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2022-04-07x86/compressed: Add SEV-SNP feature detection/setupMichael Roth1-1/+111
Initial/preliminary detection of SEV-SNP is done via the Confidential Computing blob. Check for it prior to the normal SEV/SME feature initialization, and add some sanity checks to confirm it agrees with SEV-SNP CPUID/MSR bits. Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-07x86/sev: Move MSR-based VMGEXITs for CPUID to helperMichael Roth1-0/+1
This code will also be used later for SEV-SNP-validated CPUID code in some cases, so move it to a common helper. While here, also add a check to terminate in cases where the CPUID function/subfunction is indexed and the subfunction is non-zero, since the GHCB MSR protocol does not support non-zero subfunctions. Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/acpi: Move EFI kexec handling into common codeMichael Roth2-60/+45
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. In this instance, the current acpi.c kexec handling is mainly used to get the alternative EFI config table address provided by kexec via a setup_data entry of type SETUP_EFI. If not present, the code then falls back to normal EFI config table address provided by EFI system table. This would need to be done by all call-sites attempting to access the EFI config table, so just have efi_get_conf_table() handle that automatically. Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/acpi: Move EFI vendor table lookup to helperMichael Roth3-45/+106
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Unbreak unnecessarily broken lines. ] Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/acpi: Move EFI config table lookup to helperMichael Roth3-17/+60
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Remove superfluous zeroing of a stack variable. ] Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/acpi: Move EFI system table lookup to helperMichael Roth3-14/+42
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/acpi: Move EFI detection to helperMichael Roth4-18/+77
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. First, carve out the functionality which determines the EFI environment type the machine is booting on. [ bp: Massage commit message. ] Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed: Register GHCB memory when SEV-SNP is activeBrijesh Singh1-0/+4
The SEV-SNP guest is required by the GHCB spec to register the GHCB's Guest Physical Address (GPA). This is because the hypervisor may prefer that a guest use a consistent and/or specific GPA for the GHCB associated with a vCPU. For more information, see the GHCB specification section "GHCB GPA Registration". If hypervisor can not work with the guest provided GPA then terminate the guest boot. Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Venu Busireddy <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed: Add helper for validating pages in the decompression stageBrijesh Singh3-1/+67
Many of the integrity guarantees of SEV-SNP are enforced through the Reverse Map Table (RMP). Each RMP entry contains the GPA at which a particular page of DRAM should be mapped. The VMs can request the hypervisor to add pages in the RMP table via the Page State Change VMGEXIT defined in the GHCB specification. Inside each RMP entry is a Validated flag; this flag is automatically cleared to 0 by the CPU hardware when a new RMP entry is created for a guest. Each VM page can be either validated or invalidated, as indicated by the Validated flag in the RMP entry. Memory access to a private page that is not validated generates a #VC. A VM must use the PVALIDATE instruction to validate a private page before using it. To maintain the security guarantee of SEV-SNP guests, when transitioning pages from private to shared, the guest must invalidate the pages before asking the hypervisor to change the page state to shared in the RMP table. After the pages are mapped private in the page table, the guest must issue a page state change VMGEXIT to mark the pages private in the RMP table and validate them. Upon boot, BIOS should have validated the entire system memory. During the kernel decompression stage, early_setup_ghcb() uses set_page_decrypted() to make the GHCB page shared (i.e. clear encryption attribute). And while exiting from the decompression, it calls set_page_encrypted() to make the page private. Add snp_set_page_{private,shared}() helpers that are used by set_page_{decrypted,encrypted}() to change the page state in the RMP table. [ bp: Massage commit message and comments. ] Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/sev: Check the VMPL levelBrijesh Singh1-2/+26
The Virtual Machine Privilege Level (VMPL) feature in the SEV-SNP architecture allows a guest VM to divide its address space into four levels. The level can be used to provide hardware isolated abstraction layers within a VM. VMPL0 is the highest privilege level, and VMPL3 is the least privilege level. Certain operations must be done by the VMPL0 software, such as: * Validate or invalidate memory range (PVALIDATE instruction) * Allocate VMSA page (RMPADJUST instruction when VMSA=1) The initial SNP support requires that the guest kernel is running at VMPL0. Add such a check to verify the guest is running at level 0 before continuing the boot. There is no easy method to query the current VMPL level, so use the RMPADJUST instruction to determine whether the guest is running at the VMPL0. [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/sev: Check SEV-SNP features supportBrijesh Singh2-6/+32
Version 2 of the GHCB specification added the advertisement of features that are supported by the hypervisor. If the hypervisor supports SEV-SNP then it must set the SEV-SNP features bit to indicate that the base functionality is supported. Check that feature bit while establishing the GHCB; if failed, terminate the guest. Version 2 of the GHCB specification adds several new Non-Automatic Exits (NAEs), most of them are optional except the hypervisor feature. Now that the hypervisor feature NAE is implemented, bump the GHCB maximum supported protocol version. While at it, move the GHCB protocol negotiation check from the #VC exception handler to sev_enable() so that all feature detection happens before the first #VC exception. While at it, document why the GHCB page cannot be setup from load_stage2_idt(). [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/sev: Define the Linux-specific guest termination reasonsBrijesh Singh1-3/+3
The GHCB specification defines the reason code for reason set 0. The reason codes defined in the set 0 do not cover all possible causes for a guest to request termination. The reason sets 1 to 255 are reserved for the vendor-specific codes. Reserve the reason set 1 for the Linux guest. Define the error codes for reason set 1 so that one can have meaningful termination reasons and thus better guest failure diagnosis. While at it, change sev_es_terminate() to accept a reason set parameter. [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Venu Busireddy <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/compressed/64: Detect/setup SEV/SME features earlier during bootMichael Roth4-53/+60
With upcoming SEV-SNP support, SEV-related features need to be initialized earlier during boot, at the same point the initial #VC handler is set up, so that the SEV-SNP CPUID table can be utilized during the initial feature checks. Also, SEV-SNP feature detection will rely on EFI helper functions to scan the EFI config table for the Confidential Computing blob, and so would need to be implemented at least partially in C. Currently set_sev_encryption_mask() is used to initialize the sev_status and sme_me_mask globals that advertise what SEV/SME features are available in a guest. Rename it to sev_enable() to better reflect that (SME is only enabled in the case of SEV guests in the boot/compressed kernel), and move it to just after the stage1 #VC handler is set up so that it can be used to initialize SEV-SNP as well in future patches. While at it, re-implement it as C code so that all SEV feature detection can be better consolidated with upcoming SEV-SNP feature detection, which will also be in C. The 32-bit entry path remains unchanged, as it never relied on the set_sev_encryption_mask() initialization to begin with. [ bp: Massage commit message. ] Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/boot: Use MSR read/write helpers instead of inline assemblyMichael Roth2-25/+22
Update all C code to use the new boot_rdmsr()/boot_wrmsr() helpers instead of relying on inline assembly. Suggested-by: Borislav Petkov <[email protected]> Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-06x86/boot: Introduce helpers for MSR reads/writesMichael Roth1-0/+26
The current set of helpers used throughout the run-time kernel have dependencies on code/facilities outside of the boot kernel, so there are a number of call-sites throughout the boot kernel where inline assembly is used instead. More will be added with subsequent patches that add support for SEV-SNP, so take the opportunity to provide a basic set of helpers that can be used by the boot kernel to reduce reliance on inline assembly. Use boot_* prefix so that it's clear these are helpers specific to the boot kernel to avoid any confusion with the various other MSR read/write helpers. [ bp: Disambiguate parameter names and trim comment. ] Suggested-by: Borislav Petkov <[email protected]> Signed-off-by: Michael Roth <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-04-05Merge drm/drm-next into drm-misc-nextMaxime Ripard3-5/+4
Let's start the 5.19 development cycle. Signed-off-by: Maxime Ripard <[email protected]>
2022-03-26Merge tag 'memcpy-v5.18-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull FORTIFY_SOURCE updates from Kees Cook: "This series consists of two halves: - strict compile-time buffer size checking under FORTIFY_SOURCE for the memcpy()-family of functions (for extensive details and rationale, see the first commit) - enabling FORTIFY_SOURCE for Clang, which has had many overlapping bugs that we've finally worked past" * tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: fortify: Add Clang support fortify: Make sure strlen() may still be used as a constant expression fortify: Use __diagnose_as() for better diagnostic coverage fortify: Make pointer arguments const Compiler Attributes: Add __diagnose_as for Clang Compiler Attributes: Add __overloadable for Clang Compiler Attributes: Add __pass_object_size for Clang fortify: Replace open-coded __gnu_inline attribute fortify: Update compile-time tests for Clang 14 fortify: Detect struct member overflows in memset() at compile-time fortify: Detect struct member overflows in memmove() at compile-time fortify: Detect struct member overflows in memcpy() at compile-time
2022-03-04sysfb: Enable boot time VESA graphic mode selectionMichal Suchanek1-2/+2
Since switch to simplefb/simpledrm VESA graphic mode selection with vga= kernel parameter is no longer available with legacy BIOS. The x86 realmode boot code enables the VESA graphic modes when option FB_BOOT_VESA_SUPPORT is enabled. This option is selected by vesafb but not simplefb/simpledrm. To enable use of VESA modes with simplefb in legacy BIOS boot mode drop dependency of BOOT_VESA_SUPPORT on FB, also drop the FB_ prefix. Select the option from sysfb rather than the drivers that depend on it. The BOOT_VESA_SUPPORT is not specific to framebuffer but rather to x86 platform, move it from fbdev to x86 Kconfig. Fixes: e3263ab389a7 ("x86: provide platform-devices for boot-framebuffers") Signed-off-by: Michal Suchanek <[email protected]> Reviewed-by: Javier Martinez Canillas <[email protected]> Acked-by: Borislav Petkov <[email protected]> Signed-off-by: Thomas Zimmermann <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/948c39940a4e99f5b43bdbcbe537faae71a43e1d.1645822213.git.msuchanek@suse.de
2022-02-22x86: clean up symbol aliasingMark Rutland2-4/+2
Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those to simplify the definition of function aliases across arch/x86. For clarity, where there are multiple annotations such as EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For example, where a function has a name and an alias which are both exported, this is organised as: SYM_FUNC_START(func) ... asm insns ... SYM_FUNC_END(func) EXPORT_SYMBOL(func) SYM_FUNC_ALIAS(alias, func) EXPORT_SYMBOL(alias) Where there are only aliases and no exports or other annotations, I have not bothered with line spacing, e.g. SYM_FUNC_START(func) ... asm insns ... SYM_FUNC_END(func) SYM_FUNC_ALIAS(alias, func) The tools/perf/ copies of memset_64.S and memset_64.S are updated likewise to avoid the build system complaining these are mismatched: | Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S' | diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S | Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S' | diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Acked-by: Mark Brown <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
2022-02-13fortify: Detect struct member overflows in memmove() at compile-timeKees Cook1-1/+2
As done for memcpy(), also update memmove() to use the same tightened compile-time checks under CONFIG_FORTIFY_SOURCE. Signed-off-by: Kees Cook <[email protected]>
2022-01-19Merge tag 'kbuild-v5.17' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new kconfig target 'make mod2noconfig', which will be useful to speed up the build and test iteration. - Raise the minimum supported version of LLVM to 11.0.0 - Refactor certs/Makefile - Change the format of include/config/auto.conf to stop double-quoting string type CONFIG options. - Fix ARCH=sh builds in dash - Separate compression macros for general purposes (cmd_bzip2 etc.) and the ones for decompressors (cmd_bzip2_with_size etc.) - Misc Makefile cleanups * tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: add cmd_file_size arch: decompressor: remove useless vmlinux.bin.all-y kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22} kbuild: drop $(size_append) from cmd_zstd sh: rename suffix-y to suffix_y doc: kbuild: fix default in `imply` table microblaze: use built-in function to get CPU_{MAJOR,MINOR,REV} certs: move scripts/extract-cert to certs/ kbuild: do not quote string values in include/config/auto.conf kbuild: do not include include/config/auto.conf from shell scripts certs: simplify $(srctree)/ handling and remove config_filename macro kbuild: stop using config_filename in scripts/Makefile.modsign certs: remove misleading comments about GCC PR certs: refactor file cleaning certs: remove unneeded -I$(srctree) option for system_certificates.o certs: unify duplicated cmd_extract_certs and improve the log certs: use $< and $@ to simplify the key generation rule kbuild: remove headers_check stub kbuild: move headers_check.pl to usr/include/ certs: use if_changed to re-generate the key when the key type is changed ...
2022-01-14kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}Masahiro Yamada1-6/+6
GZIP-compressed files end with 4 byte data that represents the size of the original input. The decompressors (the self-extracting kernel) exploit it to know the vmlinux size beforehand. To mimic the GZIP's trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}. Unfortunately these macros are used everywhere despite the appended size data is only useful for the decompressors. There is no guarantee that such hand-crafted trailers are safely ignored. In fact, the kernel refuses compressed initramdfs with the garbage data. That is why usr/Makefile overrides size_append to make it no-op. To limit the use of such broken compressed files, this commit renames the existing macros as follows: cmd_bzip2 --> cmd_bzip2_with_size cmd_lzma --> cmd_lzma_with_size cmd_lzo --> cmd_lzo_with_size cmd_lz4 --> cmd_lz4_with_size cmd_xzkern --> cmd_xzkern_with_size cmd_zstd22 --> cmd_zstd22_with_size To keep the decompressors working, I updated the following Makefiles accordingly: arch/arm/boot/compressed/Makefile arch/h8300/boot/compressed/Makefile arch/mips/boot/compressed/Makefile arch/parisc/boot/compressed/Makefile arch/s390/boot/compressed/Makefile arch/sh/boot/compressed/Makefile arch/x86/boot/compressed/Makefile I reused the current macro names for the normal usecases; they produce the compressed data in the proper format. I did not touch the following: arch/arc/boot/Makefile arch/arm64/boot/Makefile arch/csky/boot/Makefile arch/mips/boot/Makefile arch/riscv/boot/Makefile arch/sh/boot/Makefile kernel/Makefile This means those Makefiles will stop appending the size data. I dropped the 'override size_append' hack from usr/Makefile. Signed-off-by: Masahiro Yamada <[email protected]> Reviewed-by: Nicolas Schier <[email protected]>
2022-01-12Merge tag 'x86_core_for_v5.17_rc1' of ↵Linus Torvalds3-8/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Get rid of all the .fixup sections because this generates misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and LIVEPATCH as the backtrace misses the function which is being fixed up. - Add Straight Line Speculation mitigation support which uses a new compiler switch -mharden-sls= which sticks an INT3 after a RET or an indirect branch in order to block speculation after them. Reportedly, CPUs do speculate behind such insns. - The usual set of cleanups and improvements * tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/entry_32: Fix segment exceptions objtool: Remove .fixup handling x86: Remove .fixup section x86/word-at-a-time: Remove .fixup usage x86/usercopy: Remove .fixup usage x86/usercopy_32: Simplify __copy_user_intel_nocache() x86/sgx: Remove .fixup usage x86/checksum_32: Remove .fixup usage x86/vmx: Remove .fixup usage x86/kvm: Remove .fixup usage x86/segment: Remove .fixup usage x86/fpu: Remove .fixup usage x86/xen: Remove .fixup usage x86/uaccess: Remove .fixup usage x86/futex: Remove .fixup usage x86/msr: Remove .fixup usage x86/extable: Extend extable functionality x86/entry_32: Remove .fixup usage x86/entry_64: Remove .fixup usage x86/copy_mc_64: Remove .fixup usage ...
2022-01-11Merge tag 'efi-next-for-v5.17' of ↵Linus Torvalds1-3/+11
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: - support taking the measurement of the initrd when loaded via the LoadFile2 protocol - kobject API cleanup from Greg - some header file whitespace fixes * tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: use default_groups in kobj_type efi/libstub: measure loaded initrd info into the TPM efi/libstub: consolidate initrd handling across architectures efi/libstub: x86/mixed: increase supported argument count efi/libstub: add prototype of efi_tcg2_protocol::hash_log_extend_event() include/linux/efi.h: Remove unneeded whitespaces before tabs
2022-01-10Merge tag 'x86_build_for_v5.17_rc1' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build fix from Borislav Petkov: "A fix for cross-compiling the compressed stub on arm64 with clang" * tag 'x86_build_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGS
2022-01-10Merge tag 'x86_cleanups_for_v5.17_rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "The mandatory set of random minor cleanups all over tip" * tag 'x86_cleanups_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/events/amd/iommu: Remove redundant assignment to variable shift x86/boot/string: Add missing function prototypes x86/fpu: Remove duplicate copy_fpstate_to_sigframe() prototype x86/uaccess: Move variable into switch case statement
2021-12-23x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGSNathan Chancellor1-2/+5
When cross compiling i386_defconfig on an arm64 host with clang, there are a few instances of '-Waddress-of-packed-member' and '-Wgnu-variable-sized-type-not-at-end' in arch/x86/boot/compressed/, which should both be disabled with the cc-disable-warning calls in that directory's Makefile, which indicates that cc-disable-warning is failing at the point of testing these flags. The cc-disable-warning calls fail because at the point that the flags are tested, KBUILD_CFLAGS has '-march=i386' without $(CLANG_FLAGS), which has the '--target=' flag to tell clang what architecture it is targeting. Without the '--target=' flag, the host architecture (arm64) is used and i386 is not a valid value for '-march=' in that case. This error can be seen by adding some logging to try-run: clang-14: error: the clang compiler does not support '-march=i386' Invoking the compiler has to succeed prior to calling cc-option or cc-disable-warning in order to accurately test whether or not the flag is supported; if it doesn't, the requested flag can never be added to the compiler flags. Move $(CLANG_FLAGS) to the beginning of KBUILD_FLAGS so that any new flags that might be added in the future can be accurately tested. Fixes: d5cbd80e302d ("x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS") Signed-off-by: Nathan Chancellor <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-12-10x86/boot/string: Add missing function prototypesKees Cook1-0/+3
Silence "warning: no previous prototype for ... [-Wmissing-prototypes]" warnings from string.h when building under W=1. [ bp: Clarify commit message. ] Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-12-08x86: Prepare asm files for straight-line-speculationPeter Zijlstra3-8/+8
Replace all ret/retq instructions with RET in preparation of making RET a macro. Since AS is case insensitive it's a big no-op without RET defined. find arch/x86/ -name \*.S | while read file do sed -i 's/\<ret[q]*\>/RET/' $file done Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-11-21efi/libstub: x86/mixed: increase supported argument countArd Biesheuvel1-3/+11
Increase the number of arguments supported by mixed mode calls, so that we will be able to call into the TCG2 protocol to measure the initrd and extend the associated PCR. This involves the TCG2 protocol's hash_log_extend_event() method, which takes five arguments, three of which are u64 and need to be split, producing a total of 8 outgoing Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2021-11-15x86/sev: Shorten GHCB terminate macro namesBrijesh Singh1-3/+3
Shorten macro names for improved readability. Suggested-by: Borislav Petkov <[email protected]> Signed-off-by: Brijesh Singh <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Venu Busireddy <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2021-11-02Merge tag 'x86_core_for_v5.16_rc1' of ↵Linus Torvalds3-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to keep old userspace from breaking. Adjust the corresponding iopl selftest to that. - Improve stack overflow warnings to say which stack got overflowed and raise the exception stack sizes to 2 pages since overflowing the single page of exception stack is very easy to do nowadays with all the tracing machinery enabled. With that, rip out the custom mapping of AMD SEV's too. - A bunch of changes in preparation for FGKASLR like supporting more than 64K section headers in the relocs tool, correct ORC lookup table size to cover the whole kernel .text and other adjustments. * tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext x86/boot/compressed: Avoid duplicate malloc() implementations x86/boot: Allow a "silent" kaslr random byte fetch x86/tools/relocs: Support >64K section headers x86/sev: Make the #VC exception stacks part of the default stacks storage x86: Increase exception stack sizes x86/mm/64: Improve stack overflow warnings x86/iopl: Fake iopl(3) CLI/STI usage
2021-11-01Merge tag 'overflow-v5.16-rc1' of ↵Linus Torvalds2-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull overflow updates from Kees Cook: "The end goal of the current buffer overflow detection work[0] is to gain full compile-time and run-time coverage of all detectable buffer overflows seen via array indexing or memcpy(), memmove(), and memset(). The str*() family of functions already have full coverage. While much of the work for these changes have been on-going for many releases (i.e. 0-element and 1-element array replacements, as well as avoiding false positives and fixing discovered overflows[1]), this series contains the foundational elements of several related buffer overflow detection improvements by providing new common helpers and FORTIFY_SOURCE changes needed to gain the introspection required for compiler visibility into array sizes. Also included are a handful of already Acked instances using the helpers (or related clean-ups), with many more waiting at the ready to be taken via subsystem-specific trees[2]. The new helpers are: - struct_group() for gaining struct member range introspection - memset_after() and memset_startat() for clearing to the end of structures - DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in structs Also included is the beginning of the refactoring of FORTIFY_SOURCE to support memcpy() introspection, fix missing and regressed coverage under GCC, and to prepare to fix the currently broken Clang support. Finishing this work is part of the larger series[0], but depends on all the false positives and buffer overflow bug fixes to have landed already and those that depend on this series to land. As part of the FORTIFY_SOURCE refactoring, a set of both a compile-time and run-time tests are added for FORTIFY_SOURCE and the mem*()-family functions respectively. The compile time tests have found a legitimate (though corner-case) bug[6] already. Please note that the appearance of "panic" and "BUG" in the FORTIFY_SOURCE refactoring are the result of relocating existing code, and no new use of those code-paths are expected nor desired. Finally, there are two tree-wide conversions for 0-element arrays and flexible array unions to gain sane compiler introspection coverage that result in no known object code differences. After this series (and the changes that have now landed via netdev and usb), we are very close to finally being able to build with -Warray-bounds and -Wzero-length-bounds. However, due corner cases in GCC[3] and Clang[4], I have not included the last two patches that turn on these options, as I don't want to introduce any known warnings to the build. Hopefully these can be solved soon" Link: https://lore.kernel.org/lkml/[email protected]/ [0] Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE [1] Link: https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/ [2] Link: https://lore.kernel.org/lkml/[email protected]/ [3] Link: https://bugs.llvm.org/show_bug.cgi?id=51682 [4] Link: https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/ [5] Link: https://lore.kernel.org/lkml/[email protected]/ [6] * tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits) fortify: strlen: Avoid shadowing previous locals compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer treewide: Replace 0-element memcpy() destinations with flexible arrays treewide: Replace open-coded flex arrays in unions stddef: Introduce DECLARE_FLEX_ARRAY() helper btrfs: Use memset_startat() to clear end of struct string.h: Introduce memset_startat() for wiping trailing members and padding xfrm: Use memset_after() to clear padding string.h: Introduce memset_after() for wiping trailing members/padding lib: Introduce CONFIG_MEMCPY_KUNIT_TEST fortify: Add compile-time FORTIFY_SOURCE tests fortify: Allow strlen() and strnlen() to pass compile-time known lengths fortify: Prepare to improve strnlen() and strlen() warnings fortify: Fix dropped strcpy() compile-time write overflow check fortify: Explicitly disable Clang support fortify: Move remaining fortify helpers into fortify-string.h lib/string: Move helper functions out of string.c compiler_types.h: Remove __compiletime_object_size() cm4000_cs: Use struct_group() to zero struct cm4000_dev region can: flexcan: Use struct_group() to zero struct flexcan_regs regions ...
2021-10-27x86/boot/compressed: Avoid duplicate malloc() implementationsKees Cook3-4/+5
The early malloc() and free() implementation in include/linux/decompress/mm.h (which is also included by the static decompressors) is static. This is fine when the only thing interested in using malloc() is the decompression code, but the x86 early boot environment may use malloc() in a couple places, leading to a potential collision when the static copies of the available memory region ("malloc_ptr") gets reset to the global "free_mem_ptr" value. As it happened, the existing usage pattern was accidentally safe because each user did 1 malloc() and 1 free() before returning and were not nested: extract_kernel() (misc.c) choose_random_location() (kaslr.c) mem_avoid_init() handle_mem_options() malloc() ... free() ... parse_elf() (misc.c) malloc() ... free() Once the future FGKASLR series is added, however, it will insert additional malloc() calls local to fgkaslr.c in the middle of parse_elf()'s malloc()/free() pair: parse_elf() (misc.c) malloc() if (...) { layout_randomized_image(output, &ehdr, phdrs); malloc() <- boom ... else layout_image(output, &ehdr, phdrs); free() To avoid collisions, there must be a single implementation of malloc(). Adjust include/linux/decompress/mm.h so that visibility can be controlled, provide prototypes in misc.h, and implement the functions in misc.c. This also results in a small size savings: $ size vmlinux.before vmlinux.after text data bss dec hex filename 8842314 468 178320 9021102 89a6ae vmlinux.before 8842240 468 178320 9021028 89a664 vmlinux.after Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-09-29x86/boot: Fix make hdimage with older versions of mtoolsH. Peter Anvin (Intel)2-9/+11
Some versions of mtools (fixed somewhere between 4.0.31 and 4.0.35) generate bad output for mformat when used with the partition= option. Use the offset= option instead. An mtools.conf entry is *also* needed with partition= to support mpartition; combining them in one entry does not work either. Don't specify the -t option to mpartition; it is unnecessary and seems to confuse mpartition under some circumstances. Also do a few minor optimizations: Use a larger cluster size; there is no reason for the typical 4K clusters when we are dealing mainly with comparatively huge files. Start the partition at 32K. There is no reason to align it more than that, since the internal FAT filesystem structures will at best be cluster-aligned, and 32K is the maximum FAT cluster size. [ bp: Remove "we". ] Signed-off-by: H. Peter Anvin (Intel) <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2021-09-25lib/string: Move helper functions out of string.cKees Cook2-0/+4
The core functions of string.c are those that may be implemented by per-architecture functions, or overloaded by FORTIFY_SOURCE. As a result, it needs to be built with __NO_FORTIFY. Without this, macros will collide with function declarations. This was accidentally working due to -ffreestanding (on some architectures). Make this deterministic by explicitly setting __NO_FORTIFY and move all the helper functions into string_helpers.c so that they gain the fortification coverage they had been missing. Cc: Andrew Morton <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Andy Lavr <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Stephen Rothwell <[email protected]> Cc: Bartosz Golaszewski <[email protected]> Acked-by: Andy Shevchenko <[email protected]> Signed-off-by: Kees Cook <[email protected]>
2021-09-03Merge tag 'kbuild-v5.15' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add -s option (strict mode) to merge_config.sh to make it fail when any symbol is redefined. - Show a warning if a different compiler is used for building external modules. - Infer --target from ARCH for CC=clang to let you cross-compile the kernel without CROSS_COMPILE. - Make the integrated assembler default (LLVM_IAS=1) for CC=clang. - Add <linux/stdarg.h> to the kernel source instead of borrowing <stdarg.h> from the compiler. - Add Nick Desaulniers as a Kbuild reviewer. - Drop stale cc-option tests. - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG to handle symbols in inline assembly. - Show a warning if 'FORCE' is missing for if_changed rules. - Various cleanups * tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits) kbuild: redo fake deps at include/ksym/*.h kbuild: clean up objtool_args slightly modpost: get the *.mod file path more simply checkkconfigsymbols.py: Fix the '--ignore' option kbuild: merge vmlinux_link() between ARCH=um and other architectures kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh kbuild: merge vmlinux_link() between the ordinary link and Clang LTO kbuild: remove stale *.symversions kbuild: remove unused quiet_cmd_update_lto_symversions gen_compile_commands: extract compiler command from a series of commands x86: remove cc-option-yn test for -mtune= arc: replace cc-option-yn uses with cc-option s390: replace cc-option-yn uses with cc-option ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild sparc: move the install rule to arch/sparc/Makefile security: remove unneeded subdir-$(CONFIG_...) kbuild: sh: remove unused install script kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y kbuild: Switch to 'f' variants of integrated assembler flag kbuild: Shuffle blank line to improve comment meaning ...
2021-08-30Merge tag 'x86_cleanups_for_v5.15' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "The usual round of minor cleanups and fixes" * tag 'x86_cleanups_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kaslr: Have process_mem_region() return a boolean x86/power: Fix kernel-doc warnings in cpu.c x86/mce/inject: Replace deprecated CPU-hotplug functions. x86/microcode: Replace deprecated CPU-hotplug functions. x86/mtrr: Replace deprecated CPU-hotplug functions. x86/mmiotrace: Replace deprecated CPU-hotplug functions.
2021-08-30Merge tag 'x86_build_for_v5.15' of ↵Linus Torvalds1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build updates from Borislav Petkov: - Remove cc-option checks which are old and already supported by the minimal compiler version the kernel uses and thus avoid the need to invoke the compiler unnecessarily. - Cleanups * tag 'x86_build_for_v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Move the install rule to arch/x86/Makefile x86/build: Remove the left-over bzlilo target x86/tools/relocs: Mark die() with the printf function attr format x86/build: Remove stale cc-option checks
2021-08-25x86/build: Move the install rule to arch/x86/MakefileMasahiro Yamada1-6/+1
Currently, the install target in arch/x86/Makefile descends into arch/x86/boot/Makefile to invoke the shell script, but there is no good reason to do so. arch/x86/Makefile can run the shell script directly. Signed-off-by: Masahiro Yamada <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2021-08-24x86/kaslr: Have process_mem_region() return a booleanJing Yangyang1-1/+1
Fix the following coccicheck warning: ./arch/x86/boot/compressed/kaslr.c:671:10-11:WARNING:return of 0/1 in function 'process_mem_region' with return type bool Generated by: scripts/coccinelle/misc/boolreturn.cocci Reported-by: Zeal Robot <[email protected]> Signed-off-by: Jing Yangyang <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2021-08-21x86/efi: Restore Firmware IDT before calling ExitBootServices()Joerg Roedel2-9/+24
Commit 79419e13e808 ("x86/boot/compressed/64: Setup IDT in startup_32 boot path") introduced an IDT into the 32-bit boot path of the decompressor stub. But the IDT is set up before ExitBootServices() is called, and some UEFI firmwares rely on their own IDT. Save the firmware IDT on boot and restore it before calling into EFI functions to fix boot failures introduced by above commit. Fixes: 79419e13e808 ("x86/boot/compressed/64: Setup IDT in startup_32 boot path") Reported-by: Fabio Aiuto <[email protected]> Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Cc: [email protected] # 5.13+ Link: https://lkml.kernel.org/r/[email protected]
2021-08-19isystem: ship and use stdarg.hAlexey Dobriyan1-1/+1
Ship minimal stdarg.h (1 type, 4 macros) as <linux/stdarg.h>. stdarg.h is the only userspace header commonly used in the kernel. GPL 2 version of <stdarg.h> can be extracted from http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz Signed-off-by: Alexey Dobriyan <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Signed-off-by: Masahiro Yamada <[email protected]>
2021-06-28Merge tag 'x86-boot-2021-06-28' of ↵Linus Torvalds4-102/+249
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot update from Ingo Molnar: "Modernize the genimage.sh script, add a 'hdimage' target and EFI support" * tag 'x86-boot-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Modernize genimage script; hdimage+EFI support
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 <[email protected]> Suggested-by: Joe Perches <[email protected]> Signed-off-by: Nick Desaulniers <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Kees Cook <[email protected]> Reviewed-by: Nathan Chancellor <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-05-10x86/boot: Modernize genimage script; hdimage+EFI supportH. Peter Anvin (Intel)4-102/+249
The image generation scripts in arch/x86/boot are pretty out of date, except for the isoimage target. Update and clean up the genimage.sh script, and make it support an arbitrary number of initramfs files in the image. Add a "hdimage" target, which can be booted by either BIOS or EFI (if the kernel is compiled with the EFI stub.) For EFI to be able to pass the command line to the kernel, we need the EFI shell, but the firmware builtin EFI shell, if it even exists, is pretty much always the last resort boot option, so search for OVMF or EDK2 and explicitly include a copy of the EFI shell. To make this all work, use bash features in the script. Furthermore, this version of the script makes use of some mtools features, especially mpartition, that might not exist in very old version of mtools, but given all the other dependencies on this script this doesn't seem such a big deal. Finally, put a volume label ("LINUX_BOOT") on all generated images. Signed-off-by: H. Peter Anvin (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected]
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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Joerg Roedel <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2021-04-27Merge 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