From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/xen/efi.c | 355 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 355 insertions(+) create mode 100644 drivers/xen/efi.c (limited to 'drivers/xen/efi.c') diff --git a/drivers/xen/efi.c b/drivers/xen/efi.c new file mode 100644 index 000000000..fb321cd64 --- /dev/null +++ b/drivers/xen/efi.c @@ -0,0 +1,355 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * EFI support for Xen. + * + * Copyright (C) 1999 VA Linux Systems + * Copyright (C) 1999 Walt Drummond + * Copyright (C) 1999-2002 Hewlett-Packard Co. + * David Mosberger-Tang + * Stephane Eranian + * Copyright (C) 2005-2008 Intel Co. + * Fenghua Yu + * Bibo Mao + * Chandramouli Narayanan + * Huang Ying + * Copyright (C) 2011 Novell Co. + * Jan Beulich + * Copyright (C) 2011-2012 Oracle Co. + * Liang Tang + * Copyright (c) 2014 Oracle Co., Daniel Kiper + */ + +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include + +#include + +#define INIT_EFI_OP(name) \ + {.cmd = XENPF_efi_runtime_call, \ + .u.efi_runtime_call.function = XEN_EFI_##name, \ + .u.efi_runtime_call.misc = 0} + +#define efi_data(op) (op.u.efi_runtime_call) + +static efi_status_t xen_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) +{ + struct xen_platform_op op = INIT_EFI_OP(get_time); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + if (tm) { + BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_time.time)); + memcpy(tm, &efi_data(op).u.get_time.time, sizeof(*tm)); + } + + if (tc) { + tc->resolution = efi_data(op).u.get_time.resolution; + tc->accuracy = efi_data(op).u.get_time.accuracy; + tc->sets_to_zero = !!(efi_data(op).misc & + XEN_EFI_GET_TIME_SET_CLEARS_NS); + } + + return efi_data(op).status; +} + +static efi_status_t xen_efi_set_time(efi_time_t *tm) +{ + struct xen_platform_op op = INIT_EFI_OP(set_time); + + BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_time)); + memcpy(&efi_data(op).u.set_time, tm, sizeof(*tm)); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_get_wakeup_time(efi_bool_t *enabled, + efi_bool_t *pending, + efi_time_t *tm) +{ + struct xen_platform_op op = INIT_EFI_OP(get_wakeup_time); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + if (tm) { + BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_wakeup_time)); + memcpy(tm, &efi_data(op).u.get_wakeup_time, sizeof(*tm)); + } + + if (enabled) + *enabled = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_ENABLED); + + if (pending) + *pending = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_PENDING); + + return efi_data(op).status; +} + +static efi_status_t xen_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) +{ + struct xen_platform_op op = INIT_EFI_OP(set_wakeup_time); + + BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_wakeup_time)); + if (enabled) + efi_data(op).misc = XEN_EFI_SET_WAKEUP_TIME_ENABLE; + if (tm) + memcpy(&efi_data(op).u.set_wakeup_time, tm, sizeof(*tm)); + else + efi_data(op).misc |= XEN_EFI_SET_WAKEUP_TIME_ENABLE_ONLY; + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_get_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 *attr, unsigned long *data_size, + void *data) +{ + struct xen_platform_op op = INIT_EFI_OP(get_variable); + + set_xen_guest_handle(efi_data(op).u.get_variable.name, name); + BUILD_BUG_ON(sizeof(*vendor) != + sizeof(efi_data(op).u.get_variable.vendor_guid)); + memcpy(&efi_data(op).u.get_variable.vendor_guid, vendor, sizeof(*vendor)); + efi_data(op).u.get_variable.size = *data_size; + set_xen_guest_handle(efi_data(op).u.get_variable.data, data); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + *data_size = efi_data(op).u.get_variable.size; + if (attr) + *attr = efi_data(op).misc; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_get_next_variable(unsigned long *name_size, + efi_char16_t *name, + efi_guid_t *vendor) +{ + struct xen_platform_op op = INIT_EFI_OP(get_next_variable_name); + + efi_data(op).u.get_next_variable_name.size = *name_size; + set_xen_guest_handle(efi_data(op).u.get_next_variable_name.name, name); + BUILD_BUG_ON(sizeof(*vendor) != + sizeof(efi_data(op).u.get_next_variable_name.vendor_guid)); + memcpy(&efi_data(op).u.get_next_variable_name.vendor_guid, vendor, + sizeof(*vendor)); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + *name_size = efi_data(op).u.get_next_variable_name.size; + memcpy(vendor, &efi_data(op).u.get_next_variable_name.vendor_guid, + sizeof(*vendor)); + + return efi_data(op).status; +} + +static efi_status_t xen_efi_set_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 attr, unsigned long data_size, + void *data) +{ + struct xen_platform_op op = INIT_EFI_OP(set_variable); + + set_xen_guest_handle(efi_data(op).u.set_variable.name, name); + efi_data(op).misc = attr; + BUILD_BUG_ON(sizeof(*vendor) != + sizeof(efi_data(op).u.set_variable.vendor_guid)); + memcpy(&efi_data(op).u.set_variable.vendor_guid, vendor, sizeof(*vendor)); + efi_data(op).u.set_variable.size = data_size; + set_xen_guest_handle(efi_data(op).u.set_variable.data, data); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_query_variable_info(u32 attr, u64 *storage_space, + u64 *remaining_space, + u64 *max_variable_size) +{ + struct xen_platform_op op = INIT_EFI_OP(query_variable_info); + + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) + return EFI_UNSUPPORTED; + + efi_data(op).u.query_variable_info.attr = attr; + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + *storage_space = efi_data(op).u.query_variable_info.max_store_size; + *remaining_space = efi_data(op).u.query_variable_info.remain_store_size; + *max_variable_size = efi_data(op).u.query_variable_info.max_size; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_get_next_high_mono_count(u32 *count) +{ + struct xen_platform_op op = INIT_EFI_OP(get_next_high_monotonic_count); + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + *count = efi_data(op).misc; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules, + unsigned long count, unsigned long sg_list) +{ + struct xen_platform_op op = INIT_EFI_OP(update_capsule); + + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) + return EFI_UNSUPPORTED; + + set_xen_guest_handle(efi_data(op).u.update_capsule.capsule_header_array, + capsules); + efi_data(op).u.update_capsule.capsule_count = count; + efi_data(op).u.update_capsule.sg_list = sg_list; + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + return efi_data(op).status; +} + +static efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules, + unsigned long count, u64 *max_size, int *reset_type) +{ + struct xen_platform_op op = INIT_EFI_OP(query_capsule_capabilities); + + if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) + return EFI_UNSUPPORTED; + + set_xen_guest_handle(efi_data(op).u.query_capsule_capabilities.capsule_header_array, + capsules); + efi_data(op).u.query_capsule_capabilities.capsule_count = count; + + if (HYPERVISOR_platform_op(&op) < 0) + return EFI_UNSUPPORTED; + + *max_size = efi_data(op).u.query_capsule_capabilities.max_capsule_size; + *reset_type = efi_data(op).u.query_capsule_capabilities.reset_type; + + return efi_data(op).status; +} + +static void xen_efi_reset_system(int reset_type, efi_status_t status, + unsigned long data_size, efi_char16_t *data) +{ + switch (reset_type) { + case EFI_RESET_COLD: + case EFI_RESET_WARM: + xen_reboot(SHUTDOWN_reboot); + break; + case EFI_RESET_SHUTDOWN: + xen_reboot(SHUTDOWN_poweroff); + break; + default: + BUG(); + } +} + +/* + * Set XEN EFI runtime services function pointers. Other fields of struct efi, + * e.g. efi.systab, will be set like normal EFI. + */ +void __init xen_efi_runtime_setup(void) +{ + efi.get_time = xen_efi_get_time; + efi.set_time = xen_efi_set_time; + efi.get_wakeup_time = xen_efi_get_wakeup_time; + efi.set_wakeup_time = xen_efi_set_wakeup_time; + efi.get_variable = xen_efi_get_variable; + efi.get_next_variable = xen_efi_get_next_variable; + efi.set_variable = xen_efi_set_variable; + efi.set_variable_nonblocking = xen_efi_set_variable; + efi.query_variable_info = xen_efi_query_variable_info; + efi.query_variable_info_nonblocking = xen_efi_query_variable_info; + efi.update_capsule = xen_efi_update_capsule; + efi.query_capsule_caps = xen_efi_query_capsule_caps; + efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count; + efi.reset_system = xen_efi_reset_system; +} + +int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) +{ + static_assert(XEN_PAGE_SHIFT == EFI_PAGE_SHIFT, + "Mismatch between EFI_PAGE_SHIFT and XEN_PAGE_SHIFT"); + struct xen_platform_op op; + union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info; + int rc; + + if (!efi_enabled(EFI_PARAVIRT) || efi_enabled(EFI_MEMMAP)) + return __efi_mem_desc_lookup(phys_addr, out_md); + phys_addr &= ~(u64)(EFI_PAGE_SIZE - 1); + op = (struct xen_platform_op) { + .cmd = XENPF_firmware_info, + .u.firmware_info = { + .type = XEN_FW_EFI_INFO, + .index = XEN_FW_EFI_MEM_INFO, + .u.efi_info.mem.addr = phys_addr, + .u.efi_info.mem.size = U64_MAX - phys_addr, + }, + }; + + rc = HYPERVISOR_platform_op(&op); + if (rc) { + pr_warn("Failed to lookup header 0x%llx in Xen memory map: error %d\n", + phys_addr, rc); + } + + out_md->phys_addr = info->mem.addr; + out_md->num_pages = info->mem.size >> EFI_PAGE_SHIFT; + out_md->type = info->mem.type; + out_md->attribute = info->mem.attr; + + return 0; +} + +bool __init xen_efi_config_table_is_usable(const efi_guid_t *guid, + unsigned long table) +{ + efi_memory_desc_t md; + int rc; + + if (!efi_enabled(EFI_PARAVIRT)) + return true; + + rc = efi_mem_desc_lookup(table, &md); + if (rc) + return false; + + switch (md.type) { + case EFI_RUNTIME_SERVICES_CODE: + case EFI_RUNTIME_SERVICES_DATA: + case EFI_ACPI_RECLAIM_MEMORY: + case EFI_ACPI_MEMORY_NVS: + case EFI_RESERVED_TYPE: + return true; + default: + return false; + } +} -- cgit v1.3.1