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/firmware/efi/reboot.c | 78 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 drivers/firmware/efi/reboot.c (limited to 'drivers/firmware/efi/reboot.c') diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c new file mode 100644 index 000000000..ceae84c19 --- /dev/null +++ b/drivers/firmware/efi/reboot.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2014 Intel Corporation; author Matt Fleming + * Copyright (c) 2014 Red Hat, Inc., Mark Salter + */ +#include +#include + +static struct sys_off_handler *efi_sys_off_handler; + +int efi_reboot_quirk_mode = -1; + +void efi_reboot(enum reboot_mode reboot_mode, const char *__unused) +{ + const char *str[] = { "cold", "warm", "shutdown", "platform" }; + int efi_mode, cap_reset_mode; + + if (!efi_rt_services_supported(EFI_RT_SUPPORTED_RESET_SYSTEM)) + return; + + switch (reboot_mode) { + case REBOOT_WARM: + case REBOOT_SOFT: + efi_mode = EFI_RESET_WARM; + break; + default: + efi_mode = EFI_RESET_COLD; + break; + } + + /* + * If a quirk forced an EFI reset mode, always use that. + */ + if (efi_reboot_quirk_mode != -1) + efi_mode = efi_reboot_quirk_mode; + + if (efi_capsule_pending(&cap_reset_mode)) { + if (efi_mode != cap_reset_mode) + printk(KERN_CRIT "efi: %s reset requested but pending " + "capsule update requires %s reset... Performing " + "%s reset.\n", str[efi_mode], str[cap_reset_mode], + str[cap_reset_mode]); + efi_mode = cap_reset_mode; + } + + efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL); +} + +bool __weak efi_poweroff_required(void) +{ + return false; +} + +static int efi_power_off(struct sys_off_data *data) +{ + efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL); + + return NOTIFY_DONE; +} + +static int __init efi_shutdown_init(void) +{ + if (!efi_rt_services_supported(EFI_RT_SUPPORTED_RESET_SYSTEM)) + return -ENODEV; + + if (efi_poweroff_required()) { + /* SYS_OFF_PRIO_FIRMWARE + 1 so that it runs before acpi_power_off */ + efi_sys_off_handler = + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_FIRMWARE + 1, + efi_power_off, NULL); + if (IS_ERR(efi_sys_off_handler)) + return PTR_ERR(efi_sys_off_handler); + } + + return 0; +} +late_initcall(efi_shutdown_init); -- cgit v1.3.1