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/mm_hooks.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 include/asm-generic/mm_hooks.h (limited to 'include/asm-generic/mm_hooks.h') diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h new file mode 100644 index 000000000..6eea3b3c1 --- /dev/null +++ b/include/asm-generic/mm_hooks.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Define generic no-op hooks for arch_dup_mmap and arch_exit_mmap + * to be included in asm-FOO/mmu_context.h for any arch FOO which + * doesn't need to hook these. + */ +#ifndef _ASM_GENERIC_MM_HOOKS_H +#define _ASM_GENERIC_MM_HOOKS_H + +static inline int arch_dup_mmap(struct mm_struct *oldmm, + struct mm_struct *mm) +{ + return 0; +} + +static inline void arch_exit_mmap(struct mm_struct *mm) +{ +} + +static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, + bool write, bool execute, bool foreign) +{ + /* by default, allow everything */ + return true; +} +#endif /* _ASM_GENERIC_MM_HOOKS_H */ -- cgit v1.3.1