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/netdev-notifier-error-inject.c | 56 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 lib/netdev-notifier-error-inject.c (limited to 'lib/netdev-notifier-error-inject.c') diff --git a/lib/netdev-notifier-error-inject.c b/lib/netdev-notifier-error-inject.c new file mode 100644 index 000000000..bb930f279 --- /dev/null +++ b/lib/netdev-notifier-error-inject.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +#include "notifier-error-inject.h" + +static int priority; +module_param(priority, int, 0); +MODULE_PARM_DESC(priority, "specify netdevice notifier priority"); + +static struct notifier_err_inject netdev_notifier_err_inject = { + .actions = { + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_REGISTER) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGEMTU) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGENAME) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_UP) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_TYPE_CHANGE) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_POST_INIT) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEMTU) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEUPPER) }, + { NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGEUPPER) }, + {} + } +}; + +static struct dentry *dir; + +static int netdev_err_inject_init(void) +{ + int err; + + dir = notifier_err_inject_init("netdev", notifier_err_inject_dir, + &netdev_notifier_err_inject, priority); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + err = register_netdevice_notifier(&netdev_notifier_err_inject.nb); + if (err) + debugfs_remove_recursive(dir); + + return err; +} + +static void netdev_err_inject_exit(void) +{ + unregister_netdevice_notifier(&netdev_notifier_err_inject.nb); + debugfs_remove_recursive(dir); +} + +module_init(netdev_err_inject_init); +module_exit(netdev_err_inject_exit); + +MODULE_DESCRIPTION("Netdevice notifier error injection module"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Nikolay Aleksandrov "); -- cgit v1.3.1