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/shmbuf.h | 61 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 include/uapi/asm-generic/shmbuf.h (limited to 'include/uapi/asm-generic/shmbuf.h') diff --git a/include/uapi/asm-generic/shmbuf.h b/include/uapi/asm-generic/shmbuf.h new file mode 100644 index 000000000..2979b6dd2 --- /dev/null +++ b/include/uapi/asm-generic/shmbuf.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_SHMBUF_H +#define __ASM_GENERIC_SHMBUF_H + +#include +#include +#include + +/* + * The shmid64_ds structure for x86 architecture. + * Note extra padding because this structure is passed back and forth + * between kernel and user space. + * + * shmid64_ds 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. + * + * 64 bit architectures use a 64-bit long time field here, while + * 32 bit architectures have a pair of unsigned long values. + * On big-endian systems, the lower half is in the wrong place. + * + * + * Pad space is left for: + * - 2 miscellaneous 32-bit values + */ + +struct shmid64_ds { + struct ipc64_perm shm_perm; /* operation perms */ + __kernel_size_t shm_segsz; /* size of segment (bytes) */ +#if __BITS_PER_LONG == 64 + long shm_atime; /* last attach time */ + long shm_dtime; /* last detach time */ + long shm_ctime; /* last change time */ +#else + unsigned long shm_atime; /* last attach time */ + unsigned long shm_atime_high; + unsigned long shm_dtime; /* last detach time */ + unsigned long shm_dtime_high; + unsigned long shm_ctime; /* last change time */ + unsigned long shm_ctime_high; +#endif + __kernel_pid_t shm_cpid; /* pid of creator */ + __kernel_pid_t shm_lpid; /* pid of last operator */ + unsigned long shm_nattch; /* no. of current attaches */ + unsigned long __unused4; + unsigned long __unused5; +}; + +struct shminfo64 { + unsigned long shmmax; + unsigned long shmmin; + unsigned long shmmni; + unsigned long shmseg; + unsigned long shmall; + unsigned long __unused1; + unsigned long __unused2; + unsigned long __unused3; + unsigned long __unused4; +}; + +#endif /* __ASM_GENERIC_SHMBUF_H */ -- cgit v1.3.1