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/md/bcache/sysfs.h | 142 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 drivers/md/bcache/sysfs.h (limited to 'drivers/md/bcache/sysfs.h') diff --git a/drivers/md/bcache/sysfs.h b/drivers/md/bcache/sysfs.h new file mode 100644 index 000000000..65b8bd975 --- /dev/null +++ b/drivers/md/bcache/sysfs.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHE_SYSFS_H_ +#define _BCACHE_SYSFS_H_ + +#define KTYPE(type) \ +const struct kobj_type type ## _ktype = { \ + .release = type ## _release, \ + .sysfs_ops = &((const struct sysfs_ops) { \ + .show = type ## _show, \ + .store = type ## _store \ + }), \ + .default_groups = type ## _groups \ +} + +#define SHOW(fn) \ +static ssize_t fn ## _show(struct kobject *kobj, struct attribute *attr,\ + char *buf) \ + +#define STORE(fn) \ +static ssize_t fn ## _store(struct kobject *kobj, struct attribute *attr,\ + const char *buf, size_t size) \ + +#define SHOW_LOCKED(fn) \ +SHOW(fn) \ +{ \ + ssize_t ret; \ + mutex_lock(&bch_register_lock); \ + ret = __ ## fn ## _show(kobj, attr, buf); \ + mutex_unlock(&bch_register_lock); \ + return ret; \ +} + +#define STORE_LOCKED(fn) \ +STORE(fn) \ +{ \ + ssize_t ret; \ + mutex_lock(&bch_register_lock); \ + ret = __ ## fn ## _store(kobj, attr, buf, size); \ + mutex_unlock(&bch_register_lock); \ + return ret; \ +} + +#define __sysfs_attribute(_name, _mode) \ + static struct attribute sysfs_##_name = \ + { .name = #_name, .mode = _mode } + +#define write_attribute(n) __sysfs_attribute(n, 0200) +#define read_attribute(n) __sysfs_attribute(n, 0444) +#define rw_attribute(n) __sysfs_attribute(n, 0644) + +#define sysfs_printf(file, fmt, ...) \ +do { \ + if (attr == &sysfs_ ## file) \ + return sysfs_emit(buf, fmt "\n", __VA_ARGS__); \ +} while (0) + +#define sysfs_print(file, var) \ +do { \ + if (attr == &sysfs_ ## file) \ + return sysfs_emit(buf, \ + __builtin_types_compatible_p(typeof(var), int) \ + ? "%i\n" : \ + __builtin_types_compatible_p(typeof(var), unsigned int) \ + ? "%u\n" : \ + __builtin_types_compatible_p(typeof(var), long) \ + ? "%li\n" : \ + __builtin_types_compatible_p(typeof(var), unsigned long)\ + ? "%lu\n" : \ + __builtin_types_compatible_p(typeof(var), int64_t) \ + ? "%lli\n" : \ + __builtin_types_compatible_p(typeof(var), uint64_t) \ + ? "%llu\n" : \ + __builtin_types_compatible_p(typeof(var), const char *) \ + ? "%s\n" : "%i\n", var); \ +} while (0) + +#define sysfs_hprint(file, val) \ +do { \ + if (attr == &sysfs_ ## file) { \ + ssize_t ret = bch_hprint(buf, val); \ + strcat(buf, "\n"); \ + return ret + 1; \ + } \ +} while (0) + +#define var_printf(_var, fmt) sysfs_printf(_var, fmt, var(_var)) +#define var_print(_var) sysfs_print(_var, var(_var)) +#define var_hprint(_var) sysfs_hprint(_var, var(_var)) + +#define sysfs_strtoul(file, var) \ +do { \ + if (attr == &sysfs_ ## file) \ + return strtoul_safe(buf, var) ?: (ssize_t) size; \ +} while (0) + +#define sysfs_strtoul_bool(file, var) \ +do { \ + if (attr == &sysfs_ ## file) { \ + unsigned long v = strtoul_or_return(buf); \ + \ + var = v ? 1 : 0; \ + return size; \ + } \ +} while (0) + +#define sysfs_strtoul_clamp(file, var, min, max) \ +do { \ + if (attr == &sysfs_ ## file) { \ + unsigned long v = 0; \ + ssize_t ret; \ + ret = strtoul_safe_clamp(buf, v, min, max); \ + if (!ret) { \ + var = v; \ + return size; \ + } \ + return ret; \ + } \ +} while (0) + +#define strtoul_or_return(cp) \ +({ \ + unsigned long _v; \ + int _r = kstrtoul(cp, 10, &_v); \ + if (_r) \ + return _r; \ + _v; \ +}) + +#define strtoi_h_or_return(cp, v) \ +do { \ + int _r = strtoi_h(cp, &v); \ + if (_r) \ + return _r; \ +} while (0) + +#define sysfs_hatoi(file, var) \ +do { \ + if (attr == &sysfs_ ## file) \ + return strtoi_h(buf, &var) ?: (ssize_t) size; \ +} while (0) + +#endif /* _BCACHE_SYSFS_H_ */ -- cgit v1.3.1