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/rapidio/rio-access.c | 143 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 drivers/rapidio/rio-access.c (limited to 'drivers/rapidio/rio-access.c') diff --git a/drivers/rapidio/rio-access.c b/drivers/rapidio/rio-access.c new file mode 100644 index 000000000..f9e10647f --- /dev/null +++ b/drivers/rapidio/rio-access.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * RapidIO configuration space access support + * + * Copyright 2005 MontaVista Software, Inc. + * Matt Porter + */ + +#include +#include + +#include + +/* + * Wrappers for all RIO configuration access functions. They just check + * alignment and call the low-level functions pointed to by rio_mport->ops. + */ + +#define RIO_8_BAD 0 +#define RIO_16_BAD (offset & 1) +#define RIO_32_BAD (offset & 3) + +/** + * RIO_LOP_READ - Generate rio_local_read_config_* functions + * @size: Size of configuration space read (8, 16, 32 bits) + * @type: C type of value argument + * @len: Length of configuration space read (1, 2, 4 bytes) + * + * Generates rio_local_read_config_* functions used to access + * configuration space registers on the local device. + */ +#define RIO_LOP_READ(size,type,len) \ +int __rio_local_read_config_##size \ + (struct rio_mport *mport, u32 offset, type *value) \ +{ \ + int res; \ + u32 data = 0; \ + if (RIO_##size##_BAD) return RIO_BAD_SIZE; \ + res = mport->ops->lcread(mport, mport->id, offset, len, &data); \ + *value = (type)data; \ + return res; \ +} + +/** + * RIO_LOP_WRITE - Generate rio_local_write_config_* functions + * @size: Size of configuration space write (8, 16, 32 bits) + * @type: C type of value argument + * @len: Length of configuration space write (1, 2, 4 bytes) + * + * Generates rio_local_write_config_* functions used to access + * configuration space registers on the local device. + */ +#define RIO_LOP_WRITE(size,type,len) \ +int __rio_local_write_config_##size \ + (struct rio_mport *mport, u32 offset, type value) \ +{ \ + if (RIO_##size##_BAD) return RIO_BAD_SIZE; \ + return mport->ops->lcwrite(mport, mport->id, offset, len, value);\ +} + +RIO_LOP_READ(8, u8, 1) +RIO_LOP_READ(16, u16, 2) +RIO_LOP_READ(32, u32, 4) +RIO_LOP_WRITE(8, u8, 1) +RIO_LOP_WRITE(16, u16, 2) +RIO_LOP_WRITE(32, u32, 4) + +EXPORT_SYMBOL_GPL(__rio_local_read_config_8); +EXPORT_SYMBOL_GPL(__rio_local_read_config_16); +EXPORT_SYMBOL_GPL(__rio_local_read_config_32); +EXPORT_SYMBOL_GPL(__rio_local_write_config_8); +EXPORT_SYMBOL_GPL(__rio_local_write_config_16); +EXPORT_SYMBOL_GPL(__rio_local_write_config_32); + +/** + * RIO_OP_READ - Generate rio_mport_read_config_* functions + * @size: Size of configuration space read (8, 16, 32 bits) + * @type: C type of value argument + * @len: Length of configuration space read (1, 2, 4 bytes) + * + * Generates rio_mport_read_config_* functions used to access + * configuration space registers on the local device. + */ +#define RIO_OP_READ(size,type,len) \ +int rio_mport_read_config_##size \ + (struct rio_mport *mport, u16 destid, u8 hopcount, u32 offset, type *value) \ +{ \ + int res; \ + u32 data = 0; \ + if (RIO_##size##_BAD) return RIO_BAD_SIZE; \ + res = mport->ops->cread(mport, mport->id, destid, hopcount, offset, len, &data); \ + *value = (type)data; \ + return res; \ +} + +/** + * RIO_OP_WRITE - Generate rio_mport_write_config_* functions + * @size: Size of configuration space write (8, 16, 32 bits) + * @type: C type of value argument + * @len: Length of configuration space write (1, 2, 4 bytes) + * + * Generates rio_mport_write_config_* functions used to access + * configuration space registers on the local device. + */ +#define RIO_OP_WRITE(size,type,len) \ +int rio_mport_write_config_##size \ + (struct rio_mport *mport, u16 destid, u8 hopcount, u32 offset, type value) \ +{ \ + if (RIO_##size##_BAD) return RIO_BAD_SIZE; \ + return mport->ops->cwrite(mport, mport->id, destid, hopcount, \ + offset, len, value); \ +} + +RIO_OP_READ(8, u8, 1) +RIO_OP_READ(16, u16, 2) +RIO_OP_READ(32, u32, 4) +RIO_OP_WRITE(8, u8, 1) +RIO_OP_WRITE(16, u16, 2) +RIO_OP_WRITE(32, u32, 4) + +EXPORT_SYMBOL_GPL(rio_mport_read_config_8); +EXPORT_SYMBOL_GPL(rio_mport_read_config_16); +EXPORT_SYMBOL_GPL(rio_mport_read_config_32); +EXPORT_SYMBOL_GPL(rio_mport_write_config_8); +EXPORT_SYMBOL_GPL(rio_mport_write_config_16); +EXPORT_SYMBOL_GPL(rio_mport_write_config_32); + +/** + * rio_mport_send_doorbell - Send a doorbell message + * + * @mport: RIO master port + * @destid: RIO device destination ID + * @data: Doorbell message data + * + * Send a doorbell message to a RIO device. The doorbell message + * has a 16-bit info field provided by the data argument. + */ +int rio_mport_send_doorbell(struct rio_mport *mport, u16 destid, u16 data) +{ + return mport->ops->dsend(mport, mport->id, destid, data); +} + +EXPORT_SYMBOL_GPL(rio_mport_send_doorbell); -- cgit v1.3.1