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 --- drivers/md/dm-vdo/thread-utils.c | 108 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 drivers/md/dm-vdo/thread-utils.c (limited to 'drivers/md/dm-vdo/thread-utils.c') diff --git a/drivers/md/dm-vdo/thread-utils.c b/drivers/md/dm-vdo/thread-utils.c new file mode 100644 index 000000000..826afc952 --- /dev/null +++ b/drivers/md/dm-vdo/thread-utils.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2023 Red Hat + */ + +#include "thread-utils.h" + +#include +#include +#include +#include +#include + +#include "errors.h" +#include "logger.h" +#include "memory-alloc.h" + +static struct hlist_head thread_list; +static struct mutex thread_mutex; + +struct thread { + void (*thread_function)(void *thread_data); + void *thread_data; + struct hlist_node thread_links; + struct task_struct *thread_task; + struct completion thread_done; +}; + +void vdo_initialize_threads_mutex(void) +{ + mutex_init(&thread_mutex); +} + +static int thread_starter(void *arg) +{ + struct registered_thread allocating_thread; + struct thread *thread = arg; + + thread->thread_task = current; + mutex_lock(&thread_mutex); + hlist_add_head(&thread->thread_links, &thread_list); + mutex_unlock(&thread_mutex); + vdo_register_allocating_thread(&allocating_thread, NULL); + thread->thread_function(thread->thread_data); + vdo_unregister_allocating_thread(); + complete(&thread->thread_done); + return 0; +} + +int vdo_create_thread(void (*thread_function)(void *), void *thread_data, + const char *name, struct thread **new_thread) +{ + char *name_colon = strchr(name, ':'); + char *my_name_colon = strchr(current->comm, ':'); + struct task_struct *task; + struct thread *thread; + int result; + + result = vdo_allocate(1, __func__, &thread); + if (result != VDO_SUCCESS) { + vdo_log_warning("Error allocating memory for %s", name); + return result; + } + + thread->thread_function = thread_function; + thread->thread_data = thread_data; + init_completion(&thread->thread_done); + /* + * Start the thread, with an appropriate thread name. + * + * If the name supplied contains a colon character, use that name. This causes uds module + * threads to have names like "uds:callbackW" and the main test runner thread to be named + * "zub:runtest". + * + * Otherwise if the current thread has a name containing a colon character, prefix the name + * supplied with the name of the current thread up to (and including) the colon character. + * Thus when the "kvdo0:dedupeQ" thread opens an index session, all the threads associated + * with that index will have names like "kvdo0:foo". + * + * Otherwise just use the name supplied. This should be a rare occurrence. + */ + if ((name_colon == NULL) && (my_name_colon != NULL)) { + task = kthread_run(thread_starter, thread, "%.*s:%s", + (int) (my_name_colon - current->comm), current->comm, + name); + } else { + task = kthread_run(thread_starter, thread, "%s", name); + } + + if (IS_ERR(task)) { + vdo_free(thread); + return PTR_ERR(task); + } + + *new_thread = thread; + return VDO_SUCCESS; +} + +void vdo_join_threads(struct thread *thread) +{ + while (wait_for_completion_interruptible(&thread->thread_done)) + fsleep(1000); + + mutex_lock(&thread_mutex); + hlist_del(&thread->thread_links); + mutex_unlock(&thread_mutex); + vdo_free(thread); +} -- cgit v1.3.1