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2020-08-09Merge tag 'kbuild-v5.9' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
2020-07-09efi: Revert "efi/x86: Fix build with gcc 4"Ard Biesheuvel1-2/+1
This reverts commit 5435f73d5c4a1b75, which is no longer needed now that the minimum GCC version has been bumped to v4.9 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-07-07kbuild: remove cc-option test of -ffreestandingMasahiro Yamada1-1/+1
Some Makefiles already pass -ffreestanding unconditionally. For example, arch/arm64/lib/Makefile, arch/x86/purgatory/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -ffreestanding. I confirmed GCC 4.8 and Clang manuals document this option. Get rid of cc-option from -ffreestanding. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org>
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada1-1/+1
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-06-15efi/x86: Fix build with gcc 4Arvind Sankar1-1/+2
Commit bbf8e8b0fe04 ("efi/libstub: Optimize for size instead of speed") changed the optimization level for the EFI stub to -Os from -O2. Andrey Ignatov reports that this breaks the build with gcc 4.8.5. Testing on godbolt.org, the combination of -Os, -fno-asynchronous-unwind-tables, and ms_abi functions doesn't work, failing with the error: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it This does appear to work with gcc 4.9 onwards. Add -maccumulate-outgoing-args explicitly to unbreak the build with pre-4.9 versions of gcc. Reported-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200605150638.1011637-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-11Rebase locking/kcsan to locking/urgentThomas Gleixner1-0/+2
Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-01Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "A sizeable pile of arm64 updates for 5.8. Summary below, but the big two features are support for Branch Target Identification and Clang's Shadow Call stack. The latter is currently arm64-only, but the high-level parts are all in core code so it could easily be adopted by other architectures pending toolchain support Branch Target Identification (BTI): - Support for ARMv8.5-BTI in both user- and kernel-space. This allows branch targets to limit the types of branch from which they can be called and additionally prevents branching to arbitrary code, although kernel support requires a very recent toolchain. - Function annotation via SYM_FUNC_START() so that assembly functions are wrapped with the relevant "landing pad" instructions. - BPF and vDSO updates to use the new instructions. - Addition of a new HWCAP and exposure of BTI capability to userspace via ID register emulation, along with ELF loader support for the BTI feature in .note.gnu.property. - Non-critical fixes to CFI unwind annotations in the sigreturn trampoline. Shadow Call Stack (SCS): - Support for Clang's Shadow Call Stack feature, which reserves platform register x18 to point at a separate stack for each task that holds only return addresses. This protects function return control flow from buffer overruns on the main stack. - Save/restore of x18 across problematic boundaries (user-mode, hypervisor, EFI, suspend, etc). - Core support for SCS, should other architectures want to use it too. - SCS overflow checking on context-switch as part of the existing stack limit check if CONFIG_SCHED_STACK_END_CHECK=y. CPU feature detection: - Removed numerous "SANITY CHECK" errors when running on a system with mismatched AArch32 support at EL1. This is primarily a concern for KVM, which disabled support for 32-bit guests on such a system. - Addition of new ID registers and fields as the architecture has been extended. Perf and PMU drivers: - Minor fixes and cleanups to system PMU drivers. Hardware errata: - Unify KVM workarounds for VHE and nVHE configurations. - Sort vendor errata entries in Kconfig. Secure Monitor Call Calling Convention (SMCCC): - Update to the latest specification from Arm (v1.2). - Allow PSCI code to query the SMCCC version. Software Delegated Exception Interface (SDEI): - Unexport a bunch of unused symbols. - Minor fixes to handling of firmware data. Pointer authentication: - Add support for dumping the kernel PAC mask in vmcoreinfo so that the stack can be unwound by tools such as kdump. - Simplification of key initialisation during CPU bringup. BPF backend: - Improve immediate generation for logical and add/sub instructions. vDSO: - Minor fixes to the linker flags for consistency with other architectures and support for LLVM's unwinder. - Clean up logic to initialise and map the vDSO into userspace. ACPI: - Work around for an ambiguity in the IORT specification relating to the "num_ids" field. - Support _DMA method for all named components rather than only PCIe root complexes. - Minor other IORT-related fixes. Miscellaneous: - Initialise debug traps early for KGDB and fix KDB cacheflushing deadlock. - Minor tweaks to early boot state (documentation update, set TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections). - Refactoring and cleanup" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits) KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h KVM: arm64: Check advertised Stage-2 page size capability arm64/cpufeature: Add get_arm64_ftr_reg_nowarn() ACPI/IORT: Remove the unused __get_pci_rid() arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register arm64/cpufeature: Add remaining feature bits in ID_PFR0 register arm64/cpufeature: Introduce ID_MMFR5 CPU register arm64/cpufeature: Introduce ID_DFR1 CPU register arm64/cpufeature: Introduce ID_PFR2 CPU register arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0 arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register arm64: mm: Add asid_gen_match() helper firmware: smccc: Fix missing prototype warning for arm_smccc_version_init arm64: vdso: Fix CFI directives in sigreturn trampoline arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction ...
2020-05-19efi/libstub: Optimize for size instead of speedArvind Sankar1-2/+2
Reclaim the bloat from the addition of printf by optimizing the stub for size. With gcc 9, the text size of the stub is: ARCH before +printf -Os arm 35197 37889 34638 arm64 34883 38159 34479 i386 18571 21657 17025 x86_64 25677 29328 22144 Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200518190716.751506-6-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-19efi/libstub: Add a basic printf implementationArvind Sankar1-1/+1
Copy vsprintf from arch/x86/boot/printf.c to get a simple printf implementation. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200518190716.751506-5-nivedita@alum.mit.edu [ardb: add some missing braces in if...else clauses] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-15efi/libstub: Disable Shadow Call StackSami Tolvanen1-0/+3
Shadow stacks are not available in the EFI stub, filter out SCS flags. Suggested-by: James Morse <james.morse@arm.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-05-05efi/libstub/x86: Work around LLVM ELF quirk build regressionArd Biesheuvel1-0/+1
When building the x86 EFI stub with Clang, the libstub Makefile rules that manipulate the ELF object files may throw an error like: STUBCPY drivers/firmware/efi/libstub/efi-stub-helper.stub.o strip: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10 objcopy: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10 This is the result of a LLVM feature [0] where symbol references are stored in a LLVM specific .llvm_addrsig section in a non-transparent way, causing generic ELF tools such as strip or objcopy to choke on them. So force the compiler not to emit these sections, by passing the appropriate command line option. [0] https://sourceware.org/bugzilla/show_bug.cgi?id=23817 Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Sami Tolvanen <samitolvanen@google.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Fangrui Song <maskray@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/x86: Remove __efistub_global and add relocation checkArvind Sankar1-11/+21
Instead of using __efistub_global to force variables into the .data section, leave them in the .bss but pull the EFI stub's .bss section into .data in the linker script for the compressed kernel. Add relocation checking for x86 as well to catch non-PC-relative relocations that require runtime processing, since the EFI stub does not do any runtime relocation processing. This will catch, for example, data relocations created by static initializers of pointers. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200416151227.3360778-3-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/arm: Remove __efistub_global annotationArvind Sankar1-3/+4
Instead of using __efistub_global to force variables into the .data section, leave them in the .bss but pull the EFI stub's .bss section into .data in the linker script for the compressed kernel. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200416151227.3360778-2-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Move efi_relocate_kernel() into separate source fileArd Biesheuvel1-1/+1
Move efi_relocate_kernel() into a separate source file, so that it only gets pulled into builds for architectures that use it. Since efi_relocate_kernel() is the only user of efi_low_alloc(), let's move that over as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Add API function to allocate aligned memoryArd Biesheuvel1-1/+2
Break out the code to create an aligned page allocation from mem.c and move it into a function efi_allocate_pages_aligned() in alignedmem.c. Update efi_allocate_pages() to invoke it unless the minimum alignment equals the EFI page size (4 KB), in which case the ordinary page allocator is sufficient. This way, efi_allocate_pages_aligned() will only be pulled into the build if it is actually being used (which will be on arm64 only in the immediate future) Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-23efi/libstub: Move arm-stub to a common fileAtish Patra1-6/+6
Most of the arm-stub code is written in an architecture independent manner. As a result, RISC-V can reuse most of the arm-stub code. Rename the arm-stub.c to efi-stub.c so that ARM, ARM64 and RISC-V can use it. This patch doesn't introduce any functional changes. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Link: https://lore.kernel.org/r/20200415195422.19866-2-atish.patra@wdc.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-13Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar1-3/+6
Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-31Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "Misc cleanups and small enhancements all around the map" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/compressed: Fix debug_puthex() parameter type x86/setup: Fix static memory detection x86/vmlinux: Drop unneeded linker script discard of .eh_frame x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections x86/boot/compressed: Remove .eh_frame section from bzImage x86/boot/compressed/64: Remove .bss/.pgtable from bzImage x86/boot/compressed/64: Use 32-bit (zero-extended) MOV for z_output_len x86/boot/compressed/64: Use LEA to initialize boot stack pointer
2020-03-21Merge branch 'x86/kdump' into locking/kcsan, to resolve conflictsIngo Molnar1-1/+1
Conflicts: arch/x86/purgatory/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-02-25x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame ↵Arvind Sankar1-1/+2
sections While discussing a patch to discard .eh_frame from the compressed vmlinux using the linker script, Fangrui Song pointed out [1] that these sections shouldn't exist in the first place because arch/x86/Makefile uses -fno-asynchronous-unwind-tables. It turns out this is because the Makefiles used to build the compressed kernel redefine KBUILD_CFLAGS, dropping this flag. Add the flag to the Makefile for the compressed kernel, as well as the EFI stub Makefile to fix this. Also add the flag to boot/Makefile and realmode/rm/Makefile so that the kernel's boot code (boot/setup.elf) and realmode trampoline (realmode/rm/realmode.elf) won't be compiled with .eh_frame sections, since their linker scripts also just discard them. [1] https://lore.kernel.org/lkml/20200222185806.ywnqhfqmy67akfsa@google.com/ Suggested-by: Fangrui Song <maskray@google.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lkml.kernel.org/r/20200224232129.597160-2-nivedita@alum.mit.edu
2020-02-23efi/libstub: Clean up command line parsing routineArd Biesheuvel1-1/+2
We currently parse the command non-destructively, to avoid having to allocate memory for a copy before passing it to the standard parsing routines that are used by the core kernel, and which modify the input to delineate the parsed tokens with NUL characters. Instead, we call strstr() and strncmp() to go over the input multiple times, and match prefixes rather than tokens, which implies that we would match, e.g., 'nokaslrfoo' in the stub and disable KASLR, while the kernel would disregard the option and run with KASLR enabled. In order to avoid having to reason about whether and how this behavior may be abused, let's clean up the parsing routines, and rebuild them on top of the existing helpers. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move file I/O support code into separate fileArd Biesheuvel1-1/+1
Split off the file I/O support code into a separate source file so it ends up in a separate object file in the static library, allowing the linker to omit it if the routines are not used. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move efi_random_alloc() into separate source fileArd Biesheuvel1-1/+1
efi_random_alloc() is only used on arm64, but as it shares a source file with efi_random_get_seed(), the latter will pull in the former on other architectures as well. Let's take advantage of the fact that libstub is a static library, and so the linker will only incorporate objects that are needed to satisfy dependencies in other objects. This means we can move the random alloc code to a separate source file that gets built unconditionally, but only used when needed. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub/x86: Incorporate eboot.c into libstubArd Biesheuvel1-0/+1
Most of the EFI stub source files of all architectures reside under drivers/firmware/efi/libstub, where they share a Makefile with special CFLAGS and an include file with declarations that are only relevant for stub code. Currently, we carry a lot of stub specific stuff in linux/efi.h only because eboot.c in arch/x86 needs them as well. So let's move eboot.c into libstub/, and move the contents of eboot.h that we still care about into efistub.h Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Move memory map handling and allocation routines to mem.cArd Biesheuvel1-1/+1
Create a new source file mem.c to keep the routines involved in memory allocation and deallocation and manipulation of the EFI memory map. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23efi/libstub: Use hidden visibility for all source filesArd Biesheuvel1-0/+1
Instead of setting the visibility pragma for a small set of symbol declarations that could result in absolute references that we cannot support in the stub, declare hidden visibility for all code in the EFI stub, which is more robust and future proof. To ensure that the #pragma is taken into account before any other includes are processed, put it in a header file of its own and include it via the compiler command line using the -include option. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-22efi/libstub/arm64: Use 1:1 mapping of RT services if property table existsArd Biesheuvel1-1/+0
The UEFI spec defines (and deprecates) a misguided and shortlived memory protection feature that is based on splitting memory regions covering PE/COFF executables into separate code and data regions, without annotating them as belonging to the same executable image. When the OS assigns the virtual addresses of these regions, it may move them around arbitrarily, without taking into account that the PE/COFF code sections may contain relative references into the data sections, which means the relative placement of these segments has to be preserved or the executable image will be corrupted. The original workaround on arm64 was to ensure that adjacent regions of the same type were mapped adjacently in the virtual mapping, but this requires sorting of the memory map, which we would prefer to avoid. Considering that the native physical mapping of the PE/COFF images does not suffer from this issue, let's preserve it at runtime, and install it as the virtual mapping as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-01-10efi: Allow disabling PCI busmastering on bridges during bootMatthew Garrett1-1/+1
Add an option to disable the busmaster bit in the control register on all PCI bridges before calling ExitBootServices() and passing control to the runtime kernel. System firmware may configure the IOMMU to prevent malicious PCI devices from being able to attack the OS via DMA. However, since firmware can't guarantee that the OS is IOMMU-aware, it will tear down IOMMU configuration when ExitBootServices() is called. This leaves a window between where a hostile device could still cause damage before Linux configures the IOMMU again. If CONFIG_EFI_DISABLE_PCI_DMA is enabled or "efi=disable_early_pci_dma" is passed on the command line, the EFI stub will clear the busmaster bit on all PCI bridges before ExitBootServices() is called. This will prevent any malicious PCI devices from being able to perform DMA until the kernel reenables busmastering after configuring the IOMMU. This option may cause failures with some poorly behaved hardware and should not be enabled without testing. The kernel commandline options "efi=disable_early_pci_dma" or "efi=no_disable_early_pci_dma" may be used to override the default. Note that PCI devices downstream from PCI bridges are disconnected from their drivers first, using the UEFI driver model API, so that DMA can be disabled safely at the bridge level. [ardb: disconnect PCI I/O handles first, as suggested by Arvind] Co-developed-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <matthewgarrett@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-18-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-30Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar1-2/+3
Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-16build, kcsan: Add KCSAN build exceptionsMarco Elver1-0/+2
This blacklists several compilation units from KCSAN. See the respective inline comments for the reasoning. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2019-11-07x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG tableDominik Brodowski1-2/+3
Invoke the EFI_RNG_PROTOCOL protocol in the context of the x86 EFI stub, same as is done on arm/arm64 since commit 568bc4e87033 ("efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table"). Within the stub, a Linux-specific RNG seed UEFI config table will be seeded. The EFI routines in the core kernel will pick that up later, yet still early during boot, to seed the kernel entropy pool. If CONFIG_RANDOM_TRUST_BOOTLOADER, entropy is credited for this seed. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2019-10-31efi: libstub/arm: Account for firmware reserved memory at the base of RAMArd Biesheuvel1-0/+1
The EFI stubloader for ARM starts out by allocating a 32 MB window at the base of RAM, in order to ensure that the decompressor (which blindly copies the uncompressed kernel into that window) does not overwrite other allocations that are made while running in the context of the EFI firmware. In some cases, (e.g., U-Boot running on the Raspberry Pi 2), this is causing boot failures because this initial allocation conflicts with a page of reserved memory at the base of RAM that contains the SMP spin tables and other pieces of firmware data and which was put there by the bootloader under the assumption that the TEXT_OFFSET window right below the kernel is only used partially during early boot, and will be left alone once the memory reservations are processed and taken into account. So let's permit reserved memory regions to exist in the region starting at the base of RAM, and ending at TEXT_OFFSET - 5 * PAGE_SIZE, which is the window below the kernel that is not touched by the early boot code. Tested-by: Guillaume Gardet <Guillaume.Gardet@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Chester Lin <clin@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191029173755.27149-5-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-06Merge tag 'arm64-upstream' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Mostly just incremental improvements here: - Introduce AT_HWCAP2 for advertising CPU features to userspace - Expose SVE2 availability to userspace - Support for "data cache clean to point of deep persistence" (DC PODP) - Honour "mitigations=off" on the cmdline and advertise status via sysfs - CPU timer erratum workaround (Neoverse-N1 #1188873) - Introduce perf PMU driver for the SMMUv3 performance counters - Add config option to disable the kuser helpers page for AArch32 tasks - Futex modifications to ensure liveness under contention - Rework debug exception handling to seperate kernel and user handlers - Non-critical fixes and cleanup" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) Documentation: Add ARM64 to kernel-parameters.rst arm64/speculation: Support 'mitigations=' cmdline option arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB arm64: enable generic CPU vulnerabilites support arm64: add sysfs vulnerability show for speculative store bypass arm64: Fix size of __early_cpu_boot_status clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters clocksource/arm_arch_timer: Remove use of workaround static key clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable clocksource/arm_arch_timer: Direcly assign set_next_event workaround arm64: Use arch_timer_read_counter instead of arch_counter_get_cntvct watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct ARM: vdso: Remove dependency with the arch_timer driver internals arm64: Apply ARM64_ERRATUM_1188873 to Neoverse-N1 arm64: Add part number for Neoverse N1 arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT arm64: Restrict ARM64_ERRATUM_1188873 mitigation to AArch32 arm64: mm: Remove pte_unmap_nested() arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable arm64: compat: Reduce address limit for 64K pages ...
2019-04-09efi/arm/arm64: Makefile: Replace -pg with CC_FLAGS_FTRACETorsten Duwe1-3/+3
In preparation for arm64 supporting ftrace built on other compiler options, let's have Makefiles remove the $(CC_FLAGS_FTRACE) flags, whatever these maybe, rather than assuming '-pg'. While at it, fix arm32 as well. There should be no functional change as a result of this patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-03-29efi/libstub/arm: Omit unneeded stripping of ksymtab/kcrctab sectionsArd Biesheuvel1-2/+1
Commit f922c4abdf764 ("module: allow symbol exports to be disabled") introduced a way to inhibit generation of kcrctab/ksymtab sections when building ordinary kernel code to be used in a different execution context (decompressor, EFI stub, etc) That means we no longer have to strip those sections explicitly when building the EFI libstub objects, so drop this from the Makefile. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190328193429.21373-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-29efi/libstub: Refactor the cmd_stubcopy Makefile commandMasahiro Yamada1-6/+7
It took me a while to understand what is going on in the nested if-blocks. Simplify it by removing unneeded code. - if_changed automatically adds 'set -e', so any failure in the series of commands makes it immediately fail as a whole. So, the outer if block is entirely redundant. - Since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"), GNU Make automatically deletes the target on any failure in its recipe. The explicit 'rm -f $@' is redundant. - Surrounding commands with ( ) will spawn a subshell to execute them in it, but it is rarely useful to do so. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190328193429.21373-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04efi/fdt: Apply more cleanupsIngo Molnar1-2/+2
Apply a number of cleanups: - Introduce fdt_setprop_*var() helper macros to simplify and shorten repetitive sequences - this also makes it less likely that the wrong variable size is passed in. This change makes a lot of the property-setting calls single-line and easier to read. - Harmonize comment style: capitalization, punctuation, whitespaces, etc. - Fix some whitespace noise in the libstub Makefile which I happened to notice. - Use the standard tabular initialization style: - map.map = &runtime_map; - map.map_size = &map_size; - map.desc_size = &desc_size; - map.desc_ver = &desc_ver; - map.key_ptr = &mmap_key; - map.buff_size = &buff_size; + map.map = &runtime_map; + map.map_size = &map_size; + map.desc_size = &desc_size; + map.desc_ver = &desc_ver; + map.key_ptr = &mmap_key; + map.buff_size = &buff_size; - Use tabular structure definition for better readability. - Make all pr*() lines single-line, even if they marginally exceed 80 cols - this makes them visually less intrusive. - Unbreak line breaks into single lines when the length exceeds 80 cols only marginally, for better readability. - Move assignment closer to the actual usage site. - Plus some other smaller cleanups, spelling fixes, etc. No change in functionality intended. [ ardb: move changes to upstream libfdt into local header. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Alexander Graf <agraf@suse.de> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Lee Jones <lee.jones@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190202094119.13230-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-30efi/libstub: Disable some warnings for x86{,_64}Nathan Chancellor1-1/+4
When building the kernel with Clang, some disabled warnings appear because this Makefile overrides KBUILD_CFLAGS for x86{,_64}. Add them to this list so that the build is clean again. -Wpointer-sign was disabled for the whole kernel before the beginning of Git history. -Waddress-of-packed-member was disabled for the whole kernel and for the early boot code in these commits: bfb38988c51e ("kbuild: clang: Disable 'address-of-packed-member' warning") 20c6c1890455 ("x86/boot: Disable the address-of-packed-member compiler warning"). -Wgnu was disabled for the whole kernel and for the early boot code in these commits: 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang") 6c3b56b19730 ("x86/boot: Disable Clang warnings about GNU extensions"). [ mingo: Made the changelog more readable. ] Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arend van Spriel <arend.vanspriel@broadcom.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Eric Snowberg <eric.snowberg@oracle.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Jon Hunter <jonathanh@nvidia.com> Cc: Julien Thierry <julien.thierry@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: YiFei Zhu <zhuyifei1999@gmail.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20181129171230.18699-8-ard.biesheuvel@linaro.org Link: https://github.com/ClangBuiltLinux/linux/issues/112 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-26efi/libstub: arm: support building with clangAlistair Strachan1-1/+2
When building with CONFIG_EFI and CONFIG_EFI_STUB on ARM, the libstub Makefile would use -mno-single-pic-base without checking it was supported by the compiler. As the ARM (32-bit) clang backend does not support this flag, the build would fail. This changes the Makefile to check the compiler's support for -mno-single-pic-base before using it, similar to c1c386681bd7 ("ARM: 8767/1: add support for building ARM kernel with clang"). Signed-off-by: Alistair Strachan <astrachan@google.com> Reviewed-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2018-08-22module: allow symbol exports to be disabledArd Biesheuvel1-0/+1
To allow existing C code to be incorporated into the decompressor or the UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx declarations into nops, and #define it in places where such exports are undesirable. Note that this gets rid of a rather dodgy redefine of linux/export.h's header guard. Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-31efi/libstub: Only disable stackleak plugin for arm64Laura Abbott1-2/+4
arm64 uses the full KBUILD_CFLAGS for building libstub as opposed to x86 which doesn't. This means that x86 doesn't pick up the gcc-plugins. We need to disable the stackleak plugin but doing this unconditionally breaks x86 build since it doesn't have any plugins. Switch to disabling the stackleak plugin for arm64 only. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-26arm64: Add support for STACKLEAK gcc pluginLaura Abbott1-1/+2
This adds support for the STACKLEAK gcc plugin to arm64 by implementing stackleak_check_alloca(), based heavily on the x86 version, and adding the two helpers used by the stackleak common code: current_top_of_stack() and on_thread_stack(). The stack erasure calls are made at syscall returns. Additionally, this disables the plugin in hypervisor and EFI stub code, which are out of scope for the protection. Acked-by: Alexander Popov <alex.popov@linux.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-12efi: Use string literals for efi_char16_t variable initializersArd Biesheuvel1-1/+1
Now that we unambiguously build the entire kernel with -fshort-wchar, it is no longer necessary to open code efi_char16_t[] initializers as arrays of characters, and we can move to the L"xxx" notation instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180312084500.10764-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-08efi: call get_event_log before ExitBootServicesThiebaud Weksteen1-2/+1
With TPM 2.0 specification, the event logs may only be accessible by calling an EFI Boot Service. Modify the EFI stub to copy the log area to a new Linux-specific EFI configuration table so it remains accessible once booted. When calling this service, it is possible to specify the expected format of the logs: TPM 1.2 (SHA1) or TPM 2.0 ("Crypto Agile"). For now, only the first format is retrieved. Signed-off-by: Thiebaud Weksteen <tweek@google.com> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Tested-by: Javier Martinez Canillas <javierm@redhat.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2017-11-04Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-3/+3
Pull ARM fixes from Russell King: - omit EFI memory map sorting, which was recently introduced, but caused problems with the decompressor due to additional sections being emitted. - avoid unaligned load fault-generating instructions in the decompressor by switching to a private unaligned implementation. - add a symbol into the decompressor to further debug non-boot situations (ld's documentation is extremely poor for how "." works, ld doesn't seem to follow its own documentation!) - parse endian information to sparse * 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: add debug ".edata_real" symbol ARM: 8716/1: pass endianness info to sparse efi/libstub: arm: omit sorting of the UEFI memory map ARM: 8715/1: add a private asm/unaligned.h
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-27efi/libstub: arm: omit sorting of the UEFI memory mapArd Biesheuvel1-3/+3
ARM shares its EFI stub implementation with arm64, which has some special handling in the virtual remapping code to a) make sure that we can map everything even if the OS executes with 64k page size, and b) make sure that adjacent regions with the same attributes are not reordered or moved apart in memory. The latter is a workaround for a 'feature' that was shortly recommended by UEFI spec v2.5, but deprecated shortly after, due to the fact that it broke many OS installers, including non-Linux ones, and it was never widely implemented for ARM systems. Before implementing b), the arm64 code simply rounded up all regions to 64 KB granularity, but given that that results in moving adjacent regions apart, it had to be refined when b) was implemented. The adjacency check requires a sort() pass, due to the fact that the UEFI spec does not mandate any ordering, and the inclusion of the lib/sort.c code into the ARM EFI stub is causing some trouble with the decompressor build due to the fact that its EXPORT_SYMBOL() call triggers the creation of ksymtab/kcrctab sections. So let's simply do away with the adjacency check for ARM, and simply put all UEFI runtime regions together if they have the same memory attributes. This is guaranteed to work, given that ARM only supports 4 KB pages, and allows us to remove the sort() call entirely. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Jeffy Chen <jeffy.chen@rock-chips.com> Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Tested-by: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-08-26efi/libstub: Enable reset attack mitigationMatthew Garrett1-0/+1
If a machine is reset while secrets are present in RAM, it may be possible for code executed after the reboot to extract those secrets from untouched memory. The Trusted Computing Group specified a mechanism for requesting that the firmware clear all RAM on reset before booting another OS. This is done by setting the MemoryOverwriteRequestControl variable at startup. If userspace can ensure that all secrets are removed as part of a controlled shutdown, it can reset this variable to 0 before triggering a hardware reboot. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170825155019.6740-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-21efi/libstub/arm64: Set -fpie when building the EFI stubArd Biesheuvel1-1/+1
Clang may emit absolute symbol references when building in non-PIC mode, even when using the default 'small' code model, which is already mostly position independent to begin with, due to its use of adrp/add pairs that have a relative range of +/- 4 GB. The remedy is to pass the -fpie flag, which can be done safely now that the code has been updated to avoid GOT indirections (which may be emitted due to the compiler assuming that the PIC/PIE code may end up in a shared library that is subject to ELF symbol preemption) Passing -fpie when building code that needs to execute at an a priori unknown offset is arguably an improvement in any case, and given that the recent visibility changes allow the PIC build to pass with GCC as well, let's add -fpie for all arm64 builds rather than only for Clang. Tested-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170818194947.19347-5-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-12efi: avoid fortify checks in EFI stubKees Cook1-0/+1
This avoids CONFIG_FORTIFY_SOURCE from being enabled during the EFI stub build, as adding a panic() implementation may not work well. This can be adjusted in the future. Link: http://lkml.kernel.org/r/1497903987-21002-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Suggested-by: Daniel Micay <danielmicay@gmail.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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