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/flat.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 include/asm-generic/flat.h (limited to 'include/asm-generic/flat.h') diff --git a/include/asm-generic/flat.h b/include/asm-generic/flat.h new file mode 100644 index 000000000..1928a3596 --- /dev/null +++ b/include/asm-generic/flat.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_FLAT_H +#define _ASM_GENERIC_FLAT_H + +#include + +static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags, + u32 *addr) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + return copy_from_user(addr, rp, 4) ? -EFAULT : 0; +#else + return get_user(*addr, rp); +#endif +} + +static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + return copy_to_user(rp, &addr, 4) ? -EFAULT : 0; +#else + return put_user(addr, rp); +#endif +} + +#endif /* _ASM_GENERIC_FLAT_H */ -- cgit v1.3.1