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2022-11-09arm64: efi: Move efi-entry.S into the libstub source directoryArd Biesheuvel
We will be sharing efi-entry.S with the zboot decompressor build, which does not link against vmlinux directly. So move it into the libstub source directory so we can include in the libstub static library. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-11-09arm64: efi: Avoid dcache_clean_poc() altogether in efi_enter_kernel()Ard Biesheuvel
To allow efi_enter_kernel() to be shared with the EFI zboot decompressor build, drop another reference to dcache_clean_poc() and replace it with a single DC CVAC* instruction. To ensure that it covers the remainder of efi_enter_kernel() as intended, reorganize the code a bit so it fits in a 32-byte cacheline, and align it to 32 bytes. (Even though the architecture defines 16 as the minimum D-cache line size, even the chosen value of 32 is highly unlikely to ever be encountered on real hardware, and this works with any line size >= 32) * due to ARM64_WORKAROUND_CLEAN_CACHE, we actually use a DC CIVAC here Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2022-11-09arm64: efi: Move dcache cleaning of loaded image out of efi_enter_kernel()Ard Biesheuvel
The efi_enter_kernel() routine will be shared between the existing EFI stub and the zboot decompressor, and the version of dcache_clean_to_poc() that the core kernel exports to the stub will not be available in the latter case. So move the handling into the .c file which will remain part of the stub build that integrates directly with the kernel proper. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-25arm64: Rename arm64-internal cache maintenance functionsFuad Tabba
Although naming across the codebase isn't that consistent, it tends to follow certain patterns. Moreover, the term "flush" isn't defined in the Arm Architecture reference manual, and might be interpreted to mean clean, invalidate, or both for a cache. Rename arm64-internal functions to make the naming internally consistent, as well as making it consistent with the Arm ARM, by specifying whether it applies to the instruction, data, or both caches, whether the operation is a clean, invalidate, or both. Also specify which point the operation applies to, i.e., to the point of unification (PoU), coherency (PoC), or persistence (PoP). This commit applies the following sed transformation to all files under arch/arm64: "s/\b__flush_cache_range\b/caches_clean_inval_pou_macro/g;"\ "s/\b__flush_icache_range\b/caches_clean_inval_pou/g;"\ "s/\binvalidate_icache_range\b/icache_inval_pou/g;"\ "s/\b__flush_dcache_area\b/dcache_clean_inval_poc/g;"\ "s/\b__inval_dcache_area\b/dcache_inval_poc/g;"\ "s/__clean_dcache_area_poc\b/dcache_clean_poc/g;"\ "s/\b__clean_dcache_area_pop\b/dcache_clean_pop/g;"\ "s/\b__clean_dcache_area_pou\b/dcache_clean_pou/g;"\ "s/\b__flush_cache_user_range\b/caches_clean_inval_user_pou/g;"\ "s/\b__flush_icache_all\b/icache_inval_all_pou/g;" Note that __clean_dcache_area_poc is deliberately missing a word boundary check at the beginning in order to match the efistub symbols in image-vars.h. Also note that, despite its name, __flush_icache_range operates on both instruction and data caches. The name change here reflects that. No functional change intended. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210524083001.2586635-19-tabba@google.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-25arm64: __clean_dcache_area_poc to take end parameter instead of sizeFuad Tabba
To be consistent with other functions with similar names and functionality in cacheflush.h, cache.S, and cachetlb.rst, change to specify the range in terms of start and end, as opposed to start and size. Because the code is shared with __dma_clean_area, it changes the parameters for that as well. However, __dma_clean_area is local to cache.S, so no other users are affected. No functional change intended. Reported-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210524083001.2586635-14-tabba@google.com Signed-off-by: Will Deacon <will@kernel.org>
2020-06-01Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "A sizeable pile of arm64 updates for 5.8. Summary below, but the big two features are support for Branch Target Identification and Clang's Shadow Call stack. The latter is currently arm64-only, but the high-level parts are all in core code so it could easily be adopted by other architectures pending toolchain support Branch Target Identification (BTI): - Support for ARMv8.5-BTI in both user- and kernel-space. This allows branch targets to limit the types of branch from which they can be called and additionally prevents branching to arbitrary code, although kernel support requires a very recent toolchain. - Function annotation via SYM_FUNC_START() so that assembly functions are wrapped with the relevant "landing pad" instructions. - BPF and vDSO updates to use the new instructions. - Addition of a new HWCAP and exposure of BTI capability to userspace via ID register emulation, along with ELF loader support for the BTI feature in .note.gnu.property. - Non-critical fixes to CFI unwind annotations in the sigreturn trampoline. Shadow Call Stack (SCS): - Support for Clang's Shadow Call Stack feature, which reserves platform register x18 to point at a separate stack for each task that holds only return addresses. This protects function return control flow from buffer overruns on the main stack. - Save/restore of x18 across problematic boundaries (user-mode, hypervisor, EFI, suspend, etc). - Core support for SCS, should other architectures want to use it too. - SCS overflow checking on context-switch as part of the existing stack limit check if CONFIG_SCHED_STACK_END_CHECK=y. CPU feature detection: - Removed numerous "SANITY CHECK" errors when running on a system with mismatched AArch32 support at EL1. This is primarily a concern for KVM, which disabled support for 32-bit guests on such a system. - Addition of new ID registers and fields as the architecture has been extended. Perf and PMU drivers: - Minor fixes and cleanups to system PMU drivers. Hardware errata: - Unify KVM workarounds for VHE and nVHE configurations. - Sort vendor errata entries in Kconfig. Secure Monitor Call Calling Convention (SMCCC): - Update to the latest specification from Arm (v1.2). - Allow PSCI code to query the SMCCC version. Software Delegated Exception Interface (SDEI): - Unexport a bunch of unused symbols. - Minor fixes to handling of firmware data. Pointer authentication: - Add support for dumping the kernel PAC mask in vmcoreinfo so that the stack can be unwound by tools such as kdump. - Simplification of key initialisation during CPU bringup. BPF backend: - Improve immediate generation for logical and add/sub instructions. vDSO: - Minor fixes to the linker flags for consistency with other architectures and support for LLVM's unwinder. - Clean up logic to initialise and map the vDSO into userspace. ACPI: - Work around for an ambiguity in the IORT specification relating to the "num_ids" field. - Support _DMA method for all named components rather than only PCIe root complexes. - Minor other IORT-related fixes. Miscellaneous: - Initialise debug traps early for KGDB and fix KDB cacheflushing deadlock. - Minor tweaks to early boot state (documentation update, set TEXT_OFFSET to 0x0, increase alignment of PE/COFF sections). - Refactoring and cleanup" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits) KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h KVM: arm64: Check advertised Stage-2 page size capability arm64/cpufeature: Add get_arm64_ftr_reg_nowarn() ACPI/IORT: Remove the unused __get_pci_rid() arm64/cpuinfo: Add ID_MMFR4_EL1 into the cpuinfo_arm64 context arm64/cpufeature: Add remaining feature bits in ID_AA64PFR1 register arm64/cpufeature: Add remaining feature bits in ID_AA64PFR0 register arm64/cpufeature: Add remaining feature bits in ID_AA64ISAR0 register arm64/cpufeature: Add remaining feature bits in ID_MMFR4 register arm64/cpufeature: Add remaining feature bits in ID_PFR0 register arm64/cpufeature: Introduce ID_MMFR5 CPU register arm64/cpufeature: Introduce ID_DFR1 CPU register arm64/cpufeature: Introduce ID_PFR2 CPU register arm64/cpufeature: Make doublelock a signed feature in ID_AA64DFR0 arm64/cpufeature: Drop TraceFilt feature exposure from ID_DFR0 register arm64/cpufeature: Add explicit ftr_id_isar0[] for ID_ISAR0 register arm64: mm: Add asid_gen_match() helper firmware: smccc: Fix missing prototype warning for arm_smccc_version_init arm64: vdso: Fix CFI directives in sigreturn trampoline arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction ...
2020-05-23efi/libstub: Add missing prototype for PE/COFF entry pointArd Biesheuvel
Fix a missing prototype warning by adding a forward declaration for the PE/COFF entrypoint, and while at it, align the function name between the x86 and ARM versions of the stub. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-04-28arm64: rename stext to primary_entryArd Biesheuvel
For historical reasons, the primary entry routine living somewhere in the inittext section is called stext(), which is confusing, given that there is also a section marker called _stext which lives at a fixed offset in the image (either 64 or 4096 bytes, depending on whether CONFIG_EFI is enabled) Let's rename stext to primary_entry(), which is a better description and reflects the secondary_entry() routine that already exists for SMP boot. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200326171423.3080-1-ardb@kernel.org Reviwed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-02-29efi/arm64: Clean EFI stub exit code from cache instead of avoiding itArd Biesheuvel
Commit 9f9223778 ("efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypoint") modified the handover code written in assembler, and for maintainability, aligned the logic with the logic used in the 32-bit ARM version, which is to avoid cache maintenance on the remaining instructions in the subroutine that will be executed with the MMU and caches off, and instead, branch into the relocated copy of the kernel image. However, this assumes that this copy is executable, and this means we expect EFI_LOADER_DATA regions to be executable as well, which is not a reasonable assumption to make, even if this is true for most UEFI implementations today. So change this back, and add a __clean_dcache_area_poc() call to cover the remaining code in the subroutine. While at it, switch the other call site over to __clean_dcache_area_poc() as well, and clean up the terminology in comments to avoid using 'flush' in the context of cache maintenance. Also, let's switch to the new style asm annotations. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Hildenbrand <david@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200228121408.9075-6-ardb@kernel.org
2020-02-22efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypointArd Biesheuvel
Expose efi_entry() as the PE/COFF entrypoint directly, instead of jumping into a wrapper that fiddles with stack buffers and other stuff that the compiler is much better at. The only reason this code exists is to obtain a pointer to the base of the image, but we can get the same value from the loaded_image protocol, which we already need for other reasons anyway. Update the return type as well, to make it consistent with what is required for a PE/COFF executable entrypoint. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-12arm64: Add software workaround for Falkor erratum 1041Shanker Donthineni
The ARM architecture defines the memory locations that are permitted to be accessed as the result of a speculative instruction fetch from an exception level for which all stages of translation are disabled. Specifically, the core is permitted to speculatively fetch from the 4KB region containing the current program counter 4K and next 4K. When translation is changed from enabled to disabled for the running exception level (SCTLR_ELn[M] changed from a value of 1 to 0), the Falkor core may errantly speculatively access memory locations outside of the 4KB region permitted by the architecture. The errant memory access may lead to one of the following unexpected behaviors. 1) A System Error Interrupt (SEI) being raised by the Falkor core due to the errant memory access attempting to access a region of memory that is protected by a slave-side memory protection unit. 2) Unpredictable device behavior due to a speculative read from device memory. This behavior may only occur if the instruction cache is disabled prior to or coincident with translation being changed from enabled to disabled. The conditions leading to this erratum will not occur when either of the following occur: 1) A higher exception level disables translation of a lower exception level (e.g. EL2 changing SCTLR_EL1[M] from a value of 1 to 0). 2) An exception level disabling its stage-1 translation if its stage-2 translation is enabled (e.g. EL1 changing SCTLR_EL1[M] from a value of 1 to 0 when HCR_EL2[VM] has a value of 1). To avoid the errant behavior, software must execute an ISB immediately prior to executing the MSR that will change SCTLR_ELn[M] from 1 to 0. Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-17arm64: efi-entry.S: avoid open-coded adr_lMark Rutland
Some places in the kernel open-code sequences using ADRP for a symbol another instruction using a :lo12: relocation for that same symbol. These sequences are easy to get wrong, and more painful to read than is necessary. For these reasons, it is preferable to use the {adr,ldr,str}_l macros for these cases. This patch makes use of these in efi-entry.S, removing open-coded sequences using adrp. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-14arm64: move early boot code to the .init segmentArd Biesheuvel
Apart from the arm64/linux and EFI header data structures, there is nothing in the .head.text section that must reside at the beginning of the Image. So let's move it to the .init section where it belongs. Note that this involves some minor tweaking of the EFI header, primarily because the address of 'stext' no longer coincides with the start of the .text section. It also requires a couple of relocated symbol references to be slightly rewritten or their definition moved to the linker script. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-03-04arm64: efi: add missing frame pointer assignmentArd Biesheuvel
The prologue of the EFI entry point pushes x29 and x30 onto the stack but fails to create the stack frame correctly by omitting the assignment of x29 to the new value of the stack pointer. So fix that. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: avoid dynamic relocations in early boot codeArd Biesheuvel
Before implementing KASLR for arm64 by building a self-relocating PIE executable, we have to ensure that values we use before the relocation routine is executed are not subject to dynamic relocation themselves. This applies not only to virtual addresses, but also to values that are supplied by the linker at build time and relocated using R_AARCH64_ABS64 relocations. So instead, use assemble time constants, or force the use of static relocations by folding the constants into the instructions. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-12arm64/efi: isolate EFI stub from the kernel properArd Biesheuvel
Since arm64 does not use a builtin decompressor, the EFI stub is built into the kernel proper. So far, this has been working fine, but actually, since the stub is in fact a PE/COFF relocatable binary that is executed at an unknown offset in the 1:1 mapping provided by the UEFI firmware, we should not be seamlessly sharing code with the kernel proper, which is a position dependent executable linked at a high virtual offset. So instead, separate the contents of libstub and its dependencies, by putting them into their own namespace by prefixing all of its symbols with __efistub. This way, we have tight control over what parts of the kernel proper are referenced by the stub. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-09Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Here's the usual mixed bag of arm64 updates, also including some related EFI changes (Acked by Matt) and the MMU gather range cleanup (Acked by you). Changes include: - support for alternative instruction patching from Andre - seccomp from Akashi - some AArch32 instruction emulation, required by the Android folks - optimisations for exception entry/exit code, cmpxchg, pcpu atomics - mmu_gather range calculations moved into core code - EFI updates from Ard, including long-awaited SMBIOS support - /proc/cpuinfo fixes to align with the format used by arch/arm/ - a few non-critical fixes across the architecture" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits) arm64: remove the unnecessary arm64_swiotlb_init() arm64: add module support for alternatives fixups arm64: perf: Prevent wraparound during overflow arm64/include/asm: Fixed a warning about 'struct pt_regs' arm64: Provide a namespace to NCAPS arm64: bpf: lift restriction on last instruction arm64: Implement support for read-mostly sections arm64: compat: align cacheflush syscall with arch/arm arm64: add seccomp support arm64: add SIGSYS siginfo for compat task arm64: add seccomp syscall for compat task asm-generic: add generic seccomp.h for secure computing mode 1 arm64: ptrace: allow tracer to skip a system call arm64: ptrace: add NT_ARM_SYSTEM_CALL regset arm64: Move some head.text functions to executable section arm64: jump labels: NOP out NOP -> NOP replacement arm64: add support to dump the kernel page tables arm64: Add FIX_HOLE to permanent fixed addresses arm64: alternatives: fix pr_fmt string for consistency arm64: vmlinux.lds.S: don't discard .exit.* sections at link-time ...
2014-11-13arm64: efi: Fix stub cache maintenanceMark Rutland
While efi-entry.S mentions that efi_entry() will have relocated the kernel image, it actually means that efi_entry will have placed a copy of the kernel in the appropriate location, and until this is branched to at the end of efi_entry.S, all instructions are executed from the original image. Thus while the flush in efi_entry.S does ensure that the copy is visible to noncacheable accesses, it does not guarantee that this is true for the image instructions are being executed from. This could have disasterous effects when the MMU and caches are disabled if the image has not been naturally evicted to the PoC. Additionally, due to a missing dsb following the ic ialluis, the new kernel image is not necessarily clean in the I-cache when it is branched to, with similar potentially disasterous effects. This patch adds additional flushing to ensure that the currently executing stub text is flushed to the PoC and is thus visible to noncacheable accesses. As it is placed after the instructions cache maintenance for the new image and __flush_dcache_area already contains a dsb, we do not need to add a separate barrier to ensure completion of the icache maintenance. Comments are updated to clarify the situation with regard to the two images and the maintenance required for both. Fixes: 3c7f255039a2ad6ee1e3890505caf0d029b22e29 Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Joel Schopp <joel.schopp@amd.com> Reviewed-by: Roy Franz <roy.franz@linaro.org> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ian Campbell <ijc@hellion.org.uk> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Salter <msalter@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-11-05arm64/efi: efistub: jump to 'stext' directly, not through the headerArd Biesheuvel
After the EFI stub has done its business, it jumps into the kernel by branching to offset #0 of the loaded Image, which is where it expects to find the header containing a 'branch to stext' instruction. However, the UEFI spec 2.1.1 states the following regarding PE/COFF image loading: "A UEFI image is loaded into memory through the LoadImage() Boot Service. This service loads an image with a PE32+ format into memory. This PE32+ loader is required to load all sections of the PE32+ image into memory." In other words, it is /not/ required to load parts of the image that are not covered by a PE/COFF section, so it may not have loaded the header at the expected offset, as it is not covered by any PE/COFF section. So instead, jump to 'stext' directly, which is at the base of the PE/COFF .text section, by supplying a symbol 'stext_offset' to efi-entry.o which contains the relative offset of stext into the Image. Also replace other open coded calculations of the same value with a reference to 'stext_offset' Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Roy Franz <roy.franz@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-07-04arm64: fix el2_setup check of CurrentELMarc Zyngier
The CurrentEL system register reports the Current Exception Level of the CPU. It doesn't say anything about the stack handling, and yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h. It works by chance because PSR_MODE_EL2t happens to match the right bits, but that's otherwise a very bad idea. Just check for the EL value instead. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> [catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-04-30arm64: efi: add EFI stubMark Salter
This patch adds PE/COFF header fields to the start of the kernel Image so that it appears as an EFI application to UEFI firmware. An EFI stub is included to allow direct booting of the kernel Image. Signed-off-by: Mark Salter <msalter@redhat.com> [Add support in PE/COFF header for signed images] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>