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/trace/events/capability.h | 57 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 include/trace/events/capability.h (limited to 'include/trace/events/capability.h') diff --git a/include/trace/events/capability.h b/include/trace/events/capability.h new file mode 100644 index 000000000..173402579 --- /dev/null +++ b/include/trace/events/capability.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM capability + +#if !defined(_TRACE_CAPABILITY_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_CAPABILITY_H + +#include +#include +#include + +/** + * cap_capable - called after it's determined if a task has a particular + * effective capability + * + * @cred: The credentials used + * @target_ns: The user namespace of the resource being accessed + * @capable_ns: The user namespace in which the credential provides the + * capability to access the targeted resource. + * This will be NULL if ret is not 0. + * @cap: The capability to check for + * @ret: The return value of the check: 0 if it does, -ve if it does not + * + * Allows to trace calls to cap_capable in commoncap.c + */ +TRACE_EVENT(cap_capable, + + TP_PROTO(const struct cred *cred, struct user_namespace *target_ns, + const struct user_namespace *capable_ns, int cap, int ret), + + TP_ARGS(cred, target_ns, capable_ns, cap, ret), + + TP_STRUCT__entry( + __field(const struct cred *, cred) + __field(struct user_namespace *, target_ns) + __field(const struct user_namespace *, capable_ns) + __field(int, cap) + __field(int, ret) + ), + + TP_fast_assign( + __entry->cred = cred; + __entry->target_ns = target_ns; + __entry->capable_ns = ret == 0 ? capable_ns : NULL; + __entry->cap = cap; + __entry->ret = ret; + ), + + TP_printk("cred %p, target_ns %p, capable_ns %p, cap %d, ret %d", + __entry->cred, __entry->target_ns, __entry->capable_ns, __entry->cap, + __entry->ret) +); + +#endif /* _TRACE_CAPABILITY_H */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1