#
c888b7bd |
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30-Jan-2023 |
Mark Rutland <mark.rutland@arm.com> |
arm64: rename ARM64_HAS_IRQ_PRIO_MASKING to ARM64_HAS_GIC_PRIO_MASKING Subsequent patches will add more GIC-related cpucaps. When we do so, it would be nice to give them a consistent HAS_GIC_* prefix. In preparation for doing so, this patch renames the existing ARM64_HAS_IRQ_PRIO_MASKING cap to ARM64_HAS_GIC_PRIO_MASKING. The cpucaps file was hand-modified; all other changes were scripted with: find . -type f -name '*.[chS]' -print0 | \ xargs -0 sed -i 's/ARM64_HAS_IRQ_PRIO_MASKING/ARM64_HAS_GIC_PRIO_MASKING/' There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230130145429.903791-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
e30e8d46 |
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02-Aug-2021 |
Mark Rutland <mark.rutland@arm.com> |
arm64: fix compat syscall return truncation Due to inconsistencies in the way we manipulate compat GPRs, we have a few issues today: * For audit and tracing, where error codes are handled as a (native) long, negative error codes are expected to be sign-extended to the native 64-bits, or they may fail to be matched correctly. Thus a syscall which fails with an error may erroneously be identified as failing. * For ptrace, *all* compat return values should be sign-extended for consistency with 32-bit arm, but we currently only do this for negative return codes. * As we may transiently set the upper 32 bits of some compat GPRs while in the kernel, these can be sampled by perf, which is somewhat confusing. This means that where a syscall returns a pointer above 2G, this will be sign-extended, but will not be mistaken for an error as error codes are constrained to the inclusive range [-4096, -1] where no user pointer can exist. To fix all of these, we must consistently use helpers to get/set the compat GPRs, ensuring that we never write the upper 32 bits of the return code, and always sign-extend when reading the return code. This patch does so, with the following changes: * We re-organise syscall_get_return_value() to always sign-extend for compat tasks, and reimplement syscall_get_error() atop. We update syscall_trace_exit() to use syscall_get_return_value(). * We consistently use syscall_set_return_value() to set the return value, ensureing the upper 32 bits are never set unexpectedly. * As the core audit code currently uses regs_return_value() rather than syscall_get_return_value(), we special-case this for compat_user_mode(regs) such that this will do the right thing. Going forward, we should try to move the core audit code over to syscall_get_return_value(). Cc: <stable@vger.kernel.org> Reported-by: He Zhe <zhe.he@windriver.com> Reported-by: weiyuchen <weiyuchen3@huawei.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
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#
3d2403fd |
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02-Dec-2020 |
Mark Rutland <mark.rutland@arm.com> |
arm64: uaccess: remove set_fs() Now that the uaccess primitives dont take addr_limit into account, we have no need to manipulate this via set_fs() and get_fs(). Remove support for these, along with some infrastructure this renders redundant. We no longer need to flip UAO to access kernel memory under KERNEL_DS, and head.S unconditionally clears UAO for all kernel configurations via an ERET in init_kernel_el. Thus, we don't need to dynamically flip UAO, nor do we need to context-switch it. However, we still need to adjust PAN during SDEI entry. Masking of __user pointers no longer needs to use the dynamic value of addr_limit, and can use a constant derived from the maximum possible userspace task size. A new TASK_SIZE_MAX constant is introduced for this, which is also used by core code. In configurations supporting 52-bit VAs, this may include a region of unusable VA space above a 48-bit TTBR0 limit, but never includes any portion of TTBR1. Note that TASK_SIZE_MAX is an exclusive limit, while USER_DS and KERNEL_DS were inclusive limits, and is converted to a mask by subtracting one. As the SDEI entry code repurposes the otherwise unnecessary pt_regs::orig_addr_limit field to store the TTBR1 of the interrupted context, for now we rename that to pt_regs::sdei_ttbr1. In future we can consider factoring that out. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: James Morse <james.morse@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201202131558.39270-10-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
d87a8e65 |
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12-Nov-2020 |
Mark Rutland <mark.rutland@arm.com> |
arm64: head.S: always initialize PSTATE As with SCTLR_ELx and other control registers, some PSTATE bits are UNKNOWN out-of-reset, and we may not be able to rely on hardware or firmware to initialize them to our liking prior to entry to the kernel, e.g. in the primary/secondary boot paths and return from idle/suspend. It would be more robust (and easier to reason about) if we consistently initialized PSTATE to a default value, as we do with control registers. This will ensure that the kernel is not adversely affected by bits it is not aware of, e.g. when support for a feature such as PAN/UAO is disabled. This patch ensures that PSTATE is consistently initialized at boot time via an ERET. This is not intended to relax the existing requirements (e.g. DAIF bits must still be set prior to entering the kernel). For features detected dynamically (which may require system-wide support), it is still necessary to subsequently modify PSTATE. As ERET is not always a Context Synchronization Event, an ISB is placed before each exception return to ensure updates to control registers have taken effect. This handles the kernel being entered with SCTLR_ELx.EOS clear (or any future control bits being in an UNKNOWN state). 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/20201113124937.20574-6-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
1ec2f2c0 |
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30-Nov-2020 |
Mark Rutland <mark.rutland@arm.com> |
arm64: ptrace: prepare for EL1 irq/rcu tracking Exceptions from EL1 may be taken when RCU isn't watching (e.g. in idle sequences), or when the lockdep hardirqs transiently out-of-sync with the hardware state (e.g. in the middle of local_irq_enable()). To correctly handle these cases, we'll need to save/restore this state across some exceptions taken from EL1. A series of subsequent patches will update EL1 exception handlers to handle this. In preparation for this, and to avoid dependencies between those patches, this patch adds two new fields to struct pt_regs so that exception handlers can track this state. Note that this is placed in pt_regs as some entry/exit sequences such as el1_irq are invoked from assembly, which makes it very difficult to add a separate structure as with the irqentry_state used by x86. We can separate this once more of the exception logic is moved to C. While the fields only need to be bool, they are both made u64 to keep pt_regs 16-byte aligned. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201130115950.22492-9-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
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#
33678059 |
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12-Sep-2020 |
Alexandru Elisei <alexandru.elisei@arm.com> |
irqchip/gic-v3: Support pseudo-NMIs when SCR_EL3.FIQ == 0 The GIC's internal view of the priority mask register and the assigned interrupt priorities are based on whether GIC security is enabled and whether firmware routes Group 0 interrupts to EL3. At the moment, we support priority masking when ICC_PMR_EL1 and interrupt priorities are either both modified by the GIC, or both left unchanged. Trusted Firmware-A's default interrupt routing model allows Group 0 interrupts to be delivered to the non-secure world (SCR_EL3.FIQ == 0). Unfortunately, this is precisely the case that the GIC driver doesn't support: ICC_PMR_EL1 remains unchanged, but the GIC's view of interrupt priorities is different from the software programmed values. Support pseudo-NMIs when SCR_EL3.FIQ == 0 by using a different value to mask regular interrupts. All the other values remain the same. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200912153707.667731-3-alexandru.elisei@arm.com
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#
c4b5abba |
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25-Jul-2020 |
Randy Dunlap <rdunlap@infradead.org> |
arm64: ptrace.h: delete duplicated word Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20200726003207.20253-3-rdunlap@infradead.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
d9d7d84d |
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21-Apr-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Parametrize exception entry with a target EL We currently assume that an exception is delivered to EL1, always. Once we emulate EL2, this no longer will be the case. To prepare for this, add a target_mode parameter. While we're at it, merge the computing of the target PC and PSTATE in a single function that updates both PC and CPSR after saving their previous values in the corresponding ELR/SPSR. This ensures that they are updated in the correct order (a pretty common source of bugs...). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
8ef8f360 |
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16-Mar-2020 |
Dave Martin <Dave.Martin@arm.com> |
arm64: Basic Branch Target Identification support This patch adds the bare minimum required to expose the ARMv8.5 Branch Target Identification feature to userspace. By itself, this does _not_ automatically enable BTI for any initial executable pages mapped by execve(). This will come later, but for now it should be possible to enable BTI manually on those pages by using mprotect() from within the target process. Other arches already using the generic mman.h are already using 0x10 for arch-specific prot flags, so we use that for PROT_BTI here. For consistency, signal handler entry points in BTI guarded pages are required to be annotated as such, just like any other function. This blocks a relatively minor attack vector, but comforming userspace will have the annotations anyway, so we may as well enforce them. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
3c2483f1 |
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08-Jan-2020 |
Mark Rutland <mark.rutland@arm.com> |
KVM: arm/arm64: Correct CPSR on exception entry When KVM injects an exception into a guest, it generates the CPSR value from scratch, configuring CPSR.{M,A,I,T,E}, and setting all other bits to zero. This isn't correct, as the architecture specifies that some CPSR bits are (conditionally) cleared or set upon an exception, and others are unchanged from the original context. This patch adds logic to match the architectural behaviour. To make this simple to follow/audit/extend, documentation references are provided, and bits are configured in order of their layout in SPSR_EL2. This layout can be seen in the diagram on ARM DDI 0487E.a page C5-426. Note that this code is used by both arm and arm64, and is intended to fuction with the SPSR_EL2 and SPSR_HYP layouts. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200108134324.46500-3-mark.rutland@arm.com
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#
42d038c4 |
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06-Aug-2019 |
Leo Yan <leo.yan@linaro.org> |
arm64: Add support for function error injection Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"), this patch supports function error injection for Arm64. This patch mainly support two functions: one is regs_set_return_value() which is used to overwrite the return value; the another function is override_function_with_return() which is to override the probed function returning and jump to its caller. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
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#
677379bc |
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29-Jul-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: Lower priority mask for GIC_PRIO_IRQON On a system with two security states, if SCR_EL3.FIQ is cleared, non-secure IRQ priorities get shifted to fit the secure view but priority masks aren't. On such system, it turns out that GIC_PRIO_IRQON masks the priority of normal interrupts, which obviously ends up in a hang. Increase GIC_PRIO_IRQON value (i.e. lower priority) to make sure interrupts are not blocked by it. Cc: Oleg Nesterov <oleg@redhat.com> Fixes: bd82d4bd21880b7c ("arm64: Fix incorrect irqflag restore for priority masking") Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Thierry <julien.thierry.kdev@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [will: fixed Fixes: tag] Signed-off-by: Will Deacon <will@kernel.org>
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#
56a5d003 |
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23-Jun-2019 |
Christoph Hellwig <hch@lst.de> |
arm64: don't use asm-generic/ptrace.h Doing the indirection through macros for the regs accessors just makes them harder to read, so implement the helpers directly. Note that only the helpers actually used are implemented now. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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#
bd82d4bd |
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11-Jun-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: Fix incorrect irqflag restore for priority masking When using IRQ priority masking to disable interrupts, in order to deal with the PSR.I state, local_irq_save() would convert the I bit into a PMR value (GIC_PRIO_IRQOFF). This resulted in local_irq_restore() potentially modifying the value of PMR in undesired location due to the state of PSR.I upon flag saving [1]. In an attempt to solve this issue in a less hackish manner, introduce a bit (GIC_PRIO_IGNORE_PMR) for the PMR values that can represent whether PSR.I is being used to disable interrupts, in which case it takes precedence of the status of interrupt masking via PMR. GIC_PRIO_PSR_I_SET is chosen such that (<pmr_value> | GIC_PRIO_PSR_I_SET) does not mask more interrupts than <pmr_value> as some sections (e.g. arch_cpu_idle(), interrupt acknowledge path) requires PMR not to mask interrupts that could be signaled to the CPU when using only PSR.I. [1] https://www.spinics.net/lists/arm-kernel/msg716956.html Fixes: 4a503217ce37 ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking") Cc: <stable@vger.kernel.org> # 5.1.x- Reported-by: Zenghui Yu <yuzenghui@huawei.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Li <liwei391@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Pouloze <suzuki.poulose@arm.com> Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
caab277b |
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02-Jun-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 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 distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a823c35f |
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12-Apr-2019 |
Masami Hiramatsu <mhiramat@kernel.org> |
arm64: ptrace: Add function argument access API Add regs_get_argument() which returns N th argument of the function call. On arm64, it supports up to 8th argument. Note that this chooses most probably assignment, in some case it can be incorrect (e.g. passing data structure or floating point etc.) This enables ftrace kprobe events to access kernel function arguments via $argN syntax. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [will: tidied up the comment a bit] Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
133d0518 |
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31-Jan-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: Make PMR part of task context In order to replace PSR.I interrupt disabling/enabling with ICC_PMR_EL1 interrupt masking, ICC_PMR_EL1 needs to be saved/restored when taking/returning from an exception. This mimics the way hardware saves and restores PSR.I bit in spsr_el1 for exceptions and ERET. Add PMR to the registers to save in the pt_regs struct upon kernel entry, and restore it before ERET. Also, initialize it to a sane value when creating new tasks. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
cdbc81dd |
|
31-Jan-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: ptrace: Provide definitions for PMR values Introduce fixed values for PMR that are going to be used to mask and unmask interrupts by priority. The current priority given to GIC interrupts is 0xa0, so clearing PMR's most significant bit is enough to mask interrupts. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
e4e11cc0 |
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17-Oct-2018 |
Christoffer Dall <christoffer.dall@arm.com> |
KVM: arm64: Safety check PSTATE when entering guest and handle IL This commit adds a paranoid check when entering the guest to make sure we don't attempt running guest code in an equally or more privilged mode than the hypervisor. We also catch other accidental programming of the SPSR_EL2 which results in an illegal exception return and report this safely back to the user. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
8f04e8e6 |
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07-Aug-2018 |
Will Deacon <will@kernel.org> |
arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3 On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD state without needing to call into firmware. This patch hooks into the existing SSBD infrastructure so that SSBS is used on CPUs that support it, but it's all made horribly complicated by the very real possibility of big/little systems that don't uniformly provide the new capability. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
7373fed2 |
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05-Jul-2018 |
Mark Rutland <mark.rutland@arm.com> |
arm64: remove unused COMPAT_PSR definitions Now that users have been migrated to PSR_AA32, kill the unused COMPAT_PSR definitions. The only difference we need a definition for is COMPAT_PSR_DIT_BIT, which differs from PSR_AA32_DIT_BIT. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
d64567f6 |
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05-Jul-2018 |
Mark Rutland <mark.rutland@arm.com> |
arm64: use PSR_AA32 definitions Some code cares about the SPSR_ELx format for exceptions taken from AArch32 to inspect or manipulate the SPSR_ELx value, which is already in the SPSR_ELx format, and not in the AArch32 PSR format. To separate these from cases where we care about the AArch32 PSR format, migrate these cases to use the PSR_AA32_* definitions rather than COMPAT_PSR_*. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
25086263 |
|
05-Jul-2018 |
Mark Rutland <mark.rutland@arm.com> |
arm64: add PSR_AA32_* definitions The AArch32 CPSR/SPSR format is *almost* identical to the AArch64 SPSR_ELx format for exceptions taken from AArch32, but the two have diverged with the addition of DIT, and we need to treat the two as logically distinct. This patch adds new definitions for the SPSR_ELx format for exceptions taken from AArch32, with a consistent PSR_AA32_ prefix. The existing COMPAT_PSR_ definitions will be used for the PSR format as seen from AArch32. Definitions of DIT are provided for both, and inline functions are provided to map between the two formats. Note that for SPSR_ELx, the (RES0) J bit has been re-allocated as the DIT bit. Once users of the COMPAT_PSR definitions have been migrated over to the PSR_AA32 definitions, the (majority of) the former will be removed, so no efforts is made to avoid duplication until then. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
73267498 |
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22-Jul-2017 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: unwind: reference pt_regs via embedded stack frame As it turns out, the unwind code is slightly broken, and probably has been for a while. The problem is in the dumping of the exception stack, which is intended to dump the contents of the pt_regs struct at each level in the call stack where an exception was taken and routed to a routine marked as __exception (which means its stack frame is right below the pt_regs struct on the stack). 'Right below the pt_regs struct' is ill defined, though: the unwind code assigns 'frame pointer + 0x10' to the .sp member of the stackframe struct at each level, and dump_backtrace() happily dereferences that as the pt_regs pointer when encountering an __exception routine. However, the actual size of the stack frame created by this routine (which could be one of many __exception routines we have in the kernel) is not known, and so frame.sp is pretty useless to figure out where struct pt_regs really is. So it seems the only way to ensure that we can find our struct pt_regs when walking the stack frames is to put it at a known fixed offset of the stack frame pointer that is passed to such __exception routines. The simplest way to do that is to put it inside pt_regs itself, which is the main change implemented by this patch. As a bonus, doing this allows us to get rid of a fair amount of cruft related to walking from one stack to the other, which is especially nice since we intend to introduce yet another stack for overflow handling once we add support for vmapped stacks. It also fixes an inconsistency where we only add a stack frame pointing to ELR_EL1 if we are executing from the IRQ stack but not when we are executing from the task stack. To consistly identify exceptions regs even in the presence of exceptions taken from entry code, we must check whether the next frame was created by entry text, rather than whether the current frame was crated by exception text. To avoid backtracing using PCs that fall in the idmap, or are controlled by userspace, we must explcitly zero the FP and LR in startup paths, and must ensure that the frame embedded in pt_regs is zeroed upon entry from EL0. To avoid these NULL entries showin in the backtrace, unwind_frame() is updated to avoid them. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [Mark: compare current frame against .entry.text, avoid bogus PCs] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will.deacon@arm.com>
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#
17c28958 |
|
01-Aug-2017 |
Dave Martin <Dave.Martin@arm.com> |
arm64: Abstract syscallno manipulation The -1 "no syscall" value is written in various ways, shared with the user ABI in some places, and generally obscure. This patch attempts to make things a little more consistent and readable by replacing all these uses with a single #define. A couple of symbolic helpers are provided to clarify the intent further. Because the in-syscall check in do_signal() is changed from >= 0 to != NO_SYSCALL by this patch, different behaviour may be observable if syscallno is set to values less than -1 by a tracer. However, this is not different from the behaviour that is already observable if a tracer sets syscallno to a value >= __NR_(compat_)syscalls. It appears that this can cause spurious syscall restarting, but that is not a new behaviour either, and does not appear harmful. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
35d0e6fb |
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01-Aug-2017 |
Dave Martin <Dave.Martin@arm.com> |
arm64: syscallno is secretly an int, make it official The upper 32 bits of the syscallno field in thread_struct are handled inconsistently, being sometimes zero extended and sometimes sign-extended. In fact, only the lower 32 bits seem to have any real significance for the behaviour of the code: it's been OK to handle the upper bits inconsistently because they don't matter. Currently, the only place I can find where those bits are significant is in calling trace_sys_enter(), which may be unintentional: for example, if a compat tracer attempts to cancel a syscall by passing -1 to (COMPAT_)PTRACE_SET_SYSCALL at the syscall-enter-stop, it will be traced as syscall 4294967295 rather than -1 as might be expected (and as occurs for a native tracer doing the same thing). Elsewhere, reads of syscallno cast it to an int or truncate it. There's also a conspicuous amount of code and casting to bodge around the fact that although semantically an int, syscallno is stored as a u64. Let's not pretend any more. In order to preserve the stp x instruction that stores the syscall number in entry.S, this patch special-cases the layout of struct pt_regs for big endian so that the newly 32-bit syscallno field maps onto the low bits of the stored value. This is not beautiful, but benchmarking of the getpid syscall on Juno suggests indicates a minor slowdown if the stp is split into an stp x and stp w. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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6c23e2ff |
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09-Feb-2017 |
Mark Rutland <mark.rutland@arm.com> |
arm64: ptrace: add XZR-safe regs accessors In A64, XZR and the SP share the same encoding (31), and whether an instruction accesses XZR or SP for a particular register parameter depends on the definition of the instruction. We store the SP in pt_regs::regs[31], and thus when emulating instructions, we must be careful to not erroneously read from or write back to the saved SP. Unfortunately, we often fail to be this careful. In all cases, instructions using a transfer register parameter Xt use this to refer to XZR rather than SP. This patch adds helpers so that we can more easily and consistently handle these cases. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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9842ceae |
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02-Nov-2016 |
Pratyush Anand <panand@redhat.com> |
arm64: Add uprobe support This patch adds support for uprobe on ARM64 architecture. Unit tests for following have been done so far and they have been found working 1. Step-able instructions, like sub, ldr, add etc. 2. Simulation-able like ret, cbnz, cbz etc. 3. uretprobe 4. Reject-able instructions like sev, wfe etc. 5. trapped and abort xol path 6. probe at unaligned user address. 7. longjump test cases Currently it does not support aarch32 instruction probing. Signed-off-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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fd6380b7 |
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27-Jul-2016 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype Commit 0a8ea52c3eb1 ("arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature") inadvertently removed the arch/arm prototype instead of the arm64 one introduced by the original patch. There should not be any bisection issues since this function is not called from anywhere else (it could as well be removed from arch/arm at some point). Fixes: 0a8ea52c3eb1 ("arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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9df53ff2 |
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18-Jul-2016 |
Vladimir Murzin <vladimir.murzin@arm.com> |
arm64: ptrace: remove extra define for CPSR's E bit ...and do not confuse source navigation tools ;) Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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2dd0e8d2 |
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07-Jul-2016 |
Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com> |
arm64: Kprobes with single stepping support Add support for basic kernel probes(kprobes) and jump probes (jprobes) for ARM64. Kprobes utilizes software breakpoint and single step debug exceptions supported on ARM v8. A software breakpoint is placed at the probe address to trap the kernel execution into the kprobe handler. ARM v8 supports enabling single stepping before the break exception return (ERET), with next PC in exception return address (ELR_EL1). The kprobe handler prepares an executable memory slot for out-of-line execution with a copy of the original instruction being probed, and enables single stepping. The PC is set to the out-of-line slot address before the ERET. With this scheme, the instruction is executed with the exact same register context except for the PC (and DAIF) registers. Debug mask (PSTATE.D) is enabled only when single stepping a recursive kprobe, e.g.: during kprobes reenter so that probed instruction can be single stepped within the kprobe handler -exception- context. The recursion depth of kprobe is always 2, i.e. upon probe re-entry, any further re-entry is prevented by not calling handlers and the case counted as a missed kprobe). Single stepping from the x-o-l slot has a drawback for PC-relative accesses like branching and symbolic literals access as the offset from the new PC (slot address) may not be ensured to fit in the immediate value of the opcode. Such instructions need simulation, so reject probing them. Instructions generating exceptions or cpu mode change are rejected for probing. Exclusive load/store instructions are rejected too. Additionally, the code is checked to see if it is inside an exclusive load/store sequence (code from Pratyush). System instructions are mostly enabled for stepping, except MSR/MRS accesses to "DAIF" flags in PSTATE, which are not safe for probing. This also changes arch/arm64/include/asm/ptrace.h to use include/asm-generic/ptrace.h. Thanks to Steve Capper and Pratyush Anand for several suggested Changes. Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Pratyush Anand <panand@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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0a8ea52c |
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07-Jul-2016 |
David A. Long <dave.long@linaro.org> |
arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64, including supporting functions and defines. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> [catalin.marinas@arm.com: Remove unused functions] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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e19a6ee2 |
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20-Jun-2016 |
James Morse <james.morse@arm.com> |
arm64: kernel: Save and restore UAO and addr_limit on exception entry If we take an exception while at EL1, the exception handler inherits the original context's addr_limit and PSTATE.UAO values. To be consistent always reset addr_limit and PSTATE.UAO on (re-)entry to EL1. This prevents accidental re-use of the original context's addr_limit. Based on a similar patch for arm from Russell King. Cc: <stable@vger.kernel.org> # 4.6- Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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dbd4d7ca |
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01-Mar-2016 |
Mark Rutland <mark.rutland@arm.com> |
arm64: Rework valid_user_regs We validate pstate using PSR_MODE32_BIT, which is part of the user-provided pstate (and cannot be trusted). Also, we conflate validation of AArch32 and AArch64 pstate values, making the code difficult to reason about. Instead, validate the pstate value based on the associated task. The task may or may not be current (e.g. when using ptrace), so this must be passed explicitly by callers. To avoid circular header dependencies via sched.h, is_compat_task is pulled out of asm/ptrace.h. To make the code possible to reason about, the AArch64 and AArch32 validation is split into separate functions. Software must respect the RES0 policy for SPSR bits, and thus the kernel mirrors the hardware policy (RAZ/WI) for bits as-yet unallocated. When these acquire an architected meaning writes may be permitted (potentially with additional validation). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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5accd17d |
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22-Oct-2015 |
Robin Murphy <robin.murphy@arm.com> |
arm64: Fix compat register mappings For reasons not entirely apparent, but now enshrined in history, the architectural mapping of AArch32 banked registers to AArch64 registers actually orders SP_<mode> and LR_<mode> backwards compared to the intuitive r13/r14 order, for all modes except FIQ. Fix the compat_<reg>_<mode> macros accordingly, in the hope of avoiding subtle bugs with KVM and AArch32 guests. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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4b3dc967 |
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29-May-2015 |
Will Deacon <will@kernel.org> |
arm64: force CONFIG_SMP=y and remove redundant #ifdefs Nobody seems to be producing !SMP systems anymore, so this is just becoming a source of kernel bugs, particularly if people want to use coherent DMA with non-shared pages. This patch forces CONFIG_SMP=y for arm64, removing a modest amount of code in the process. Signed-off-by: Will Deacon <will.deacon@arm.com>
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2d888f48 |
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20-Jan-2015 |
Suzuki K. Poulose <suzuki.poulose@arm.com> |
arm64: Emulate SETEND for AArch32 tasks Emulate deprecated 'setend' instruction for AArch32 bit tasks. setend [le/be] - Sets the endianness of EL0 On systems with CPUs which support mixed endian at EL0, the hardware support for the instruction can be enabled by setting the SCTLR_EL1.SED bit. Like the other emulated instructions it is controlled by an entry in /proc/sys/abi/. For more information see : Documentation/arm64/legacy_instructions.txt The instruction is emulated by setting/clearing the SPSR_EL1.E bit, which will be reflected in the PSTATE.E in AArch32 context. This patch also restores the native endianness for the execution of signal handlers, since the process could have changed the endianness. Note: All CPUs on the system must have mixed endian support at EL0. Once the handler is registered, hotplugging a CPU which doesn't support mixed endian, could lead to unexpected results/behavior in applications. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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2520d039 |
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29-Aug-2014 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Add brackets around user_stack_pointer() Commit 5f888a1d33 (ARM64: perf: support dwarf unwinding in compat mode) changes user_stack_pointer() to return the compat SP for 32-bit tasks but without brackets around the whole definition, with possible issues on the call sites (noticed with a subsequent fix for KSTK_ESP). Fixes: 5f888a1d33c4 (ARM64: perf: support dwarf unwinding in compat mode) Reported-by: Sudeep Holla <sudeep.holla@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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974c8e45 |
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06-Jun-2014 |
Marc Zyngier <maz@kernel.org> |
arm64: fix el2_setup check of CurrentEL 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>
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d34a3ebd |
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30-Apr-2014 |
AKASHI Takahiro <takahiro.akashi@linaro.org> |
arm64: Add regs_return_value() in syscall.h This macro, regs_return_value, is used mainly for audit to record system call's results, but may also be used in test_kprobes.c. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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5f888a1d |
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03-Feb-2014 |
Jean Pihet <jean.pihet@linaro.org> |
ARM64: perf: support dwarf unwinding in compat mode Add support for unwinding using the dwarf information in compat mode. Using the correct user stack pointer allows perf to record the frames correctly in the native and compat modes. Note that although the dwarf frame unwinding works ok using libunwind in native mode (on ARMv7 & ARMv8), some changes are required to the libunwind code for the compat mode. Those changes are posted separately on the libunwind mailing list. Tested on ARMv8 platform with v8 and compat v7 binaries, the latter are statically built. Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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2ee0d7fd |
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03-Feb-2014 |
Jean Pihet <jean.pihet@linaro.org> |
ARM64: perf: add support for perf registers API This patch implements the functions required for the perf registers API, allowing the perf tool to interface kernel register dumps with libunwind in order to provide userspace backtracing. Compat mode is also supported. Only the general purpose user space registers are exported, i.e.: PERF_REG_ARM_X0, ... PERF_REG_ARM_X28, PERF_REG_ARM_FP, PERF_REG_ARM_LR, PERF_REG_ARM_SP, PERF_REG_ARM_PC and not the PERF_REG_ARM_V* registers. Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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58dcc204 |
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28-Jan-2014 |
Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> |
misc: debug: remove compilation warnings typecast instruction_pointer macro to unsigned long to resolve following compiler warnings like warning: format '%lx' expects argument of type 'long unsigned int', but argument 2 has type 'u64' [-Wformat] Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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a795a38e |
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11-Oct-2013 |
Will Deacon <will@kernel.org> |
arm64: compat: add support for big-endian (BE8) AArch32 binaries This patch adds support for BE8 AArch32 tasks to the compat layer. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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1442b6ed |
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16-Mar-2013 |
Will Deacon <will@kernel.org> |
arm64: debug: consolidate software breakpoint handlers The software breakpoint handlers are hooked in directly from ptrace, which makes it difficult to add additional handlers for things like kprobes and kgdb. This patch moves the handling code into debug-monitors.c, where we can dispatch to different debug subsystems more easily. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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10a3cc2f |
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23-Jan-2013 |
Marc Zyngier <maz@kernel.org> |
arm64: add COMPAT_PSR_*_BIT flags In order to mess with the processor state when running 32bit guests, define all the AArch32 PSR flags. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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9ec218b8 |
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04-Oct-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: add AArch32 execution modes to ptrace.h Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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88483ec6 |
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03-Oct-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: expand register mapping between AArch32 and AArch64 The general purpose registers in AArch32 are mapped in an architecturally defined manner into the AArch64 registers. It allows the AArch32 registers of an application or a virtual machine to be inspected by the OS or an hypervisor. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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4262a727 |
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11-Oct-2012 |
David Howells <dhowells@redhat.com> |
UAPI: (Scripted) Disintegrate arch/arm64/include/asm Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
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7606c37d |
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10-Oct-2012 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Do not export the compat-specific definitions to the user This patch adds #ifdef __KERNEL__ guards around the COMPAT_* definitions to avoid exporting them to user. AArch32 user requiring the kernel headers must use those generated with ARCH=arm. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com>
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27aa55c5 |
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27-Sep-2012 |
Will Deacon <will@kernel.org> |
arm64: ptrace: remove obsolete ptrace request numbers from user headers The use of regsets has removed the need for many private ptrace requests, so remove the corresponding definitions from the user-visible ptrace.h Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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60ffc30d |
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05-Mar-2012 |
Catalin Marinas <catalin.marinas@arm.com> |
arm64: Exception handling The patch contains the exception entry code (kernel/entry.S), pt_regs structure and related accessors, undefined instruction trapping and stack tracing. AArch64 Linux kernel (including kernel threads) runs in EL1 mode using the SP1 stack. The vectors don't have a fixed address, only alignment (2^11) requirements. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
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