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2023-06-30Merge tag 'efi-next-for-v6.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "Although some more stuff is brewing, the EFI changes that are ready for mainline are few this cycle: - improve the PCI DMA paranoia logic in the EFI stub - some constification changes - add statfs support to efivarfs - allow user space to enumerate updatable firmware resources without CAP_SYS_ADMIN" * tag 'efi-next-for-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi/libstub: Disable PCI DMA before grabbing the EFI memory map efi/esrt: Allow ESRT access without CAP_SYS_ADMIN efivarfs: expose used and total size efi: make kobj_type structure constant efi: x86: make kobj_type structure constant
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: Add unaccepted memory supportKirill A. Shutemov
efi_config_parse_tables() reserves memory that holds unaccepted memory configuration table so it won't be reused by page allocator. Core-mm requires few helpers to support unaccepted memory: - accept_memory() checks the range of addresses against the bitmap and accept memory if needed. - range_contains_unaccepted_memory() checks if anything within the range requires acceptance. Architectural code has to provide efi_get_unaccepted_table() that returns pointer to the unaccepted memory configuration table. arch_accept_memory() handles arch-specific part of memory acceptance. 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> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20230606142637.5171-6-kirill.shutemov@linux.intel.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
2023-05-25efi: fix missing prototype warningsArnd Bergmann
The cper.c file needs to include an extra header, and efi_zboot_entry needs an extern declaration to avoid these 'make W=1' warnings: drivers/firmware/efi/libstub/zboot.c:65:1: error: no previous prototype for 'efi_zboot_entry' [-Werror=missing-prototypes] drivers/firmware/efi/efi.c:176:16: error: no previous prototype for 'efi_attr_is_visible' [-Werror=missing-prototypes] drivers/firmware/efi/cper.c:626:6: error: no previous prototype for 'cper_estatus_print' [-Werror=missing-prototypes] drivers/firmware/efi/cper.c:649:5: error: no previous prototype for 'cper_estatus_check_header' [-Werror=missing-prototypes] drivers/firmware/efi/cper.c:662:5: error: no previous prototype for 'cper_estatus_check' [-Werror=missing-prototypes] To make this easier, move the cper specific declarations to include/linux/cper.h. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-17efivarfs: expose used and total sizeAnisse Astier
When writing EFI variables, one might get errors with no other message on why it fails. Being able to see how much is used by EFI variables helps analyzing such issues. Since this is not a conventional filesystem, block size is intentionally set to 1 instead of PAGE_SIZE. x86 quirks of reserved size are taken into account; so that available and free size can be different, further helping debugging space issues. With this patch, one can see the remaining space in EFI variable storage via efivarfs, like this: $ df -h /sys/firmware/efi/efivars/ Filesystem Size Used Avail Use% Mounted on efivarfs 176K 106K 66K 62% /sys/firmware/efi/efivars Signed-off-by: Anisse Astier <an.astier@criteo.com> [ardb: - rename efi_reserved_space() to efivar_reserved_space() - whitespace/coding style tweaks] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-03-13efi: earlycon: Reprobe after parsing config tablesArd Biesheuvel
Commit 732ea9db9d8a ("efi: libstub: Move screen_info handling to common code") reorganized the earlycon handling so that all architectures pass the screen_info data via a EFI config table instead of populating struct screen_info directly, as the latter is only possible when the EFI stub is baked into the kernel (and not into the decompressor). However, this means that struct screen_info may not have been populated yet by the time the earlycon probe takes place, and this results in a non-functional early console. So let's probe again right after parsing the config tables and populating struct screen_info. Note that this means that earlycon output starts a bit later than before, and so it may fail to capture issues that occur while doing the early EFI initialization. Fixes: 732ea9db9d8a ("efi: libstub: Move screen_info handling to common code") Reported-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-23Merge tag 'efi-next-for-v6.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "A healthy mix of EFI contributions this time: - Performance tweaks for efifb earlycon (Andy) - Preparatory refactoring and cleanup work in the efivar layer, which is needed to accommodate the Snapdragon arm64 laptops that expose their EFI variable store via a TEE secure world API (Johan) - Enhancements to the EFI memory map handling so that Xen dom0 can safely access EFI configuration tables (Demi Marie) - Wire up the newly introduced IBT/BTI flag in the EFI memory attributes table, so that firmware that is generated with ENDBR/BTI landing pads will be mapped with enforcement enabled - Clean up how we check and print the EFI revision exposed by the firmware - Incorporate EFI memory attributes protocol definition and wire it up in the EFI zboot code (Evgeniy) This ensures that these images can execute under new and stricter rules regarding the default memory permissions for EFI page allocations (More work is in progress here) - CPER header cleanup (Dan Williams) - Use a raw spinlock to protect the EFI runtime services stack on arm64 to ensure the correct semantics under -rt (Pierre) - EFI framebuffer quirk for Lenovo Ideapad (Darrell)" * tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) firmware/efi sysfb_efi: Add quirk for Lenovo IdeaPad Duet 3 arm64: efi: Make efi_rt_lock a raw_spinlock efi: Add mixed-mode thunk recipe for GetMemoryAttributes efi: x86: Wire up IBT annotation in memory attributes table efi: arm64: Wire up BTI annotation in memory attributes table efi: Discover BTI support in runtime services regions efi/cper, cxl: Remove cxl_err.h efi: Use standard format for printing the EFI revision efi: Drop minimum EFI version check at boot efi: zboot: Use EFI protocol to remap code/data with the right attributes efi/libstub: Add memory attribute protocol definitions efi: efivars: prevent double registration efi: verify that variable services are supported efivarfs: always register filesystem efi: efivars: add efivars printk prefix efi: Warn if trying to reserve memory under Xen efi: Actually enable the ESRT under Xen efi: Apply allowlist to EFI configuration tables when running under Xen efi: xen: Implement memory descriptor lookup based on hypercall efi: memmap: Disregard bogus entries instead of returning them ...
2023-02-04efi: Discover BTI support in runtime services regionsArd Biesheuvel
Add the generic plumbing to detect whether or not the runtime code regions were constructed with BTI/IBT landing pads by the firmware, permitting the OS to enable enforcement when mapping these regions into the OS's address space. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org>
2023-02-03efi: Drop minimum EFI version check at bootArd Biesheuvel
We currently pass a minimum major version to the generic EFI helper that checks the system table magic and version, and refuse to boot if the value is lower. The motivation for this check is unknown, and even the code that uses major version 2 as the minimum (ARM, arm64 and RISC-V) should make it past this check without problems, and boot to a point where we have access to a console or some other means to inform the user that the firmware's major revision number made us unhappy. (Revision 2.0 of the UEFI specification was released in January 2006, whereas ARM, arm64 and RISC-V support where added in 2009, 2013 and 2017, respectively, so checking for major version 2 or higher is completely arbitrary) So just drop the check. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-30efi/libstub: Add memory attribute protocol definitionsEvgeniy Baskov
EFI_MEMORY_ATTRIBUTE_PROTOCOL servers as a better alternative to DXE services for setting memory attributes in EFI Boot Services environment. This protocol is better since it is a part of UEFI specification itself and not UEFI PI specification like DXE services. Add EFI_MEMORY_ATTRIBUTE_PROTOCOL definitions. Support mixed mode properly for its calls. Tested-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Evgeniy Baskov <baskov@ispras.ru> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-23efi: Apply allowlist to EFI configuration tables when running under XenDemi Marie Obenour
As it turns out, Xen does not guarantee that EFI boot services data regions in memory are preserved, which means that EFI configuration tables pointing into such memory regions may be corrupted before the dom0 OS has had a chance to inspect them. This is causing problems for Qubes OS when it attempts to perform system firmware updates, which requires that the contents of the EFI System Resource Table are valid when the fwupd userspace program runs. However, other configuration tables such as the memory attributes table or the runtime properties table are equally affected, and so we need a comprehensive workaround that works for any table type. So when running under Xen, check the EFI memory descriptor covering the start of the table, and disregard the table if it does not reside in memory that is preserved by Xen. Co-developed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-22efi: xen: Implement memory descriptor lookup based on hypercallDemi Marie Obenour
Xen on x86 boots dom0 in EFI mode but without providing a memory map. This means that some consistency checks we would like to perform on configuration tables or other data structures in memory are not currently possible. Xen does, however, expose EFI memory descriptor info via a Xen hypercall, so let's wire that up instead. It turns out that the returned information is not identical to what Linux's efi_mem_desc_lookup would return: the address returned is the address passed to the hypercall, and the size returned is the number of bytes remaining in the configuration table. However, none of the callers of efi_mem_desc_lookup() currently care about this. In the future, Xen may gain a hypercall that returns the actual start address, which can be used instead. Co-developed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-17efi: efivars: make efivar_supports_writes() return boolJohan Hovold
For consistency with the new efivar_is_available() function, change the return type of efivar_supports_writes() to bool. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-17efi: efivars: drop kobject from efivars_register()Johan Hovold
Since commit 0f5b2c69a4cb ("efi: vars: Remove deprecated 'efivars' sysfs interface") and the removal of the sysfs interface there are no users of the efivars kobject. Drop the kobject argument from efivars_register() and add a new efivar_is_available() helper in favour of the old efivars_kobject(). Note that the new helper uses the prefix 'efivar' (i.e. without an 's') for consistency with efivar_supports_writes() and the rest of the interface (except the registration functions). For the benefit of drivers with optional EFI support, also provide a dummy implementation of efivar_is_available(). Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-09rtc: efi: Enable SET/GET WAKEUP services as optionalShanker Donthineni
The current implementation of rtc-efi is expecting all the 4 time services GET{SET}_TIME{WAKEUP} must be supported by UEFI firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform specific implementations can choose to enable selective time services based on the RTC device capabilities. This patch does the following changes to provide GET/SET RTC services on platforms that do not support the WAKEUP feature. 1) Relax time services cap check when creating a platform device. 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services. 3) Conditional alarm entries in '/proc/driver/rtc'. Cc: <stable@vger.kernel.org> # v6.0+ Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Link: https://lore.kernel.org/r/20230102230630.192911-1-sdonthineni@nvidia.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-18efi: random: combine bootloader provided RNG seed with RNG protocol outputArd Biesheuvel
Instead of blindly creating the EFI random seed configuration table if the RNG protocol is implemented and works, check whether such a EFI configuration table was provided by an earlier boot stage and if so, concatenate the existing and the new seeds, leaving it up to the core code to mix it in and credit it the way it sees fit. This can be used for, e.g., systemd-boot, to pass an additional seed to Linux in a way that can be consumed by the kernel very early. In that case, the following definitions should be used to pass the seed to the EFI stub: struct linux_efi_random_seed { u32 size; // of the 'seed' array in bytes u8 seed[]; }; The memory for the struct must be allocated as EFI_ACPI_RECLAIM_MEMORY pool memory, and the address of the struct in memory should be installed as a EFI configuration table using the following GUID: LINUX_EFI_RANDOM_SEED_TABLE_GUID 1ce1e5bc-7ceb-42f2-81e5-8aadf180f57b Note that doing so is safe even on kernels that were built without this patch applied, but the seed will simply be overwritten with a seed derived from the EFI RNG protocol, if available. The recommended seed size is 32 bytes, and seeds larger than 512 bytes are considered corrupted and ignored entirely. In order to preserve forward secrecy, seeds from previous bootloaders are memzero'd out, and in order to preserve memory, those older seeds are also freed from memory. Freeing from memory without first memzeroing is not safe to do, as it's possible that nothing else will ever overwrite those pages used by EFI. Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> [ardb: incorporate Jason's followup changes to extend the maximum seed size on the consumer end, memzero() it and drop a needless printk] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18efi: x86: Move EFI runtime map sysfs code to arch/x86Ard Biesheuvel
The EFI runtime map code is only wired up on x86, which is the only architecture that has a need for it in its implementation of kexec. So let's move this code under arch/x86 and drop all references to it from generic code. To ensure that the efi_runtime_map_init() is invoked at the appropriate time use a 'sync' subsys_initcall() that will be called right after the EFI initcall made from generic code where the original invocation of efi_runtime_map_init() resided. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Dave Young <dyoung@redhat.com>
2022-11-18efi: memmap: Move manipulation routines into x86 arch treeArd Biesheuvel
The EFI memory map is a description of the memory layout as provided by the firmware, and only x86 manipulates it in various different ways for its own memory bookkeeping. So let's move the memmap routines that are only used by x86 into the x86 arch tree. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18efi: memmap: Move EFI fake memmap support into x86 arch treeArd Biesheuvel
The EFI fake memmap support is specific to x86, which manipulates the EFI memory map in various different ways after receiving it from the EFI stub. On other architectures, we have managed to push back on this, and the EFI memory map is kept pristine. So let's move the fake memmap code into the x86 arch tree, where it arguably belongs. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18efi: libstub: Implement devicepath support for initrd commandline loaderArd Biesheuvel
Currently, the initrd= command line option to the EFI stub only supports loading files that reside on the same volume as the loaded image, which is not workable for loaders like GRUB that don't even implement the volume abstraction (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL), and load the kernel from an anonymous buffer in memory. For this reason, another method was devised that relies on the LoadFile2 protocol. However, the command line loader is rather useful when using the UEFI shell or other generic loaders that have no awareness of Linux specific protocols so let's make it a bit more flexible, by permitting textual device paths to be provided to initrd= as well, provided that they refer to a file hosted on a EFI_SIMPLE_FILE_SYSTEM_PROTOCOL volume. E.g., initrd=PciRoot(0x0)/Pci(0x3,0x0)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)/rootfs.cpio.gz Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18Merge tag 'efi-zboot-direct-for-v6.2' into efi/nextArd Biesheuvel
2022-11-10arm64: efi: Force the use of SetVirtualAddressMap() on Altra machinesArd Biesheuvel
Ampere Altra machines are reported to misbehave when the SetTime() EFI runtime service is called after ExitBootServices() but before calling SetVirtualAddressMap(). Given that the latter is horrid, pointless and explicitly documented as optional by the EFI spec, we no longer invoke it at boot if the configured size of the VA space guarantees that the EFI runtime memory regions can remain mapped 1:1 like they are at boot time. On Ampere Altra machines, this results in SetTime() calls issued by the rtc-efi driver triggering synchronous exceptions during boot. We can now recover from those without bringing down the system entirely, due to commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous exceptions occurring in firmware"). However, it would be better to avoid the issue entirely, given that the firmware appears to remain in a funny state after this. So attempt to identify these machines based on the 'family' field in the type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally in that case. Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09efi: libstub: Merge zboot decompressor with the ordinary stubArd Biesheuvel
Even though our EFI zboot decompressor is pedantically spec compliant and idiomatic for EFI image loaders, calling LoadImage() and StartImage() for the nested image is a bit of a burden. Not only does it create workflow issues for the distros (as both the inner and outer PE/COFF images need to be signed for secure boot), it also copies the image around in memory numerous times: - first, the image is decompressed into a buffer; - the buffer is consumed by LoadImage(), which copies the sections into a newly allocated memory region to hold the executable image; - once the EFI stub is invoked by StartImage(), it will also move the image in memory in case of KASLR, mirrored memory or if the image must execute from a certain a priori defined address. There are only two EFI spec compliant ways to load code into memory and execute it: - use LoadImage() and StartImage(), - call ExitBootServices() and take ownership of the entire system, after which anything goes. Given that the EFI zboot decompressor always invokes the EFI stub, and given that both are built from the same set of objects, let's merge the two, so that we can avoid LoadImage()/StartImage but still load our image into memory without breaking the above rules. This also means we can decompress the image directly into its final location, which could be randomized or meet other platform specific constraints that LoadImage() does not know how to adhere to. It also means that, even if the encapsulated image still has the EFI stub incorporated as well, it does not need to be signed for secure boot when wrapping it in the EFI zboot decompressor. In the future, we might decide to retire the EFI stub attached to the decompressed image, but for the time being, they can happily coexist. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09efi: libstub: Move screen_info handling to common codeArd Biesheuvel
Currently, arm64, RISC-V and LoongArch rely on the fact that struct screen_info can be accessed directly, due to the fact that the EFI stub and the core kernel are part of the same image. This will change after a future patch, so let's ensure that the screen_info handling is able to deal with this, by adopting the arm32 approach of passing it as a configuration table. While at it, switch to ACPI reclaim memory to hold the screen_info data, which is more appropriate for this kind of allocation. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-24efi: random: reduce seed size to 32 bytesArd Biesheuvel
We no longer need at least 64 bytes of random seed to permit the early crng init to complete. The RNG is now based on Blake2s, so reduce the EFI seed size to the Blake2s hash size, which is sufficient for our purposes. While at it, drop the READ_ONCE(), which was supposed to prevent size from being evaluated after seed was unmapped. However, this cannot actually happen, so READ_ONCE() is unnecessary here. Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2022-10-21efi: efivars: Fix variable writes without query_variable_store()Ard Biesheuvel
Commit bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer") refactored the efivars layer so that the 'business logic' related to which UEFI variables affect the boot flow in which way could be moved out of it, and into the efivarfs driver. This inadvertently broke setting variables on firmware implementations that lack the QueryVariableInfo() boot service, because we no longer tolerate a EFI_UNSUPPORTED result from check_var_size() when calling efivar_entry_set_get_size(), which now ends up calling check_var_size() a second time inadvertently. If QueryVariableInfo() is missing, we support writes of up to 64k - let's move that logic into check_var_size(), and drop the redundant call. Cc: <stable@vger.kernel.org> # v6.0 Fixes: bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-27efi: zboot: create MemoryMapped() device path for the parent if neededArd Biesheuvel
LoadImage() is supposed to install an instance of the protocol EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL onto the loaded image's handle so that the program can figure out where it was loaded from. The reference implementation even does this (with a NULL protocol pointer) if the call to LoadImage() used the source buffer and size arguments, and passed NULL for the image device path. Hand rolled implementations of LoadImage may behave differently, though, and so it is better to tolerate situations where the protocol is missing. And actually, concatenating an Offset() node to a NULL device path (as we do currently) is not great either. So in cases where the protocol is absent, or when it points to NULL, construct a MemoryMapped() device node as the base node that describes the parent image's footprint in memory. Cc: Daan De Meyer <daandemeyer@fb.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-27Merge tag 'efi-loongarch-for-v6.1-2' into HEADArd Biesheuvel
Second shared stable tag between EFI and LoongArch trees This is necessary because the EFI libstub refactoring patches are mostly directed at enabling LoongArch to wire up generic EFI boot support without being forced to consume DT properties that conflict with information that EFI also provides, e.g., memory map and reservations, etc.
2022-09-27efi: libstub: install boot-time memory map as config tableArd Biesheuvel
Expose the EFI boot time memory map to the kernel via a configuration table. This is arch agnostic and enables future changes that remove the dependency on DT on architectures that don't otherwise rely on it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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>
2022-09-20efi/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>
2022-09-17efi/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>
2022-08-03Merge tag 'efi-efivars-removal-for-v5.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull efivars sysfs interface removal from Ard Biesheuvel: "Remove the obsolete 'efivars' sysfs based interface to the EFI variable store, now that all users have moved to the efivarfs pseudo file system, which was created ~10 years ago to address some fundamental shortcomings in the sysfs based driver. Move the 'business logic' related to which EFI variables are important and may affect the boot flow from the efivars support layer into the efivarfs pseudo file system, so it is no longer exposed to other parts of the kernel" * tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: vars: Move efivar caching layer into efivarfs efi: vars: Switch to new wrapper layer efi: vars: Remove deprecated 'efivars' sysfs interface
2022-06-28efi: Simplify arch_efi_call_virt() macroSudeep Holla
Currently, the arch_efi_call_virt() assumes all users of it will have defined a type 'efi_##f##_t' to make use of it. Simplify the arch_efi_call_virt() macro by eliminating the explicit need for efi_##f##_t type for every user of this macro. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [ardb: apply Sudeep's ARM fix to i686, Loongarch and RISC-V too] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Move efivar caching layer into efivarfsArd Biesheuvel
Move the fiddly bits of the efivar layer into its only remaining user, efivarfs, and confine its use to that particular module. All other uses of the EFI variable store have no need for this additional layer of complexity, given that they either only read variables, or read and write variables into a separate GUIDed namespace, and cannot be used to manipulate EFI variables that are covered by the EFI spec and/or affect the boot flow. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Drop __efivar_entry_iter() helper which is no longer usedArd Biesheuvel
__efivar_entry_iter() uses a list iterator in a dubious way, i.e., it assumes that the iteration variable always points to an object of the appropriate type, even if the list traversal exhausts the list completely, in which case it will point somewhere in the vicinity of the list's anchor instead. Fortunately, we no longer use this function so we can just get rid of it entirely. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Use locking version to iterate over efivars linked listsArd Biesheuvel
Both efivars and efivarfs uses __efivar_entry_iter() to go over the linked list that shadows the list of EFI variables held by the firmware, but fail to call the begin/end helpers that are documented as a prerequisite. So switch to the proper version, which is efivar_entry_iter(). Given that in both cases, efivar_entry_remove() is invoked with the lock held already, don't take the lock there anymore. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Remove deprecated 'efivars' sysfs interfaceArd Biesheuvel
Commit 5d9db883761a ("efi: Add support for a UEFI variable filesystem") dated Oct 5, 2012, introduced a new efivarfs pseudo-filesystem to replace the efivars sysfs interface that was used up to that point to expose EFI variables to user space. The main problem with the sysfs interface was that it only supported up to 1024 bytes of payload per file, whereas the underlying variables themselves are only bounded by a platform specific per-variable and global limit that is typically much higher than 1024 bytes. The deprecated sysfs interface is only enabled on x86 and Itanium, other EFI enabled architectures only support the efivarfs pseudo-filesystem. So let's finally rip off the band aid, and drop the old interface entirely. This will make it easier to refactor and clean up the underlying infrastructure that is shared between efivars, efivarfs and efi-pstore, and is long overdue for a makeover. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: pstore: Omit efivars caching EFI varstore access layerArd Biesheuvel
Avoid the efivars layer and simply call the newly introduced EFI varstore helpers instead. This simplifies the code substantially, and also allows us to remove some hacks in the shared efivars layer that were added for efi-pstore specifically. In order to be able to delete the EFI variable associated with a record, store the UTF-16 name of the variable in the pstore record's priv field. That way, we don't have to make guesses regarding which variable the record may have been loaded from. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Add thin wrapper around EFI get/set variable interfaceArd Biesheuvel
The current efivars layer is a jumble of list iterators, shadow data structures and safe variable manipulation helpers that really belong in the efivarfs pseudo file system once the obsolete sysfs access method to EFI variables is removed. So split off a minimal efivar get/set variable API that reuses the existing efivars_lock semaphore to mediate access to the various runtime services, primarily to ensure that performing a SetVariable() on one CPU while another is calling GetNextVariable() in a loop to enumerate the contents of the EFI variable store does not result in surprises. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-24efi: vars: Don't drop lock in the middle of efivar_init()Ard Biesheuvel
Even though the efivars_lock lock is documented as protecting the efivars->ops pointer (among other things), efivar_init() happily releases and reacquires the lock for every EFI variable that it enumerates. This used to be needed because the lock was originally a spinlock, which prevented the callback that is invoked for every variable from being able to sleep. However, releasing the lock could potentially invalidate the ops pointer, but more importantly, it might allow a SetVariable() runtime service call to take place concurrently, and the UEFI spec does not define how this affects an enumeration that is running in parallel using the GetNextVariable() runtime service, which is what efivar_init() uses. In the meantime, the lock has been converted into a semaphore, and the only reason we need to drop the lock is because the efivarfs pseudo filesystem driver will otherwise deadlock when it invokes the efivars API from the callback to create the efivar_entry items and insert them into the linked list. (EFI pstore is affected in a similar way) So let's switch to helpers that can be used while the lock is already taken. This way, we can hold on to the lock throughout the enumeration. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-15efi: Make code to find mirrored memory ranges genericMa Wupeng
Commit b05b9f5f9dcf ("x86, mirror: x86 enabling - find mirrored memory ranges") introduce the efi_find_mirror() function on x86. In order to reuse the API we make it public. Arm64 can support mirrored memory too, so function efi_find_mirror() is added to efi_init() to this support for arm64. Since efi_init() is shared by ARM, arm64 and riscv, this patch will bring mirror memory support for these architectures, but this support is only tested in arm64. Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Link: https://lore.kernel.org/r/20220614092156.1972846-2-mawupeng1@huawei.com [ardb: fix subject to better reflect the payload] Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-25Merge tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drmLinus Torvalds
Pull drm updates from Dave Airlie: "Intel have enabled DG2 on certain SKUs for laptops, AMD has started some new GPU support, msm has user allocated VA controls dma-buf: - add dma_resv_replace_fences - add dma_resv_get_singleton - make dma_excl_fence private core: - EDID parser refactorings - switch drivers to drm_mode_copy/duplicate - DRM managed mutex initialization display-helper: - put HDMI, SCDC, HDCP, DSC and DP into new module gem: - rework fence handling ttm: - rework bulk move handling - add common debugfs for resource managers - convert to kvcalloc format helpers: - support monochrome formats - RGB888, RGB565 to XRGB8888 conversions fbdev: - cfb/sys_imageblit fixes - pagelist corruption fix - create offb platform device - deferred io improvements sysfb: - Kconfig rework - support for VESA mode selection bridge: - conversions to devm_drm_of_get_bridge - conversions to panel_bridge - analogix_dp - autosuspend support - it66121 - audio support - tc358767 - DSI to DPI support - icn6211 - PLL/I2C fixes, DT property - adv7611 - enable DRM_BRIDGE_OP_HPD - anx7625 - fill ELD if no monitor - dw_hdmi - add audio support - lontium LT9211 support, i.MXMP LDB - it6505: Kconfig fix, DPCD set power fix - adv7511 - CEC support for ADV7535 panel: - ltk035c5444t, B133UAN01, NV3052C panel support - DataImage FG040346DSSWBG04 support - st7735r - DT bindings fix - ssd130x - fixes i915: - DG2 laptop PCI-IDs ("motherboard down") - Initial RPL-P PCI IDs - compute engine ABI - DG2 Tile4 support - DG2 CCS clear color compression support - DG2 render/media compression formats support - ATS-M platform info - RPL-S PCI IDs added - Bump ADL-P DMC version to v2.16 - Support static DRRS - Support multiple eDP/LVDS native mode refresh rates - DP HDR support for HSW+ - Lots of display refactoring + fixes - GuC hwconfig support and query - sysfs support for multi-tile - fdinfo per-client gpu utilisation - add geometry subslices query - fix prime mmap with LMEM - fix vm open count and remove vma refcounts - contiguous allocation fixes - steered register write support - small PCI BAR enablement - GuC error capture support - sunset igpu legacy mmap support for newer devices - GuC version 70.1.1 support amdgpu: - Initial SoC21 support - SMU 13.x enablement - SMU 13.0.4 support - ttm_eu cleanups - USB-C, GPUVM updates - TMZ fixes for RV - RAS support for VCN - PM sysfs code cleanup - DC FP rework - extend CG/PG flags to 64-bit - SI dpm lockdep fix - runtime PM fixes amdkfd: - RAS/SVM fixes - TLB flush fixes - CRIU GWS support - ignore bogus MEC signals more efficiently msm: - Fourcc modifier for tiled but not compressed layouts - Support for userspace allocated IOVA (GPU virtual address) - DPU: DSC (Display Stream Compression) support - DP: eDP support - DP: conversion to use drm_bridge and drm_bridge_connector - Merge DPU1 and MDP5 MDSS driver - DPU: writeback support nouveau: - make some structures static - make some variables static - switch to drm_gem_plane_helper_prepare_fb radeon: - misc fixes/cleanups mxsfb: - rework crtc mode setting - LCDIF CRC support etnaviv: - fencing improvements - fix address space collisions - cleanup MMU reference handling gma500: - GEM/GTT improvements - connector handling fixes komeda: - switch to plane reset helper mediatek: - MIPI DSI improvements omapdrm: - GEM improvements qxl: - aarch64 support vc4: - add a CL submission tracepoint - HDMI YUV support - HDMI/clock improvements - drop is_hdmi caching virtio: - remove restriction of non-zero blob types vmwgfx: - support for cursormob and cursorbypass 4 - fence improvements tidss: - reset DISPC on startup solomon: - SPI support - DT improvements sun4i: - allwinner D1 support - drop is_hdmi caching imx: - use swap() instead of open-coding - use devm_platform_ioremap_resource - remove redunant initializations ast: - Displayport support rockchip: - Refactor IOMMU initialisation - make some structures static - replace drm_detect_hdmi_monitor with drm_display_info.is_hdmi - support swapped YUV formats, - clock improvements - rk3568 support - VOP2 support mediatek: - MT8186 support tegra: - debugabillity improvements" * tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drm: (1740 commits) drm/i915/dsi: fix VBT send packet port selection for ICL+ drm/i915/uc: Fix undefined behavior due to shift overflowing the constant drm/i915/reg: fix undefined behavior due to shift overflowing the constant drm/i915/gt: Fix use of static in macro mismatch drm/i915/audio: fix audio code enable/disable pipe logging drm/i915: Fix CFI violation with show_dynamic_id() drm/i915: Fix 'mixing different enum types' warnings in intel_display_power.c drm/i915/gt: Fix build error without CONFIG_PM drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path drm/msm/dpu: add DRM_MODE_ROTATE_180 back to supported rotations drm/msm: don't free the IRQ if it was not requested drm/msm/dpu: limit writeback modes according to max_linewidth drm/amd: Don't reset dGPUs if the system is going to s2idle drm/amdgpu: Unmap legacy queue when MES is enabled drm: msm: fix possible memory leak in mdp5_crtc_cursor_set() drm/msm: Fix fb plane offset calculation drm/msm/a6xx: Fix refcount leak in a6xx_gpu_init drm/msm/dsi: don't powerup at modeset time for parade-ps8640 drm/rockchip: Change register space names in vop2 dt-bindings: display: rockchip: make reg-names mandatory for VOP2 ...
2022-05-23Merge tag 'x86_sev_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull AMD SEV-SNP support from Borislav Petkov: "The third AMD confidential computing feature called Secure Nested Paging. Add to confidential guests the necessary memory integrity protection against malicious hypervisor-based attacks like data replay, memory remapping and others, thus achieving a stronger isolation from the hypervisor. At the core of the functionality is a new structure called a reverse map table (RMP) with which the guest has a say in which pages get assigned to it and gets notified when a page which it owns, gets accessed/modified under the covers so that the guest can take an appropriate action. In addition, add support for the whole machinery needed to launch a SNP guest, details of which is properly explained in each patch. And last but not least, the series refactors and improves parts of the previous SEV support so that the new code is accomodated properly and not just bolted on" * tag 'x86_sev_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) x86/entry: Fixup objtool/ibt validation x86/sev: Mark the code returning to user space as syscall gap x86/sev: Annotate stack change in the #VC handler x86/sev: Remove duplicated assignment to variable info x86/sev: Fix address space sparse warning x86/sev: Get the AP jump table address from secrets page x86/sev: Add missing __init annotations to SEV init routines virt: sevguest: Rename the sevguest dir and files to sev-guest virt: sevguest: Change driver name to reflect generic SEV support x86/boot: Put globals that are accessed early into the .data section x86/boot: Add an efi.h header for the decompressor virt: sevguest: Fix bool function returning negative value virt: sevguest: Fix return value check in alloc_shared_pages() x86/sev-es: Replace open-coded hlt-loop with sev_es_terminate() virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement virt: sevguest: Add support to get extended report virt: sevguest: Add support to derive key virt: Add SEV-SNP guest driver x86/sev: Register SEV-SNP guest request platform device x86/sev: Provide support for SNP guest request NAEs ...
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>
2022-05-03efi/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: 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>
2022-04-13efi: Add missing prototype for efi_capsule_setup_infoJan Kiszka
Fixes "no previous declaration for 'efi_capsule_setup_info'" warnings under W=1. Fixes: 2959c95d510c ("efi/capsule: Add support for Quark security header") Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Link: https://lore.kernel.org/r/c28d3f86-dd72-27d1-e2c2-40971b8da6bd@siemens.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>