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2024-12-19arm64/sysreg: Get rid of the TCR2_EL1x SysregFieldsMarc Zyngier
TCR2_EL1x is a pretty bizarre construct, as it is shared between TCR2_EL1 and TCR2_EL12. But the latter is obviously only an accessor to the former. In order to make things more consistent, upgrade TCR2_EL1x to a full-blown sysreg definition for TCR2_EL1, and describe TCR2_EL12 as a mapping to TCR2_EL1. This results in a couple of minor changes to the actual code. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20241219173351.1123087-3-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2024-11-05arm64: Add support for FEAT_HAFTYicong Yang
Armv8.9/v9.4 introduces the feature Hardware managed Access Flag for Table descriptors (FEAT_HAFT). The feature is indicated by ID_AA64MMFR1_EL1.HAFDBS == 0b0011 and can be enabled by TCR2_EL1.HAFT so it has a dependency on FEAT_TCR2. Adds the Kconfig for FEAT_HAFT and support detecting and enabling the feature. The feature is enabled in __cpu_setup() before MMU on just like HA. A CPU capability is added to notify the user of the feature. Add definition of P{G,4,U,M}D_TABLE_AF bit and set the AF bit when creating the page table, which will save the hardware from having to update them at runtime. This will be ignored if FEAT_HAFT is not enabled. The AF bit of table descriptors cannot be managed by the software per spec, unlike the HA. So this should be used only if it's supported system wide by system_supports_haft(). Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Link: https://lore.kernel.org/r/20241102104235.62560-4-yangyicong@huawei.com Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [catalin.marinas@arm.com: added the ID check back to __cpu_setup in case of future CPU errata] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-05arm64: setup: name 'tcr2' registerYicong Yang
TCR2_EL1 introduced some additional controls besides TCR_EL1. Currently only PIE is supported and enabled by writing TCR2_EL1 directly if PIE detected. Introduce a named register 'tcr2' just like 'tcr' we've already had. It'll be initialized to 0 and updated if certain feature detected and needs to be enabled. Touch the TCR2_EL1 registers at last with the updated 'tcr2' value if FEAT_TCR2 supported by checking ID_AA64MMFR3_EL1.TCRX. Then we can extend the support of other features controlled by TCR2_EL1. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Link: https://lore.kernel.org/r/20241102104235.62560-3-yangyicong@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-08-16arm64/mm: Drop TCR_SMP_FLAGSAnshuman Khandual
Earlier TCR_SMP_FLAGS gets conditionally set as TCR_SHARED with CONFIG_SMP. Currently CONFIG_SMP is always enabled on arm64 platforms, hence drop this indirection via TCR_SMP_FLAGS and instead always directly use TCR_SHARED. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://lore.kernel.org/r/20240724041428.573748-1-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2024-04-28arm64: defer clearing DAIF.DMark Rutland
For historical reasons we unmask debug exceptions in __cpu_setup(), but it's not necessary to unmask debug exceptions this early in the boot/idle entry paths. It would be better to unmask debug exceptions later in C code as this simplifies the current code and will make it easier to rework exception masking logic to handle non-DAIF bits in future (e.g. PSTATE.{ALLINT,PM}). We started clearing DAIF.D in __cpu_setup() in commit: 2ce39ad15182604b ("arm64: debug: unmask PSTATE.D earlier") At the time, we needed to ensure that DAIF.D was clear on the primary CPU before scheduling and preemption were possible, and chose to do this in __cpu_setup() so that this occurred in the same place for primary and secondary CPUs. As we cannot handle debug exceptions this early, we placed an ISB between initializing MDSCR_EL1 and clearing DAIF.D so that no exceptions should be triggered. Subsequently we rewrote the return-from-{idle,suspend} paths to use __cpu_setup() in commit: cabe1c81ea5be983 ("arm64: Change cpu_resume() to enable mmu early then access sleep_sp by va") ... which allowed for earlier use of the MMU and had the desirable property of using the same code to reset the CPU in the cold and warm boot paths. This introduced a bug: DAIF.D was clear while cpu_do_resume() restored MDSCR_EL1 and other control registers (e.g. breakpoint/watchpoint control/value registers), and so we could unexpectedly take debug exceptions. We fixed that in commit: 744c6c37cc18705d ("arm64: kernel: Fix unmasked debug exceptions when restoring mdscr_el1") ... by having cpu_do_resume() use the `disable_dbg` macro to set DAIF.D before restoring MDSCR_EL1 and other control registers. This relies on DAIF.D being subsequently cleared again in cpu_resume(). Subsequently we reworked DAIF masking in commit: 0fbeb318754860b3 ("arm64: explicitly mask all exceptions") ... where we began enforcing a policy that DAIF.D being set implies all other DAIF bits are set, and so e.g. we cannot take an IRQ while DAIF.D is set. As part of this the use of `disable_dbg` in cpu_resume() was replaced with `disable_daif` for consistency with the rest of the kernel. These days, there's no need to clear DAIF.D early within __cpu_setup(): * setup_arch() clears DAIF.DA before scheduling and preemption are possible on the primary CPU, avoiding the problem we we originally trying to work around. Note: DAIF.IF get cleared later when interrupts are enabled for the first time. * secondary_start_kernel() clears all DAIF bits before scheduling and preemption are possible on secondary CPUs. Note: with pseudo-NMI, the PMR is initialized here before any DAIF bits are cleared. Similar will be necessary for the architectural NMI. * cpu_suspend() restores all DAIF bits when returning from idle, ensuring that we don't unexpectedly leave DAIF.D clear or set. Note: with pseudo-NMI, the PMR is initialized here before DAIF is cleared. Similar will be necessary for the architectural NMI. This patch removes the unmasking of debug exceptions from __cpu_setup(), relying on the above locations to initialize DAIF. This allows some other cleanups: * It is no longer necessary for cpu_resume() to explicitly mask debug (or other) exceptions, as it is always called with all DAIF bits set. Thus we drop the use of `disable_daif`. * The `enable_dbg` macro is no longer used, and so is dropped. * It is no longer necessary to have an ISB immediately after initializing MDSCR_EL1 in __cpu_setup(), and we can revert to relying on the context synchronization that occurs when the MMU is enabled between __cpu_setup() and code which clears DAIF.D Comments are added to setup_arch() and secondary_start_kernel() to explain the initial unmasking of the DAIF bits. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240422113523.4070414-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2024-03-13Revert "arm64: mm: add support for WXN memory translation attribute"Catalin Marinas
This reverts commit 50e3ed0f93f4f62ed2aa83de5db6cb84ecdd5707. The SCTLR_EL1.WXN control forces execute-never when a page has write permissions. While the idea of hardening such write/exec combinations is good, with permissions indirection enabled (FEAT_PIE) this control becomes RES0. FEAT_PIE introduces a slightly different form of WXN which only has an effect when the base permission is RWX and the write is toggled by the permission overlay (FEAT_POE, not yet supported by the arm64 kernel). Revert the patch for now. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/ZfGESD3a91lxH367@arm.com
2024-02-16arm64: mm: add support for WXN memory translation attributeArd Biesheuvel
The AArch64 virtual memory system supports a global WXN control, which can be enabled to make all writable mappings implicitly no-exec. This is a useful hardening feature, as it prevents mistakes in managing page table permissions from being exploited to attack the system. When enabled at EL1, the restrictions apply to both EL1 and EL0. EL1 is completely under our control, and has been cleaned up to allow WXN to be enabled from boot onwards. EL0 is not under our control, but given that widely deployed security features such as selinux or PaX already limit the ability of user space to create mappings that are writable and executable at the same time, the impact of enabling this for EL0 is expected to be limited. (For this reason, common user space libraries that have a legitimate need for manipulating executable code already carry fallbacks such as [0].) If enabled at compile time, the feature can still be disabled at boot if needed, by passing arm64.nowxn on the kernel command line. [0] https://github.com/libffi/libffi/blob/master/src/closures.c#L440 Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240214122845.2033971-88-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: Enable LPA2 at boot if supported by the systemArd Biesheuvel
Update the early kernel mapping code to take 52-bit virtual addressing into account based on the LPA2 feature. This is a bit more involved than LVA (which is supported with 64k pages only), given that some page table descriptor bits change meaning in this case. To keep the handling in asm to a minimum, the initial ID map is still created with 48-bit virtual addressing, which implies that the kernel image must be loaded into 48-bit addressable physical memory. This is currently required by the boot protocol, even though we happen to support placement outside of that for LVA/64k based configurations. Enabling LPA2 involves more than setting TCR.T1SZ to a lower value, there is also a DS bit in TCR that needs to be set, and which changes the meaning of bits [9:8] in all page table descriptors. Since we cannot enable DS and every live page table descriptor at the same time, let's pivot through another temporary mapping. This avoids the need to reintroduce manipulations of the page tables with the MMU and caches disabled. To permit the LPA2 feature to be overridden on the kernel command line, which may be necessary to work around silicon errata, or to deal with mismatched features on heterogeneous SoC designs, test for CPU feature overrides first, and only then enable LPA2. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-78-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: mm: add LPA2 and 5 level paging support to G-to-nG conversionArd Biesheuvel
Add support for 5 level paging in the G-to-nG routine that creates its own temporary page tables to traverse the swapper page tables. Also add support for running the 5 level configuration with the top level folded at runtime, to support CPUs that do not implement the LPA2 extension. While at it, wire up the level skipping logic so it will also trigger on 4 level configurations with LPA2 enabled at build time but not active at runtime, as we'll fall back to 3 level paging in that case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-77-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: mm: Add LPA2 support to phys<->pte conversion routinesArd Biesheuvel
In preparation for enabling LPA2 support, introduce the mask values for converting between physical addresses and their representations in a page table descriptor. While at it, move the pte_to_phys asm macro into its only user, so that we can freely modify it to use its input value register as a temp register. For LPA2, the PTE_ADDR_MASK contains two non-adjacent sequences of zero bits, which means it no longer fits into the immediate field of an ordinary ALU instruction. So let's redefine it to include the bits in between as well, and only use it when converting from physical address to PTE representation, where the distinction does not matter. Also update the name accordingly to emphasize this. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-75-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: mm: Wire up TCR.DS bit to PTE shareability fieldsArd Biesheuvel
When LPA2 is enabled, bits 8 and 9 of page and block descriptors become part of the output address instead of carrying shareability attributes for the region in question. So avoid setting these bits if TCR.DS == 1, which means LPA2 is enabled. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-74-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: Avoid #define'ing PTE_MAYBE_NG to 0x0 for asm useArd Biesheuvel
The PROT_* macros resolve to expressions that are only valid in C and not in assembler, and so they are only usable from C code. Currently, we make an exception for the permission indirection init code in proc.S, which doesn't care about the bits that are conditionally set, and so we just #define PTE_MAYBE_NG to 0x0 for any assembler file that includes these definitions. This is dodgy because this means that PROT_NORMAL and friends is generally available in asm code, but defined in a way that deviates from the definition that C code will observe, which might lead to hard to diagnose issues down the road. So instead, #define PTE_MAYBE_NG only in the place where the PIE constants are evaluated, and #undef it again right after. This allows us to drop the #define from pgtable-prot.h, and avoid the risk of deviating definitions between asm and C. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-72-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: mm: Handle LVA support as a CPU featureArd Biesheuvel
Currently, we detect CPU support for 52-bit virtual addressing (LVA) extremely early, before creating the kernel page tables or enabling the MMU. We cannot override the feature this early, and so large virtual addressing is always enabled on CPUs that implement support for it if the software support for it was enabled at build time. It also means we rely on non-trivial code in asm to deal with this feature. Given that both the ID map and the TTBR1 mapping of the kernel image are guaranteed to be 48-bit addressable, it is not actually necessary to enable support this early, and instead, we can model it as a CPU feature. That way, we can rely on code patching to get the correct TCR.T1SZ values programmed on secondary boot and resume from suspend. On the primary boot path, we simply enable the MMU with 48-bit virtual addressing initially, and update TCR.T1SZ if LVA is supported from C code, right before creating the kernel mapping. Given that TTBR1 still points to reserved_pg_dir at this point, updating TCR.T1SZ should be safe without the need for explicit TLB maintenance. Since this gets rid of all accesses to the vabits_actual variable from asm code that occurred before TCR.T1SZ had been programmed, we no longer have a need for this variable, and we can replace it with a C expression that produces the correct value directly, based on the value of TCR.T1SZ. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-70-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: kernel: Create initial ID map from C codeArd Biesheuvel
The asm code that creates the initial ID map is rather intricate and hard to follow. This is problematic because it makes adding support for things like LPA2 or WXN more difficult than necessary. Also, it is parameterized like the rest of the MM code to run with a configurable number of levels, which is rather pointless, given that all AArch64 CPUs implement support for 48-bit virtual addressing, and that many systems exist with DRAM located outside of the 39-bit addressable range, which is the only smaller VA size that is widely used, and we need additional tricks to make things work in that combination. So let's bite the bullet, and rip out all the asm macros, and fiddly code, and replace it with a C implementation based on the newly added routines for creating the early kernel VA mappings. And while at it, create the initial ID map based on 48-bit virtual addressing as well, regardless of the number of configured levels for the kernel proper. Note that this code may execute with the MMU and caches disabled, and is therefore not permitted to make unaligned accesses. This shouldn't generally happen in any case for the algorithm as implemented, but to be sure, let's pass -mstrict-align to the compiler just in case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-66-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: mm: Use 48-bit virtual addressing for the permanent ID mapArd Biesheuvel
Even though we support loading kernels anywhere in 48-bit addressable physical memory, we create the ID maps based on the number of levels that we happened to configure for the kernel VA and user VA spaces. The reason for this is that the PGD/PUD/PMD based classification of translation levels, along with the associated folding when the number of levels is less than 5, does not permit creating a page table hierarchy of a set number of levels. This means that, for instance, on 39-bit VA kernels we need to configure an additional level above PGD level on the fly, and 36-bit VA kernels still only support 47-bit virtual addressing with this trick applied. Now that we have a separate helper to populate page table hierarchies that does not define the levels in terms of PUDS/PMDS/etc at all, let's reuse it to create the permanent ID map with a fixed VA size of 48 bits. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-64-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-16arm64: head: Move early kernel mapping routines into C codeArd Biesheuvel
The asm version of the kernel mapping code works fine for creating a coarse grained identity map, but for mapping the kernel down to its exact boundaries with the right attributes, it is not suitable. This is why we create a preliminary RWX kernel mapping first, and then rebuild it from scratch later on. So let's reimplement this in C, in a way that will make it unnecessary to create the kernel page tables yet another time in paging_init(). Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-63-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-10-16arm64: Use a positive cpucap for FP/SIMDMark Rutland
Currently we have a negative cpucap which describes the *absence* of FP/SIMD rather than *presence* of FP/SIMD. This largely works, but is somewhat awkward relative to other cpucaps that describe the presence of a feature, and it would be nicer to have a cpucap which describes the presence of FP/SIMD: * This will allow the cpucap to be treated as a standard ARM64_CPUCAP_SYSTEM_FEATURE, which can be detected with the standard has_cpuid_feature() function and ARM64_CPUID_FIELDS() description. * This ensures that the cpucap will only transition from not-present to present, reducing the risk of unintentional and/or unsafe usage of FP/SIMD before cpucaps are finalized. * This will allow using arm64_cpu_capabilities::cpu_enable() to enable the use of FP/SIMD later, with FP/SIMD being disabled at boot time otherwise. This will ensure that any unintentional and/or unsafe usage of FP/SIMD prior to this is trapped, and will ensure that FP/SIMD is never unintentionally enabled for userspace in mismatched big.LITTLE systems. This patch replaces the negative ARM64_HAS_NO_FPSIMD cpucap with a positive ARM64_HAS_FPSIMD cpucap, making changes as described above. Note that as FP/SIMD will now be trapped when not supported system-wide, do_fpsimd_acc() must handle these traps in the same way as for SVE and SME. The commentary in fpsimd_restore_current_state() is updated to describe the new scheme. No users of system_supports_fpsimd() need to know that FP/SIMD is available prior to alternatives being patched, so this is updated to use alternative_has_cap_likely() to check for the ARM64_HAS_FPSIMD cpucap, without generating code to test the system_cpucaps bitmap. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-07-27arm64/mm: Replace an open coding with ID_AA64MMFR1_EL1_HAFDBS_MASKAnshuman Khandual
Replace '0xf' with ID_AA64MMFR1_EL1_HAFDBS_MASK while evaluating if the cpu supports implicit page table entry access flag update in HW. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20230711090458.238346-1-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2023-06-06arm64: enable Permission Indirection Extension (PIE)Joey Gouly
Now that the necessary changes have been made, set the Permission Indirection registers and enable the Permission Indirection Extension. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20230606145859.697944-17-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-06-06arm64: add PTE_UXN/PTE_WRITE to SWAPPER_*_FLAGSJoey Gouly
With PIE enabled, the swapper PTEs would have a Permission Indirection Index (PIIndex) of 0. A PIIndex of 0 is not currently used by any other PTEs. To avoid using index 0 specifically for the swapper PTEs, mark them as PTE_UXN and PTE_WRITE, so that they map to a PAGE_KERNEL_EXEC equivalent. This also adds PTE_WRITE to KPTI_NG_PTE_FLAGS, which was tested by booting with kpti=on. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20230606145859.697944-12-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-05-02arm64: kernel: remove SHF_WRITE|SHF_EXECINSTR from .idmap.textndesaulniers@google.com
commit d54170812ef1 ("arm64: fix .idmap.text assertion for large kernels") modified some of the section assembler directives that declare .idmap.text to be SHF_ALLOC instead of SHF_ALLOC|SHF_WRITE|SHF_EXECINSTR. This patch fixes up the remaining stragglers that were left behind. Add Fixes tag so that this doesn't precede related change in stable. Fixes: d54170812ef1 ("arm64: fix .idmap.text assertion for large kernels") Reported-by: Greg Thelen <gthelen@google.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20230428-awx-v2-1-b197ffa16edc@google.com Signed-off-by: Will Deacon <will@kernel.org>
2023-01-24arm64: kernel: move identity map out of .text mappingArd Biesheuvel
Reorganize the ID map slightly so that only code that is executed with the MMU off or via the 1:1 mapping remains. This allows us to move the identity map out of the .text segment, as it will no longer need executable permissions via the kernel mapping. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20230111102236.1430401-3-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-11-25arm64/kpti: Move DAIF masking to C codeMark Brown
We really don't want to take an exception while replacing TTBR1 so we mask DAIF during the actual update. Currently this is done in the assembly function idmap_cpu_replace_ttbr1() but it could equally be done in the only caller of that function, cpu_replace_ttbr1(). This simplifies the assembly code slightly and means that when working with the code around masking DAIF flags there is one less piece of assembly code which needs to be considered. While we're at it add a comment which makes explicit why we are masking DAIF in this code. There should be no functional effect. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20221123180209.634650-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-10-06Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - arm64 perf: DDR PMU driver for Alibaba's T-Head Yitian 710 SoC, SVE vector granule register added to the user regs together with SVE perf extensions documentation. - SVE updates: add HWCAP for SVE EBF16, update the SVE ABI documentation to match the actual kernel behaviour (zeroing the registers on syscall rather than "zeroed or preserved" previously). - More conversions to automatic system registers generation. - vDSO: use self-synchronising virtual counter access in gettimeofday() if the architecture supports it. - arm64 stacktrace cleanups and improvements. - arm64 atomics improvements: always inline assembly, remove LL/SC trampolines. - Improve the reporting of EL1 exceptions: rework BTI and FPAC exception handling, better EL1 undefs reporting. - Cortex-A510 erratum 2658417: remove BF16 support due to incorrect result. - arm64 defconfig updates: build CoreSight as a module, enable options necessary for docker, memory hotplug/hotremove, enable all PMUs provided by Arm. - arm64 ptrace() support for TPIDR2_EL0 (register provided with the SME extensions). - arm64 ftraces updates/fixes: fix module PLTs with mcount, remove unused function. - kselftest updates for arm64: simple HWCAP validation, FP stress test improvements, validation of ZA regs in signal handlers, include larger SVE and SME vector lengths in signal tests, various cleanups. - arm64 alternatives (code patching) improvements to robustness and consistency: replace cpucap static branches with equivalent alternatives, associate callback alternatives with a cpucap. - Miscellaneous updates: optimise kprobe performance of patching single-step slots, simplify uaccess_mask_ptr(), move MTE registers initialisation to C, support huge vmalloc() mappings, run softirqs on the per-CPU IRQ stack, compat (arm32) misalignment fixups for multiword accesses. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (126 commits) arm64: alternatives: Use vdso/bits.h instead of linux/bits.h arm64/kprobe: Optimize the performance of patching single-step slot arm64: defconfig: Add Coresight as module kselftest/arm64: Handle EINTR while reading data from children kselftest/arm64: Flag fp-stress as exiting when we begin finishing up kselftest/arm64: Don't repeat termination handler for fp-stress ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs arm64/mm: fold check for KFENCE into can_set_direct_map() arm64: ftrace: fix module PLTs with mcount arm64: module: Remove unused plt_entry_is_initialized() arm64: module: Make plt_equals_entry() static arm64: fix the build with binutils 2.27 kselftest/arm64: Don't enable v8.5 for MTE selftest builds arm64: uaccess: simplify uaccess_mask_ptr() arm64: asm/perf_regs.h: Avoid C++-style comment in UAPI header kselftest/arm64: Fix typo in hwcap check arm64: mte: move register initialization to C arm64: mm: handle ARM64_KERNEL_USES_PMD_MAPS in vmemmap_populate() arm64: dma: Drop cache invalidation from arch_dma_prep_coherent() arm64/sve: Add Perf extensions documentation ...
2022-09-26arm64: Add types to indirect called assembly functionsSami Tolvanen
With CONFIG_CFI_CLANG, assembly functions indirectly called from C code must be annotated with type identifiers to pass CFI checking. Use SYM_TYPED_FUNC_START for the indirectly called functions, and ensure we emit `bti c` also with SYM_TYPED_FUNC_START. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-10-samitolvanen@google.com
2022-09-22arm64: mte: move register initialization to CPeter Collingbourne
If FEAT_MTE2 is disabled via the arm64.nomte command line argument on a CPU that claims to support FEAT_MTE2, the kernel will use Tagged Normal in the MAIR. If we interpret arm64.nomte to mean that the CPU does not in fact implement FEAT_MTE2, setting the system register like this may lead to UNSPECIFIED behavior. Fix it by arranging for MAIR to be set in the C function cpu_enable_mte which is called based on the sanitized version of the system register. There is no need for the rest of the MTE-related system register initialization to happen from assembly, with the exception of TCR_EL1, which must be set to include at least TBI1 because the secondary CPUs access KASan-allocated data structures early. Therefore, make the TCR_EL1 initialization unconditional and move the rest of the initialization to cpu_enable_mte so that we no longer have a dependency on the unsanitized ID register value. Co-developed-by: Evgenii Stepanov <eugenis@google.com> Signed-off-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Evgenii Stepanov <eugenis@google.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: kernel test robot <lkp@intel.com> Fixes: 3b714d24ef17 ("arm64: mte: CPU feature detection and initial sysreg configuration") Cc: <stable@vger.kernel.org> # 5.10.x Link: https://lore.kernel.org/r/20220915222053.3484231-1-eugenis@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-07-25Merge branch 'for-next/boot' into for-next/coreWill Deacon
* for-next/boot: (34 commits) arm64: fix KASAN_INLINE arm64: Add an override for ID_AA64SMFR0_EL1.FA64 arm64: Add the arm64.nosve command line option arm64: Add the arm64.nosme command line option arm64: Expose a __check_override primitive for oddball features arm64: Allow the idreg override to deal with variable field width arm64: Factor out checking of a feature against the override into a macro arm64: Allow sticky E2H when entering EL1 arm64: Save state of HCR_EL2.E2H before switch to EL1 arm64: Rename the VHE switch to "finalise_el2" arm64: mm: fix booting with 52-bit address space arm64: head: remove __PHYS_OFFSET arm64: lds: use PROVIDE instead of conditional definitions arm64: setup: drop early FDT pointer helpers arm64: head: avoid relocating the kernel twice for KASLR arm64: kaslr: defer initialization to initcall where permitted arm64: head: record CPU boot mode after enabling the MMU arm64: head: populate kernel page tables with MMU and caches on arm64: head: factor out TTBR1 assignment into a macro arm64: idreg-override: use early FDT mapping in ID map ...
2022-07-01arm64: mm: fix booting with 52-bit address spaceArd Biesheuvel
Joey reports that booting 52-bit VA capable builds on 52-bit VA capable CPUs is broken since commit 0d9b1ffefabe ("arm64: mm: make vabits_actual a build time constant if possible"). This is due to the fact that the primary CPU reads the vabits_actual variable before it has been assigned. The reason for deferring the assignment of vabits_actual was that we try to perform as few stores to memory as we can with the MMU and caches off, due to the cache coherency issues it creates. Since __cpu_setup() [which is where the read of vabits_actual occurs] is also called on the secondary boot path, we cannot just read the CPU ID registers directly, given that the size of the VA space is decided by the capabilities of the primary CPU. So let's read vabits_actual only on the secondary boot path, and read the CPU ID registers directly on the primary boot path, by making it a function parameter of __cpu_setup(). To ensure that all users of vabits_actual (including kasan_early_init()) observe the correct value, move the assignment of vabits_actual back into asm code, but still defer it to after the MMU and caches have been enabled. Cc: Will Deacon <will@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Fixes: 0d9b1ffefabe ("arm64: mm: make vabits_actual a build time constant if possible") Reported-by: Joey Gouly <joey.gouly@arm.com> Co-developed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220701111045.2944309-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-06-24arm64: head: cover entire kernel image in initial ID mapArd Biesheuvel
As a first step towards avoiding the need to create, tear down and recreate the kernel virtual mapping with MMU and caches disabled, start by expanding the ID map so it covers the page tables as well as all executable code. This will allow us to populate the page tables with the MMU and caches on, and call KASLR init code before setting up the virtual mapping. Since this ID map is only needed at boot, create it as a temporary set of page tables, and populate the permanent ID map after enabling the MMU and caches. While at it, switch to read-only attributes for the where possible, as writable permissions are only needed for the initial kernel page tables. Note that on 4k granule configurations, the permanent ID map will now be reduced to a single page rather than a 2M block mapping. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220624150651.1358849-13-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-06-24arm64: head: move assignment of idmap_t0sz to C codeArd Biesheuvel
Setting idmap_t0sz involves fiddling with the caches if done with the MMU off. Since we will be creating an initial ID map with the MMU and caches off, and the permanent ID map with the MMU and caches on, let's move this assignment of idmap_t0sz out of the startup code, and replace it with a macro that simply issues the three instructions needed to calculate the value wherever it is needed before the MMU is turned on. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220624150651.1358849-4-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-06-23arm64: mm: install KPTI nG mappings with MMU enabledArd Biesheuvel
In cases where we unmap the kernel while running in user space, we rely on ASIDs to distinguish the minimal trampoline from the full kernel mapping, and this means we must use non-global attributes for those mappings, to ensure they are scoped by ASID and will not hit in the TLB inadvertently. We only do this when needed, as this is generally more costly in terms of TLB pressure, and so we boot without these non-global attributes, and apply them to all existing kernel mappings once all CPUs are up and we know whether or not the non-global attributes are needed. At this point, we cannot simply unmap and remap the entire address space, so we have to update all existing block and page descriptors in place. Currently, we go through a lot of trouble to perform these updates with the MMU and caches off, to avoid violating break before make (BBM) rules imposed by the architecture. Since we make changes to page tables that are not covered by the ID map, we gain access to those descriptors by disabling translations altogether. This means that the stores to memory are issued with device attributes, and require extra care in terms of coherency, which is costly. We also rely on the ID map to access a shared flag, which requires the ID map to be executable and writable at the same time, which is another thing we'd prefer to avoid. So let's switch to an approach where we replace the kernel mapping with a minimal mapping of a few pages that can be used for a minimal, ad-hoc fixmap that we can use to map each page table in turn as we traverse the hierarchy. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220609174320.4035379-3-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-06-23arm64: kpti-ng: simplify page table traversal logicArd Biesheuvel
Simplify the KPTI G-to-nG asm helper code by: - pulling the 'table bit' test into the get/put macros so we can combine them and incorporate the entire loop; - moving the 'table bit' test after the update of bit #11 so we no longer need separate next_xxx and skip_xxx labels; - redefining the pmd/pud register aliases and the next_pmd/next_pud labels instead of branching to them if the number of configured page table levels is less than 3 or 4, respectively. No functional change intended, except for the fact that we now descend into a next level table after setting bit #11 on its descriptor but this should make no difference in practice. While at it, switch to .L prefixed local labels so they don't clutter up the symbol tables, kallsyms, etc, and clean up the indentation for legibility. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20220609174320.4035379-2-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-02-15arm64/mm: Consolidate TCR_EL1 fieldsAnshuman Khandual
This renames and moves SYS_TCR_EL1_TCMA1 and SYS_TCR_EL1_TCMA0 definitions into pgtable-hwdef.h thus consolidating all TCR fields in a single header. This does not cause any functional change. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/1643121513-21854-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02arm64: kasan: mte: use a constant kernel GCR_EL1 valueMark Rutland
When KASAN_HW_TAGS is selected, KASAN is enabled at boot time, and the hardware supports MTE, we'll initialize `kernel_gcr_excl` with a value dependent on KASAN_TAG_MAX. While the resulting value is a constant which depends on KASAN_TAG_MAX, we have to perform some runtime work to generate the value, and have to read the value from memory during the exception entry path. It would be better if we could generate this as a constant at compile-time, and use it as such directly. Early in boot within __cpu_setup(), we initialize GCR_EL1 to a safe value, and later override this with the value required by KASAN. If CONFIG_KASAN_HW_TAGS is not selected, or if KASAN is disabeld at boot time, the kernel will not use IRG instructions, and so the initial value of GCR_EL1 is does not matter to the kernel. Thus, we can instead have __cpu_setup() initialize GCR_EL1 to a value consistent with KASAN_TAG_MAX, and avoid the need to re-initialize it during hotplug and resume form suspend. This patch makes arem64 use a compile-time constant KERNEL_GCR_EL1 value, which is compatible with KASAN_HW_TAGS when this is selected. This removes the need to re-initialize GCR_EL1 dynamically, and acts as an optimization to the entry assembly, which no longer needs to load this value from memory. The redundant initialization hooks are removed. In order to do this, KASAN_TAG_MAX needs to be visible outside of the core KASAN code. To do this, I've moved the KASAN_TAG_* values into <linux/kasan-tags.h>. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20210714143843.56537-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-06-24Merge branch 'for-next/mte' into for-next/coreWill Deacon
KASAN optimisations for the hardware tagging (MTE) implementation. * for-next/mte: kasan: disable freed user page poisoning with HW tags arm64: mte: handle tags zeroing at page allocation time kasan: use separate (un)poison implementation for integrated init mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable() kasan: speed up mte_set_mem_tag_range
2021-06-24Merge branch 'for-next/mm' into for-next/coreWill Deacon
Lots of cleanup to our various page-table definitions, but also some non-critical fixes and removal of some unnecessary memory types. The most interesting change here is the reduction of ARCH_DMA_MINALIGN back to 64 bytes, since we're not aware of any machines that need a higher value with the way the code is structured (only needed for non-coherent DMA). * for-next/mm: arm64: tlb: fix the TTL value of tlb_get_level arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS arm64: head: fix code comments in set_cpu_boot_mode_flag arm64: mm: drop unused __pa(__idmap_text_start) arm64: mm: fix the count comments in compute_indices arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan arm64: mm: Pass original fault address to handle_mm_fault() arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK] arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT arm64/mm: Drop SWAPPER_INIT_MAP_SIZE arm64: mm: decode xFSC in mem_abort_decode() arm64: mm: Add is_el1_data_abort() helper arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES) arm64: mm: Remove unused support for Normal-WT memory type arm64: acpi: Map EFI_MEMORY_WT memory as Normal-NC arm64: mm: Remove unused support for Device-GRE memory type arm64: mm: Use better bitmap_zalloc() arm64/mm: Make vmemmap_free() available only with CONFIG_MEMORY_HOTPLUG arm64/mm: Remove [PUD|PMD]_TABLE_BIT from [pud|pmd]_bad() arm64/mm: Validate CONFIG_PGTABLE_LEVELS
2021-06-04arm64: mte: handle tags zeroing at page allocation timePeter Collingbourne
Currently, on an anonymous page fault, the kernel allocates a zeroed page and maps it in user space. If the mapping is tagged (PROT_MTE), set_pte_at() additionally clears the tags. It is, however, more efficient to clear the tags at the same time as zeroing the data on allocation. To avoid clearing the tags on any page (which may not be mapped as tagged), only do this if the vma flags contain VM_MTE. This requires introducing a new GFP flag that is used to determine whether to clear the tags. The DC GZVA instruction with a 0 top byte (and 0 tag) requires top-byte-ignore. Set the TCR_EL1.{TBI1,TBID1} bits irrespective of whether KASAN_HW is enabled. Signed-off-by: Peter Collingbourne <pcc@google.com> Co-developed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://linux-review.googlesource.com/id/Id46dc94e30fe11474f7e54f5d65e7658dbdddb26 Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20210602235230.3928842-4-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: mm: Remove unused support for Normal-WT memory typeWill Deacon
The Normal-WT memory type is unused, so remove it and reclaim a MAIR. Cc: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210527110319.22157-4-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01arm64: mm: Remove unused support for Device-GRE memory typeWill Deacon
The Device-GRE memory type is unused, so remove it and reclaim a MAIR. Cc: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210505180228.GA3874@arm.com Link: https://lore.kernel.org/r/20210527110319.22157-2-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26arm64: assembler: add set_this_cpu_offsetMark Rutland
There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210520115031.18509-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-10arm64: mte: initialize RGSR_EL1.SEED in __cpu_setupPeter Collingbourne
A valid implementation choice for the ChooseRandomNonExcludedTag() pseudocode function used by IRG is to behave in the same way as with GCR_EL1.RRND=0. This would mean that RGSR_EL1.SEED is used as an LFSR which must have a non-zero value in order for IRG to properly produce pseudorandom numbers. However, RGSR_EL1 is reset to an UNKNOWN value on soft reset and thus may reset to 0. Therefore we must initialize RGSR_EL1.SEED to a non-zero value in order to ensure that IRG behaves as expected. Signed-off-by: Peter Collingbourne <pcc@google.com> Fixes: 3b714d24ef17 ("arm64: mte: CPU feature detection and initial sysreg configuration") Cc: <stable@vger.kernel.org> # 5.10 Link: https://linux-review.googlesource.com/id/I2b089b6c7d6f17ee37e2f0db7df5ad5bcc04526c Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210507185905.1745402-1-pcc@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-28arm64: setup: name `tcr` registerMark Rutland
In __cpu_setup we conditionally manipulate the TCR_EL1 value in x10 after previously using x10 as a scratch register for unrelated temporary variables. To make this a bit clearer, let's move the TCR_EL1 value into a named register `tcr`. To simplify the register allocation, this is placed in the highest available caller-saved scratch register, tcr. Following the example of `mair`, we initialise the register with the default value prior to any feature discovery, and write it to MAIR_EL1 after all feature discovery is complete, which allows us to simplify the featuere discovery code. The existing `mte_tcr` register is no longer needed, and is replaced by the use of x10 as a temporary, matching the rest of the MTE feature discovery assembly in __cpu_setup. As x20 is no longer used, the function is now AAPCS compliant, as we've generally aimed for in our assembly functions. There should be no functional change as as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210326180137.43119-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-28arm64: setup: name `mair` registerMark Rutland
In __cpu_setup we conditionally manipulate the MAIR_EL1 value in x5 before later reusing x5 as a scratch register for unrelated temporary variables. To make this a bit clearer, let's move the MAIR_EL1 value into a named register `mair`. To simplify the register allocation, this is placed in the highest available caller-saved scratch register, x17. As it is no longer clobbered by other usage, we can write the value to MAIR_EL1 at the end of the function as we do for TCR_EL1 rather than part-way though feature discovery. There should be no functional change as as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210326180137.43119-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-02-08arm64: Turn the MMU-on sequence into a macroMarc Zyngier
Turning the MMU on is a popular sport in the arm64 kernel, and we do it more than once, or even twice. As we are about to add even more, let's turn it into a macro. No expected functional change. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Brazdil <dbrazdil@google.com> Link: https://lore.kernel.org/r/20210208095732.3267263-4-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-02-08arm64: Fix outdated TCR setup commentMarc Zyngier
The arm64 kernel has long be able to use more than 39bit VAs. Since day one, actually. Let's rewrite the offending comment. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Brazdil <dbrazdil@google.com> Link: https://lore.kernel.org/r/20210208095732.3267263-3-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-01-05arm64: kasan: Set TCR_EL1.TBID1 when KASAN_HW_TAGS is enabledCatalin Marinas
Commit 49b3cf035edc ("kasan: arm64: set TCR_EL1.TBID1 when enabled") set the TBID1 bit for the KASAN_SW_TAGS configuration, freeing up 8 bits to be used by PAC. With in-kernel MTE now in mainline, also set this bit for the KASAN_HW_TAGS configuration. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Collingbourne <pcc@google.com> Acked-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Andrey Konovalov <andreyknvl@google.com>
2020-12-22arm64: kasan: allow enabling in-kernel MTEVincenzo Frascino
Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) feature and requires it to be enabled. MTE supports This patch adds a new mte_enable_kernel() helper, that enables MTE in Synchronous mode in EL1 and is intended to be called from KASAN runtime during initialization. The Tag Checking operation causes a synchronous data abort as a consequence of a tag check fault when MTE is configured in synchronous mode. As part of this change enable match-all tag for EL1 to allow the kernel to access user pages without faulting. This is required because the kernel does not have knowledge of the tags set by the user in a page. Note: For MTE, the TCF bit field in SCTLR_EL1 affects only EL1 in a similar way as TCF0 affects EL0. MTE that is built on top of the Top Byte Ignore (TBI) feature hence we enable it as part of this patch as well. Link: https://lkml.kernel.org/r/7352b0a0899af65c2785416c8ca6bf3845b66fa1.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Co-developed-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-09Merge branch 'for-next/misc' into for-next/coreCatalin Marinas
* for-next/misc: : Miscellaneous patches arm64: vmlinux.lds.S: Drop redundant *.init.rodata.* kasan: arm64: set TCR_EL1.TBID1 when enabled arm64: mte: optimize asynchronous tag check fault flag check arm64/mm: add fallback option to allocate virtually contiguous memory arm64/smp: Drop the macro S(x,s) arm64: consistently use reserved_pg_dir arm64: kprobes: Remove redundant kprobe_step_ctx # Conflicts: # arch/arm64/kernel/vmlinux.lds.S
2020-12-02arm64: head.S: cleanup SCTLR_ELx initializationMark Rutland
Let's make SCTLR_ELx initialization a bit clearer by using meaningful names for the initialization values, following the same scheme for SCTLR_EL1 and SCTLR_EL2. These definitions will be used more widely in subsequent patches. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201113124937.20574-5-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-25kasan: arm64: set TCR_EL1.TBID1 when enabledPeter Collingbourne
On hardware supporting pointer authentication, we previously ended up enabling TBI on instruction accesses when tag-based ASAN was enabled, but this was costing us 8 bits of PAC entropy, which was unnecessary since tag-based ASAN does not require TBI on instruction accesses. Get them back by setting TCR_EL1.TBID1. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Link: https://linux-review.googlesource.com/id/I3dded7824be2e70ea64df0aabab9598d5aebfcc4 Link: https://lore.kernel.org/r/20f64e26fc8a1309caa446fffcb1b4e2fe9e229f.1605952129.git.pcc@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>