summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/efi.c
AgeCommit message (Collapse)Author
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-18efi: Fix reservation of unaccepted memory tableKiryl Shutsemau (Meta)
The reserve_unaccepted() function incorrectly calculates the size of the memblock reservation for the unaccepted memory table. It aligns the size of the table, but fails to account for cases where the table's starting physical address (efi.unaccepted) is not page-aligned. If the table starts at an offset within a page and its end crosses into a subsequent page that the aligned size does not cover, the end of the table will not be reserved. This can lead to the table being overwritten or inaccessible, causing a kernel panic in accept_memory(). This issue was observed when starting Intel TDX VMs with specific memory sizes (e.g., > 64GB). Fix this by calculating the end address first (including the unaligned start) and then aligning it up, ensuring the entire range is covered by the reservation. Fixes: 8dbe33956d96 ("efi/unaccepted: Make sure unaccepted table is mapped") Reported-by: Moritz Sanft <ms@edgeless.systems> Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-02-09Merge tag 'efi-next-for-v7.0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: - Quirk the broken EFI framebuffer geometry on the Valve Steam Deck - Capture the EDID information of the primary display also on non-x86 EFI systems when booting via the EFI stub. * tag 'efi-next-for-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Support EDID information sysfb: Move edid_info into sysfb_primary_display sysfb: Pass sysfb_primary_display to devices sysfb: Replace screen_info with sysfb_primary_display sysfb: Add struct sysfb_display_info efi: sysfb_efi: Reduce number of references to global screen_info efi: earlycon: Reduce number of references to global screen_info efi: sysfb_efi: Fix efidrmfb and simpledrmfb on Valve Steam Deck efi: sysfb_efi: Convert swap width and height quirk to a callback efi: sysfb_efi: Fix lfb_linelength calculation when applying quirks efi: sysfb_efi: Replace open coded swap with the macro
2026-01-19mm: rename cpu_bitmap field to flexible_arrayMathieu Desnoyers
The cpu_bitmap flexible array now contains more than just the cpu_bitmap. In preparation for changing the static mm_struct definitions to cover for the additional space required, change the cpu_bitmap type from "unsigned long" to "char", require an unsigned long alignment of the flexible array, and rename the field from "cpu_bitmap" to "flexible_array". Introduce the MM_STRUCT_FLEXIBLE_ARRAY_INIT macro to statically initialize the flexible array. This covers the init_mm and efi_mm static definitions. This is a preparation step for fixing the missing mm_cid size for static mm_struct definitions. Link: https://lkml.kernel.org/r/20251224173358.647691-3-mathieu.desnoyers@efficios.com Fixes: af7f588d8f73 ("sched: Introduce per-memory-map concurrency ID") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Thomas Gleixner <tglx@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Aboorva Devarajan <aboorvad@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Liam R . Howlett" <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Martin Liu <liumartin@google.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-08efi: Wipe INITRD config table from memory after consumptionArd Biesheuvel
When the EFI stub itself loads the initrd and puts it in memory (rather than simply passing on a struct boot_params or device tree that already carries initrd information), it exposes this information to the core kernel via a INITRD configuration table. Given that config tables are preserved across kexec, this means that subsequent kexec boots will observe the same information, even though it most likely has become stale by that point. On x86, this information is usually superseded by the initrd info passed via bootparams, in which case this stale information is simply ignored. However, when performing a kexec boot without passing an initrd, the loader falls back to this stale information and explodes. So wipe the base and size from the INITRD config table as soon as it has been consumed. This fixes the issue for kexec on all EFI architectures. Reported-by: James Le Cuirot <chewi@gentoo.org> Tested-by: James Le Cuirot <chewi@gentoo.org> Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com> Link: https://lore.kernel.org/all/20251126173209.374755-2-chewi@gentoo.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-12-24arm64: efi: Fix NULL pointer dereference by initializing user_nsBreno Leitao
Linux 6.19-rc2 (9448598b22c5 ("Linux 6.19-rc2")) is crashing with a NULL pointer dereference on arm64 hosts: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c8 pc : cap_capable (security/commoncap.c:82 security/commoncap.c:128) Call trace: cap_capable (security/commoncap.c:82 security/commoncap.c:128) (P) security_capable (security/security.c:?) ns_capable_noaudit (kernel/capability.c:342 kernel/capability.c:381) __ptrace_may_access (./include/linux/rcupdate.h:895 kernel/ptrace.c:326) ptrace_may_access (kernel/ptrace.c:353) do_task_stat (fs/proc/array.c:467) proc_tgid_stat (fs/proc/array.c:673) proc_single_show (fs/proc/base.c:803) I've bissected the problem to commit a5baf582f4c0 ("arm64/efi: Call EFI runtime services without disabling preemption"). >From my analyzes, the crash occurs because efi_mm lacks a user_ns field initialization. This was previously harmless, but commit a5baf582f4c0 ("arm64/efi: Call EFI runtime services without disabling preemption") changed the EFI runtime call path to use kthread_use_mm(&efi_mm), which temporarily adopts efi_mm as the current mm for the calling kthread. When a thread has an active mm, LSM hooks like cap_capable() expect mm->user_ns to be valid for credential checks. With efi_mm.user_ns being NULL, capability checks during possible /proc access dereference the NULL pointer and crash. Fix by initializing efi_mm.user_ns to &init_user_ns. Fixes: a5baf582f4c0 ("arm64/efi: Call EFI runtime services without disabling preemption") Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Rik van Riel <riel@surriel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-12-16efi: Support EDID informationThomas Zimmermann
In the EFI config table, rename LINUX_EFI_SCREEN_INFO_TABLE_GUID to LINUX_EFI_PRIMARY_DISPLAY_TABLE_GUID. Read sysfb_primary_display from the entry. In addition to the screen_info, the entry now also contains EDID information. In libstub, replace struct screen_info with struct sysfb_display_info from the kernel's sysfb_primary_display and rename functions accordingly. Transfer it to the runtime kernel using the kernel's global state or the LINUX_EFI_PRIMARY_DISPLAY_TABLE_GUID config-table entry. With CONFIG_FIRMWARE_EDID=y, libstub now transfers the GOP device's EDID information to the kernel. If CONFIG_FIRMWARE_EDID=n, EDID information is disabled. Make the Kconfig symbol CONFIG_FIRMWARE_EDID available with EFI. Setting the value to 'n' disables EDID support. Also rename screen_info.c to primary_display.c and adapt the contained comment according to the changes. Link: https://lore.kernel.org/all/20251126160854.553077-8-tzimmermann@suse.de/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> [ardb: depend on EFI_GENERIC_STUB not EFI, fix conflicts after dropping the preceding patch from the series] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-12-02Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "These are the arm64 updates for 6.19. The biggest part is the Arm MPAM driver under drivers/resctrl/. There's a patch touching mm/ to handle spurious faults for huge pmd (similar to the pte version). The corresponding arm64 part allows us to avoid the TLB maintenance if a (huge) page is reused after a write fault. There's EFI refactoring to allow runtime services with preemption enabled and the rest is the usual perf/PMU updates and several cleanups/typos. Summary: Core features: - Basic Arm MPAM (Memory system resource Partitioning And Monitoring) driver under drivers/resctrl/ which makes use of the fs/rectrl/ API Perf and PMU: - Avoid cycle counter on multi-threaded CPUs - Extend CSPMU device probing and add additional filtering support for NVIDIA implementations - Add support for the PMUs on the NoC S3 interconnect - Add additional compatible strings for new Cortex and C1 CPUs - Add support for data source filtering to the SPE driver - Add support for i.MX8QM and "DB" PMU in the imx PMU driver Memory managemennt: - Avoid broadcast TLBI if page reused in write fault - Elide TLB invalidation if the old PTE was not valid - Drop redundant cpu_set_*_tcr_t0sz() macros - Propagate pgtable_alloc() errors outside of __create_pgd_mapping() - Propagate return value from __change_memory_common() ACPI and EFI: - Call EFI runtime services without disabling preemption - Remove unused ACPI function Miscellaneous: - ptrace support to disable streaming on SME-only systems - Improve sysreg generation to include a 'Prefix' descriptor - Replace __ASSEMBLY__ with __ASSEMBLER__ - Align register dumps in the kselftest zt-test - Remove some no longer used macros/functions - Various spelling corrections" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits) arm64/mm: Document why linear map split failure upon vm_reset_perms is not problematic arm64/pageattr: Propagate return value from __change_memory_common arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS KVM: arm64: selftests: Consider all 7 possible levels of cache KVM: arm64: selftests: Remove ARM64_FEATURE_FIELD_BITS and its last user arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros Documentation/arm64: Fix the typo of register names ACPI: GTDT: Get rid of acpi_arch_timer_mem_init() perf: arm_spe: Add support for filtering on data source perf: Add perf_event_attr::config4 perf/imx_ddr: Add support for PMU in DB (system interconnects) perf/imx_ddr: Get and enable optional clks perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe() dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT arm64: mm: use untagged address to calculate page index MAINTAINERS: new entry for MPAM Driver arm_mpam: Add kunit tests for props_mismatch() arm_mpam: Add kunit test for bitmap reset arm_mpam: Add helper to reset saved mbwu state ...
2025-11-11efi: Add missing static initializer for efi_mm::cpus_allowed_lockArd Biesheuvel
Initialize the cpus_allowed_lock struct member of efi_mm. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-09efi: add ovmf debug log driverGerd Hoffmann
Recent OVMF versions (edk2-stable202508 + newer) can write their debug log to a memory buffer. This driver exposes the log content via sysfs (/sys/firmware/efi/ovmf_debug_log). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-04-09efi: Export symbol efi_mem_desc_lookupThomas Zimmermann
Building efidrm as module requires efi_mem_desc_lookup(). Export the symbol. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://lore.kernel.org/r/20250408091837.407401-2-tzimmermann@suse.de
2025-02-04efi: Avoid cold plugged memory for placing the kernelArd Biesheuvel
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>
2025-01-14x86/efistub: Drop long obsolete UGA supportArd Biesheuvel
UGA is the EFI graphical output protocol that preceded GOP, and has been long obsolete. Drop support for it from the x86 implementation of the EFI stub - other architectures never bothered to implement it (save for ia64) Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-17efi: Fix memory leak in efivar_ssdt_loadCyrill Gorcunov
When we load SSDT from efi variable (specified with efivar_ssdt=<var> boot command line argument) a name for the variable is allocated dynamically because we traverse all EFI variables. Unlike ACPI table data, which is later used by ACPI engine, the name is no longer needed once traverse is complete -- don't forget to free this memory. Same time we silently ignore any errors happened here let's print a message if something went wrong (but do not exit since this is not a critical error and the system should continue to boot). Also while here -- add a note why we keep SSDT table on success. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-09-13efi: Remove redundant null pointer checks in efi_debugfs_init()Li Zetao
Since the debugfs_create_dir() never returns a null pointer, checking the return value for a null pointer is redundant, and using IS_ERR is safe enough. Signed-off-by: Li Zetao <lizetao1@huawei.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-24efi: fix panic in kdump kernelOleksandr Tymoshenko
Check if get_next_variable() is actually valid pointer before calling it. In kdump kernel this method is set to NULL that causes panic during the kexec-ed kernel boot. Tested with QEMU and OVMF firmware. Fixes: bad267f9e18f ("efi: verify that variable services are supported") Signed-off-by: Oleksandr Tymoshenko <ovt@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-09efi/libstub: Add get_event_log() support for CC platformsKuppuswamy Sathyanarayanan
To allow event log info access after boot, EFI boot stub extracts the event log information and installs it in an EFI configuration table. Currently, EFI boot stub only supports installation of event log only for TPM 1.2 and TPM 2.0 protocols. Extend the same support for CC protocol. Since CC platform also uses TCG2 format, reuse TPM2 support code as much as possible. Link: https://uefi.org/specs/UEFI/2.10/38_Confidential_Computing.html#efi-cc-measurement-protocol [1] Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Link: https://lkml.kernel.org/r/0229a87e-fb19-4dad-99fc-4afd7ed4099a%40collabora.com [ardb: Split out final events table handling to avoid version confusion] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-03-09efi/tpm: Use symbolic GUID name from spec for final events tableArd Biesheuvel
The LINUX_EFI_ GUID identifiers are only intended to be used to refer to GUIDs that are part of the Linux implementation, and are not considered external ABI. (Famous last words). GUIDs that already have a symbolic name in the spec should use that name, to avoid confusion between firmware components. So use the official name EFI_TCG2_FINAL_EVENTS_TABLE_GUID for the TCG2 'final events' configuration table. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11efivarfs: automatically update super block flagMasahisa Kojima
efivar operation is updated when the tee_stmm_efi module is probed. tee_stmm_efi module supports SetVariable runtime service, but user needs to manually remount the efivarfs as RW to enable the write access if the previous efivar operation does not support SetVariable and efivarfs is mounted as read-only. This commit notifies the update of efivar operation to efivarfs subsystem, then drops SB_RDONLY flag if the efivar operation supports SetVariable. Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org> [ardb: use per-superblock instance of the notifier block] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-12-11efi: expose efivar generic ops register functionMasahisa Kojima
This is a preparation for supporting efivar operations provided by other than efi subsystem. Both register and unregister functions are exposed so that non-efi subsystem can revert the efi generic operation. Acked-by: Sumit Garg <sumit.garg@linaro.org> Co-developed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-11-01Merge tag 'asm-generic-6.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture
2023-10-20Merge 3rd batch of EFI fixes into efi/urgentArd Biesheuvel
2023-10-13efi: fix memory leak in krealloc failure handlingKuan-Wei Chiu
In the previous code, there was a memory leak issue where the previously allocated memory was not freed upon a failed krealloc operation. This patch addresses the problem by releasing the old memory before setting the pointer to NULL in case of a krealloc failure. This ensures that memory is properly managed and avoids potential memory leaks. Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-19efi/unaccepted: Make sure unaccepted table is mappedKirill A. Shutemov
Unaccepted table is now allocated from EFI_ACPI_RECLAIM_MEMORY. It translates into E820_TYPE_ACPI, which is not added to memblock and therefore not mapped in the direct mapping. This causes a crash on the first touch of the table. Use memblock_add() to make sure that the table is mapped in direct mapping. Align the range to the nearest page borders. Ranges smaller than page size are not mapped. Fixes: e7761d827e99 ("efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table") Reported-by: Hongyu Ning <hongyu.ning@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11arch: Remove Itanium (IA-64) architectureArd Biesheuvel
The Itanium architecture is obsolete, and an informal survey [0] reveals that any residual use of Itanium hardware in production is mostly HP-UX or OpenVMS based. The use of Linux on Itanium appears to be limited to enthusiasts that occasionally boot a fresh Linux kernel to see whether things are still working as intended, and perhaps to churn out some distro packages that are rarely used in practice. None of the original companies behind Itanium still produce or support any hardware or software for the architecture, and it is listed as 'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers that contributed on behalf of those companies (nor anyone else, for that matter) have been willing to support or maintain the architecture upstream or even be responsible for applying the odd fix. The Intel firmware team removed all IA-64 support from the Tianocore/EDK2 reference implementation of EFI in 2018. (Itanium is the original architecture for which EFI was developed, and the way Linux supports it deviates significantly from other architectures.) Some distros, such as Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have dropped support years ago. While the argument is being made [1] that there is a 'for the common good' angle to being able to build and run existing projects such as the Grid Community Toolkit [2] on Itanium for interoperability testing, the fact remains that none of those projects are known to be deployed on Linux/ia64, and very few people actually have access to such a system in the first place. Even if there were ways imaginable in which Linux/ia64 could be put to good use today, what matters is whether anyone is actually doing that, and this does not appear to be the case. There are no emulators widely available, and so boot testing Itanium is generally infeasible for ordinary contributors. GCC still supports IA-64 but its compile farm [3] no longer has any IA-64 machines. GLIBC would like to get rid of IA-64 [4] too because it would permit some overdue code cleanups. In summary, the benefits to the ecosystem of having IA-64 be part of it are mostly theoretical, whereas the maintenance overhead of keeping it supported is real. So let's rip off the band aid, and remove the IA-64 arch code entirely. This follows the timeline proposed by the Debian/ia64 maintainer [5], which removes support in a controlled manner, leaving IA-64 in a known good state in the most recent LTS release. Other projects will follow once the kernel support is removed. [0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/ [1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/ [2] https://gridcf.org/gct-docs/latest/index.html [3] https://cfarm.tetaneutral.net/machines/list/ [4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/ [5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/ Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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
2023-06-26Merge tag 'x86_cc_for_v6.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 confidential computing update from Borislav Petkov: - Add support for unaccepted memory as specified in the UEFI spec v2.9. The gist of it all is that Intel TDX and AMD SEV-SNP confidential computing guests define the notion of accepting memory before using it and thus preventing a whole set of attacks against such guests like memory replay and the like. There are a couple of strategies of how memory should be accepted - the current implementation does an on-demand way of accepting. * tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: virt: sevguest: Add CONFIG_CRYPTO dependency x86/efi: Safely enable unaccepted memory in UEFI x86/sev: Add SNP-specific unaccepted memory support x86/sev: Use large PSC requests if applicable x86/sev: Allow for use of the early boot GHCB for PSC requests x86/sev: Put PSC struct on the stack in prep for unaccepted memory support x86/sev: Fix calculation of end address based on number of pages x86/tdx: Add unaccepted memory support x86/tdx: Refactor try_accept_one() x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory efi: Add unaccepted memory support x86/boot/compressed: Handle unaccepted memory efi/libstub: Implement support for unaccepted memory efi/x86: Get full memory map in allocate_e820() mm: Add support for unaccepted memory
2023-06-21Revert "efi: random: refresh non-volatile random seed when RNG is initialized"Linus Torvalds
This reverts commit e7b813b32a42a3a6281a4fd9ae7700a0257c1d50 (and the subsequent fix for it: 41a15855c1ee "efi: random: fix NULL-deref when refreshing seed"). It turns otu to cause non-deterministic boot stalls on at least a HP 6730b laptop. Reported-and-bisected-by: Sami Korkalainen <sami.korkalainen@proton.me> Link: https://lore.kernel.org/all/GQUnKz2al3yke5mB2i1kp3SzNHjK8vi6KJEh7rnLrOQ24OrlljeCyeWveLW9pICEmB9Qc8PKdNt3w1t_g3-Uvxq1l8Wj67PpoMeWDoH8PKk=@proton.me/ Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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
2023-05-17efivarfs: 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>
2023-02-23Merge 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 ...
2023-02-03efi: Use standard format for printing the EFI revisionArd Biesheuvel
The UEFI spec section 4.2.1 describes the way the human readable EFI revision should be constructed from the 32-bit revision field in the system table: The upper 16 bits of this field contain the major revision value, and the lower 16 bits contain the minor revision value. The minor revision values are binary coded decimals and are limited to the range of 00..99. When printed or displayed UEFI spec revision is referred as (Major revision).(Minor revision upper decimal).(Minor revision lower decimal) or (Major revision).(Minor revision upper decimal) in case Minor revision lower decimal is set to 0. Let's adhere to this when logging the EFI revision to the kernel log. Note that the bit about binary coded decimals is bogus, and the minor revision lower decimal is simply the minor revision modulo 10, given the symbolic definitions provided by the spec itself: #define EFI_2_40_SYSTEM_TABLE_REVISION ((2<<16) | (40)) #define EFI_2_31_SYSTEM_TABLE_REVISION ((2<<16) | (31)) #define EFI_2_30_SYSTEM_TABLE_REVISION ((2<<16) | (30)) Signed-off-by: Ard Biesheuvel <ardb@kernel.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>
2023-02-03efi: fix potential NULL deref in efi_mem_reserve_persistentAnton Gusev
When iterating on a linked list, a result of memremap is dereferenced without checking it for NULL. This patch adds a check that falls back on allocating a new page in case memremap doesn't succeed. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 18df7577adae ("efi/memreserve: deal with memreserve entries in unmapped memory") Signed-off-by: Anton Gusev <aagusev@ispras.ru> [ardb: return -ENOMEM instead of breaking out of the loop] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-26efi: verify that variable services are supportedJohan Hovold
Current Qualcomm UEFI firmware does not implement the variable services but not all revisions clear the corresponding bits in the RT_PROP table services mask and instead the corresponding calls return EFI_UNSUPPORTED. This leads to efi core registering the generic efivar ops even when the variable services are not supported or when they are accessed through some other interface (e.g. Google SMI or the upcoming Qualcomm SCM implementation). Instead of playing games with init call levels to make sure that the custom implementations are registered after the generic one, make sure that get_next_variable() is actually supported before registering the generic ops. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-23efi: Warn if trying to reserve memory under XenDemi Marie Obenour
Doing so cannot work and should never happen. 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>
2023-01-23efi: 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>
2023-01-22efi: memmap: Disregard bogus entries instead of returning themDemi Marie Obenour
The ESRT code currently contains two consistency checks on the memory descriptor it obtains, but one of them is both incomplete and can only trigger on invalid descriptors. So let's drop these checks, and instead disregard descriptors entirely if the start address is misaligned, or if the number of pages reaches to or beyond the end of the address space. Note that the memory map as a whole could still be inconsistent: multiple entries might cover the same area, or the address could be outside of the addressable PA space, but validating that goes beyond the scope of these helpers. Also note that since the physical address space is never 64-bits wide, a descriptor that includes the last page of memory is not valid. This is fortunate, since it means that a valid physical address will never be an error pointer and that the length of a memory descriptor in bytes will fit in a 64-bit unsigned integer. 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: 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>
2023-01-03efi: fix NULL-deref in init error pathJohan Hovold
In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable@vger.kernel.org Cc: Li Heng <liheng40@huawei.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-20efi: random: fix NULL-deref when refreshing seedJohan Hovold
Do not try to refresh the RNG seed in case the firmware does not support setting variables. This is specifically needed to prevent a NULL-pointer dereference on the Lenovo X13s with some firmware revisions, or more generally, whenever the runtime services have been disabled (e.g. efi=noruntime or with PREEMPT_RT). Fixes: e7b813b32a42 ("efi: random: refresh non-volatile random seed when RNG is initialized") Reported-by: Steev Klimaszewski <steev@kali.org> Reported-by: Bjorn Andersson <andersson@kernel.org> Tested-by: Steev Klimaszewski <steev@kali.org> Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-12-13Merge tag 'efi-next-for-v6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: "Another fairly sizable pull request, by EFI subsystem standards. Most of the work was done by me, some of it in collaboration with the distro and bootloader folks (GRUB, systemd-boot), where the main focus has been on removing pointless per-arch differences in the way EFI boots a Linux kernel. - Refactor the zboot code so that it incorporates all the EFI stub logic, rather than calling the decompressed kernel as a EFI app. - Add support for initrd= command line option to x86 mixed mode. - Allow initrd= to be used with arbitrary EFI accessible file systems instead of just the one the kernel itself was loaded from. - Move some x86-only handling and manipulation of the EFI memory map into arch/x86, as it is not used anywhere else. - More flexible handling of any random seeds provided by the boot environment (i.e., systemd-boot) so that it becomes available much earlier during the boot. - Allow improved arch-agnostic EFI support in loaders, by setting a uniform baseline of supported features, and adding a generic magic number to the DOS/PE header. This should allow loaders such as GRUB or systemd-boot to reduce the amount of arch-specific handling substantially. - (arm64) Run EFI runtime services from a dedicated stack, and use it to recover from synchronous exceptions that might occur in the firmware code. - (arm64) Ensure that we don't allocate memory outside of the 48-bit addressable physical range. - Make EFI pstore record size configurable - Add support for decoding CXL specific CPER records" * tag 'efi-next-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (43 commits) arm64: efi: Recover from synchronous exceptions occurring in firmware arm64: efi: Execute runtime services from a dedicated stack arm64: efi: Limit allocations to 48-bit addressable physical region efi: Put Linux specific magic number in the DOS header efi: libstub: Always enable initrd command line loader and bump version efi: stub: use random seed from EFI variable efi: vars: prohibit reading random seed variables efi: random: combine bootloader provided RNG seed with RNG protocol output efi/cper, cxl: Decode CXL Error Log efi/cper, cxl: Decode CXL Protocol Error Section efi: libstub: fix efi_load_initrd_dev_path() kernel-doc comment efi: x86: Move EFI runtime map sysfs code to arch/x86 efi: runtime-maps: Clarify purpose and enable by default for kexec efi: pstore: Add module parameter for setting the record size efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures efi: memmap: Move manipulation routines into x86 arch tree efi: memmap: Move EFI fake memmap support into x86 arch tree efi: libstub: Undeprecate the command line initrd loader efi: libstub: Add mixed mode support to command line initrd loader efi: libstub: Permit mixed mode return types other than efi_status_t ...
2022-11-22efi: random: refresh non-volatile random seed when RNG is initializedJason A. Donenfeld
EFI has a rather unique benefit that it has access to some limited non-volatile storage, where the kernel can store a random seed. Register a notification for when the RNG is initialized, and at that point, store a new random seed. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.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>
2022-11-09efi: 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: ssdt: Don't free memory if ACPI table was loaded successfullyArd Biesheuvel
Amadeusz reports KASAN use-after-free errors introduced by commit 3881ee0b1edc ("efi: avoid efivars layer when loading SSDTs from variables"). The problem appears to be that the memory that holds the new ACPI table is now freed unconditionally, instead of only when the ACPI core reported a failure to load the table. So let's fix this, by omitting the kfree() on success. Cc: <stable@vger.kernel.org> # v6.0 Link: https://lore.kernel.org/all/a101a10a-4fbb-5fae-2e3c-76cf96ed8fbd@linux.intel.com/ Fixes: 3881ee0b1edc ("efi: avoid efivars layer when loading SSDTs from variables") Reported-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>