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2022-09-26efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmapArd Biesheuvel
Currently, struct efi_boot_memmap is a struct that is passed around between callers of efi_get_memory_map() and the users of the resulting data, and which carries pointers to various variables whose values are provided by the EFI GetMemoryMap() boot service. This is overly complex, and it is much easier to carry these values in the struct itself. So turn the struct into one that carries these data items directly, including a flex array for the variable number of EFI memory descriptors that the boot service may return. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-26efi: libstub: avoid efi_get_memory_map() for allocating the virt mapArd Biesheuvel
The virt map is a set of efi_memory_desc_t descriptors that are passed to SetVirtualAddressMap() to inform the firmware about the desired virtual mapping of the regions marked as EFI_MEMORY_RUNTIME. The only reason we currently call the efi_get_memory_map() helper is that it gives us an allocation that is guaranteed to be of sufficient size. However, efi_get_memory_map() has grown some additional complexity over the years, and today, we're actually better off calling the EFI boot service directly with a zero size, which tells us how much memory should be enough for the virt map. While at it, avoid creating the VA map allocation if we will not be using it anyway, i.e., if efi_novamap is true. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-26treewide: Filter out CC_FLAGS_CFISami Tolvanen
In preparation for removing CC_FLAGS_CFI from CC_FLAGS_LTO, explicitly filter out CC_FLAGS_CFI in all the makefiles where we currently filter out CC_FLAGS_LTO. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-2-samitolvanen@google.com
2022-09-22efi: libstub: check Shim mode using MokSBStateRTArd Biesheuvel
We currently check the MokSBState variable to decide whether we should treat UEFI secure boot as being disabled, even if the firmware thinks otherwise. This is used by shim to indicate that it is not checking signatures on boot images. In the kernel, we use this to relax lockdown policies. However, in cases where shim is not even being used, we don't want this variable to interfere with lockdown, given that the variable may be non-volatile and therefore persist across a reboot. This means setting it once will persistently disable lockdown checks on a given system. So switch to the mirrored version of this variable, called MokSBStateRT, which is supposed to be volatile, and this is something we can check. Cc: <stable@vger.kernel.org> # v4.19+ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Peter Jones <pjones@redhat.com>
2022-09-22efi: x86: Wipe setup_data on pure EFI bootArd Biesheuvel
When booting the x86 kernel via EFI using the LoadImage/StartImage boot services [as opposed to the deprecated EFI handover protocol], the setup header is taken from the image directly, and given that EFI's LoadImage has no Linux/x86 specific knowledge regarding struct bootparams or struct setup_header, any absolute addresses in the setup header must originate from the file and not from a prior loading stage. Since we cannot generally predict where LoadImage() decides to load an image (*), such absolute addresses must be treated as suspect: even if a prior boot stage intended to make them point somewhere inside the [signed] image, there is no way to validate that, and if they point at an arbitrary location in memory, the setup_data nodes will not be covered by any signatures or TPM measurements either, and could be made to contain an arbitrary sequence of SETUP_xxx nodes, which could interfere quite badly with the early x86 boot sequence. (*) Note that, while LoadImage() does take a buffer/size tuple in addition to a device path, which can be used to provide the image contents directly, it will re-allocate such images, as the memory footprint of an image is generally larger than the PE/COFF file representation. Cc: <stable@vger.kernel.org> # v5.10+ Link: https://lore.kernel.org/all/20220904165321.1140894-1-Jason@zx2c4.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-09-20efi: libstub: drop pointless get_memory_map() callArd Biesheuvel
Currently, the non-x86 stub code calls get_memory_map() redundantly, given that the data it returns is never used anywhere. So drop the call. Cc: <stable@vger.kernel.org> # v4.14+ Fixes: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-20efi: libstub: fix type confusion for load_options_sizeArd Biesheuvel
Even though it is unlikely to ever make a difference, let's use u32 consistently for the size of the load_options provided by the firmware (aka the command line) While at it, do some general cleanup too: use efi_char16_t, avoid using options_chars in places where it really means options_size, etc. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-20efi/libstub: implement generic EFI zbootArd Biesheuvel
Implement a minimal EFI app that decompresses the real kernel image and launches it using the firmware's LoadImage and StartImage boot services. This removes the need for any arch-specific hacks. Note that on systems that have UEFI secure boot policies enabled, LoadImage/StartImage require images to be signed, or their hashes known a priori, in order to be permitted to boot. There are various possible strategies to work around this requirement, but they all rely either on overriding internal PI/DXE protocols (which are not part of the EFI spec) or omitting the firmware provided LoadImage() and StartImage() boot services, which is also undesirable, given that they encapsulate platform specific policies related to secure boot and measured boot, but also related to memory permissions (whether or not and which types of heap allocations have both write and execute permissions.) The only generic and truly portable way around this is to simply sign both the inner and the outer image with the same key/cert pair, so this is what is implemented here. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-19efi/libstub: move efi_system_table global var into separate objectArd Biesheuvel
To avoid pulling in the wrong object when using the libstub static library to build the decompressor, define efi_system_table in a separate compilation unit. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-17efi/libstub: use EFI provided memcpy/memset routinesArd Biesheuvel
The stub is used in different execution environments, but on arm64, RISC-V and LoongArch, we still use the core kernel's implementation of memcpy and memset, as they are just a branch instruction away, and can generally be reused even from code such as the EFI stub that runs in a completely different address space. KAsan complicates this slightly, resulting in the need for some hacks to expose the uninstrumented, __ prefixed versions as the normal ones, as the latter are instrumented to include the KAsan checks, which only work in the core kernel. Unfortunately, #define'ing memcpy to __memcpy when building C code does not guarantee that no explicit memcpy() calls will be emitted. And with the upcoming zboot support, which consists of a separate binary which therefore needs its own implementation of memcpy/memset anyway, it's better to provide one explicitly instead of linking to the existing one. Given that EFI exposes implementations of memmove() and memset() via the boot services table, let's wire those up in the appropriate way, and drop the references to the core kernel ones. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-17efi/libstub: add some missing EFI prototypesArd Biesheuvel
Define the correct prototypes for the load_image, start_image and unload_image boot service pointers so we can call them from the EFI zboot code. Also add some prototypes related to installation and deinstallation of protocols in to the EFI protocol database, including some definitions related to device paths. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-09arm64/sysreg: Add _EL1 into ID_AA64MMFR0_EL1 definition namesMark Brown
Normally we include the full register name in the defines for fields within registers but this has not been followed for ID registers. In preparation for automatic generation of defines add the _EL1s into the defines for ID_AA64MMFR0_EL1 to follow the convention. No functional changes. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com> Link: https://lore.kernel.org/r/20220905225425.1871461-5-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-07efi/x86: libstub: remove unused variablechen zhang
The variable "has_system_memory" is unused in function ‘adjust_memory_range_protection’, remove it. Signed-off-by: chen zhang <chenzhang@kylinos.cn> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-06efi/loongarch: Add efistub booting supportHuacai Chen
This patch adds efistub booting support, which is the standard UEFI boot protocol for LoongArch to use. We use generic efistub, which means we can pass boot information (i.e., system table, memory map, kernel command line, initrd) via a light FDT and drop a lot of non-standard code. We use a flat mapping to map the efi runtime in the kernel's address space. In efi, VA = PA; in kernel, VA = PA + PAGE_OFFSET. As a result, flat mapping is not identity mapping, SetVirtualAddressMap() is still needed for the efi runtime. Tested-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> [ardb: change fpic to fpie as suggested by Xi Ruoyao] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-08-25efi: libstub: Disable struct randomizationArd Biesheuvel
The EFI stub is a wrapper around the core kernel that makes it look like a EFI compatible PE/COFF application to the EFI firmware. EFI applications run on top of the EFI runtime, which is heavily based on so-called protocols, which are struct types consisting [mostly] of function pointer members that are instantiated and recorded in a protocol database. These structs look like the ideal randomization candidates to the randstruct plugin (as they only carry function pointers), but of course, these protocols are contracts between the firmware that exposes them, and the EFI applications (including our stubbed kernel) that invoke them. This means that struct randomization for EFI protocols is not a great idea, and given that the stub shares very little data with the core kernel that is represented as a randomizable struct, we're better off just disabling it completely here. Cc: <stable@vger.kernel.org> # v4.14+ Reported-by: Daniel Marth <daniel.marth@inso.tuwien.ac.at> Tested-by: Daniel Marth <daniel.marth@inso.tuwien.ac.at> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Kees Cook <keescook@chromium.org>
2022-07-19riscv/efi_stub: Add 64bit boot-hartid support on RV64Sunil V L
The boot-hartid can be a 64bit value on RV64 platforms but the "boot-hartid" in DT is assumed to be 32bit only. Detect the size of the "boot-hartid" in DT and use 32bit or 64bit read appropriately. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Link: https://lore.kernel.org/r/20220527051743.2829940-6-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-01efi/x86: libstub: Make DXE calls mixed mode safeArd Biesheuvel
The newly added DXE calls use 64-bit quantities, which means we need to marshall them explicitly when running in mixed mode. Currently, we get away without it because we just bail when GetMemorySpaceDescriptor() fails, which is guaranteed to happen due to the function argument mixup. Let's fix this properly, though, by defining the macros that describe how to marshall the arguments. While at it, drop an incorrect cast on a status variable. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-19riscv/efi_stub: Add support for RISCV_EFI_BOOT_PROTOCOLSunil V L
Add support for getting the boot hart ID from the Linux EFI stub using RISCV_EFI_BOOT_PROTOCOL. This method is preferred over the existing DT based approach since it works irrespective of DT or ACPI. The specification of the protocol is hosted at: https://github.com/riscv-non-isa/riscv-uefi Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Link: https://lore.kernel.org/r/20220519051512.136724-2-sunilvl@ventanamicro.com [ardb: minor tweaks for coding style and whitespace] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-06efi: stub: prefer mirrored memory for randomized allocationsArd Biesheuvel
If the system exposes memory regions with the EFI_MORE_RELIABLE attribute, it is implied that it is intended to be used for allocations that are relatively important, such as the kernel's static image. Since efi_random_alloc() is mostly (only) used for allocating space for the kernel image, let's update it to take this into account, and disregard all memory without the EFI_MORE_RELIABLE attribute if there is sufficient memory available that does have this attribute. Note that this change only affects booting with randomization enabled. In other cases, the EFI stub runs the kernel image in place unless its placement is unsuitable for some reason (i.e., misaligned, or its BSS overlaps with another allocation), and it is left to the bootloader to ensure that the kernel was loaded into EFI_MORE_RELIABLE memory if this is desired. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
2022-05-03efi/arm64: libstub: run image in place if randomized by the loaderArd Biesheuvel
If the loader has already placed the EFI kernel image randomly in physical memory, and indicates having done so by installing the 'fixed placement' protocol onto the image handle, don't bother randomizing the placement again in the EFI stub. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-03efi: libstub: pass image handle to handle_kernel_image()Ard Biesheuvel
In a future patch, arm64's implementation of handle_kernel_image() will omit randomizing the placement of the kernel if the load address was chosen randomly by the loader. In order to do this, it needs to locate a protocol on the image handle, so pass it to handle_kernel_image(). Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-03efi: libstub: ensure allocated memory to be executableBaskov Evgeniy
There are UEFI versions that restrict execution of memory regions, preventing the kernel from booting. Parts that needs to be executable are: * Area used for trampoline placement. * All memory regions that the kernel may be relocated before and during extraction. Use DXE services to ensure aforementioned address ranges to be executable. Only modify attributes that does not have appropriate attributes. Signed-off-by: Baskov Evgeniy <baskov@ispras.ru> Link: https://lore.kernel.org/r/20220303142120.1975-3-baskov@ispras.ru Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-03efi: libstub: declare DXE services tableBaskov Evgeniy
UEFI DXE services are not yet used in kernel code but are required to manipulate page table memory protection flags. Add required declarations to use DXE services functions. Signed-off-by: Baskov Evgeniy <baskov@ispras.ru> Link: https://lore.kernel.org/r/20220303142120.1975-2-baskov@ispras.ru [ardb: ignore absent DXE table but warn if the signature check fails] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-02-28riscv/efi_stub: Fix get_boot_hartid_from_fdt() return valueSunil V L
The get_boot_hartid_from_fdt() function currently returns U32_MAX for failure case which is not correct because U32_MAX is a valid hartid value. This patch fixes the issue by returning error code. Cc: <stable@vger.kernel.org> Fixes: d7071743db31 ("RISC-V: Add EFI stub support.") Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-01-23efi/libstub: arm64: Fix image check alignment at entryMihai Carabas
The kernel is aligned at SEGMENT_SIZE and this is the size populated in the PE headers: arch/arm64/kernel/efi-header.S: .long SEGMENT_ALIGN // SectionAlignment EFI_KIMG_ALIGN is defined as: (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN) So it depends on THREAD_ALIGN. On newer builds this message started to appear even though the loader is taking into account the PE header (which is stating SEGMENT_ALIGN). Fixes: c32ac11da3f8 ("efi/libstub: arm64: Double check image alignment at entry") Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-01-19RISC-V: Introduce sv48 support without relocatable kernelPalmer Dabbelt
This patchset allows to have a single kernel for sv39 and sv48 without being relocatable. The idea comes from Arnd Bergmann who suggested to do the same as x86, that is mapping the kernel to the end of the address space, which allows the kernel to be linked at the same address for both sv39 and sv48 and then does not require to be relocated at runtime. This implements sv48 support at runtime. The kernel will try to boot with 4-level page table and will fallback to 3-level if the HW does not support it. Folding the 4th level into a 3-level page table has almost no cost at runtime. Note that kasan region had to be moved to the end of the address space since its location must be known at compile-time and then be valid for both sv39 and sv48 (and sv57 that is coming). * riscv-sv48-v3: riscv: Explicit comment about user virtual address space size riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo riscv: Implement sv48 support asm-generic: Prepare for riscv use of pud_alloc_one and pud_free riscv: Allow to dynamically define VA_BITS riscv: Introduce functions to switch pt_ops riscv: Split early kasan mapping to prepare sv48 introduction riscv: Move KASAN mapping next to the kernel mapping riscv: Get rid of MAXPHYSMEM configs Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-19riscv: Implement sv48 supportAlexandre Ghiti
By adding a new 4th level of page table, give the possibility to 64bit kernel to address 2^48 bytes of virtual address: in practice, that offers 128TB of virtual address space to userspace and allows up to 64TB of physical memory. If the underlying hardware does not support sv48, we will automatically fallback to a standard 3-level page table by folding the new PUD level into PGDIR level. In order to detect HW capabilities at runtime, we use SATP feature that ignores writes with an unsupported mode. Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-06efi/libstub: measure loaded initrd info into the TPMIlias Apalodimas
In an effort to ensure the initrd observed and used by the OS is the same one that was meant to be loaded, which is difficult to guarantee otherwise, let's measure the initrd if the EFI stub and specifically the newly introduced LOAD_FILE2 protocol was used. Modify the initrd loading sequence so that the contents of the initrd are measured into PCR9. Note that the patch is currently using EV_EVENT_TAG to create the eventlog entry instead of EV_IPL. According to the TCP PC Client specification this is used for PCRs defined for OS and application usage. Co-developed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Link: https://lore.kernel.org/r/20211119114745.1560453-5-ilias.apalodimas@linaro.org [ardb: add braces to initializer of tagged_event_data] Link: https://github.com/ClangBuiltLinux/linux/issues/1547 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-11-21efi/libstub: consolidate initrd handling across architecturesArd Biesheuvel
Before adding TPM measurement of the initrd contents, refactor the initrd handling slightly to be more self-contained and consistent. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Link: https://lore.kernel.org/r/20211119114745.1560453-4-ilias.apalodimas@linaro.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-11-21efi/libstub: add prototype of efi_tcg2_protocol::hash_log_extend_event()Ard Biesheuvel
Define the right prototype for efi_tcg2_protocol::hash_log_extend_event() and add the required structs so we can start using it to measure the initrd into the TPM if it was loaded by the EFI stub itself. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Link: https://lore.kernel.org/r/20211119114745.1560453-2-ilias.apalodimas@linaro.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-10-05efi/libstub: Simplify "Exiting bootservices" messageHeinrich Schuchardt
The message "Exiting boot services and installing virtual address map...\n" is even shown if we have efi=novamap on the command line or the firmware does not provide EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP. To avoid confusion just print "Exiting boot services...\n" Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-09-03Merge tag 'kbuild-v5.15' of ↵Linus Torvalds
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 ...
2021-08-19isystem: ship and use stdarg.hAlexey Dobriyan
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 <adobriyan@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-03efi/libstub: arm64: Double check image alignment at entryArd Biesheuvel
On arm64, the stub only moves the kernel image around in memory if needed, which is typically only for KASLR, given that relocatable kernels (which is the default) can run from any 64k aligned address, which is also the minimum alignment communicated to EFI via the PE/COFF header. Unfortunately, some loaders appear to ignore this header, and load the kernel at some arbitrary offset in memory. We can deal with this, but let's check for this condition anyway, so non-compliant code can be spotted and fixed. Cc: <stable@vger.kernel.org> # v5.10+ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2021-08-03efi/libstub: arm64: Warn when efi_random_alloc() failsArd Biesheuvel
Randomization of the physical load address of the kernel image relies on efi_random_alloc() returning successfully, and currently, we ignore any failures and just carry on, using the ordinary, non-randomized page allocator routine. This means we never find out if a failure occurs, which could harm security, so let's at least warn about this condition. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2021-08-03efi/libstub: arm64: Relax 2M alignment again for relocatable kernelsArd Biesheuvel
Commit 82046702e288 ("efi/libstub/arm64: Replace 'preferred' offset with alignment check") simplified the way the stub moves the kernel image around in memory before booting it, given that a relocatable image does not need to be copied to a 2M aligned offset if it was loaded on a 64k boundary by EFI. Commit d32de9130f6c ("efi/arm64: libstub: Deal gracefully with EFI_RNG_PROTOCOL failure") inadvertently defeated this logic by overriding the value of efi_nokaslr if EFI_RNG_PROTOCOL is not available, which was mistaken by the loader logic as an explicit request on the part of the user to disable KASLR and any associated relocation of an Image not loaded on a 2M boundary. So let's reinstate this functionality, by capturing the value of efi_nokaslr at function entry to choose the minimum alignment. Fixes: d32de9130f6c ("efi/arm64: libstub: Deal gracefully with EFI_RNG_PROTOCOL failure") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2021-08-03efi/libstub: arm64: Force Image reallocation if BSS was not reservedArd Biesheuvel
Distro versions of GRUB replace the usual LoadImage/StartImage calls used to load the kernel image with some local code that fails to honor the allocation requirements described in the PE/COFF header, as it does not account for the image's BSS section at all: it fails to allocate space for it, and fails to zero initialize it. Since the EFI stub itself is allocated in the .init segment, which is in the middle of the image, its BSS section is not impacted by this, and the main consequence of this omission is that the BSS section may overlap with memory regions that are already used by the firmware. So let's warn about this condition, and force image reallocation to occur in this case, which works around the problem. Fixes: 82046702e288 ("efi/libstub/arm64: Replace 'preferred' offset with alignment check") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2021-07-20arm64: efi: kaslr: Fix occasional random alloc (and boot) failureBenjamin Herrenschmidt
The EFI stub random allocator used for kaslr on arm64 has a subtle bug. In function get_entry_num_slots() which counts the number of possible allocation "slots" for the image in a given chunk of free EFI memory, "last_slot" can become negative if the chunk is smaller than the requested allocation size. The test "if (first_slot > last_slot)" doesn't catch it because both first_slot and last_slot are unsigned. I chose not to make them signed to avoid problems if this is ever used on architectures where there are meaningful addresses with the top bit set. Instead, fix it with an additional test against the allocation size. This can cause a boot failure in addition to a loss of randomisation due to another bug in the arm64 stub fixed separately. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Fixes: 2ddbfc81eac8 ("efi: stub: add implementation of efi_random_alloc()") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-07-16efi/libstub: Fix the efi_load_initrd function descriptionAtish Patra
The soft_limit and hard_limit in the function efi_load_initrd describes the preferred and max address of initrd loading location respectively. However, the description wrongly describes it as the size of the allocated memory. Fix the function description. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-05-22efi/libstub: prevent read overflow in find_file_option()Dan Carpenter
If the buffer has slashes up to the end then this will read past the end of the array. I don't anticipate that this is an issue for many people in real life, but it's the right thing to do and it makes static checkers happy. Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-03-26efi/libstub: Add $(CLANG_FLAGS) to x86 flagsNathan Chancellor
When cross compiling x86 on an ARM machine with clang, there are several errors along the lines of: arch/x86/include/asm/page_64.h:52:7: error: invalid output constraint '=D' in asm This happens because the x86 flags in the EFI stub are not derived from KBUILD_CFLAGS like the other architectures are and the clang flags that set the target architecture ('--target=') and the path to the GNU cross tools ('--prefix=') are not present, meaning that the host architecture is targeted. These flags are available as $(CLANG_FLAGS) from the main Makefile so add them to the cflags for x86 so that cross compiling works as expected. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lkml.kernel.org/r/20210326000435.4785-4-nathan@kernel.org
2021-03-14Merge tag 'efi-urgent-for-v5.12-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI fix from Ard Biesheuvel via Borislav Petkov: "Fix an oversight in the handling of EFI_RT_PROPERTIES_TABLE, which was added v5.10, but failed to take the SetVirtualAddressMap() RT service into account" * tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table
2021-03-10arm64/mm: Fix __enable_mmu() for new TGRAN range valuesJames Morse
As per ARM ARM DDI 0487G.a, when FEAT_LPA2 is implemented, ID_AA64MMFR0_EL1 might contain a range of values to describe supported translation granules (4K and 16K pages sizes in particular) instead of just enabled or disabled values. This changes __enable_mmu() function to handle complete acceptable range of values (depending on whether the field is signed or unsigned) now represented with ID_AA64MMFR0_TGRAN_SUPPORTED_[MIN..MAX] pair. While here, also fix similar situations in EFI stub and KVM as well. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/1615355590-21102-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-03-07efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP tableArd Biesheuvel
The EFI_RT_PROPERTIES_TABLE contains a mask of runtime services that are available after ExitBootServices(). This mostly does not concern the EFI stub at all, given that it runs before that. However, there is one call that is made at runtime, which is the call to SetVirtualAddressMap() (which is not even callable at boot time to begin with) So add the missing handling of the RT_PROP table to ensure that we only call SetVirtualAddressMap() if it is not being advertised as unsupported by the firmware. Cc: <stable@vger.kernel.org> # v5.10+ Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-02-23Merge tag 'clang-lto-v5.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull clang LTO updates from Kees Cook: "Clang Link Time Optimization. This is built on the work done preparing for LTO by arm64 folks, tracing folks, etc. This includes the core changes as well as the remaining pieces for arm64 (LTO has been the default build method on Android for about 3 years now, as it is the prerequisite for the Control Flow Integrity protections). While x86 LTO enablement is done, it depends on some pending objtool clean-ups. It's possible that I'll send a "part 2" pull request for LTO that includes x86 support. For merge log posterity, and as detailed in commit dc5723b02e52 ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO build: make LLVM=1 LLVM_IAS=1 defconfig scripts/config -e LTO_CLANG_THIN make LLVM=1 LLVM_IAS=1 (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-" and "ARCH=arm64" to the "make" command lines.) Summary: - Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen) - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)" * tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds arm64: allow LTO to be selected arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS arm64: vdso: disable LTO drivers/misc/lkdtm: disable LTO for rodata.o efi/libstub: disable LTO scripts/mod: disable LTO for empty.c modpost: lto: strip .lto from module names PCI: Fix PREL32 relocations for LTO init: lto: fix PREL32 relocations init: lto: ensure initcall ordering kbuild: lto: add a default list of used symbols kbuild: lto: merge module sections kbuild: lto: limit inlining kbuild: lto: fix module versioning kbuild: add support for Clang LTO tracing: move function tracer options to Kconfig
2021-01-21efi/arm64: Update debug prints to reflect other entropy sourcesMark Brown
Currently the EFI stub prints a diagnostic on boot saying that KASLR will be disabled if it is unable to use the EFI RNG protocol to obtain a seed for KASLR. With the addition of support for v8.5-RNG and the SMCCC RNG protocol it is now possible for KASLR to obtain entropy even if the EFI RNG protocol is unsupported in the system, and the main kernel now explicitly says if KASLR is active itself. This can result in a boot log where the stub says KASLR has been disabled and the main kernel says that it is enabled which is confusing for users. Remove the explicit reference to KASLR from the diagnostics, the warnings are still useful as EFI is the only source of entropy the stub uses when randomizing the physical address of the kernel and the other sources may not be available. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210120163810.14973-1-broonie@kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-01-19efi/libstub: move TPM related prototypes into efistub.hArd Biesheuvel
Move TPM related definitions that are only used in the EFI stub into efistub.h, which is a local header. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-01-19efi/libstub: fix prototype of efi_tcg2_protocol::get_event_log()Ard Biesheuvel
efi_tcg2_protocol::get_event_log() takes a protocol pointer as the first argument, not a EFI handle. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-01-14efi/libstub: disable LTOSami Tolvanen
With CONFIG_LTO_CLANG, we produce LLVM bitcode instead of ELF object files. Since LTO is not really needed here and the Makefile assumes we produce an object file, disable LTO for libstub. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-13-samitolvanen@google.com
2020-12-09efi: stub: get rid of efi_get_max_fdt_addr()Ard Biesheuvel
Now that ARM started following the example of arm64 and RISC-V, and no longer imposes any restrictions on the placement of the FDT in memory at boot, we no longer need per-arch implementations of efi_get_max_fdt_addr() to factor out the differences. So get rid of it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20201029134901.9773-1-ardb@kernel.org