summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/libstub
AgeCommit message (Collapse)AuthorFilesLines
2025-03-29efi/libstub: Avoid physical address 0x0 when doing random allocationArd Biesheuvel1-0/+4
commit cb16dfed0093217a68c0faa9394fa5823927e04c upstream. Ben reports spurious EFI zboot failures on a system where physical RAM starts at 0x0. When doing random memory allocation from the EFI stub on such a platform, a random seed of 0x0 (which means no entropy source is available) will result in the allocation to be placed at address 0x0 if sufficient space is available. When this allocation is subsequently passed on to the decompression code, the 0x0 address is mistaken for NULL and the code complains and gives up. So avoid address 0x0 when doing random allocation, and set the minimum address to the minimum alignment. Cc: <stable@vger.kernel.org> Reported-by: Ben Schneider <ben@bens.haus> Tested-by: Ben Schneider <ben@bens.haus> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21efi: Avoid cold plugged memory for placing the kernelArd Biesheuvel2-0/+6
commit ba69e0750b0362870294adab09339a0c39c3beaf upstream. UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory regions that are 'cold plugged' at boot, i.e., hot pluggable memory that is available from early boot, and described as system RAM by the firmware. Existing loaders and EFI applications running in the boot context will happily use this memory for allocating data structures that cannot be freed or moved at runtime, and this prevents the memory from being unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute should be tested, and memory annotated as such should be avoided for such allocations. In the EFI stub, there are a couple of occurrences where, instead of the high-level AllocatePages() UEFI boot service, a low-level code sequence is used that traverses the EFI memory map and carves out the requested number of pages from a free region. This is needed, e.g., for allocating as low as possible, or for allocating pages at random. While AllocatePages() should presumably avoid special purpose memory and cold plugged regions, this manual approach needs to incorporate this logic itself, in order to prevent the kernel itself from ending up in a hot unpluggable region, preventing it from being unplugged. So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it where appropriate. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17efi: libstub: Use '-std=gnu11' to fix build with GCC 15Nathan Chancellor1-1/+1
commit 8ba14d9f490aef9fd535c04e9e62e1169eb7a055 upstream. GCC 15 changed the default C standard version to C23, which should not have impacted the kernel because it requests the gnu11 standard via '-std=' in the main Makefile. However, the EFI libstub Makefile uses its own set of KBUILD_CFLAGS for x86 without a '-std=' value (i.e., using the default), resulting in errors from the kernel's definitions of bool, true, and false in stddef.h, which are reserved keywords under C23. ./include/linux/stddef.h:11:9: error: expected identifier before ‘false’ 11 | false = 0, ./include/linux/types.h:35:33: error: two or more data types in declaration specifiers 35 | typedef _Bool bool; Set '-std=gnu11' in the x86 cflags to resolve the error and consistently use the same C standard version for the entire kernel. All other architectures reuse KBUILD_CFLAGS from the rest of the kernel, so this issue is not visible for them. Cc: stable@vger.kernel.org Reported-by: Kostadin Shishmanov <kostadinshishmanov@protonmail.com> Closes: https://lore.kernel.org/4OAhbllK7x4QJGpZjkYjtBYNLd_2whHx9oFiuZcGwtVR4hIzvduultkgfAIRZI3vQpZylu7Gl929HaYFRGeMEalWCpeMzCIIhLxxRhq4U-Y=@protonmail.com/ Reported-by: Jakub Jelinek <jakub@redhat.com> Closes: https://lore.kernel.org/Z4467umXR2PZ0M1H@tucnak/ Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-06efi/zboot: Limit compression options to GZIP and ZSTDArd Biesheuvel1-12/+6
For historical reasons, the legacy decompressor code on various architectures supports 7 different compression types for the compressed kernel image. EFI zboot is not a compression library museum, and so the options can be limited to what is likely to be useful in practice: - GZIP is tried and tested, and is still one of the fastest at decompression time, although the compression ratio is not very high; moreover, Fedora is already shipping EFI zboot kernels for arm64 that use GZIP, and QEMU implements direct support for it when booting a kernel without firmware loaded; - ZSTD has a very high compression ratio (although not the highest), and is almost as fast as GZIP at decompression time. Reducing the number of options makes it less of a hassle for other consumers of the EFI zboot format (such as QEMU today, and kexec in the future) to support it transparently without having to carry 7 different decompression libraries. Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-17efi/libstub: Take command line overrides into account for loaded filesArd Biesheuvel1-1/+2
When CONFIG_CMDLINE_OVERRIDE or CONFIG_CMDLINE_FORCE are configured, the command line provided by the boot stack should be ignored, and only the built-in command line should be taken into account. Add the required handling of this when dealing with initrd= or dtb= command line options in the EFI stub. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-17efi/libstub: Fix command line fallback handling when loading filesArd Biesheuvel1-0/+21
CONFIG_CMDLINE, when set, is supposed to serve either as a fallback when no command line is provided by the bootloader, or to be taken into account unconditionally, depending on the configured options. The initrd and dtb loader ignores CONFIG_CMDLINE in either case, and only takes the EFI firmware provided load options into account. This means that configuring the kernel with initrd= or dtb= on the built-in command line does not produce the expected result. Fix this by doing a separate pass over the built-in command line when dealing with initrd= or dtb= options. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-15efi/libstub: Parse builtin command line after bootloader provided oneArd Biesheuvel1-11/+8
When CONFIG_CMDLINE_EXTEND is set, the core kernel command line handling logic appends CONFIG_CMDLINE to the bootloader provided command line. The EFI stub does the opposite, and parses the builtin one first. The usual behavior of command line options is that the last one takes precedence if it appears multiple times, unless there is a meaningful way to combine them. In either case, parsing the builtin command line first while the core kernel does it in the opposite order is likely to produce inconsistent results in such cases. Therefore, switch the order in the stub to match the core kernel. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-15efi/libstub: Free correct pointer on failureArd Biesheuvel1-1/+1
cmdline_ptr is an out parameter, which is not allocated by the function itself, and likely points into the caller's stack. cmdline refers to the pool allocation that should be freed when cleaning up after a failure, so pass this instead to free_pool(). Fixes: 42c8ea3dca09 ("efi: libstub: Factor out EFI stub entrypoint ...") Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-15libstub,tpm: do not ignore failure case when reading final event logGregory Price1-0/+3
Current code fails to check for an error case when reading events from final event log to calculate offsets. Check the error case, and break early because all subsequent calls will also fail. Signed-off-by: Gregory Price <gourry@gourry.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-15tpm: fix unsigned/signed mismatch errors related to __calc_tpm2_event_sizeGregory Price1-3/+3
__calc_tpm2_event_size returns 0 or a positive length, but return values are often interpreted as ints. Convert everything over to u32 to avoid signed/unsigned logic errors. Signed-off-by: Gregory Price <gourry@gourry.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-15efi/libstub: measure initrd to PCR9 independent of sourceJeremy Linton1-4/+5
Currently the initrd is only measured if it can be loaded using the INITRD_MEDIA_GUID, if we are loading it from a path provided via the command line it is never measured. Lets move the check down a couple lines so the measurement happens independent of the source. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-15efi/libstub: remove unnecessary cmd_line_len from efi_convert_cmdline()Jonathan Marek4-8/+5
efi_convert_cmdline() always sets cmdline_size to at least 1 on success, so the "cmdline_size > 0" does nothing and can be removed (the intent was to avoid parsing an empty string, but there is nothing wrong with parsing an empty string, it is only making boot negligibly slower). Then the cmd_line_len argument to efi_convert_cmdline can be removed because there is nothing left using it. Signed-off-by: Jonathan Marek <jonathan@marek.ca> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-15efi/libstub: fix efi_parse_options() ignoring the default command lineJonathan Marek1-1/+1
efi_convert_cmdline() always returns a size of at least 1 because it counts the NUL terminator, so the "cmdline_size == 0" condition is never satisfied. Change it to check if the string starts with a NUL character to get the intended behavior: to use CONFIG_CMDLINE when load_options_size == 0. Fixes: 60f38de7a8d4 ("efi/libstub: Unify command line param parsing") Signed-off-by: Jonathan Marek <jonathan@marek.ca> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-10-03move asm/unaligned.h to linux/unaligned.hAl Viro3-3/+3
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-26Merge tag 'efi-next-for-v6.12' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "Not a lot happening in EFI land this cycle. - Prevent kexec from crashing on a corrupted TPM log by using a memory type that is reserved by default - Log correctable errors reported via CPER - A couple of cosmetic fixes" * tag 'efi-next-for-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Remove redundant null pointer checks in efi_debugfs_init() efistub/tpm: Use ACPI reclaim memory for event log to avoid corruption efi/cper: Print correctable AER information efi: Remove unused declaration efi_initialize_iomem_resources()
2024-09-13efistub/tpm: Use ACPI reclaim memory for event log to avoid corruptionArd Biesheuvel1-1/+1
The TPM event log table is a Linux specific construct, where the data produced by the GetEventLog() boot service is cached in memory, and passed on to the OS using an EFI configuration table. The use of EFI_LOADER_DATA here results in the region being left unreserved in the E820 memory map constructed by the EFI stub, and this is the memory description that is passed on to the incoming kernel by kexec, which is therefore unaware that the region should be reserved. Even though the utility of the TPM2 event log after a kexec is questionable, any corruption might send the parsing code off into the weeds and crash the kernel. So let's use EFI_ACPI_RECLAIM_MEMORY instead, which is always treated as reserved by the E820 conversion logic. Cc: <stable@vger.kernel.org> Reported-by: Breno Leitao <leitao@debian.org> Tested-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-09-02mm: rework accept memory helpersKirill A. Shutemov2-2/+3
Make accept_memory() and range_contains_unaccepted_memory() take 'start' and 'size' arguments instead of 'start' and 'end'. Remove accept_page(), replacing it with direct calls to accept_memory(). The accept_page() name is going to be used for a different function. Link: https://lkml.kernel.org/r/20240809114854.3745464-6-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-29Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linuxLinus Torvalds1-1/+6
Pull ARM updates from Russell King: - ftrace: don't assume stack frames are contiguous in memory - remove unused mod_inwind_map structure - spelling fixes - allow use of LD dead code/data elimination - fix callchain_trace() return value - add support for stackleak gcc plugin - correct some reset asm function prototypes for CFI [ Missed the merge window because Russell forgot to push out ] * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux: ARM: 9408/1: mm: CFI: Fix some erroneous reset prototypes ARM: 9407/1: Add support for STACKLEAK gcc plugin ARM: 9406/1: Fix callchain_trace() return value ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION ARM: 9403/1: Alpine: Spelling s/initialiing/initializing/ ARM: 9402/1: Kconfig: Spelling s/Cortex A-/Cortex-A/ ARM: 9400/1: Remove unused struct 'mod_unwind_map'
2024-07-27Merge tag 'riscv-for-linus-6.11-mw2' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - Support for NUMA (via SRAT and SLIT), console output (via SPCR), and cache info (via PPTT) on ACPI-based systems. - The trap entry/exit code no longer breaks the return address stack predictor on many systems, which results in an improvement to trap latency. - Support for HAVE_ARCH_STACKLEAK. - The sv39 linear map has been extended to support 128GiB mappings. - The frequency of the mtime CSR is now visible via hwprobe. * tag 'riscv-for-linus-6.11-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits) RISC-V: Provide the frequency of time CSR via hwprobe riscv: Extend sv39 linear mapping max size to 128G riscv: enable HAVE_ARCH_STACKLEAK riscv: signal: Remove unlikely() from WARN_ON() condition riscv: Improve exception and system call latency RISC-V: Select ACPI PPTT drivers riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init() RISC-V: ACPI: Enable SPCR table for console output on RISC-V riscv: boot: remove duplicated targets line trace: riscv: Remove deprecated kprobe on ftrace support riscv: cpufeature: Extract common elements from extension checking riscv: Introduce vendor variants of extension helpers riscv: Add vendor extensions to /proc/cpuinfo riscv: Extend cpufeature.c to detect vendor extensions RISC-V: run savedefconfig for defconfig RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabetically ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init ACPI: NUMA: change the ACPI_NUMA to a hidden option ACPI: NUMA: Add handler for SRAT RINTC affinity structure ...
2024-07-26riscv: enable HAVE_ARCH_STACKLEAKJisheng Zhang1-1/+2
Add support for the stackleak feature. Whenever the kernel returns to user space the kernel stack is filled with a poison value. At the same time, disables the plugin in EFI stub code because EFI stub is out of scope for the protection. Tested on qemu and milkv duo: / # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT [ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING [ 38.678448] lkdtm: stackleak stack usage: [ 38.678448] high offset: 288 bytes [ 38.678448] current: 496 bytes [ 38.678448] lowest: 1328 bytes [ 38.678448] tracked: 1328 bytes [ 38.678448] untracked: 448 bytes [ 38.678448] poisoned: 14312 bytes [ 38.678448] low offset: 8 bytes [ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-25Merge tag 'efi-fixes-for-v6.11-1' of ↵Linus Torvalds2-5/+17
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: - Wipe screen_info after allocating it from the heap - used by arm32 and EFI zboot, other EFI architectures allocate it statically - Revert to allocating boot_params from the heap on x86 when entering via the native PE entrypoint, to work around a regression on older Dell hardware * tag 'efi-fixes-for-v6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: x86/efistub: Revert to heap allocated boot_params for PE entrypoint efi/libstub: Zero initialize heap allocated struct screen_info
2024-07-22Merge tag 'loongarch-6.11' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson Pull LoongArch updates from Huacai Chen: - Define __ARCH_WANT_NEW_STAT in unistd.h - Always enumerate MADT and setup logical-physical CPU mapping - Add irq_work support via self IPIs - Add RANDOMIZE_KSTACK_OFFSET support - Add ARCH_HAS_PTE_DEVMAP support - Add ARCH_HAS_DEBUG_VM_PGTABLE support - Add writecombine support for DMW-based ioremap() - Add architectural preparation for CPUFreq - Add ACPI standard hardware register based S3 support - Add support for relocating the kernel with RELR relocation - Some bug fixes and other small changes * tag 'loongarch-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: LoongArch: Make the users of larch_insn_gen_break() constant LoongArch: Check TIF_LOAD_WATCH to enable user space watchpoint LoongArch: Use rustc option -Zdirect-access-external-data LoongArch: Add support for relocating the kernel with RELR relocation LoongArch: Remove a redundant checking in relocator LoongArch: Use correct API to map cmdline in relocate_kernel() LoongArch: Automatically disable KASLR for hibernation LoongArch: Add ACPI standard hardware register based S3 support LoongArch: Add architectural preparation for CPUFreq LoongArch: Add writecombine support for DMW-based ioremap() LoongArch: Add ARCH_HAS_DEBUG_VM_PGTABLE support LoongArch: Add ARCH_HAS_PTE_DEVMAP support LoongArch: Add RANDOMIZE_KSTACK_OFFSET support LoongArch: Add irq_work support via self IPIs LoongArch: Always enumerate MADT and setup logical-physical CPU mapping LoongArch: Define __ARCH_WANT_NEW_STAT in unistd.h
2024-07-20LoongArch: Add writecombine support for DMW-based ioremap()Huacai Chen1-0/+2
Currently, only TLB-based ioremap() support writecombine, so add the counterpart for DMW-based ioremap() with help of DMW2. The base address (WRITECOMBINE_BASE) is configured as 0xa000000000000000. DMW3 is unused by kernel now, however firmware may leave garbage in them and interfere kernel's address mapping. So clear it as necessary. BTW, centralize the DMW configuration to macro SETUP_DMWINS. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-19x86/efistub: Revert to heap allocated boot_params for PE entrypointArd Biesheuvel1-5/+15
This is a partial revert of commit 8117961d98f ("x86/efi: Disregard setup header of loaded image") which triggers boot issues on older Dell laptops. As it turns out, switching back to a heap allocation for the struct boot_params constructed by the EFI stub works around this, even though it is unclear why. Cc: Christian Heusel <christian@heusel.eu> Reported-by: <mavrix#kernel@simplelogin.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-17efi/libstub: Zero initialize heap allocated struct screen_infoQiang Ma1-0/+2
After calling uefi interface allocate_pool to apply for memory, we should clear 0 to prevent the possibility of using random values. Signed-off-by: Qiang Ma <maqianga@uniontech.com> Cc: <stable@vger.kernel.org> # v6.6+ Fixes: 732ea9db9d8a ("efi: libstub: Move screen_info handling to common code") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-12efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr()Kees Cook3-3/+3
The "early" part of the helper's name isn't accurate[1]. Drop it in preparation for adding a new (not early) usage. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/lkml/CAMj1kXEyDjH0uu3Z4eBesV3PEnKGi5ArXXMp7R-hn8HdRytiPg@mail.gmail.com [1] Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-10arm64/efistub: Clean up KASLR logicArd Biesheuvel2-20/+13
Clean up some redundant code in the KASLR placement handling logic. No functional change intended. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-08x86/efistub: Drop redundant clearing of BSSArd Biesheuvel1-3/+0
As it turns out, clearing the BSS was not the right fix for the issue that was ultimately fixed by commit decd347c2a75 ("x86/efistub: Reinstate soft limit for initrd loading"), and given that the Windows EFI loader becomes very unhappy when entered with garbage in BSS, this is one thing that x86 PC EFI implementations can be expected to get right. So drop it from the pure PE entrypoint. The handover protocol entrypoint still needs this - it is used by the flaky distro bootloaders that barely implement PE/COFF at all. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-08x86/efistub: Avoid returning EFI_SUCCESS on errorArd Biesheuvel1-4/+1
The fail label is only used in a situation where the previous EFI API call succeeded, and so status will be set to EFI_SUCCESS. Fix this, by dropping the goto entirely, and call efi_exit() with the correct error code. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-08x86/efistub: Call Apple set_os protocol on dual GPU Intel MacsAditya Garg1-3/+68
0c18184de990 ("platform/x86: apple-gmux: support MMIO gmux on T2 Macs") brought support for T2 Macs in apple-gmux. But in order to use dual GPU, the integrated GPU has to be enabled. On such dual GPU EFI Macs, the EFI stub needs to report that it is booting macOS in order to prevent the firmware from disabling the iGPU. This patch is also applicable for some non T2 Intel Macs. Based on this patch for GRUB by Andreas Heider <andreas@heider.io>: https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html Credits also goto Kerem Karabay <kekrby@gmail.com> for helping porting the patch to the Linux kernel. Cc: Orlando Chamberlain <orlandoch.dev@gmail.com> Signed-off-by: Aditya Garg <gargaditya08@live.com> [ardb: limit scope using list of DMI matches provided by Lukas and Orlando] Reviewed-by: Lukas Wunner <lukas@wunner.de> Tested-by: Aditya Garg <gargaditya08@live.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-08x86/efistub: Enable SMBIOS protocol handling for x86Ard Biesheuvel2-15/+26
The smbios.c source file is not currently included in the x86 build, and before we can do so, it needs some tweaks to build correctly in combination with the EFI mixed mode support. Reviewed-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-02ARM: 9407/1: Add support for STACKLEAK gcc pluginJinjie Ruan1-1/+2
Add the STACKLEAK gcc plugin to arm32 by adding the helper used by stackleak common code: on_thread_stack(). It initialize the stack with the poison value before returning from system calls which improves the kernel security. Additionally, this disables the plugin in EFI stub code and decompress code, which are out of scope for the protection. Before the test on Qemu versatilepb board: # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT lkdtm: Performing direct entry STACKLEAK_ERASING lkdtm: XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n) After: # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT lkdtm: Performing direct entry STACKLEAK_ERASING lkdtm: stackleak stack usage: high offset: 80 bytes current: 280 bytes lowest: 696 bytes tracked: 696 bytes untracked: 192 bytes poisoned: 7220 bytes low offset: 4 bytes lkdtm: OK: the rest of the thread stack is properly erased Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2024-07-02efistub/smbios: Simplify SMBIOS enumeration APIArd Biesheuvel3-9/+7
Update the efi_get_smbios_string() macro to take a pointer to the entire record struct rather than the header. This removes the need to pass the type explicitly, as it can be inferred from the typed pointer. Also, drop 'type' from the prototype of __efi_get_smbios_string(), as it is never referenced. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-02x86/efi: Drop support for fake EFI memory mapsArd Biesheuvel1-1/+1
Between kexec and confidential VM support, handling the EFI memory maps correctly on x86 is already proving to be rather difficult (as opposed to other EFI architectures which manage to never modify the EFI memory map to begin with) EFI fake memory map support is essentially a development hack (for testing new support for the 'special purpose' and 'more reliable' EFI memory attributes) that leaked into production code. The regions marked in this manner are not actually recognized as such by the firmware itself or the EFI stub (and never have), and marking memory as 'more reliable' seems rather futile if the underlying memory is just ordinary RAM. Marking memory as 'special purpose' in this way is also dubious, but may be in use in production code nonetheless. However, the same should be achievable by using the memmap= command line option with the ! operator. EFI fake memmap support is not enabled by any of the major distros (Debian, Fedora, SUSE, Ubuntu) and does not exist on other architectures, so let's drop support for it. Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-06-10ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATIONYuntao Liu1-0/+4
The current arm32 architecture does not yet support the HAVE_LD_DEAD_CODE_DATA_ELIMINATION feature. arm32 is widely used in embedded scenarios, and enabling this feature would be beneficial for reducing the size of the kernel image. In order to make this work, we keep the necessary tables by annotating them with KEEP, also it requires further changes to linker script to KEEP some tables and wildcard compiler generated sections into the right place. When using ld.lld for linking, KEEP is not recognized within the OVERLAY command, and Ard proposed a concise method to solve this problem. It boots normally with defconfig, vexpress_defconfig and tinyconfig. The size comparison of zImage is as follows: defconfig vexpress_defconfig tinyconfig 5137712 5138024 424192 no dce 5032560 4997824 298384 dce 2.0% 2.7% 29.7% shrink When using smaller config file, there is a significant reduction in the size of the zImage. We also tested this patch on a commercially available single-board computer, and the comparison is as follows: a15eb_config 2161384 no dce 2092240 dce 3.2% shrink The zImage size has been reduced by approximately 3.2%, which is 70KB on 2.1M. Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com> Tested-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2024-06-06Merge tag 'efi-fixes-for-v6.10-2' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: - Ensure that .discard sections are really discarded in the EFI zboot image build - Return proper error numbers from efi-pstore - Add __nocfi annotations to EFI runtime wrappers * tag 'efi-fixes-for-v6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Add missing __nocfi annotations to runtime wrappers efi: pstore: Return proper errors on UEFI failures efi/libstub: zboot.lds: Discard .discard sections
2024-06-04Merge branch 'efi/next' into efi/urgentArd Biesheuvel1-0/+1
2024-06-03LoongArch: Fix entry point in kernel image headerJiaxun Yang1-1/+1
Currently kernel entry in head.S is in DMW address range, firmware is instructed to jump to this address after loading the kernel image. However kernel should not make any assumption on firmware's DMW setting, thus the entry point should be a physical address falls into direct translation region. Fix by converting entry address to physical and amend entry calculation logic in libstub accordingly. BTW, use ABSOLUTE() to calculate variables to make Clang/LLVM happy. Cc: stable@vger.kernel.org Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-23efi/libstub: zboot.lds: Discard .discard sectionsNathan Chancellor1-0/+1
When building ARCH=loongarch defconfig + CONFIG_UNWINDER_ORC=y using LLVM, there is a warning from ld.lld when linking the EFI zboot image due to the use of unreachable() in number() in vsprintf.c: ld.lld: warning: drivers/firmware/efi/libstub/lib.a(vsprintf.stub.o):(.discard.unreachable+0x0): has non-ABS relocation R_LARCH_32_PCREL against symbol '' If the compiler cannot eliminate the default case for any reason, the .discard.unreachable section will remain in the final binary but the entire point of any section prefixed with .discard is that it is only used at compile time, so it can be discarded via /DISCARD/ in a linker script. The asm-generic vmlinux.lds.h includes .discard and .discard.* in the COMMON_DISCARDS macro but that is not used for zboot.lds, as it is not a kernel image linker script. Add .discard and .discard.* to /DISCARD/ in zboot.lds, so that any sections meant to be discarded at link time are not included in the final zboot image. This issue is not specific to LoongArch, it is just the first architecture to select CONFIG_OBJTOOL, which defines annotate_unreachable() as an asm statement to add the .discard.unreachable section, and use the EFI stub. Closes: https://github.com/ClangBuiltLinux/linux/issues/2023 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-05-21Merge tag 'efi-fixes-for-v6.10-1' of ↵Linus Torvalds1-2/+26
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fix from Ard Biesheuvel: - Followup fix for the EFI boot sequence refactor, which may result in physical KASLR putting the kernel in a region which is being used for a special purpose via a command line argument. * tag 'efi-fixes-for-v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: x86/efistub: Omit physical KASLR when memory reservations exist
2024-05-18Merge tag 'kbuild-v6.10' of ↵Linus Torvalds1-11/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...
2024-05-17x86/efistub: Omit physical KASLR when memory reservations existArd Biesheuvel1-2/+26
The legacy decompressor has elaborate logic to ensure that the randomized physical placement of the decompressed kernel image does not conflict with any memory reservations, including ones specified on the command line using mem=, memmap=, efi_fake_mem= or hugepages=, which are taken into account by the kernel proper at a later stage. When booting in EFI mode, it is the firmware's job to ensure that the chosen range does not conflict with any memory reservations that it knows about, and this is trivially achieved by using the firmware's memory allocation APIs. That leaves reservations specified on the command line, though, which the firmware knows nothing about, as these regions have no other special significance to the platform. Since commit a1b87d54f4e4 ("x86/efistub: Avoid legacy decompressor when doing EFI boot") these reservations are not taken into account when randomizing the physical placement, which may result in conflicts where the memory cannot be reserved by the kernel proper because its own executable image resides there. To avoid having to duplicate or reuse the existing complicated logic, disable physical KASLR entirely when such overrides are specified. These are mostly diagnostic tools or niche features, and physical KASLR (as opposed to virtual KASLR, which is much more important as it affects the memory addresses observed by code executing in the kernel) is something we can live without. Closes: https://lkml.kernel.org/r/FA5F6719-8824-4B04-803E-82990E65E627%40akamai.com Reported-by: Ben Chaney <bchaney@akamai.com> Fixes: a1b87d54f4e4 ("x86/efistub: Avoid legacy decompressor when doing EFI boot") Cc: <stable@vger.kernel.org> # v6.1+ Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-05-15Merge tag 'efi-next-for-v6.10' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "Only a handful of changes this cycle, consisting of cleanup work and a low-prio bugfix: - Additional cleanup by Tim for the efivarfs variable name length confusion - Avoid freeing a bogus pointer when virtual remapping is omitted in the EFI boot stub" * tag 'efi-next-for-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: libstub: only free priv.runtime_map when allocated efi: Clear up misconceptions about a maximum variable name size efivarfs: Remove unused internal struct members Documentation: Mark the 'efivars' sysfs interface as removed efi: pstore: Request at most 512 bytes for variable names
2024-05-14Makefile: remove redundant tool coverage variablesMasahiro Yamada1-11/+0
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-04-29efi: libstub: only free priv.runtime_map when allocatedHagar Hemdan1-2/+2
priv.runtime_map is only allocated when efi_novamap is not set. Otherwise, it is an uninitialized value. In the error path, it is freed unconditionally. Avoid passing an uninitialized value to free_pool. Free priv.runtime_map only when it was allocated. This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc. Fixes: f80d26043af9 ("efi: libstub: avoid efi_get_memory_map() for allocating the virt map") Cc: <stable@vger.kernel.org> Signed-off-by: Hagar Hemdan <hagarhem@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-28x86/efistub: Reinstate soft limit for initrd loadingArd Biesheuvel1-0/+1
Commit 8117961d98fb2 ("x86/efi: Disregard setup header of loaded image") dropped the memcopy of the image's setup header into the boot_params struct provided to the core kernel, on the basis that EFI boot does not need it and should rely only on a single protocol to interface with the boot chain. It is also a prerequisite for being able to increase the section alignment to 4k, which is needed to enable memory protections when running in the boot services. So only the setup_header fields that matter to the core kernel are populated explicitly, and everything else is ignored. One thing was overlooked, though: the initrd_addr_max field in the setup_header is not used by the core kernel, but it is used by the EFI stub itself when it loads the initrd, where its default value of INT_MAX is used as the soft limit for memory allocation. This means that, in the old situation, the initrd was virtually always loaded in the lower 2G of memory, but now, due to initrd_addr_max being 0x0, the initrd may end up anywhere in memory. This should not be an issue principle, as most systems can deal with this fine. However, it does appear to tickle some problems in older UEFI implementations, where the memory ends up being corrupted, resulting in errors when unpacking the initramfs. So set the initrd_addr_max field to INT_MAX like it was before. Fixes: 8117961d98fb2 ("x86/efi: Disregard setup header of loaded image") Reported-by: Radek Podgorny <radek@podgorny.cz> Closes: https://lore.kernel.org/all/a99a831a-8ad5-4cb0-bff9-be637311f771@podgorny.cz Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-28efi/libstub: Cast away type warning in use of max()Ard Biesheuvel1-1/+1
Avoid a type mismatch warning in max() by switching to max_t() and providing the type explicitly. Fixes: 3cb4a4827596abc82e ("efi/libstub: fix efi_random_alloc() ...") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-24Merge tag 'efi-fixes-for-v6.9-2' of ↵Linus Torvalds2-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: - Fix logic that is supposed to prevent placement of the kernel image below LOAD_PHYSICAL_ADDR - Use the firmware stack in the EFI stub when running in mixed mode - Clear BSS only once when using mixed mode - Check efi.get_variable() function pointer for NULL before trying to call it * tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: fix panic in kdump kernel x86/efistub: Don't clear BSS twice in mixed mode x86/efistub: Call mixed mode boot services on the firmware's stack efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
2024-03-24x86/efistub: Don't clear BSS twice in mixed modeArd Biesheuvel1-1/+2
Clearing BSS should only be done once, at the very beginning. efi_pe_entry() is the entrypoint from the firmware, which may not clear BSS and so it is done explicitly. However, efi_pe_entry() is also used as an entrypoint by the mixed mode startup code, in which case BSS will already have been cleared, and doing it again at this point will corrupt global variables holding the firmware's GDT/IDT and segment selectors. So make the memset() conditional on whether the EFI stub is running in native mode. Fixes: b3810c5a2cc4a666 ("x86/efistub: Clear decompressor BSS in native EFI entrypoint") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-22efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or ↵KONDO KAZUMA(近藤 和真)1-1/+1
higher address Following warning is sometimes observed while booting my servers: [ 3.594838] DMA: preallocated 4096 KiB GFP_KERNEL pool for atomic allocations [ 3.602918] swapper/0: page allocation failure: order:10, mode:0xcc1(GFP_KERNEL|GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0-1 ... [ 3.851862] DMA: preallocated 1024 KiB GFP_KERNEL|GFP_DMA pool for atomic allocation If 'nokaslr' boot option is set, the warning always happens. On x86, ZONE_DMA is small zone at the first 16MB of physical address space. When this problem happens, most of that space seems to be used by decompressed kernel. Thereby, there is not enough space at DMA_ZONE to meet the request of DMA pool allocation. The commit 2f77465b05b1 ("x86/efistub: Avoid placing the kernel below LOAD_PHYSICAL_ADDR") tried to fix this problem by introducing lower bound of allocation. But the fix is not complete. efi_random_alloc() allocates pages by following steps. 1. Count total available slots ('total_slots') 2. Select a slot ('target_slot') to allocate randomly 3. Calculate a starting address ('target') to be included target_slot 4. Allocate pages, which starting address is 'target' In step 1, 'alloc_min' is used to offset the starting address of memory chunk. But in step 3 'alloc_min' is not considered at all. As the result, 'target' can be miscalculated and become lower than 'alloc_min'. When KASLR is disabled, 'target_slot' is always 0 and the problem happens everytime if the EFI memory map of the system meets the condition. Fix this problem by calculating 'target' considering 'alloc_min'. Cc: linux-efi@vger.kernel.org Cc: Tom Englund <tomenglund26@gmail.com> Cc: linux-kernel@vger.kernel.org Fixes: 2f77465b05b1 ("x86/efistub: Avoid placing the kernel below LOAD_PHYSICAL_ADDR") Signed-off-by: Kazuma Kondo <kazuma-kondo@nec.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>