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2023-10-30Merge tag 'x86-boot-2023-10-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: - Rework PE header generation, primarily to generate a modern, 4k aligned kernel image view with narrower W^X permissions. - Further refine init-lifetime annotations - Misc cleanups & fixes * tag 'x86-boot-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/boot: efistub: Assign global boot_params variable x86/boot: Rename conflicting 'boot_params' pointer to 'boot_params_ptr' x86/head/64: Move the __head definition to <asm/init.h> x86/head/64: Add missing __head annotation to startup_64_load_idt() x86/head/64: Mark 'startup_gdt[]' and 'startup_gdt_descr' as __initdata x86/boot: Harmonize the style of array-type parameter for fixup_pointer() calls x86/boot: Fix incorrect startup_gdt_descr.size x86/boot: Compile boot code with -std=gnu11 too x86/boot: Increase section and file alignment to 4k/512 x86/boot: Split off PE/COFF .data section x86/boot: Drop PE/COFF .reloc section x86/boot: Construct PE/COFF .text section from assembler x86/boot: Derive file size from _edata symbol x86/boot: Define setup size in linker script x86/boot: Set EFI handover offset directly in header asm x86/boot: Grab kernel_info offset from zoffset header directly x86/boot: Drop references to startup_64 x86/boot: Drop redundant code setting the root device x86/boot: Omit compression buffer from PE/COFF image memory footprint x86/boot: Remove the 'bugger off' message ...
2023-10-18x86/boot: efistub: Assign global boot_params variableArd Biesheuvel
Now that the x86 EFI stub calls into some APIs exposed by the decompressor (e.g., kaslr_get_random_long()), it is necessary to ensure that the global boot_params variable is set correctly before doing so. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org
2023-10-17x86/boot: efistub: Assign global boot_params variableArd Biesheuvel
Now that the x86 EFI stub calls into some APIs exposed by the decompressor (e.g., kaslr_get_random_long()), it is necessary to ensure that the global boot_params variable is set correctly before doing so. Note that the decompressor and the kernel proper carry conflicting declarations for the global variable 'boot_params' so refer to it via an alias to work around this. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-10-13x86/efistub: Don't try to print after ExitBootService()Nikolay Borisov
setup_e820() is executed after UEFI's ExitBootService has been called. This causes the firmware to throw an exception because the Console IO protocol is supposed to work only during boot service environment. As per UEFI 2.9, section 12.1: "This protocol is used to handle input and output of text-based information intended for the system user during the operation of code in the boot services environment." So drop the diagnostic warning from this function. We might add back a warning that is issued later when initializing the kernel itself. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-15x86/efi: Disregard setup header of loaded imageArd Biesheuvel
The native EFI entrypoint does not take a struct boot_params from the loader, but instead, it constructs one from scratch, using the setup header data placed at the start of the image. This setup header is placed in a way that permits legacy loaders to manipulate the contents (i.e., to pass the kernel command line or the address and size of an initial ramdisk), but EFI boot does not use it in that way - it only copies the contents that were placed there at build time, but EFI loaders will not (and should not) manipulate the setup header to configure the boot. (Commit 63bf28ceb3ebbe76 "efi: x86: Wipe setup_data on pure EFI boot" deals with some of the fallout of using setup_data in a way that breaks EFI boot.) Given that none of the non-zero values that are copied from the setup header into the EFI stub's struct boot_params are relevant to the boot now that the EFI stub no longer enters via the legacy decompressor, the copy can be omitted altogether. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-19-ardb@google.com
2023-08-28Merge tag 'efi-next-for-v6.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "This primarily covers some cleanup work on the EFI runtime wrappers, which are shared between all EFI architectures except Itanium, and which provide some level of isolation to prevent faults occurring in the firmware code (which runs at the same privilege level as the kernel) from bringing down the system. Beyond that, there is a fix that did not make it into v6.5, and some doc fixes and dead code cleanup. - one bugfix for x86 mixed mode that did not make it into v6.5 - first pass of cleanup for the EFI runtime wrappers - some cosmetic touchups" * tag 'efi-next-for-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: x86/efistub: Fix PCI ROM preservation in mixed mode efi/runtime-wrappers: Clean up white space and add __init annotation acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers efi/runtime-wrappers: Don't duplicate setup/teardown code efi/runtime-wrappers: Remove duplicated macro for service returning void efi/runtime-wrapper: Move workqueue manipulation out of line efi/runtime-wrappers: Use type safe encapsulation of call arguments efi/riscv: Move EFI runtime call setup/teardown helpers out of line efi/arm64: Move EFI runtime call setup/teardown helpers out of line efi/riscv: libstub: Fix comment about absolute relocation efi: memmap: Remove kernel-doc warnings efi: Remove unused extern declaration efi_lookup_mapped_addr()
2023-08-24x86/efistub: Fix PCI ROM preservation in mixed modeMikel Rychliski
preserve_pci_rom_image() was accessing the romsize field in efi_pci_io_protocol_t directly instead of using the efi_table_attr() helper. This prevents the ROM image from being saved correctly during a mixed mode boot. Fixes: 2c3625cb9fa2 ("efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one function") Signed-off-by: Mikel Rychliski <mikel@mikelr.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-08-07x86/efistub: Avoid legacy decompressor when doing EFI bootArd Biesheuvel
The bare metal decompressor code was never really intended to run in a hosted environment such as the EFI boot services, and does a few things that are becoming problematic in the context of EFI boot now that the logo requirements are getting tighter: EFI executables will no longer be allowed to consist of a single executable section that is mapped with read, write and execute permissions if they are intended for use in a context where Secure Boot is enabled (and where Microsoft's set of certificates is used, i.e., every x86 PC built to run Windows). To avoid stepping on reserved memory before having inspected the E820 tables, and to ensure the correct placement when running a kernel build that is non-relocatable, the bare metal decompressor moves its own executable image to the end of the allocation that was reserved for it, in order to perform the decompression in place. This means the region in question requires both write and execute permissions, which either need to be given upfront (which EFI will no longer permit), or need to be applied on demand using the existing page fault handling framework. However, the physical placement of the kernel is usually randomized anyway, and even if it isn't, a dedicated decompression output buffer can be allocated anywhere in memory using EFI APIs when still running in the boot services, given that EFI support already implies a relocatable kernel. This means that decompression in place is never necessary, nor is moving the compressed image from one end to the other. Since EFI already maps all of memory 1:1, it is also unnecessary to create new page tables or handle page faults when decompressing the kernel. That means there is also no need to replace the special exception handlers for SEV. Generally, there is little need to do any of the things that the decompressor does beyond - initialize SEV encryption, if needed, - perform the 4/5 level paging switch, if needed, - decompress the kernel - relocate the kernel So do all of this from the EFI stub code, and avoid the bare metal decompressor altogether. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-24-ardb@kernel.org
2023-08-07x86/efistub: Perform SNP feature test while running in the firmwareArd Biesheuvel
Before refactoring the EFI stub boot flow to avoid the legacy bare metal decompressor, duplicate the SNP feature check in the EFI stub before handing over to the kernel proper. The SNP feature check can be performed while running under the EFI boot services, which means it can force the boot to fail gracefully and return an error to the bootloader if the loaded kernel does not implement support for all the features that the hypervisor enabled. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-23-ardb@kernel.org
2023-08-07x86/efistub: Prefer EFI memory attributes protocol over DXE servicesArd Biesheuvel
Currently, the EFI stub relies on DXE services in some cases to clear non-execute restrictions from page allocations that need to be executable. This is dodgy, because DXE services are not specified by UEFI but by PI, and they are not intended for consumption by OS loaders. However, no alternative existed at the time. Now, there is a new UEFI protocol that should be used instead, so if it exists, prefer it over the DXE services calls. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-18-ardb@kernel.org
2023-08-07x86/efistub: Perform 4/5 level paging switch from the stubArd Biesheuvel
In preparation for updating the EFI stub boot flow to avoid the bare metal decompressor code altogether, implement the support code for switching between 4 and 5 levels of paging before jumping to the kernel proper. Reuse the newly refactored trampoline that the bare metal decompressor uses, but relies on EFI APIs to allocate 32-bit addressable memory and remap it with the appropriate permissions. Given that the bare metal decompressor will no longer call into the trampoline if the number of paging levels is already set correctly, it is no longer needed to remove NX restrictions from the memory range where this trampoline may end up. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lore.kernel.org/r/20230807162720.545787-17-ardb@kernel.org
2023-08-07x86/efistub: Clear BSS in EFI handover protocol entrypointArd Biesheuvel
The so-called EFI handover protocol is value-add from the distros that permits a loader to simply copy a PE kernel image into memory and call an alternative entrypoint that is described by an embedded boot_params structure. Most implementations of this protocol do not bother to check the PE header for minimum alignment, section placement, etc, and therefore also don't clear the image's BSS, or even allocate enough memory for it. Allocating more memory on the fly is rather difficult, but at least clear the BSS region explicitly when entering in this manner, so that the EFI stub code does not get confused by global variables that were not zero-initialized correctly. When booting in mixed mode, this BSS clearing must occur before any global state is created, so clear it in the 32-bit asm entry point. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-7-ardb@kernel.org
2023-08-07x86/efistub: Simplify and clean up handover entry codeArd Biesheuvel
Now that the EFI entry code in assembler is only used by the optional and deprecated EFI handover protocol, and given that the EFI stub C code no longer returns to it, most of it can simply be dropped. While at it, clarify the symbol naming, by merging efi_main() and efi_stub_entry(), making the latter the shared entry point for all different boot modes that enter via the EFI stub. The efi32_stub_entry() and efi64_stub_entry() names are referenced explicitly by the tooling that populates the setup header, so these must be retained, but can be emitted as aliases of efi_stub_entry() where appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-5-ardb@kernel.org
2023-08-07x86/efistub: Branch straight to kernel entry point from C codeArd Biesheuvel
Instead of returning to the calling code in assembler that does nothing more than perform an indirect call with the boot_params pointer in register ESI/RSI, perform the jump directly from the EFI stub C code. This will allow the asm entrypoint code to be dropped entirely in subsequent patches. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-4-ardb@kernel.org
2023-06-06x86/efi: Safely enable unaccepted memory in UEFIDionna Glaze
The UEFI v2.9 specification includes a new memory type to be used in environments where the OS must accept memory that is provided from its host. Before the introduction of this memory type, all memory was accepted eagerly in the firmware. In order for the firmware to safely stop accepting memory on the OS's behalf, the OS must affirmatively indicate support to the firmware. This is only a problem for AMD SEV-SNP, since Linux has had support for it since 5.19. The other technology that can make use of unaccepted memory, Intel TDX, does not yet have Linux support, so it can strictly require unaccepted memory support as a dependency of CONFIG_TDX and not require communication with the firmware. Enabling unaccepted memory requires calling a 0-argument enablement protocol before ExitBootServices. This call is only made if the kernel is compiled with UNACCEPTED_MEMORY=y This protocol will be removed after the end of life of the first LTS that includes it, in order to give firmware implementations an expiration date for it. When the protocol is removed, firmware will strictly infer that a SEV-SNP VM is running an OS that supports the unaccepted memory type. At the earliest convenience, when unaccepted memory support is added to Linux, SEV-SNP may take strict dependence in it. After the firmware removes support for the protocol, this should be reverted. [tl: address some checkscript warnings] Signed-off-by: Dionna Glaze <dionnaglaze@google.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/0d5f3d9a20b5cf361945b7ab1263c36586a78a42.1686063086.git.thomas.lendacky@amd.com
2023-06-06efi/libstub: Implement support for unaccepted memoryKirill A. Shutemov
UEFI Specification version 2.9 introduces the concept of memory acceptance: Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, requiring memory to be accepted before it can be used by the guest. Accepting happens via a protocol specific for the Virtual Machine platform. Accepting memory is costly and it makes VMM allocate memory for the accepted guest physical address range. It's better to postpone memory acceptance until memory is needed. It lowers boot time and reduces memory overhead. The kernel needs to know what memory has been accepted. Firmware communicates this information via memory map: a new memory type -- EFI_UNACCEPTED_MEMORY -- indicates such memory. Range-based tracking works fine for firmware, but it gets bulky for the kernel: e820 (or whatever the arch uses) has to be modified on every page acceptance. It leads to table fragmentation and there's a limited number of entries in the e820 table. Another option is to mark such memory as usable in e820 and track if the range has been accepted in a bitmap. One bit in the bitmap represents a naturally aligned power-2-sized region of address space -- unit. For x86, unit size is 2MiB: 4k of the bitmap is enough to track 64GiB or physical address space. In the worst-case scenario -- a huge hole in the middle of the address space -- It needs 256MiB to handle 4PiB of the address space. Any unaccepted memory that is not aligned to unit_size gets accepted upfront. The bitmap is allocated and constructed in the EFI stub and passed down to the kernel via EFI configuration table. allocate_e820() allocates the bitmap if unaccepted memory is present, according to the size of unaccepted region. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20230606142637.5171-4-kirill.shutemov@linux.intel.com
2023-06-06efi/x86: Get full memory map in allocate_e820()Kirill A. Shutemov
Currently allocate_e820() is only interested in the size of map and size of memory descriptor to determine how many e820 entries the kernel needs. UEFI Specification version 2.9 introduces a new memory type -- unaccepted memory. To track unaccepted memory, the kernel needs to allocate a bitmap. The size of the bitmap is dependent on the maximum physical address present in the system. A full memory map is required to find the maximum address. Modify allocate_e820() to get a full memory map. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20230606142637.5171-3-kirill.shutemov@linux.intel.com
2022-11-24x86/boot/compressed, efi: Merge multiple definitions of image_offset into oneArd Biesheuvel
There is no need for head_32.S and head_64.S both declaring a copy of the global 'image_offset' variable, so drop those and make the extern C declaration the definition. When image_offset is moved to the .c file, it needs to be placed particularly in the .data section because it lands by default in the .bss section which is cleared too late, in .Lrelocated, before the first access to it and thus garbage gets read, leading to SEV guests exploding in early boot. This happens only when the SEV guest kernel is loaded through grub. If supplied with qemu's -kernel command line option, that memory is always cleared upfront by qemu and all is fine there. [ bp: Expand commit message with SEV aspect. ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221122161017.2426828-8-ardb@kernel.org
2022-10-21efi: libstub: Give efi_main() asmlinkage qualificationArd Biesheuvel
To stop the bots from sending sparse warnings to me and the list about efi_main() not having a prototype, decorate it with asmlinkage so that it is clear that it is called from assembly, and therefore needs to remain external, even if it is never declared in a header file. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-09Merge tag 'efi-next-for-v6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "A bit more going on than usual in the EFI subsystem. The main driver for this has been the introduction of the LoonArch architecture last cycle, which inspired some cleanup and refactoring of the EFI code. Another driver for EFI changes this cycle and in the future is confidential compute. The LoongArch architecture does not use either struct bootparams or DT natively [yet], and so passing information between the EFI stub and the core kernel using either of those is undesirable. And in general, overloading DT has been a source of issues on arm64, so using DT for this on new architectures is a to avoid for the time being (even if we might converge on something DT based for non-x86 architectures in the future). For this reason, in addition to the patch that enables EFI boot for LoongArch, there are a number of refactoring patches applied on top of which separate the DT bits from the generic EFI stub bits. These changes are on a separate topich branch that has been shared with the LoongArch maintainers, who will include it in their pull request as well. This is not ideal, but the best way to manage the conflicts without stalling LoongArch for another cycle. Another development inspired by LoongArch is the newly added support for EFI based decompressors. Instead of adding yet another arch-specific incarnation of this pattern for LoongArch, we are introducing an EFI app based on the existing EFI libstub infrastructure that encapulates the decompression code we use on other architectures, but in a way that is fully generic. This has been developed and tested in collaboration with distro and systemd folks, who are eager to start using this for systemd-boot and also for arm64 secure boot on Fedora. Note that the EFI zimage files this introduces can also be decompressed by non-EFI bootloaders if needed, as the image header describes the location of the payload inside the image, and the type of compression that was used. (Note that Fedora's arm64 GRUB is buggy [0] so you'll need a recent version or switch to systemd-boot in order to use this.) Finally, we are adding TPM measurement of the kernel command line provided by EFI. There is an oversight in the TCG spec which results in a blind spot for command line arguments passed to loaded images, which means that either the loader or the stub needs to take the measurement. Given the combinatorial explosion I am anticipating when it comes to firmware/bootloader stacks and firmware based attestation protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now when it comes to EFI measured boot, which is that the kernel measures the initrd and command line. Intermediate loaders can measure additional assets if needed, but with the baseline in place, we can deploy measured boot in a meaningful way even if you boot into Linux straight from the EFI firmware. Summary: - implement EFI boot support for LoongArch - implement generic EFI compressed boot support for arm64, RISC-V and LoongArch, none of which implement a decompressor today - measure the kernel command line into the TPM if measured boot is in effect - refactor the EFI stub code in order to isolate DT dependencies for architectures other than x86 - avoid calling SetVirtualAddressMap() on arm64 if the configured size of the VA space guarantees that doing so is unnecessary - move some ARM specific code out of the generic EFI source files - unmap kernel code from the x86 mixed mode 1:1 page tables" * tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) efi/arm64: libstub: avoid SetVirtualAddressMap() when possible efi: zboot: create MemoryMapped() device path for the parent if needed efi: libstub: fix up the last remaining open coded boot service call efi/arm: libstub: move ARM specific code out of generic routines efi/libstub: measure EFI LoadOptions efi/libstub: refactor the initrd measuring functions efi/loongarch: libstub: remove dependency on flattened DT efi: libstub: install boot-time memory map as config table efi: libstub: remove DT dependency from generic stub efi: libstub: unify initrd loading between architectures efi: libstub: remove pointless goto kludge efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap efi: libstub: avoid efi_get_memory_map() for allocating the virt map efi: libstub: drop pointless get_memory_map() call efi: libstub: fix type confusion for load_options_size arm64: efi: enable generic EFI compressed boot loongarch: efi: enable generic EFI compressed boot riscv: efi: enable generic EFI compressed boot efi/libstub: implement generic EFI zboot efi/libstub: move efi_system_table global var into separate object ...
2022-09-27efi: libstub: unify initrd loading between architecturesArd Biesheuvel
Use a EFI configuration table to pass the initrd to the core kernel, instead of per-arch methods. This cleans up the code considerably, and should make it easier for architectures to get rid of their reliance on DT for doing EFI boot in the future. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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>
2022-09-22efi: 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>
2022-09-07efi/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>
2022-06-01efi/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>
2022-05-03efi: 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>
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>
2020-10-26efi/x86: Only copy the compressed kernel image in efi_relocate_kernel()Arvind Sankar
The image_size argument to efi_relocate_kernel() is currently specified as init_size, but this is unnecessarily large. The compressed kernel is much smaller, in fact, its image only extends up to the start of _bss, since at this point, the .bss section is still uninitialized. Depending on compression level, this can reduce the amount of data copied by 4-5x. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20201011142012.96493-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-25efi/x86: Only copy upto the end of setup_headerArvind Sankar
When copying the setup_header into the boot_params buffer, only the data that is actually part of the setup_header should be copied. efi_pe_entry() currently copies the entire second sector, which initializes some of the fields in boot_params beyond the setup_header with garbage (i.e. part of the real-mode boot code gets copied into those fields). This does not cause any issues currently because the fields that are overwritten are padding, BIOS EDD information that won't get used, and the E820 table which will get properly filled in later. Fix this to only copy data that is actually part of the setup_header structure. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-25efi/x86: Remove unused variablesArvind Sankar
Commit 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main") made the ramdisk_addr/ramdisk_size variables in efi_pe_entry unused, but neglected to delete them. Delete these unused variables. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-28efi/x86: Don't blow away existing initrdArvind Sankar
Commit 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main") moved the command-line initrd loading into efi_main(), with a check to ensure that it was attempted only if the EFI stub was booted via efi_pe_entry rather than the EFI handover entry. However, in the case where it was booted via handover entry, and thus an initrd may have already been loaded by the bootloader, it then wrote 0 for the initrd address and size, removing any existing initrd. Fix this by checking if size is positive before setting the fields in the bootparams structure. Fixes: 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main") Reported-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Dan Williams <dan.j.williams@intel.com> Link: https://lkml.kernel.org/r/20200527232602.21596-1-nivedita@alum.mit.edu
2020-05-25Merge tag 'efi-changes-for-v5.8' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core More EFI changes for v5.8: - Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them consistently - Simplify and unify initrd loading - Parse the builtin command line on x86 (if provided) - Implement printk() support, including support for wide character strings - Some fixes for issues introduced by the first batch of v5.8 changes - Fix a missing prototypes warning - Simplify GDT handling in early mixed mode thunking code - Some other minor fixes and cleanups Conflicts: drivers/firmware/efi/libstub/efistub.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-05-25Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-05-22efi/libstub: Use pool allocation for the command lineArd Biesheuvel
Now that we removed the memory limit for the allocation of the command line, there is no longer a need to use the page based allocator so switch to a pool allocation instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-14efi/libstub/x86: Avoid EFI map buffer alloc in allocate_e820()Lenny Szubowicz
In allocate_e820(), call the EFI get_memory_map() service directly instead of indirectly via efi_get_memory_map(). This avoids allocation of a buffer and return of the full EFI memory map, which is not needed here and would otherwise need to be freed. Routine allocate_e820() only needs to know how many EFI memory descriptors there are in the map to allocate an adequately sized e820ext buffer, if it's needed. Note that since efi_get_memory_map() returns a memory map buffer sized with extra headroom, allocate_e820() now needs to explicitly factor that into the e820ext size calculation. Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com> Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/libstub: Check return value of efi_parse_optionsArvind Sankar
efi_parse_options can fail if it is unable to allocate space for a copy of the command line. Check the return value to make sure it succeeded. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-12-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/x86: Support builtin command lineArvind Sankar
Add support for the x86 CMDLINE_BOOL and CMDLINE_OVERRIDE configuration options. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-11-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/libstub: Unify initrd loading across architecturesArvind Sankar
Factor out the initrd loading into a common function that can be called both from the generic efi-stub.c and the x86-specific x86-stub.c. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-10-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/x86: Move command-line initrd loading to efi_mainArvind Sankar
Consolidate the initrd loading in efi_main. The command line options now need to be parsed only once. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-9-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/x86: Use efi_err for error messagesArvind Sankar
Use efi_err instead of bare efi_printk for error messages. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-5-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/libstub: Add a helper function to split 64-bit valuesArvind Sankar
In several places 64-bit values need to be split up into two 32-bit fields, in order to be backward-compatible with the old 32-bit ABIs. Instead of open-coding this, add a helper function to set a 64-bit value as two 32-bit fields. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-3-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-01efi/x86: Use correct size for boot_paramsArvind Sankar
struct boot_params is only 4096 bytes, not 16384. Fix this by using sizeof(struct boot_params) instead of hardcoding the incorrect value. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200430182843.2510180-2-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub/x86: Avoid getter function for efi_is64Ard Biesheuvel
We no longer need to take special care when using global variables in the EFI stub, so switch to a simple symbol reference for efi_is64. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Drop __pure getters for EFI stub optionsArd Biesheuvel
The practice of using __pure getter functions to access global variables in the EFI stub dates back to the time when we had to carefully prevent GOT entries from being emitted, because we could not rely on the toolchain to do this for us. Today, we use the hidden visibility pragma for all EFI stub source files, which now all live in the same subdirectory, and we apply a sanity check on the objects, so we can get rid of these getter functions and simply refer to global data objects directly. So switch over the remaining boolean variables carrying options set on the kernel command line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi/libstub: Drop __pure getter for efi_system_tableArd Biesheuvel
The practice of using __pure getter functions to access global variables in the EFI stub dates back to the time when we had to carefully prevent GOT entries from being emitted, because we could not rely on the toolchain to do this for us. Today, we use the hidden visibility pragma for all EFI stub source files, which now all live in the same subdirectory, and we apply a sanity check on the objects, so we can get rid of these getter functions and simply refer to global data objects directly. Start with efi_system_table(), and convert it into a global variable. While at it, make it a pointer-to-const, because we can. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-24efi: Kill __efistub_globalArvind Sankar
Now that both arm and x86 are using the linker script to place the EFI stub's global variables in the correct section, remove __efistub_global. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200416151227.3360778-4-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-14efi/x86: Always relocate the kernel for EFI handover entryArvind Sankar
Commit d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary") tries to avoid relocating the kernel in the EFI stub as far as possible. However, when systemd-boot is used to boot a unified kernel image [1], the image is constructed by embedding the bzImage as a .linux section in a PE executable that contains a small stub loader from systemd that will call the EFI stub handover entry, together with additional sections and potentially an initrd. When this image is constructed, by for example dracut, the initrd is placed after the bzImage without ensuring that at least init_size bytes are available for the bzImage. If the kernel is not relocated by the EFI stub, this could result in the compressed kernel's startup code in head_{32,64}.S overwriting the initrd. To prevent this, unconditionally relocate the kernel if the EFI stub was entered via the handover entry point. [1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images Fixes: d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary") Reported-by: Sergey Shatunov <me@prok.pw> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200406180614.429454-2-nivedita@alum.mit.edu Link: https://lore.kernel.org/r/20200409130434.6736-5-ardb@kernel.org
2020-04-14efi/x86: Move efi stub globals from .bss to .dataArvind Sankar
Commit 3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage") removed the .bss section from the bzImage. However, while a PE loader is required to zero-initialize the .bss section before calling the PE entry point, the EFI handover protocol does not currently document any requirement that .bss be initialized by the bootloader prior to calling the handover entry. When systemd-boot is used to boot a unified kernel image [1], the image is constructed by embedding the bzImage as a .linux section in a PE executable that contains a small stub loader from systemd together with additional sections and potentially an initrd. As the .bss section within the bzImage is no longer explicitly present as part of the file, it is not initialized before calling the EFI handover entry. Furthermore, as the size of the embedded .linux section is only the size of the bzImage file itself, the .bss section's memory may not even have been allocated. In particular, this can result in efi_disable_pci_dma being true even when it was not specified via the command line or configuration option, which in turn causes crashes while booting on some systems. To avoid issues, place all EFI stub global variables into the .data section instead of .bss. As of this writing, only boolean flags for a few command line arguments and the sys_table pointer were in .bss and will now move into the .data section. [1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images Fixes: 3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage") Reported-by: Sergey Shatunov <me@prok.pw> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200406180614.429454-1-nivedita@alum.mit.edu Link: https://lore.kernel.org/r/20200409130434.6736-4-ardb@kernel.org
2020-04-14efi/libstub/x86: Remove redundant assignment to pointer hdrColin Ian King
The pointer hdr is being assigned a value that is never read and it is being updated later with a new value. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200402102537.503103-1-colin.king@canonical.com Link: https://lore.kernel.org/r/20200409130434.6736-3-ardb@kernel.org