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/uapi/asm-generic/ipcbuf.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 include/uapi/asm-generic/ipcbuf.h (limited to 'include/uapi/asm-generic/ipcbuf.h') diff --git a/include/uapi/asm-generic/ipcbuf.h b/include/uapi/asm-generic/ipcbuf.h new file mode 100644 index 000000000..41a01b494 --- /dev/null +++ b/include/uapi/asm-generic/ipcbuf.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_IPCBUF_H +#define __ASM_GENERIC_IPCBUF_H + +#include + +/* + * The generic ipc64_perm structure: + * Note extra padding because this structure is passed back and forth + * between kernel and user space. + * + * ipc64_perm was originally meant to be architecture specific, but + * everyone just ended up making identical copies without specific + * optimizations, so we may just as well all use the same one. + * + * Pad space is left for: + * - 32-bit mode_t on architectures that only had 16 bit + * - 32-bit seq + * - 2 miscellaneous 32-bit values + */ + +struct ipc64_perm { + __kernel_key_t key; + __kernel_uid32_t uid; + __kernel_gid32_t gid; + __kernel_uid32_t cuid; + __kernel_gid32_t cgid; + __kernel_mode_t mode; + /* pad if mode_t is u16: */ + unsigned char __pad1[4 - sizeof(__kernel_mode_t)]; + unsigned short seq; + unsigned short __pad2; + __kernel_ulong_t __unused1; + __kernel_ulong_t __unused2; +}; + +#endif /* __ASM_GENERIC_IPCBUF_H */ -- cgit v1.3.1