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2023-09-08Merge patch series "riscv: Introduce KASLR"Palmer Dabbelt1-0/+2
Alexandre Ghiti <alexghiti@rivosinc.com> says: The following KASLR implementation allows to randomize the kernel mapping: - virtually: we expect the bootloader to provide a seed in the device-tree - physically: only implemented in the EFI stub, it relies on the firmware to provide a seed using EFI_RNG_PROTOCOL. arm64 has a similar implementation hence the patch 3 factorizes KASLR related functions for riscv to take advantage. The new virtual kernel location is limited by the early page table that only has one PUD and with the PMD alignment constraint, the kernel can only take < 512 positions. * b4-shazam-merge: riscv: libstub: Implement KASLR by using generic functions libstub: Fix compilation warning for rv32 arm64: libstub: Move KASLR handling functions to kaslr.c riscv: Dump out kernel offset information on panic riscv: Introduce virtual kernel mapping KASLR Link: https://lore.kernel.org/r/20230722123850.634544-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-06riscv: libstub: Implement KASLR by using generic functionsAlexandre Ghiti1-0/+2
We can now use arm64 functions to handle the move of the kernel physical mapping: if KASLR is enabled, we will try to get a random seed from the firmware, if not possible, the kernel will be moved to a location that suits its alignment constraints. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Song Shuai <songshuaishuai@tinylab.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230722123850.634544-6-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-21efi/riscv: Move EFI runtime call setup/teardown helpers out of lineArd Biesheuvel1-8/+2
Only the arch_efi_call_virt() macro that some architectures override needs to be a macro, given that it is variadic and encapsulates calls via function pointers that have different prototypes. The associated setup and teardown code are not special in this regard, and don't need to be instantiated at each call site. So turn them into ordinary C functions and move them out of line. Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-04efi: Discover BTI support in runtime services regionsArd Biesheuvel1-1/+1
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>
2022-12-07Merge tag 'v6.1-rc8' into efi/nextArd Biesheuvel1-1/+5
Linux 6.1-rc8
2022-11-29riscv: Sync efi page table's kernel mappings before switchingAlexandre Ghiti1-1/+5
The EFI page table is initially created as a copy of the kernel page table. With VMAP_STACK enabled, kernel stacks are allocated in the vmalloc area: if the stack is allocated in a new PGD (one that was not present at the moment of the efi page table creation or not synced in a previous vmalloc fault), the kernel will take a trap when switching to the efi page table when the vmalloc kernel stack is accessed, resulting in a kernel panic. Fix that by updating the efi kernel mappings before switching to the efi page table. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Fixes: b91540d52a08 ("RISC-V: Add EFI runtime services") Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20221121133303.1782246-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-11-09efi/riscv: libstub: Split off kernel image relocation for builtin stubArd Biesheuvel1-0/+2
The RISC-V build of the EFI stub is part of the core kernel image, and therefore accesses section markers directly when it needs to figure out the size of the various section. The zboot decompressor does not have access to those symbols, but doesn't really need that either. So let's move handle_kernel_image() into a separate file (or rather, move everything else into a separate file) so that the zboot build does not pull in unused code that links to symbols that it does not define. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09efi: libstub: Factor out min alignment and preferred kernel load addressArd Biesheuvel1-0/+11
Factor out the expressions that describe the preferred placement of the loaded image as well as the minimum alignment so we can reuse them in the decompressor. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-09efi: libstub: Move screen_info handling to common codeArd Biesheuvel1-6/+0
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>
2022-06-28efi: Simplify arch_efi_call_virt() macroSudeep Holla1-2/+0
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>
2021-12-13efi: Move efifb_setup_from_dmi() prototype from arch headersJavier Martinez Canillas1-1/+0
Commit 8633ef82f101 ("drivers/firmware: consolidate EFI framebuffer setup for all arches") made the Generic System Framebuffers (sysfb) driver able to be built on non-x86 architectures. But it left the efifb_setup_from_dmi() function prototype declaration in the architecture specific headers. This could lead to the following compiler warning as reported by the kernel test robot: drivers/firmware/efi/sysfb_efi.c:70:6: warning: no previous prototype for function 'efifb_setup_from_dmi' [-Wmissing-prototypes] void efifb_setup_from_dmi(struct screen_info *si, const char *opt) ^ drivers/firmware/efi/sysfb_efi.c:70:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void efifb_setup_from_dmi(struct screen_info *si, const char *opt) Fixes: 8633ef82f101 ("drivers/firmware: consolidate EFI framebuffer setup for all arches") Reported-by: kernel test robot <lkp@intel.com> Cc: <stable@vger.kernel.org> # 5.15.x Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://lore.kernel.org/r/20211126001333.555514-1-javierm@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-07-26Backmerge tag 'v5.14-rc3' into drm-nextDave Airlie1-2/+2
Linux 5.14-rc3 Daniel said we should pull the nouveau fix from fixes in here, probably a good plan. Signed-off-by: Dave Airlie <airlied@redhat.com>
2021-07-22RISC-V: load initrd wherever it fits into memoryHeinrich Schuchardt1-2/+2
Requiring that initrd is loaded below RAM start + 256 MiB led to failure to boot SUSE Linux with GRUB on QEMU, cf. https://lists.gnu.org/archive/html/grub-devel/2021-06/msg00037.html Remove the constraint. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Fixes: d7071743db31 ("RISC-V: Add EFI stub support.") Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-21drivers/firmware: consolidate EFI framebuffer setup for all archesJavier Martinez Canillas1-4/+1
The register_gop_device() function registers an "efi-framebuffer" platform device to match against the efifb driver, to have an early framebuffer for EFI platforms. But there is already support to do exactly the same by the Generic System Framebuffers (sysfb) driver. This used to be only for X86 but it has been moved to drivers/firmware and could be reused by other architectures. Also, besides supporting registering an "efi-framebuffer", this driver can register a "simple-framebuffer" allowing to use the siple{fb,drm} drivers on non-X86 EFI platforms. For example, on aarch64 these drivers can only be used with DT and doesn't have code to register a "simple-frambuffer" platform device when booting with EFI. For these reasons, let's remove the register_gop_device() duplicated code and instead move the platform specific logic that's there to sysfb driver. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210625131359.1804394-1-javierm@redhat.com
2020-12-09efi: stub: get rid of efi_get_max_fdt_addr()Ard Biesheuvel1-6/+0
Now that ARM started following the example of arm64 and RISC-V, and no longer imposes any restrictions on the placement of the FDT in memory at boot, we no longer need per-arch implementations of efi_get_max_fdt_addr() to factor out the differences. So get rid of it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20201029134901.9773-1-ardb@kernel.org
2020-10-03RISC-V: Add EFI runtime servicesAtish Patra1-0/+20
This patch adds EFI runtime service support for RISC-V. Signed-off-by: Atish Patra <atish.patra@wdc.com> [ardb: - Remove the page check] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-10-03RISC-V: Add EFI stub support.Atish Patra1-0/+35
Add a RISC-V architecture specific stub code that actually copies the actual kernel image to a valid address and jump to it after boot services are terminated. Enable UEFI related kernel configs as well for RISC-V. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com [ardb: - move hartid fetch into check_platform_features() - use image_size not reserve_size - select ISA_C - do not use dram_base] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>