Adapt to #VC handling infrastructure - Make it available early ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-55-joro@8bytes.org
2020-09-07x86/sev-es: Add CPUID handling to #VC handlerTom Lendacky1-0/+4
Handle #VC exceptions caused by CPUID instructions. These happen in early boot code when the KASLR code checks for RDTSC. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling framework ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-28-joro@8bytes.org
2020-09-07x86/sev-es: Add support for handling IOIO exceptionsTom Lendacky1-0/+32
Add support for decoding and handling #VC exceptions for IOIO events. [ jroedel@suse.de: Adapted code to #VC handling framework ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-26-joro@8bytes.org
2020-09-07x86/boot/compressed/64: Unmap GHCB page before booting the kernelJoerg Roedel3-2/+35
Force a page-fault on any further accesses to the GHCB page when they shouldn't happen anymore. This will catch any bugs where a #VC exception is raised even though none is expected anymore. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-25-joro@8bytes.org
2020-09-07x86/boot/compressed/64: Setup a GHCB-based VC Exception handlerJoerg Roedel6-1/+136
Install an exception handler for #VC exception that uses a GHCB. Also add the infrastructure for handling different exit-codes by decoding the instruction that caused the exception and error handling. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-24-joro@8bytes.org
2020-09-07x86/boot/compressed/64: Add set_page_en/decrypted() helpersJoerg Roedel2-0/+135
The functions are needed to map the GHCB for SEV-ES guests. The GHCB is used for communication with the hypervisor, so its content must not be encrypted. After the GHCB is not needed anymore it must be mapped encrypted again so that the running kernel image can safely re-use the memory. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-23-joro@8bytes.org
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