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/acpi/ec_sys.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 drivers/acpi/ec_sys.c (limited to 'drivers/acpi/ec_sys.c') diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c new file mode 100644 index 000000000..c074a0fae --- /dev/null +++ b/drivers/acpi/ec_sys.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ec_sys.c + * + * Copyright (C) 2010 SUSE Products GmbH/Novell + * Author: + * Thomas Renninger + */ + +#include +#include +#include +#include +#include +#include "internal.h" + +MODULE_AUTHOR("Thomas Renninger "); +MODULE_DESCRIPTION("ACPI EC sysfs access driver"); +MODULE_LICENSE("GPL"); + +static bool write_support; +module_param_hw(write_support, bool, other, 0644); +MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may " + "be needed."); + +#define EC_SPACE_SIZE 256 + +static struct dentry *acpi_ec_debugfs_dir; + +static ssize_t acpi_ec_read_io(struct file *f, char __user *buf, + size_t count, loff_t *off) +{ + /* Use this if support reading/writing multiple ECs exists in ec.c: + * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; + */ + unsigned int size = EC_SPACE_SIZE; + loff_t init_off = *off; + int err = 0; + + if (*off >= size) + return 0; + if (*off + count >= size) { + size -= *off; + count = size; + } else + size = count; + + while (size) { + u8 byte_read; + err = ec_read(*off, &byte_read); + if (err) + return err; + if (put_user(byte_read, buf + *off - init_off)) { + if (*off - init_off) + return *off - init_off; /* partial read */ + return -EFAULT; + } + *off += 1; + size--; + } + return count; +} + +static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf, + size_t count, loff_t *off) +{ + /* Use this if support reading/writing multiple ECs exists in ec.c: + * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; + */ + + unsigned int size = count; + loff_t init_off = *off; + int err = 0; + + if (!write_support) + return -EINVAL; + + if (*off >= EC_SPACE_SIZE) + return 0; + if (*off + count >= EC_SPACE_SIZE) { + size = EC_SPACE_SIZE - *off; + count = size; + } + + while (size) { + u8 byte_write; + if (get_user(byte_write, buf + *off - init_off)) { + if (*off - init_off) + return *off - init_off; /* partial write */ + return -EFAULT; + } + err = ec_write(*off, byte_write); + if (err) + return err; + + *off += 1; + size--; + } + return count; +} + +static const struct file_operations acpi_ec_io_ops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = acpi_ec_read_io, + .write = acpi_ec_write_io, + .llseek = default_llseek, +}; + +static void acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) +{ + struct dentry *dev_dir; + char name[64]; + umode_t mode = 0400; + + if (ec_device_count == 0) + acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); + + sprintf(name, "ec%u", ec_device_count); + dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); + + debugfs_create_x32("gpe", 0444, dev_dir, &first_ec->gpe); + debugfs_create_bool("use_global_lock", 0444, dev_dir, + &first_ec->global_lock); + + if (write_support) + mode = 0600; + debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops); +} + +static int __init acpi_ec_sys_init(void) +{ + if (first_ec) + acpi_ec_add_debugfs(first_ec, 0); + return 0; +} + +static void __exit acpi_ec_sys_exit(void) +{ + debugfs_remove_recursive(acpi_ec_debugfs_dir); +} + +module_init(acpi_ec_sys_init); +module_exit(acpi_ec_sys_exit); -- cgit v1.3.1