kernel/linux.git/arch/riscv/include, branch v7.1.12

RISC-V: KVM: Serialize virtual interrupt pending state updates

2026-08-03T09:25:25+00:00

commit d024a0a7879e6f37c0152aacf6d8e37b214a1738 upstream. KVM RISC-V tracks guest local interrupt state with two bitmaps: - irqs_pending: interrupts that should be visible to the guest - irqs_pending_mask: interrupts whose pending state changed The current code updates those bitmaps with independent atomic bitops and assumes a multiple-producer, single-consumer protocol. That model does not actually hold. kvm_riscv_vcpu_sync_interrupts() is not a pure consumer. When the guest changes guest-visible HVIP state, sync_interrupts() writes both irqs_pending and irqs_pending_mask to reflect the new guest state back into KVM state. As a result, irqs_pending and irqs_pending_mask form a single logical state transition, but they are not updated atomically as a pair. This allows a race where a newly injected interrupt is lost. For example: CPU0 CPU1 ---- ---- kvm_riscv_vcpu_set_interrupt(VS_SOFT) set_bit(VS_SOFT, irqs_pending) kvm_riscv_vcpu_sync_interrupts() sees guest-cleared HVIP.VSSIP sets irqs_pending_mask clear_bit(IRQ_VS_SOFT, irqs_pending) set_bit(VS_SOFT, irqs_pending_mask) kvm_vcpu_kick() After that interleaving, a later flush can update HVIP without VSSIP even though a new virtual interrupt was injected. In practice, the guest can remain blocked in WFI with work pending. The same pending/mask protocol is shared by VS soft interrupts, PMU overflow delivery, and AIA high interrupt synchronization, so the race is not limited to one interrupt source. Fix this by serializing all updates to irqs_pending and irqs_pending_mask with a per-vCPU raw spinlock. This keeps the pending bit and the dirty mask as one state transition across: - set/unset interrupt - guest HVIP sync - interrupt flush to guest CSR state - vCPU reset - AIA CSR writes that clear dirty state Use non-atomic bitmap operations while holding the lock. Hold the lock across the AIA sync, flush, and pending checks as well, so both bitmap words share the same serialization domain. This intentionally replaces the existing lockless protocol instead of trying to repair it with additional barriers. The problem is not memory ordering on a single field; it is that two separate bitmaps encode one shared state machine while both producers and sync paths can modify them. A per-vCPU raw spinlock keeps the fix small, local, and suitable for backporting. Fixes: cce69aff689e ("RISC-V: KVM: Implement VCPU interrupts and requests handling") Cc: stable@vger.kernel.org [ Adapted for 7.1.y: place the new 'unsigned long flags;' declaration in kvm_riscv_vcpu_general_set_csr() explicitly. A direct apply anchors it in kvm_riscv_vcpu_general_get_csr(), whose prologue is byte-identical, leaving 'flags' undeclared at its use site. ] Signed-off-by: Xie Bo Reviewed-by: Anup Patel Signed-off-by: Anup Patel Signed-off-by: Sasha Levin

riscv: vdso: Always declare vdso_start symbols

2026-07-24T14:21:16+00:00

[ Upstream commit 499578e22ae0cc33d05803f22e5c71ffb7077b2f ] Make the declarations of vdso_start and its related symbols always visible. With that their users don't have to use ifdeffery but can use the better IS_ENABLED() compile-time checks. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20260504-riscv-cfi-vdso-alternative-v1-1-bcdf3d37f62e@linutronix.de Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin

riscv: cpu_ops: Change return value type of cpu_is_stopped() to bool

2026-07-24T14:19:36+00:00

[ Upstream commit 2b2b207e1162e577cd6208e184d3d3a0fcfa9cca ] In the original sbi_cpu_is_stopped(), if rc doesn't equal to the SBI_HSM_STATE_STOPPED, it will return rc to the caller directly. But there is a hidden problem, the rc could be SBI_HSM_STATE_STARTED, if so, this function will report cpu stopped while the cpu isn't really stopped. Furthermore, from the name of cpu_is_stopped(), it gives a sense the return value is a bool type, true means the cpu is stopped, conversely false means the cpu is not stopped. Here change the return value type to bool and change the callers accordingly. This could fix the above two issues. Fixes: f1e58583b9c7c ("RISC-V: Support cpu hotplug") Signed-off-by: Hui Wang Link: https://patch.msgid.link/20260413123515.48423-1-hui.wang@canonical.com [pjw@kernel.org: cleaned up some of the pr_warn() messages] Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin

riscv: mm: Define DIRECT_MAP_PHYSMEM_END

2026-07-18T14:55:44+00:00

commit f3336b48cf9d3f2d1fc78e3289c0ded2f00876ee upstream. On RISC-V, the actual mappable range of physical address space is dependent on the current MMU mode i.e. satp_mode (See Documentation/arch/riscv/vm-layout.rst). Define the DIRECT_MAP_PHYSMEM_END macro based on the existing virtual address space layout macros to expose this information to get_free_mem_region(). Otherwise, it returns a region that couldn't be mapped, which breaks ZONE_DEVICE. Cc: stable@vger.kernel.org # v6.13+ Tested-by: Han Gao # SG2044 Signed-off-by: Vivian Wang Link: https://patch.msgid.link/20260309-riscv-sparsemem-vmemmap-limits-v1-2-f40efe18e3cd@iscas.ac.cn Signed-off-by: Paul Walmsley Signed-off-by: Greg Kroah-Hartman

riscv: kfence: Call mark_new_valid_map() for kfence_unprotect()

2026-07-04T11:45:07+00:00

commit 8d6c8c40e733b3fcaf92fed0a078bba2f6941a3b upstream. In kfence_protect_page(), which kfence_unprotect() calls, we cannot send IPIs to other CPUs to ask them to flush TLB. This may lead to those CPUs spuriously faulting on a recently allocated kfence object despite it being valid, leading to false positive use-after-free reports. Fix this by calling mark_new_valid_map() so that the page fault handling code path notices the spurious fault and flushes TLB then retries the access. Update the comment in handle_exception to indicate that new_valid_map_cpus_check also handles kfence_unprotect() spurious faults. Note that kfence_protect() has the same stale TLB entries problem, but that leads to false negatives, which is fine with kfence. Cc: stable@vger.kernel.org Reported-by: Yanko Kaneti Fixes: b3431a8bb336 ("riscv: Fix IPIs usage in kfence_protect_page()") Signed-off-by: Vivian Wang Link: https://patch.msgid.link/20260303-handle-kfence-protect-spurious-fault-v2-2-f80d8354d79d@iscas.ac.cn Signed-off-by: Paul Walmsley Signed-off-by: Greg Kroah-Hartman

riscv: mm: Extract helper mark_new_valid_map()

2026-07-04T11:45:07+00:00

commit 9ee25d0a70ff4494b4e1d266b962d0a574ef318a upstream. In preparation of a future patch using the same mechanism for non-vmalloc addresses, extract the mark_new_valid_map() helper from flush_cache_vmap(). No functional change intended. Cc: stable@vger.kernel.org Signed-off-by: Vivian Wang Link: https://patch.msgid.link/20260303-handle-kfence-protect-spurious-fault-v2-1-f80d8354d79d@iscas.ac.cn Signed-off-by: Paul Walmsley Signed-off-by: Greg Kroah-Hartman

Merge tag 'riscv-for-linux-7.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2026-06-10T14:18:32+00:00

Pull RISC-V fixes from Paul Walmsley: - Fix the implementation of the CFI branch landing pad control prctl()s to return -EINVAL if unknown control bits are set, rather than silently ignoring the request; and add a kselftest for this case - Fix unaligned access performance testing to happen earlier in boot, which fixes a performance regression in the lib/checksum code - Fix a binfmt_elf warning when dumping core (due to missing .core_note_name for CFI registers) * tag 'riscv-for-linux-7.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: cfi: reject unknown flags in PR_SET_CFI riscv: Fix fast_unaligned_access_speed_key not getting initialized riscv/ptrace: Use USER_REGSET_NOTE_TYPE for REGSET_CFI

riscv: cfi: reject unknown flags in PR_SET_CFI

2026-06-07T02:17:05+00:00

prctl(PR_SET_CFI,PR_CFI_BRANCH_LANDING_PADS) silently ignored unknown control values. Only PR_CFI_{ENABLE,DISABLE,LOCK} should be permitted. This changes the behavior of the uABI (fails previously accepted bits with EINVAL). Fixes: 08ee1559052b ("prctl: cfi: change the branch landing pad prctl()s to be more descriptive") Signed-off-by: Richard Patel Link: https://patch.msgid.link/20260518183918.322545-1-ripatel@wii.dev [pjw@kernel.org: change the patch description to note that although this is a uABI change, it does not break the uABI] Signed-off-by: Paul Walmsley

Merge tag 'clang-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/nathan/linux

2026-05-29T22:17:53+00:00

Pull clang build fix from Nathan Chancellor: "A small fix to disable -Wattribute-alias for clang in the few places it is already disabled for GCC, now that tip of tree clang has implemented -Wattribute-alias as GCC has" * tag 'clang-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/nathan/linux: Disable -Wattribute-alias for clang-23 and newer

Disable -Wattribute-alias for clang-23 and newer

2026-05-28T13:51:30+00:00

Clang recently added support for -Wattribute-alias [1], which results in the same warnings that necessitated commit bee20031772a ("disable -Wattribute-alias warning for SYSCALL_DEFINEx()") for GCC. kernel/time/itimer.c:325:1: error: alias and aliasee have different types 'long (unsigned int)' and 'long (typeof (__builtin_choose_expr((__builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0LL)) || __builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0ULL))), 0LL, 0L)))' (aka 'long (long)') [-Werror,-Wattribute-alias] 325 | SYSCALL_DEFINE1(alarm, unsigned int, seconds) | ^ include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:251:18: note: expanded from macro '__SYSCALL_DEFINEx' 251 | __attribute__((alias(__stringify(__se_sys##name)))); \ | ^ kernel/time/itimer.c:325:1: note: aliasee is declared here include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:255:18: note: expanded from macro '__SYSCALL_DEFINEx' 255 | asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ | ^ :16:1: note: expanded from here 16 | __se_sys_alarm | ^ Disable the warnings in the same way for clang-23 and newer. Disable the warning about unknown warning options to avoid breaking the build for versions of clang-23 that do not have -Wattribute-alias, such as ones deployed by vendors like Android or CI systems or when bisecting LLVM between llvmorg-23-init and release/23.x. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2163 Link: https://github.com/llvm/llvm-project/commit/40da6920a0d71d49dfa2392b09153600b0759f5e [1] Link: https://patch.msgid.link/20260515-syscall-disable-attribute-alias-for-clang-v1-1-9a9d95d41df6@kernel.org Signed-off-by: Nathan Chancellor