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2024-10-04kselftest/arm64: Always run signals tests with GCS enabledMark Brown
Since it is not possible to return from the function that enabled GCS without disabling GCS it is very inconvenient to use the signal handling tests to cover GCS when GCS is not enabled by the toolchain and runtime, something that no current distribution does. Since none of the testcases do anything with stacks that would cause problems with GCS we can sidestep this issue by unconditionally enabling GCS on startup and exiting with a call to exit() rather than a return from main(). Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-33-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04kselftest/arm64: Allow signals tests to specify an expected si_codeMark Brown
Currently we ignore si_code unless the expected signal is a SIGSEGV, in which case we enforce it being SEGV_ACCERR. Allow test cases to specify exactly which si_code should be generated so we can validate this, and test for other segfault codes. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-32-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04kselftest/arm64: Add framework support for GCS to signal handling testsMark Brown
Teach the framework about the GCS signal context, avoiding warnings on the unknown context. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-31-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04kselftest/arm64: Add GCS as a detected feature in the signal testsMark Brown
In preparation for testing GCS related signal handling add it as a feature we check for in the signal handling support code. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-30-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04kselftest/arm64: Verify the GCS hwcapMark Brown
Add coverage of the GCS hwcap to the hwcap selftest, using a read of GCSPR_EL0 to generate SIGILL without having to worry about enabling GCS. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Tested-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-29-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64: Add Kconfig for Guarded Control Stack (GCS)Mark Brown
Provide a Kconfig option allowing the user to select if GCS support is built into the kernel. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-28-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/ptrace: Expose GCS via ptrace and core filesMark Brown
Provide a new register type NT_ARM_GCS reporting the current GCS mode and pointer for EL0. Due to the interactions with allocation and deallocation of Guarded Control Stacks we do not permit any changes to the GCS mode via ptrace, only GCSPR_EL0 may be changed. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-27-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/signal: Expose GCS state in signal framesMark Brown
Add a context for the GCS state and include it in the signal context when running on a system that supports GCS. We reuse the same flags that the prctl() uses to specify which GCS features are enabled and also provide the current GCS pointer. We do not support enabling GCS via signal return, there is a conflict between specifying GCSPR_EL0 and allocation of a new GCS and this is not an ancticipated use case. We also enforce GCS configuration locking on signal return. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-26-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/signal: Set up and restore the GCS context for signal handlersMark Brown
When invoking a signal handler we use the GCS configuration and stack for the current thread. Since we implement signal return by calling the signal handler with a return address set up pointing to a trampoline in the vDSO we need to also configure any active GCS for this by pushing a frame for the trampoline onto the GCS. If we do not do this then signal return will generate a GCS protection fault. In order to guard against attempts to bypass GCS protections via signal return we only allow returning with GCSPR_EL0 pointing to an address where it was previously preempted by a signal. We do this by pushing a cap onto the GCS, this takes the form of an architectural GCS cap token with the top bit set and token type of 0 which we add on signal entry and validate and pop off on signal return. The combination of the top bit being set and the token type mean that this can't be interpreted as a valid token or address. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-25-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/mm: Implement map_shadow_stack()Mark Brown
As discussed extensively in the changelog for the addition of this syscall on x86 ("x86/shstk: Introduce map_shadow_stack syscall") the existing mmap() and madvise() syscalls do not map entirely well onto the security requirements for guarded control stacks since they lead to windows where memory is allocated but not yet protected or stacks which are not properly and safely initialised. Instead a new syscall map_shadow_stack() has been defined which allocates and initialises a shadow stack page. Implement this for arm64. Two flags are provided, allowing applications to request that the stack be initialised with a valid cap token at the top of the stack and optionally also an end of stack marker above that. We support requesting an end of stack marker alone but since this is a NULL pointer it is indistinguishable from not initialising anything by itself. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-24-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Implement shadow stack prctl() interfaceMark Brown
Implement the architecture neutral prctl() interface for setting the shadow stack status, this supports setting and reading the current GCS configuration for the current thread. Userspace can enable basic GCS functionality and additionally also support for GCS pushes and arbitrary GCS stores. It is expected that this prctl() will be called very early in application startup, for example by the dynamic linker, and not subsequently adjusted during normal operation. Users should carefully note that after enabling GCS for a thread GCS will become active with no call stack so it is not normally possible to return from the function that invoked the prctl(). State is stored per thread, enabling GCS for a thread causes a GCS to be allocated for that thread. Userspace may lock the current GCS configuration by specifying PR_SHADOW_STACK_ENABLE_LOCK, this prevents any further changes to the GCS configuration via any means. If GCS is not being enabled then all flags other than _LOCK are ignored, it is not possible to enable stores or pops without enabling GCS. When disabling the GCS we do not free the allocated stack, this allows for inspection of the GCS after disabling as part of fault reporting. Since it is not an expected use case and since it presents some complications in determining what to do with previously initialsed data on the GCS attempts to reenable GCS after this are rejected. This can be revisted if a use case arises. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-23-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Ensure that new threads have a GCSMark Brown
When a new thread is created by a thread with GCS enabled the GCS needs to be specified along with the regular stack. Unfortunately plain clone() is not extensible and existing clone3() users will not specify a stack so all existing code would be broken if we mandated specifying the stack explicitly. For compatibility with these cases and also x86 (which did not initially implement clone3() support for shadow stacks) if no GCS is specified we will allocate one so when a thread is created which has GCS enabled allocate one for it. We follow the extensively discussed x86 implementation and allocate min(RLIMIT_STACK/2, 2G). Since the GCS only stores the call stack and not any variables this should be more than sufficient for most applications. GCSs allocated via this mechanism will be freed when the thread exits. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-22-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Context switch GCS state for EL0Mark Brown
There are two registers controlling the GCS state of EL0, GCSPR_EL0 which is the current GCS pointer and GCSCRE0_EL1 which has enable bits for the specific GCS functionality enabled for EL0. Manage these on context switch and process lifetime events, GCS is reset on exec(). Also ensure that any changes to the GCS memory are visible to other PEs and that changes from other PEs are visible on this one by issuing a GCSB DSYNC when moving to or from a thread with GCS. Since the current GCS configuration of a thread will be visible to userspace we store the configuration in the format used with userspace and provide a helper which configures the system register as needed. On systems that support GCS we always allow access to GCSPR_EL0, this facilitates reporting of GCS faults if userspace implements disabling of GCS on error - the GCS can still be discovered and examined even if GCS has been disabled. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-21-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/mm: Handle GCS data abortsMark Brown
All GCS operations at EL0 must happen on a page which is marked as having UnprivGCS access, including read operations. If a GCS operation attempts to access a page without this then it will generate a data abort with the GCS bit set in ESR_EL1.ISS2. EL0 may validly generate such faults, for example due to copy on write which will cause the GCS data to be stored in a read only page with no GCS permissions until the actual copy happens. Since UnprivGCS allows both reads and writes to the GCS (though only through GCS operations) we need to ensure that the memory management subsystem handles GCS accesses as writes at all times. Do this by adding FAULT_FLAG_WRITE to any GCS page faults, adding handling to ensure that invalid cases are identfied as such early so the memory management core does not think they will succeed. The core cannot distinguish between VMAs which are generally writeable and VMAs which are only writeable through GCS operations. EL1 may validly write to EL0 GCS for management purposes (eg, while initialising with cap tokens). We also report any GCS faults in VMAs not marked as part of a GCS as access violations, causing a fault to be delivered to userspace if it attempts to do GCS operations outside a GCS. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-20-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/traps: Handle GCS exceptionsMark Brown
A new exception code is defined for GCS specific faults other than standard load/store faults, for example GCS token validation failures, add handling for this. These faults are reported to userspace as segfaults with code SEGV_CPERR (protection error), mirroring the reporting for x86 shadow stack errors. GCS faults due to memory load/store operations generate data aborts with a flag set, these will be handled separately as part of the data abort handling. Since we do not currently enable GCS for EL1 we should not get any faults there but while we're at it we wire things up there, treating any GCS fault as fatal. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-19-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/hwcap: Add hwcap for GCSMark Brown
Provide a hwcap to enable userspace to detect support for GCS. Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-18-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/idreg: Add overrride for GCSMark Brown
Hook up an override for GCS, allowing it to be disabled from the command line by specifying arm64.nogcs in case there are problems. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-17-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/mm: Map pages for guarded control stackMark Brown
Map pages flagged as being part of a GCS as such rather than using the full set of generic VM flags. This is done using a conditional rather than extending the size of protection_map since that would make for a very sparse array. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-15-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04mm: Define VM_SHADOW_STACK for arm64 when we support GCSMark Brown
Use VM_HIGH_ARCH_5 for guarded control stack pages. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-14-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/mm: Allocate PIE slots for EL0 guarded control stackMark Brown
Pages used for guarded control stacks need to be described to the hardware using the Permission Indirection Extension, GCS is not supported without PIE. In order to support copy on write for guarded stacks we allocate two values, one for active GCSs and one for GCS pages marked as read only prior to copy. Since the actual effect is defined using PIE the specific bit pattern used does not matter to the hardware but we choose two values which differ only in PTE_WRITE in order to help share code with non-PIE cases. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-13-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS)Mark Brown
Add a cpufeature for GCS, allowing other code to conditionally support it at runtime. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-12-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Provide basic EL2 setup to allow GCS usage at EL0 and EL1Mark Brown
There is a control HCRX_EL2.GCSEn which must be set to allow GCS features to take effect at lower ELs and also fine grained traps for GCS usage at EL0 and EL1. Configure all these to allow GCS usage by EL0 and EL1. We also initialise GCSCR_EL1 and GCSCRE0_EL1 to ensure that we can execute function call instructions without faulting regardless of the state when the kernel is started. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-11-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Provide put_user_gcs()Mark Brown
In order for EL1 to write to an EL0 GCS it must use the GCSSTTR instruction rather than a normal STTR. Provide a put_user_gcs() which does this. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-10-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Add manual encodings of GCS instructionsMark Brown
Define C callable functions for GCS instructions used by the kernel. In order to avoid ambitious toolchain requirements for GCS support these are manually encoded, this means we have fixed register numbers which will be a bit limiting for the compiler but none of these should be used in sufficiently fast paths for this to be a problem. Note that GCSSTTR is used to store to EL0. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-9-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/sysreg: Add definitions for architected GCS capsMark Brown
The architecture defines a format for guarded control stack caps, used to mark the top of an unused GCS in order to limit the potential for exploitation via stack switching. Add definitions associated with these. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-8-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/gcs: Document the ABI for Guarded Control StacksMark Brown
Add some documentation of the userspace ABI for Guarded Control Stacks. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-7-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64: Document boot requirements for Guarded Control StacksMark Brown
FEAT_GCS introduces a number of new system registers, we require that access to these registers is not trapped when we identify that the feature is present. There is also a HCRX_EL2 control to make GCS operations functional. Since if GCS is enabled any function call instruction will cause a fault we also require that the feature be specifically disabled, existing kernels implicitly have this requirement and especially given that the MMU must be disabled it is difficult to see a situation where leaving GCS enabled would be reasonable. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-6-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04mman: Add map_shadow_stack() flagsMark Brown
In preparation for adding arm64 GCS support make the map_shadow_stack() SHADOW_STACK_SET_TOKEN flag generic and add _SET_MARKER. The existing flag indicates that a token usable for stack switch should be added to the top of the newly mapped GCS region while the new flag indicates that a top of stack marker suitable for use by unwinders should be added above that. For arm64 the top of stack marker is all bits 0. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-5-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04prctl: arch-agnostic prctl for shadow stackMark Brown
Three architectures (x86, aarch64, riscv) have announced support for shadow stacks with fairly similar functionality. While x86 is using arch_prctl() to control the functionality neither arm64 nor riscv uses that interface so this patch adds arch-agnostic prctl() support to get and set status of shadow stacks and lock the current configuation to prevent further changes, with support for turning on and off individual subfeatures so applications can limit their exposure to features that they do not need. The features are: - PR_SHADOW_STACK_ENABLE: Tracking and enforcement of shadow stacks, including allocation of a shadow stack if one is not already allocated. - PR_SHADOW_STACK_WRITE: Writes to specific addresses in the shadow stack. - PR_SHADOW_STACK_PUSH: Push additional values onto the shadow stack. These features are expected to be inherited by new threads and cleared on exec(), unknown features should be rejected for enable but accepted for locking (in order to allow for future proofing). This is based on a patch originally written by Deepak Gupta but modified fairly heavily, support for indirect landing pads is removed, additional modes added and the locking interface reworked. The set status prctl() is also reworked to just set flags, if setting/reading the shadow stack pointer is required this could be a separate prctl. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Yury Khrustalev <yury.khrustalev@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Deepak Gupta <debug@rivosinc.com> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-4-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/mm: Restructure arch_validate_flags() for extensibilityMark Brown
Currently arch_validate_flags() is written in a very non-extensible fashion, returning immediately if MTE is not supported and writing the MTE check as a direct return. Since we will want to add more checks for GCS refactor the existing code to be more extensible, no functional change intended. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-3-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04mm: Define VM_HIGH_ARCH_6Mark Brown
The addition of protection keys means that on arm64 we now use all of the currently defined VM_HIGH_ARCH_x bits. In order to allow us to allocate a new flag for GCS pages define VM_HIGH_ARCH_6. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-2-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04mm: Introduce ARCH_HAS_USER_SHADOW_STACKMark Brown
Since multiple architectures have support for shadow stacks and we need to select support for this feature in several places in the generic code provide a generic config option that the architectures can select. Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Deepak Gupta <debug@rivosinc.com> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <kees@kernel.org> Tested-by: Kees Cook <kees@kernel.org> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-1-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04ALSA: hda/conexant: Fix conflicting quirk for System76 PangolinTakashi Iwai
We received a regression report for System76 Pangolin (pang14) due to the recent fix for Tuxedo Sirius devices to support the top speaker. The reason was the conflicting PCI SSID, as often seen. As a workaround, now the codec SSID is checked and the quirk is applied conditionally only to Sirius devices. Fixes: 4178d78cd7a8 ("ALSA: hda/conexant: Add pincfg quirk to enable top speakers on Sirius devices") Reported-by: Christian Heusel <christian@heusel.eu> Reported-by: Jerry <jerryluo225@gmail.com> Closes: https://lore.kernel.org/c930b6a6-64e5-498f-b65a-1cd5e0a1d733@heusel.eu Link: https://patch.msgid.link/20241004082602.29016-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-10-04ALSA: line6: add hw monitor volume control to POD HD500XHans P. Moller
Add hw monitor volume control for POD HD500X. This is done adding LINE6_CAP_HWMON_CTL to the capabilities Signed-off-by: Hans P. Moller <hmoller@uc.cl> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://patch.msgid.link/20241003232828.5819-1-hmoller@uc.cl
2024-10-04ALSA: gus: Fix some error handling paths related to get_bpos() usageChristophe JAILLET
If get_bpos() fails, it is likely that the corresponding error code should be returned. Fixes: a6970bb1dd99 ("ALSA: gus: Convert to the new PCM ops") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://patch.msgid.link/d9ca841edad697154afa97c73a5d7a14919330d9.1727984008.git.christophe.jaillet@wanadoo.fr Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-10-03scsi: scsi_transport_fc: Allow setting rport state to current stateBenjamin Marzinski
The only input fc_rport_set_marginal_state() currently accepts is "Marginal" when port_state is "Online", and "Online" when the port_state is "Marginal". It should also allow setting port_state to its current state, either "Marginal or "Online". Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Link: https://lore.kernel.org/r/20240917230643.966768-1-bmarzins@redhat.com Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-10-03scsi: wd33c93: Don't use stale scsi_pointer valueDaniel Palmer
A regression was introduced with commit dbb2da557a6a ("scsi: wd33c93: Move the SCSI pointer to private command data") which results in an oops in wd33c93_intr(). That commit added the scsi_pointer variable and initialized it from hostdata->connected. However, during selection, hostdata->connected is not yet valid. Fix this by getting the current scsi_pointer from hostdata->selecting. Cc: Daniel Palmer <daniel@0x0f.com> Cc: Michael Schmitz <schmitzmic@gmail.com> Cc: stable@kernel.org Fixes: dbb2da557a6a ("scsi: wd33c93: Move the SCSI pointer to private command data") Signed-off-by: Daniel Palmer <daniel@0x0f.com> Co-developed-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Finn Thain <fthain@linux-m68k.org> Link: https://lore.kernel.org/r/09e11a0a54e6aa2a88bd214526d305aaf018f523.1727926187.git.fthain@linux-m68k.org Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-10-03scsi: fnic: Move flush_work initialization out of if blockMartin Wilck
After commit 379a58caa199 ("scsi: fnic: Move fnic_fnic_flush_tx() to a work queue"), it can happen that a work item is sent to an uninitialized work queue. This may has the effect that the item being queued is never actually queued, and any further actions depending on it will not proceed. The following warning is observed while the fnic driver is loaded: kernel: WARNING: CPU: 11 PID: 0 at ../kernel/workqueue.c:1524 __queue_work+0x373/0x410 kernel: <IRQ> kernel: queue_work_on+0x3a/0x50 kernel: fnic_wq_copy_cmpl_handler+0x54a/0x730 [fnic 62fbff0c42e7fb825c60a55cde2fb91facb2ed24] kernel: fnic_isr_msix_wq_copy+0x2d/0x60 [fnic 62fbff0c42e7fb825c60a55cde2fb91facb2ed24] kernel: __handle_irq_event_percpu+0x36/0x1a0 kernel: handle_irq_event_percpu+0x30/0x70 kernel: handle_irq_event+0x34/0x60 kernel: handle_edge_irq+0x7e/0x1a0 kernel: __common_interrupt+0x3b/0xb0 kernel: common_interrupt+0x58/0xa0 kernel: </IRQ> It has been observed that this may break the rediscovery of Fibre Channel devices after a temporary fabric failure. This patch fixes it by moving the work queue initialization out of an if block in fnic_probe(). Signed-off-by: Martin Wilck <mwilck@suse.com> Fixes: 379a58caa199 ("scsi: fnic: Move fnic_fnic_flush_tx() to a work queue") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240930133014.71615-1-mwilck@suse.com Reviewed-by: Lee Duncan <lduncan@suse.com> Reviewed-by: Karan Tilak Kumar <kartilak@cisco.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-10-03scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()Avri Altman
Replace manual offset calculations for response_upiu and prd_table in ufshcd_init_lrb() with pre-calculated offsets already stored in the utp_transfer_req_desc structure. The pre-calculated offsets are set differently in ufshcd_host_memory_configure() based on the UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk, ensuring correct alignment and access. Fixes: 26f968d7de82 ("scsi: ufs: Introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk") Cc: stable@vger.kernel.org Signed-off-by: Avri Altman <avri.altman@wdc.com> Link: https://lore.kernel.org/r/20240910044543.3812642-1-avri.altman@wdc.com Acked-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2024-10-04Merge tag 'drm-xe-fixes-2024-10-03' of ↵Dave Airlie
https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes Driver Changes: - Restore pci state on resume (Rodrigo Vivi) - Fix locking on submission, queue and vm (Matthew Auld, Matthew Brost) - Fix UAF on queue destruction (Matthew Auld) - Fix resource release on freq init error path (He Lugang) - Use rw_semaphore to reduce contention on ASID->VM lookup (Matthew Brost) - Fix steering for media on Xe2_HPM (Gustavo Sousa) - Tuning updates to Xe2 (Gustavo Sousa) - Resume TDR after GT reset to prevent jobs running forever (Matthew Brost) - Move id allocation to avoid userspace using a guessed number to trigger UAF (Matthew Auld, Matthew Brost) - Fix OA stream close preventing pbatch buffers to complete (José) - Fix NPD when migrating memory on LNL (Zhanjun Dong) - Fix memory leak when aborting binds (Matthew Brost) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Lucas De Marchi <lucas.demarchi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/2fiv63yanlal5mpw3mxtotte6yvkvtex74c7mkjxca4bazlyja@o4iejcfragxy
2024-10-03Merge branch '100GbE' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue Tony Nguyen says: ==================== Intel Wired LAN Driver Updates 2024-09-30 (ice, idpf) This series contains updates to ice and idpf drivers: For ice: Michal corrects setting of dst VSI on LAN filters and adds clearing of port VLAN configuration during reset. Gui-Dong Han corrects failures to decrement refcount in some error paths. Przemek resolves a memory leak in ice_init_tx_topology(). Arkadiusz prevents setting of DPLL_PIN_STATE_SELECTABLE to an improper value. Dave stops clearing of VLAN tracking bit to allow for VLANs to be properly restored after reset. For idpf: Ahmed sets uninitialized dyn_ctl_intrvl_s value. Josh corrects use and reporting of mailbox size. Larysa corrects order of function calls during de-initialization. * '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue: idpf: deinit virtchnl transaction manager after vport and vectors idpf: use actual mbx receive payload length idpf: fix VF dynamic interrupt ctl register initialization ice: fix VLAN replay after reset ice: disallow DPLL_PIN_STATE_SELECTABLE for dpll output pins ice: fix memleak in ice_init_tx_topology() ice: clear port vlan config during reset ice: Fix improper handling of refcount in ice_sriov_set_msix_vec_count() ice: Fix improper handling of refcount in ice_dpll_init_rclk_pins() ice: set correct dst VSI in only LAN filters ==================== Link: https://patch.msgid.link/20240930223601.3137464-1-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03Merge tag 'rust-fixes-6.12' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull Rust fixes from Miguel Ojeda: "Toolchain and infrastructure: - Fix/improve a couple 'depends on' on the newly added CFI/KASAN suppport to avoid build errors/warnings - Fix ARCH_SLAB_MINALIGN multiple definition error for RISC-V under !CONFIG_MMU - Clean upcoming (Rust 1.83.0) Clippy warnings 'kernel' crate: - 'sync' module: fix soundness issue by requiring 'T: Sync' for 'LockedBy::access'; and fix helpers build error under PREEMPT_RT - Fix trivial sorting issue ('rustfmtcheck') on the v6.12 Rust merge" * tag 'rust-fixes-6.12' of https://github.com/Rust-for-Linux/linux: rust: kunit: use C-string literals to clean warning cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig rust: KASAN+RETHUNK requires rustc 1.83.0 rust: cfi: fix `patchable-function-entry` starting version rust: mutex: fix __mutex_init() usage in case of PREEMPT_RT rust: fix `ARCH_SLAB_MINALIGN` multiple definition error rust: sync: require `T: Sync` for `LockedBy::access` rust: kernel: sort Rust modules
2024-10-03Merge tag 'pull-fixes.ufs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ufs fix from Al Viro: "Fix ufs_rename() braino introduced this cycle. The 'folio_release_kmap(dir_folio, new_dir)' in ufs_rename() part of folio conversion should've been getting a pointer to ufs directory entry within the page, rather than a pointer to directory struct inode..." * tag 'pull-fixes.ufs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ufs_rename(): fix bogus argument of folio_release_kmap()
2024-10-03Documentation: networking/tcp_ao: typo and grammar fixesLeo Stone
Fix multiple grammatical issues and add a missing period to improve readability. Signed-off-by: Leo Stone <leocstone@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240929005001.370991-1-leocstone@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03Merge branch 'rxrpc-miscellaneous-fixes'Jakub Kicinski
David Howells says: ==================== rxrpc: Miscellaneous fixes Here some miscellaneous fixes for AF_RXRPC: (1) Fix a race in the I/O thread vs UDP socket setup. (2) Fix an uninitialised variable. ==================== Link: https://patch.msgid.link/20241001132702.3122709-1-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03rxrpc: Fix uninitialised variable in rxrpc_send_data()David Howells
Fix the uninitialised txb variable in rxrpc_send_data() by moving the code that loads it above all the jumps to maybe_error, txb being stored back into call->tx_pending right before the normal return. Fixes: b0f571ecd794 ("rxrpc: Fix locking in rxrpc's sendmsg") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lists.infradead.org/pipermail/linux-afs/2024-October/008896.html Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241001132702.3122709-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03rxrpc: Fix a race between socket set up and I/O thread creationDavid Howells
In rxrpc_open_socket(), it sets up the socket and then sets up the I/O thread that will handle it. This is a problem, however, as there's a gap between the two phases in which a packet may come into rxrpc_encap_rcv() from the UDP packet but we oops when trying to wake the not-yet created I/O thread. As a quick fix, just make rxrpc_encap_rcv() discard the packet if there's no I/O thread yet. A better, but more intrusive fix would perhaps be to rearrange things such that the socket creation is done by the I/O thread. Fixes: a275da62e8c1 ("rxrpc: Create a per-local endpoint receive queue and I/O thread") Signed-off-by: David Howells <dhowells@redhat.com> cc: yuxuanzhe@outlook.com cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241001132702.3122709-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03Merge branch 'tcp-3-fixes-for-retrans_stamp-and-undo-logic'Jakub Kicinski
Neal Cardwell says: ==================== tcp: 3 fixes for retrans_stamp and undo logic Geumhwan Yu <geumhwan.yu@samsung.com> recently reported and diagnosed a regression in TCP loss recovery undo logic in the case where a TCP connection enters fast recovery, is unable to retransmit anything due to TSQ, and then receives an ACK allowing forward progress. The sender should be able to undo the spurious loss recovery in this case, but was not doing so. The first patch fixes this regression. Running our suite of packetdrill tests with the first fix, the tests highlighted two other small bugs in the way retrans_stamp is updated in some rare corner cases. The second two patches fix those other two small bugs. Thanks to Geumhwan Yu for the bug report! ==================== Link: https://patch.msgid.link/20241001200517.2756803-1-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03tcp: fix TFO SYN_RECV to not zero retrans_stamp with retransmits outNeal Cardwell
Fix tcp_rcv_synrecv_state_fastopen() to not zero retrans_stamp if retransmits are outstanding. tcp_fastopen_synack_timer() sets retrans_stamp, so typically we'll need to zero retrans_stamp here to prevent spurious retransmits_timed_out(). The logic to zero retrans_stamp is from this 2019 commit: commit cd736d8b67fb ("tcp: fix retrans timestamp on passive Fast Open") However, in the corner case where the ACK of our TFO SYNACK carried some SACK blocks that caused us to enter TCP_CA_Recovery then that non-zero retrans_stamp corresponds to the active fast recovery, and we need to leave retrans_stamp with its current non-zero value, for correct ETIMEDOUT and undo behavior. Fixes: cd736d8b67fb ("tcp: fix retrans timestamp on passive Fast Open") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241001200517.2756803-4-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-03tcp: fix tcp_enter_recovery() to zero retrans_stamp when it's safeNeal Cardwell
Fix tcp_enter_recovery() so that if there are no retransmits out then we zero retrans_stamp when entering fast recovery. This is necessary to fix two buggy behaviors. Currently a non-zero retrans_stamp value can persist across multiple back-to-back loss recovery episodes. This is because we generally only clears retrans_stamp if we are completely done with loss recoveries, and get to tcp_try_to_open() and find !tcp_any_retrans_done(sk). This behavior causes two bugs: (1) When a loss recovery episode (CA_Loss or CA_Recovery) is followed immediately by a new CA_Recovery, the retrans_stamp value can persist and can be a time before this new CA_Recovery episode starts. That means that timestamp-based undo will be using the wrong retrans_stamp (a value that is too old) when comparing incoming TS ecr values to retrans_stamp to see if the current fast recovery episode can be undone. (2) If there is a roughly minutes-long sequence of back-to-back fast recovery episodes, one after another (e.g. in a shallow-buffered or policed bottleneck), where each fast recovery successfully makes forward progress and recovers one window of sequence space (but leaves at least one retransmit in flight at the end of the recovery), followed by several RTOs, then the ETIMEDOUT check may be using the wrong retrans_stamp (a value set at the start of the first fast recovery in the sequence). This can cause a very premature ETIMEDOUT, killing the connection prematurely. This commit changes the code to zero retrans_stamp when entering fast recovery, when this is known to be safe (no retransmits are out in the network). That ensures that when starting a fast recovery episode, and it is safe to do so, retrans_stamp is set when we send the fast retransmit packet. That addresses both bug (1) and bug (2) by ensuring that (if no retransmits are out when we start a fast recovery) we use the initial fast retransmit of this fast recovery as the time value for undo and ETIMEDOUT calculations. This makes intuitive sense, since the start of a new fast recovery episode (in a scenario where no lost packets are out in the network) means that the connection has made forward progress since the last RTO or fast recovery, and we should thus "restart the clock" used for both undo and ETIMEDOUT logic. Note that if when we start fast recovery there *are* retransmits out in the network, there can still be undesirable (1)/(2) issues. For example, after this patch we can still have the (1) and (2) problems in cases like this: + round 1: sender sends flight 1 + round 2: sender receives SACKs and enters fast recovery 1, retransmits some packets in flight 1 and then sends some new data as flight 2 + round 3: sender receives some SACKs for flight 2, notes losses, and retransmits some packets to fill the holes in flight 2 + fast recovery has some lost retransmits in flight 1 and continues for one or more rounds sending retransmits for flight 1 and flight 2 + fast recovery 1 completes when snd_una reaches high_seq at end of flight 1 + there are still holes in the SACK scoreboard in flight 2, so we enter fast recovery 2, but some retransmits in the flight 2 sequence range are still in flight (retrans_out > 0), so we can't execute the new retrans_stamp=0 added here to clear retrans_stamp It's not yet clear how to fix these remaining (1)/(2) issues in an efficient way without breaking undo behavior, given that retrans_stamp is currently used for undo and ETIMEDOUT. Perhaps the optimal (but expensive) strategy would be to set retrans_stamp to the timestamp of the earliest outstanding retransmit when entering fast recovery. But at least this commit makes things better. Note that this does not change the semantics of retrans_stamp; it simply makes retrans_stamp accurate in some cases where it was not before: (1) Some loss recovery, followed by an immediate entry into a fast recovery, where there are no retransmits out when entering the fast recovery. (2) When a TFO server has a SYNACK retransmit that sets retrans_stamp, and then the ACK that completes the 3-way handshake has SACK blocks that trigger a fast recovery. In this case when entering fast recovery we want to zero out the retrans_stamp from the TFO SYNACK retransmit, and set the retrans_stamp based on the timestamp of the fast recovery. We introduce a tcp_retrans_stamp_cleanup() helper, because this two-line sequence already appears in 3 places and is about to appear in 2 more as a result of this bug fix patch series. Once this bug fix patches series in the net branch makes it into the net-next branch we'll update the 3 other call sites to use the new helper. This is a long-standing issue. The Fixes tag below is chosen to be the oldest commit at which the patch will apply cleanly, which is from Linux v3.5 in 2012. Fixes: 1fbc340514fc ("tcp: early retransmit: tcp_enter_recovery()") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241001200517.2756803-3-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>