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/reset/tegra/Kconfig | 4 +++ drivers/reset/tegra/Makefile | 2 ++ drivers/reset/tegra/reset-bpmp.c | 75 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) create mode 100644 drivers/reset/tegra/Kconfig create mode 100644 drivers/reset/tegra/Makefile create mode 100644 drivers/reset/tegra/reset-bpmp.c (limited to 'drivers/reset/tegra') diff --git a/drivers/reset/tegra/Kconfig b/drivers/reset/tegra/Kconfig new file mode 100644 index 000000000..4a2d26d12 --- /dev/null +++ b/drivers/reset/tegra/Kconfig @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +config RESET_TEGRA_BPMP + bool "Tegra BPMP Reset Driver" if COMPILE_TEST + default TEGRA_BPMP diff --git a/drivers/reset/tegra/Makefile b/drivers/reset/tegra/Makefile new file mode 100644 index 000000000..eccba896a --- /dev/null +++ b/drivers/reset/tegra/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_RESET_TEGRA_BPMP) += reset-bpmp.o diff --git a/drivers/reset/tegra/reset-bpmp.c b/drivers/reset/tegra/reset-bpmp.c new file mode 100644 index 000000000..4c5bba52b --- /dev/null +++ b/drivers/reset/tegra/reset-bpmp.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 NVIDIA Corporation + */ + +#include + +#include +#include + +static struct tegra_bpmp *to_tegra_bpmp(struct reset_controller_dev *rstc) +{ + return container_of(rstc, struct tegra_bpmp, rstc); +} + +static int tegra_bpmp_reset_common(struct reset_controller_dev *rstc, + enum mrq_reset_commands command, + unsigned int id) +{ + struct tegra_bpmp *bpmp = to_tegra_bpmp(rstc); + struct mrq_reset_request request; + struct tegra_bpmp_message msg; + int err; + + memset(&request, 0, sizeof(request)); + request.cmd = command; + request.reset_id = id; + + memset(&msg, 0, sizeof(msg)); + msg.mrq = MRQ_RESET; + msg.tx.data = &request; + msg.tx.size = sizeof(request); + + err = tegra_bpmp_transfer(bpmp, &msg); + if (err) + return err; + if (msg.rx.ret) + return -EINVAL; + + return 0; +} + +static int tegra_bpmp_reset_module(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_MODULE, id); +} + +static int tegra_bpmp_reset_assert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_ASSERT, id); +} + +static int tegra_bpmp_reset_deassert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_DEASSERT, id); +} + +static const struct reset_control_ops tegra_bpmp_reset_ops = { + .reset = tegra_bpmp_reset_module, + .assert = tegra_bpmp_reset_assert, + .deassert = tegra_bpmp_reset_deassert, +}; + +int tegra_bpmp_init_resets(struct tegra_bpmp *bpmp) +{ + bpmp->rstc.ops = &tegra_bpmp_reset_ops; + bpmp->rstc.owner = THIS_MODULE; + bpmp->rstc.of_node = bpmp->dev->of_node; + bpmp->rstc.nr_resets = bpmp->soc->num_resets; + + return devm_reset_controller_register(bpmp->dev, &bpmp->rstc); +} -- cgit v1.3.1