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/base/regmap/regmap-fsi.c | 231 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 231 insertions(+) create mode 100644 drivers/base/regmap/regmap-fsi.c (limited to 'drivers/base/regmap/regmap-fsi.c') diff --git a/drivers/base/regmap/regmap-fsi.c b/drivers/base/regmap/regmap-fsi.c new file mode 100644 index 000000000..3d2f3cb31 --- /dev/null +++ b/drivers/base/regmap/regmap-fsi.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register map access API - FSI support +// +// Copyright 2022 IBM Corp +// +// Author: Eddie James + +#include +#include +#include + +#include "internal.h" + +static int regmap_fsi32_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + u32 v; + int ret; + + ret = fsi_slave_read(context, reg, &v, sizeof(v)); + if (ret) + return ret; + + *val = v; + return 0; +} + +static int regmap_fsi32_reg_write(void *context, unsigned int reg, unsigned int val) +{ + u32 v = val; + + return fsi_slave_write(context, reg, &v, sizeof(v)); +} + +static const struct regmap_bus regmap_fsi32 = { + .reg_write = regmap_fsi32_reg_write, + .reg_read = regmap_fsi32_reg_read, +}; + +static int regmap_fsi32le_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + __be32 v; + int ret; + + ret = fsi_slave_read(context, reg, &v, sizeof(v)); + if (ret) + return ret; + + *val = be32_to_cpu(v); + return 0; +} + +static int regmap_fsi32le_reg_write(void *context, unsigned int reg, unsigned int val) +{ + __be32 v = cpu_to_be32(val); + + return fsi_slave_write(context, reg, &v, sizeof(v)); +} + +static const struct regmap_bus regmap_fsi32le = { + .reg_write = regmap_fsi32le_reg_write, + .reg_read = regmap_fsi32le_reg_read, +}; + +static int regmap_fsi16_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + u16 v; + int ret; + + ret = fsi_slave_read(context, reg, &v, sizeof(v)); + if (ret) + return ret; + + *val = v; + return 0; +} + +static int regmap_fsi16_reg_write(void *context, unsigned int reg, unsigned int val) +{ + u16 v; + + if (val > 0xffff) + return -EINVAL; + + v = val; + return fsi_slave_write(context, reg, &v, sizeof(v)); +} + +static const struct regmap_bus regmap_fsi16 = { + .reg_write = regmap_fsi16_reg_write, + .reg_read = regmap_fsi16_reg_read, +}; + +static int regmap_fsi16le_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + __be16 v; + int ret; + + ret = fsi_slave_read(context, reg, &v, sizeof(v)); + if (ret) + return ret; + + *val = be16_to_cpu(v); + return 0; +} + +static int regmap_fsi16le_reg_write(void *context, unsigned int reg, unsigned int val) +{ + __be16 v; + + if (val > 0xffff) + return -EINVAL; + + v = cpu_to_be16(val); + return fsi_slave_write(context, reg, &v, sizeof(v)); +} + +static const struct regmap_bus regmap_fsi16le = { + .reg_write = regmap_fsi16le_reg_write, + .reg_read = regmap_fsi16le_reg_read, +}; + +static int regmap_fsi8_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + u8 v; + int ret; + + ret = fsi_slave_read(context, reg, &v, sizeof(v)); + if (ret) + return ret; + + *val = v; + return 0; +} + +static int regmap_fsi8_reg_write(void *context, unsigned int reg, unsigned int val) +{ + u8 v; + + if (val > 0xff) + return -EINVAL; + + v = val; + return fsi_slave_write(context, reg, &v, sizeof(v)); +} + +static const struct regmap_bus regmap_fsi8 = { + .reg_write = regmap_fsi8_reg_write, + .reg_read = regmap_fsi8_reg_read, +}; + +static const struct regmap_bus *regmap_get_fsi_bus(struct fsi_device *fsi_dev, + const struct regmap_config *config) +{ + const struct regmap_bus *bus = NULL; + + if (config->reg_bits == 8 || config->reg_bits == 16 || config->reg_bits == 32) { + switch (config->val_bits) { + case 8: + bus = ®map_fsi8; + break; + case 16: + switch (regmap_get_val_endian(&fsi_dev->dev, NULL, config)) { + case REGMAP_ENDIAN_LITTLE: +#ifdef __LITTLE_ENDIAN + case REGMAP_ENDIAN_NATIVE: +#endif + bus = ®map_fsi16le; + break; + case REGMAP_ENDIAN_DEFAULT: + case REGMAP_ENDIAN_BIG: +#ifdef __BIG_ENDIAN + case REGMAP_ENDIAN_NATIVE: +#endif + bus = ®map_fsi16; + break; + default: + break; + } + break; + case 32: + switch (regmap_get_val_endian(&fsi_dev->dev, NULL, config)) { + case REGMAP_ENDIAN_LITTLE: +#ifdef __LITTLE_ENDIAN + case REGMAP_ENDIAN_NATIVE: +#endif + bus = ®map_fsi32le; + break; + case REGMAP_ENDIAN_DEFAULT: + case REGMAP_ENDIAN_BIG: +#ifdef __BIG_ENDIAN + case REGMAP_ENDIAN_NATIVE: +#endif + bus = ®map_fsi32; + break; + default: + break; + } + break; + } + } + + return bus ?: ERR_PTR(-EOPNOTSUPP); +} + +struct regmap *__regmap_init_fsi(struct fsi_device *fsi_dev, const struct regmap_config *config, + struct lock_class_key *lock_key, const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_fsi_bus(fsi_dev, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __regmap_init(&fsi_dev->dev, bus, fsi_dev->slave, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_fsi); + +struct regmap *__devm_regmap_init_fsi(struct fsi_device *fsi_dev, + const struct regmap_config *config, + struct lock_class_key *lock_key, const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_fsi_bus(fsi_dev, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __devm_regmap_init(&fsi_dev->dev, bus, fsi_dev->slave, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_fsi); + +MODULE_LICENSE("GPL"); -- cgit v1.3.1