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/usb/host/ehci-grlib.c | 177 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 drivers/usb/host/ehci-grlib.c (limited to 'drivers/usb/host/ehci-grlib.c') diff --git a/drivers/usb/host/ehci-grlib.c b/drivers/usb/host/ehci-grlib.c new file mode 100644 index 000000000..bd9762eaa --- /dev/null +++ b/drivers/usb/host/ehci-grlib.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for Aeroflex Gaisler GRLIB GRUSBHC EHCI host controller + * + * GRUSBHC is typically found on LEON/GRLIB SoCs + * + * (c) Jan Andersson + * + * Based on ehci-ppc-of.c which is: + * (c) Valentine Barshak + * and in turn based on "ehci-ppc-soc.c" by Stefan Roese + * and "ohci-ppc-of.c" by Sylvain Munaut + */ + +#include +#include + +#include +#include +#include + +#define GRUSBHC_HCIVERSION 0x0100 /* Known value of cap. reg. HCIVERSION */ + +static const struct hc_driver ehci_grlib_hc_driver = { + .description = hcd_name, + .product_desc = "GRLIB GRUSBHC EHCI", + .hcd_priv_size = sizeof(struct ehci_hcd), + + /* + * generic hardware linkage + */ + .irq = ehci_irq, + .flags = HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH, + + /* + * basic lifecycle operations + */ + .reset = ehci_setup, + .start = ehci_run, + .stop = ehci_stop, + .shutdown = ehci_shutdown, + + /* + * managing i/o requests and associated device resources + */ + .urb_enqueue = ehci_urb_enqueue, + .urb_dequeue = ehci_urb_dequeue, + .endpoint_disable = ehci_endpoint_disable, + .endpoint_reset = ehci_endpoint_reset, + + /* + * scheduling support + */ + .get_frame_number = ehci_get_frame, + + /* + * root hub support + */ + .hub_status_data = ehci_hub_status_data, + .hub_control = ehci_hub_control, +#ifdef CONFIG_PM + .bus_suspend = ehci_bus_suspend, + .bus_resume = ehci_bus_resume, +#endif + .relinquish_port = ehci_relinquish_port, + .port_handed_over = ehci_port_handed_over, + + .clear_tt_buffer_complete = ehci_clear_tt_buffer_complete, +}; + + +static int ehci_hcd_grlib_probe(struct platform_device *op) +{ + struct device_node *dn = op->dev.of_node; + struct usb_hcd *hcd; + struct ehci_hcd *ehci = NULL; + struct resource res; + u32 hc_capbase; + int irq; + int rv; + + if (usb_disabled()) + return -ENODEV; + + dev_dbg(&op->dev, "initializing GRUSBHC EHCI USB Controller\n"); + + rv = of_address_to_resource(dn, 0, &res); + if (rv) + return rv; + + /* usb_create_hcd requires dma_mask != NULL */ + op->dev.dma_mask = &op->dev.coherent_dma_mask; + hcd = usb_create_hcd(&ehci_grlib_hc_driver, &op->dev, + "GRUSBHC EHCI USB"); + if (!hcd) + return -ENOMEM; + + hcd->rsrc_start = res.start; + hcd->rsrc_len = resource_size(&res); + + irq = irq_of_parse_and_map(dn, 0); + if (!irq) { + dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n", + __FILE__); + rv = -EBUSY; + goto err_irq; + } + + hcd->regs = devm_ioremap_resource(&op->dev, &res); + if (IS_ERR(hcd->regs)) { + rv = PTR_ERR(hcd->regs); + goto err_ioremap; + } + + ehci = hcd_to_ehci(hcd); + + ehci->caps = hcd->regs; + + /* determine endianness of this implementation */ + hc_capbase = ehci_readl(ehci, &ehci->caps->hc_capbase); + if (HC_VERSION(ehci, hc_capbase) != GRUSBHC_HCIVERSION) { + ehci->big_endian_mmio = 1; + ehci->big_endian_desc = 1; + ehci->big_endian_capbase = 1; + } + + rv = usb_add_hcd(hcd, irq, 0); + if (rv) + goto err_ioremap; + + device_wakeup_enable(hcd->self.controller); + return 0; + +err_ioremap: + irq_dispose_mapping(irq); +err_irq: + usb_put_hcd(hcd); + + return rv; +} + + +static void ehci_hcd_grlib_remove(struct platform_device *op) +{ + struct usb_hcd *hcd = platform_get_drvdata(op); + + dev_dbg(&op->dev, "stopping GRLIB GRUSBHC EHCI USB Controller\n"); + + usb_remove_hcd(hcd); + + irq_dispose_mapping(hcd->irq); + + usb_put_hcd(hcd); +} + + +static const struct of_device_id ehci_hcd_grlib_of_match[] = { + { + .name = "GAISLER_EHCI", + }, + { + .name = "01_026", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, ehci_hcd_grlib_of_match); + + +static struct platform_driver ehci_grlib_driver = { + .probe = ehci_hcd_grlib_probe, + .remove = ehci_hcd_grlib_remove, + .shutdown = usb_hcd_platform_shutdown, + .driver = { + .name = "grlib-ehci", + .of_match_table = ehci_hcd_grlib_of_match, + }, +}; -- cgit v1.3.1