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/pci/remove.c | 187 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 187 insertions(+) create mode 100644 drivers/pci/remove.c (limited to 'drivers/pci/remove.c') diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c new file mode 100644 index 000000000..e711ac1d4 --- /dev/null +++ b/drivers/pci/remove.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +#include "pci.h" + +static void pci_free_resources(struct pci_dev *dev) +{ + struct resource *res; + + pci_dev_for_each_resource(dev, res) { + if (res->parent) + release_resource(res); + } +} + +static void pci_stop_dev(struct pci_dev *dev) +{ + pci_pme_active(dev, false); + + if (!pci_dev_test_and_clear_added(dev)) + return; + + device_release_driver(&dev->dev); + pci_proc_detach_device(dev); + of_pci_remove_node(dev); +} + +static void pci_destroy_dev(struct pci_dev *dev) +{ + if (pci_dev_test_and_set_removed(dev)) + return; + + platform_pci_remove_wake(dev); + pci_doe_sysfs_teardown(dev); + pci_npem_remove(dev); + + /* + * While device is in D0 drop the device from TSM link operations + * including unbind and disconnect (IDE + SPDM teardown). + */ + pci_tsm_destroy(dev); + + device_del(&dev->dev); + + down_write(&pci_bus_sem); + list_del(&dev->bus_list); + up_write(&pci_bus_sem); + + pci_doe_destroy(dev); + pci_ide_destroy(dev); + pcie_aspm_exit_link_state(dev); + pci_bridge_d3_update(dev); + pci_free_resources(dev); + put_device(&dev->dev); +} + +void pci_remove_bus(struct pci_bus *bus) +{ + pci_proc_detach_bus(bus); + + down_write(&pci_bus_sem); + list_del(&bus->node); + pci_bus_release_busn_res(bus); + up_write(&pci_bus_sem); + if (bus->ops->remove_bus) + bus->ops->remove_bus(bus); + + pcibios_remove_bus(bus); + device_unregister(&bus->dev); +} +EXPORT_SYMBOL(pci_remove_bus); + +static void pci_stop_bus_device(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->subordinate; + struct pci_dev *child, *tmp; + + /* + * Stopping an SR-IOV PF device removes all the associated VFs, + * which will update the bus->devices list and confuse the + * iterator. Therefore, iterate in reverse so we remove the VFs + * first, then the PF. + */ + if (bus) { + list_for_each_entry_safe_reverse(child, tmp, + &bus->devices, bus_list) + pci_stop_bus_device(child); + } + + pci_stop_dev(dev); +} + +static void pci_remove_bus_device(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->subordinate; + struct pci_dev *child, *tmp; + + if (bus) { + list_for_each_entry_safe(child, tmp, + &bus->devices, bus_list) + pci_remove_bus_device(child); + + pci_remove_bus(bus); + dev->subordinate = NULL; + } + + pci_destroy_dev(dev); +} + +/** + * pci_stop_and_remove_bus_device - remove a PCI device and any children + * @dev: the device to remove + * + * Remove a PCI device from the device lists, informing the drivers + * that the device has been removed. We also remove any subordinate + * buses and children in a depth-first manner. + * + * For each device we remove, delete the device structure from the + * device lists, remove the /proc entry, and notify userspace + * (/sbin/hotplug). + */ +void pci_stop_and_remove_bus_device(struct pci_dev *dev) +{ + lockdep_assert_held(&pci_rescan_remove_lock); + pci_stop_bus_device(dev); + pci_remove_bus_device(dev); +} +EXPORT_SYMBOL(pci_stop_and_remove_bus_device); + +void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev) +{ + pci_lock_rescan_remove(); + pci_stop_and_remove_bus_device(dev); + pci_unlock_rescan_remove(); +} +EXPORT_SYMBOL_GPL(pci_stop_and_remove_bus_device_locked); + +void pci_stop_root_bus(struct pci_bus *bus) +{ + struct pci_dev *child, *tmp; + struct pci_host_bridge *host_bridge; + + if (!pci_is_root_bus(bus)) + return; + + host_bridge = to_pci_host_bridge(bus->bridge); + list_for_each_entry_safe_reverse(child, tmp, + &bus->devices, bus_list) + pci_stop_bus_device(child); + + of_pci_remove_host_bridge_node(host_bridge); + + /* stop the host bridge */ + device_release_driver(&host_bridge->dev); +} +EXPORT_SYMBOL_GPL(pci_stop_root_bus); + +void pci_remove_root_bus(struct pci_bus *bus) +{ + struct pci_dev *child, *tmp; + struct pci_host_bridge *host_bridge; + + if (!pci_is_root_bus(bus)) + return; + + host_bridge = to_pci_host_bridge(bus->bridge); + list_for_each_entry_safe(child, tmp, + &bus->devices, bus_list) + pci_remove_bus_device(child); + +#ifdef CONFIG_PCI_DOMAINS_GENERIC + /* Release domain_nr if it was dynamically allocated */ + if (host_bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) + pci_bus_release_domain_nr(host_bridge->dev.parent, bus->domain_nr); +#endif + + pci_remove_bus(bus); + host_bridge->bus = NULL; + + /* remove the host bridge */ + device_del(&host_bridge->dev); +} +EXPORT_SYMBOL_GPL(pci_remove_root_bus); -- cgit v1.3.1