From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- include/asm-generic/mmu_context.h | 76 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 include/asm-generic/mmu_context.h (limited to 'include/asm-generic/mmu_context.h') diff --git a/include/asm-generic/mmu_context.h b/include/asm-generic/mmu_context.h new file mode 100644 index 000000000..91727065b --- /dev/null +++ b/include/asm-generic/mmu_context.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_MMU_CONTEXT_H +#define __ASM_GENERIC_MMU_CONTEXT_H + +/* + * Generic hooks to implement no-op functionality. + */ + +struct task_struct; +struct mm_struct; + +/* + * enter_lazy_tlb - Called when "tsk" is about to enter lazy TLB mode. + * + * @mm: the currently active mm context which is becoming lazy + * @tsk: task which is entering lazy tlb + * + * tsk->mm will be NULL + */ +#ifndef enter_lazy_tlb +static inline void enter_lazy_tlb(struct mm_struct *mm, + struct task_struct *tsk) +{ +} +#endif + +/** + * init_new_context - Initialize context of a new mm_struct. + * @tsk: task struct for the mm + * @mm: the new mm struct + * @return: 0 on success, -errno on failure + */ +#ifndef init_new_context +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + return 0; +} +#endif + +/** + * destroy_context - Undo init_new_context when the mm is going away + * @mm: old mm struct + */ +#ifndef destroy_context +static inline void destroy_context(struct mm_struct *mm) +{ +} +#endif + +/** + * activate_mm - called after exec switches the current task to a new mm, to switch to it + * @prev_mm: previous mm of this task + * @next_mm: new mm + */ +#ifndef activate_mm +static inline void activate_mm(struct mm_struct *prev_mm, + struct mm_struct *next_mm) +{ + switch_mm(prev_mm, next_mm, current); +} +#endif + +/** + * dectivate_mm - called when an mm is released after exit or exec switches away from it + * @tsk: the task + * @mm: the old mm + */ +#ifndef deactivate_mm +static inline void deactivate_mm(struct task_struct *tsk, + struct mm_struct *mm) +{ +} +#endif + +#endif /* __ASM_GENERIC_MMU_CONTEXT_H */ -- cgit v1.3.1