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 --- lib/kunit/user_alloc.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 lib/kunit/user_alloc.c (limited to 'lib/kunit/user_alloc.c') diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c new file mode 100644 index 000000000..b8cac765e --- /dev/null +++ b/lib/kunit/user_alloc.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit userspace memory allocation resource management. + */ +#include +#include +#include +#include + +struct kunit_vm_mmap_resource { + unsigned long addr; + size_t size; +}; + +/* vm_mmap() arguments */ +struct kunit_vm_mmap_params { + struct file *file; + unsigned long addr; + unsigned long len; + unsigned long prot; + unsigned long flag; + unsigned long offset; +}; + +int kunit_attach_mm(void) +{ + struct mm_struct *mm; + + if (current->mm) + return 0; + + /* arch_pick_mmap_layout() is only sane with MMU systems. */ + if (!IS_ENABLED(CONFIG_MMU)) + return -EINVAL; + + mm = mm_alloc(); + if (!mm) + return -ENOMEM; + + /* Define the task size. */ + mm->task_size = TASK_SIZE; + + /* Make sure we can allocate new VMAs. */ + arch_pick_mmap_layout(mm, ¤t->signal->rlim[RLIMIT_STACK]); + + /* Attach the mm. It will be cleaned up when the process dies. */ + kthread_use_mm(mm); + + return 0; +} +EXPORT_SYMBOL_GPL(kunit_attach_mm); + +static int kunit_vm_mmap_init(struct kunit_resource *res, void *context) +{ + struct kunit_vm_mmap_params *p = context; + struct kunit_vm_mmap_resource vres; + int ret; + + ret = kunit_attach_mm(); + if (ret) + return ret; + + vres.size = p->len; + vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset); + if (!vres.addr) + return -ENOMEM; + res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL); + if (!res->data) { + vm_munmap(vres.addr, vres.size); + return -ENOMEM; + } + + return 0; +} + +static void kunit_vm_mmap_free(struct kunit_resource *res) +{ + struct kunit_vm_mmap_resource *vres = res->data; + + /* + * Since this is executed from the test monitoring process, + * the test's mm has already been torn down. We don't need + * to run vm_munmap(vres->addr, vres->size), only clean up + * the vres. + */ + + kfree(vres); + res->data = NULL; +} + +unsigned long kunit_vm_mmap(struct kunit *test, struct file *file, + unsigned long addr, unsigned long len, + unsigned long prot, unsigned long flag, + unsigned long offset) +{ + struct kunit_vm_mmap_params params = { + .file = file, + .addr = addr, + .len = len, + .prot = prot, + .flag = flag, + .offset = offset, + }; + struct kunit_vm_mmap_resource *vres; + + vres = kunit_alloc_resource(test, + kunit_vm_mmap_init, + kunit_vm_mmap_free, + GFP_KERNEL, + ¶ms); + if (vres) + return vres->addr; + return 0; +} +EXPORT_SYMBOL_GPL(kunit_vm_mmap); + +MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"); -- cgit v1.3.1