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/net/mdio/mdio-thunder.c | 148 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 drivers/net/mdio/mdio-thunder.c (limited to 'drivers/net/mdio/mdio-thunder.c') diff --git a/drivers/net/mdio/mdio-thunder.c b/drivers/net/mdio/mdio-thunder.c new file mode 100644 index 000000000..a3047f725 --- /dev/null +++ b/drivers/net/mdio/mdio-thunder.c @@ -0,0 +1,148 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2009-2016 Cavium, Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mdio-cavium.h" + +struct thunder_mdiobus_nexus { + void __iomem *bar0; + struct cavium_mdiobus *buses[4]; +}; + +static int thunder_mdiobus_pci_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + struct device_node *node; + struct thunder_mdiobus_nexus *nexus; + int err; + int i; + + nexus = devm_kzalloc(&pdev->dev, sizeof(*nexus), GFP_KERNEL); + if (!nexus) + return -ENOMEM; + + pci_set_drvdata(pdev, nexus); + + err = pcim_enable_device(pdev); + if (err) { + dev_err(&pdev->dev, "Failed to enable PCI device\n"); + pci_set_drvdata(pdev, NULL); + return err; + } + + err = pcim_request_all_regions(pdev, KBUILD_MODNAME); + if (err) { + dev_err(&pdev->dev, "pcim_request_all_regions failed\n"); + goto err_disable_device; + } + + nexus->bar0 = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0)); + if (!nexus->bar0) { + err = -ENOMEM; + goto err_disable_device; + } + + i = 0; + device_for_each_child_node_scoped(&pdev->dev, fwn) { + struct resource r; + struct mii_bus *mii_bus; + struct cavium_mdiobus *bus; + union cvmx_smix_en smi_en; + + /* If it is not an OF node we cannot handle it yet, so + * exit the loop. + */ + node = to_of_node(fwn); + if (!node) + break; + + err = of_address_to_resource(node, 0, &r); + if (err) { + dev_err(&pdev->dev, + "Couldn't translate address for \"%pOFn\"\n", + node); + break; + } + + mii_bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*bus)); + if (!mii_bus) + break; + bus = mii_bus->priv; + bus->mii_bus = mii_bus; + + nexus->buses[i] = bus; + i++; + + bus->register_base = nexus->bar0 + + r.start - pci_resource_start(pdev, 0); + + smi_en.u64 = 0; + smi_en.s.en = 1; + oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN); + bus->mii_bus->name = KBUILD_MODNAME; + snprintf(bus->mii_bus->id, MII_BUS_ID_SIZE, "%llx", r.start); + bus->mii_bus->parent = &pdev->dev; + bus->mii_bus->read = cavium_mdiobus_read_c22; + bus->mii_bus->write = cavium_mdiobus_write_c22; + bus->mii_bus->read_c45 = cavium_mdiobus_read_c45; + bus->mii_bus->write_c45 = cavium_mdiobus_write_c45; + + err = of_mdiobus_register(bus->mii_bus, node); + if (err) + dev_err(&pdev->dev, "of_mdiobus_register failed\n"); + + dev_info(&pdev->dev, "Added bus at %llx\n", r.start); + if (i >= ARRAY_SIZE(nexus->buses)) + break; + } + return 0; + +err_disable_device: + pci_set_drvdata(pdev, NULL); + return err; +} + +static void thunder_mdiobus_pci_remove(struct pci_dev *pdev) +{ + int i; + struct thunder_mdiobus_nexus *nexus = pci_get_drvdata(pdev); + + for (i = 0; i < ARRAY_SIZE(nexus->buses); i++) { + struct cavium_mdiobus *bus = nexus->buses[i]; + + if (!bus) + continue; + + mdiobus_unregister(bus->mii_bus); + oct_mdio_writeq(0, bus->register_base + SMI_EN); + } + pci_set_drvdata(pdev, NULL); +} + +static const struct pci_device_id thunder_mdiobus_id_table[] = { + { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa02b) }, + { 0, } /* End of table. */ +}; +MODULE_DEVICE_TABLE(pci, thunder_mdiobus_id_table); + +static struct pci_driver thunder_mdiobus_driver = { + .name = KBUILD_MODNAME, + .id_table = thunder_mdiobus_id_table, + .probe = thunder_mdiobus_pci_probe, + .remove = thunder_mdiobus_pci_remove, +}; + +module_pci_driver(thunder_mdiobus_driver); + +MODULE_DESCRIPTION("Cavium ThunderX MDIO bus driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1