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/imx/misc.c | 137 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 drivers/firmware/imx/misc.c (limited to 'drivers/firmware/imx/misc.c') diff --git a/drivers/firmware/imx/misc.c b/drivers/firmware/imx/misc.c new file mode 100644 index 000000000..d073cb3ce --- /dev/null +++ b/drivers/firmware/imx/misc.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2016 Freescale Semiconductor, Inc. + * Copyright 2017~2018 NXP + * Author: Dong Aisheng + * + * File containing client-side RPC functions for the MISC service. These + * function are ported to clients that communicate to the SC. + * + */ + +#include + +struct imx_sc_msg_req_misc_set_ctrl { + struct imx_sc_rpc_msg hdr; + u32 ctrl; + u32 val; + u16 resource; +} __packed __aligned(4); + +struct imx_sc_msg_req_cpu_start { + struct imx_sc_rpc_msg hdr; + u32 address_hi; + u32 address_lo; + u16 resource; + u8 enable; +} __packed __aligned(4); + +struct imx_sc_msg_req_misc_get_ctrl { + struct imx_sc_rpc_msg hdr; + u32 ctrl; + u16 resource; +} __packed __aligned(4); + +struct imx_sc_msg_resp_misc_get_ctrl { + struct imx_sc_rpc_msg hdr; + u32 val; +} __packed __aligned(4); + +/* + * This function sets a miscellaneous control value. + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * @param[in] ctrl control to change + * @param[in] val value to apply to the control + * + * @return Returns 0 for success and < 0 for errors. + */ + +int imx_sc_misc_set_control(struct imx_sc_ipc *ipc, u32 resource, + u8 ctrl, u32 val) +{ + struct imx_sc_msg_req_misc_set_ctrl msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = (uint8_t)IMX_SC_RPC_SVC_MISC; + hdr->func = (uint8_t)IMX_SC_MISC_FUNC_SET_CONTROL; + hdr->size = 4; + + msg.ctrl = ctrl; + msg.val = val; + msg.resource = resource; + + return imx_scu_call_rpc(ipc, &msg, true); +} +EXPORT_SYMBOL(imx_sc_misc_set_control); + +/* + * This function gets a miscellaneous control value. + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * @param[in] ctrl control to get + * @param[out] val pointer to return the control value + * + * @return Returns 0 for success and < 0 for errors. + */ + +int imx_sc_misc_get_control(struct imx_sc_ipc *ipc, u32 resource, + u8 ctrl, u32 *val) +{ + struct imx_sc_msg_req_misc_get_ctrl msg; + struct imx_sc_msg_resp_misc_get_ctrl *resp; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + int ret; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = (uint8_t)IMX_SC_RPC_SVC_MISC; + hdr->func = (uint8_t)IMX_SC_MISC_FUNC_GET_CONTROL; + hdr->size = 3; + + msg.ctrl = ctrl; + msg.resource = resource; + + ret = imx_scu_call_rpc(ipc, &msg, true); + if (ret) + return ret; + + resp = (struct imx_sc_msg_resp_misc_get_ctrl *)&msg; + if (val != NULL) + *val = resp->val; + + return 0; +} +EXPORT_SYMBOL(imx_sc_misc_get_control); + +/* + * This function starts/stops a CPU identified by @resource + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * @param[in] enable true for start, false for stop + * @param[in] phys_addr initial instruction address to be executed + * + * @return Returns 0 for success and < 0 for errors. + */ +int imx_sc_pm_cpu_start(struct imx_sc_ipc *ipc, u32 resource, + bool enable, u64 phys_addr) +{ + struct imx_sc_msg_req_cpu_start msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_PM; + hdr->func = IMX_SC_PM_FUNC_CPU_START; + hdr->size = 4; + + msg.address_hi = phys_addr >> 32; + msg.address_lo = phys_addr; + msg.resource = resource; + msg.enable = enable; + + return imx_scu_call_rpc(ipc, &msg, true); +} +EXPORT_SYMBOL(imx_sc_pm_cpu_start); -- cgit v1.3.1