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 --- net/atm/atm_sysfs.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100644 net/atm/atm_sysfs.c (limited to 'net/atm/atm_sysfs.c') diff --git a/net/atm/atm_sysfs.c b/net/atm/atm_sysfs.c new file mode 100644 index 000000000..0676a9c33 --- /dev/null +++ b/net/atm/atm_sysfs.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0 +/* ATM driver model support. */ + +#include +#include +#include +#include +#include +#include "common.h" +#include "resources.h" + +#define to_atm_dev(cldev) container_of(cldev, struct atm_dev, class_dev) + +static ssize_t type_show(struct device *cdev, + struct device_attribute *attr, char *buf) +{ + struct atm_dev *adev = to_atm_dev(cdev); + + return scnprintf(buf, PAGE_SIZE, "%s\n", adev->type); +} + +static ssize_t address_show(struct device *cdev, + struct device_attribute *attr, char *buf) +{ + struct atm_dev *adev = to_atm_dev(cdev); + + return scnprintf(buf, PAGE_SIZE, "%pM\n", adev->esi); +} + +static ssize_t atmindex_show(struct device *cdev, + struct device_attribute *attr, char *buf) +{ + struct atm_dev *adev = to_atm_dev(cdev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", adev->number); +} + +static ssize_t carrier_show(struct device *cdev, + struct device_attribute *attr, char *buf) +{ + struct atm_dev *adev = to_atm_dev(cdev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", + adev->signal == ATM_PHY_SIG_LOST ? 0 : 1); +} + +static ssize_t link_rate_show(struct device *cdev, + struct device_attribute *attr, char *buf) +{ + struct atm_dev *adev = to_atm_dev(cdev); + int link_rate; + + /* show the link rate, not the data rate */ + switch (adev->link_rate) { + case ATM_OC3_PCR: + link_rate = 155520000; + break; + case ATM_OC12_PCR: + link_rate = 622080000; + break; + case ATM_25_PCR: + link_rate = 25600000; + break; + default: + link_rate = adev->link_rate * 8 * 53; + } + return scnprintf(buf, PAGE_SIZE, "%d\n", link_rate); +} + +static DEVICE_ATTR_RO(address); +static DEVICE_ATTR_RO(atmindex); +static DEVICE_ATTR_RO(carrier); +static DEVICE_ATTR_RO(type); +static DEVICE_ATTR_RO(link_rate); + +static struct device_attribute *atm_attrs[] = { + &dev_attr_address, + &dev_attr_atmindex, + &dev_attr_carrier, + &dev_attr_type, + &dev_attr_link_rate, + NULL +}; + + +static int atm_uevent(const struct device *cdev, struct kobj_uevent_env *env) +{ + const struct atm_dev *adev; + + if (!cdev) + return -ENODEV; + + adev = to_atm_dev(cdev); + + if (add_uevent_var(env, "NAME=%s%d", adev->type, adev->number)) + return -ENOMEM; + + return 0; +} + +static void atm_release(struct device *cdev) +{ + struct atm_dev *adev = to_atm_dev(cdev); + + kfree(adev); +} + +static struct class atm_class = { + .name = "atm", + .dev_release = atm_release, + .dev_uevent = atm_uevent, +}; + +int atm_register_sysfs(struct atm_dev *adev, struct device *parent) +{ + struct device *cdev = &adev->class_dev; + int i, j, err; + + cdev->class = &atm_class; + cdev->parent = parent; + dev_set_drvdata(cdev, adev); + + dev_set_name(cdev, "%s%d", adev->type, adev->number); + err = device_register(cdev); + if (err < 0) + return err; + + for (i = 0; atm_attrs[i]; i++) { + err = device_create_file(cdev, atm_attrs[i]); + if (err) + goto err_out; + } + + return 0; + +err_out: + for (j = 0; j < i; j++) + device_remove_file(cdev, atm_attrs[j]); + device_del(cdev); + return err; +} + +void atm_unregister_sysfs(struct atm_dev *adev) +{ + struct device *cdev = &adev->class_dev; + + device_del(cdev); +} + +int __init atm_sysfs_init(void) +{ + return class_register(&atm_class); +} + +void __exit atm_sysfs_exit(void) +{ + class_unregister(&atm_class); +} -- cgit v1.3.1