ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 254 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-ps3.c b/drivers/usb/host/ehci-ps3.c
new file mode 100644
index 000000000..98568b046
--- /dev/null
+++ b/drivers/usb/host/ehci-ps3.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  PS3 EHCI Host Controller driver
+ *
+ *  Copyright (C) 2006 Sony Computer Entertainment Inc.
+ *  Copyright 2006 Sony Corp.
+ */
+
+#include <asm/firmware.h>
+#include <asm/ps3.h>
+
+static void ps3_ehci_setup_insnreg(struct ehci_hcd *ehci)
+{
+	/* PS3 HC internal setup register offsets. */
+
+	enum ps3_ehci_hc_insnreg {
+		ps3_ehci_hc_insnreg01 = 0x084,
+		ps3_ehci_hc_insnreg02 = 0x088,
+		ps3_ehci_hc_insnreg03 = 0x08c,
+	};
+
+	/* PS3 EHCI HC errata fix 316 - The PS3 EHCI HC will reset its
+	 * internal INSNREGXX setup regs back to the chip default values
+	 * on Host Controller Reset (CMD_RESET) or Light Host Controller
+	 * Reset (CMD_LRESET).  The work-around for this is for the HC
+	 * driver to re-initialise these regs when ever the HC is reset.
+	 */
+
+	/* Set burst transfer counts to 256 out, 32 in. */
+
+	writel_be(0x01000020, (void __iomem *)ehci->regs +
+		ps3_ehci_hc_insnreg01);
+
+	/* Enable burst transfer counts. */
+
+	writel_be(0x00000001, (void __iomem *)ehci->regs +
+		ps3_ehci_hc_insnreg03);
+}
+
+static int ps3_ehci_hc_reset(struct usb_hcd *hcd)
+{
+	int result;
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+	ehci->big_endian_mmio = 1;
+	ehci->caps = hcd->regs;
+
+	result = ehci_setup(hcd);
+	if (result)
+		return result;
+
+	ps3_ehci_setup_insnreg(ehci);
+
+	return result;
+}
+
+static const struct hc_driver ps3_ehci_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "PS3 EHCI Host Controller",
+	.hcd_priv_size		= sizeof(struct ehci_hcd),
+	.irq			= ehci_irq,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
+	.reset			= ps3_ehci_hc_reset,
+	.start			= ehci_run,
+	.stop			= ehci_stop,
+	.shutdown		= ehci_shutdown,
+	.urb_enqueue		= ehci_urb_enqueue,
+	.urb_dequeue		= ehci_urb_dequeue,
+	.endpoint_disable	= ehci_endpoint_disable,
+	.endpoint_reset		= ehci_endpoint_reset,
+	.get_frame_number	= ehci_get_frame,
+	.hub_status_data	= ehci_hub_status_data,
+	.hub_control		= ehci_hub_control,
+#if defined(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 ps3_ehci_probe(struct ps3_system_bus_device *dev)
+{
+	int result;
+	struct usb_hcd *hcd;
+	unsigned int virq;
+	static u64 dummy_mask;
+
+	if (usb_disabled()) {
+		result = -ENODEV;
+		goto fail_start;
+	}
+
+	result = ps3_open_hv_device(dev);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_open_hv_device failed\n",
+			__func__, __LINE__);
+		goto fail_open;
+	}
+
+	result = ps3_dma_region_create(dev->d_region);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_dma_region_create failed: "
+			"(%d)\n", __func__, __LINE__, result);
+		BUG_ON("check region type");
+		goto fail_dma_region;
+	}
+
+	result = ps3_mmio_region_create(dev->m_region);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_map_mmio_region failed\n",
+			__func__, __LINE__);
+		result = -EPERM;
+		goto fail_mmio_region;
+	}
+
+	dev_dbg(&dev->core, "%s:%d: mmio mapped_addr %lxh\n", __func__,
+		__LINE__, dev->m_region->lpar_addr);
+
+	result = ps3_io_irq_setup(PS3_BINDING_CPU_ANY, dev->interrupt_id, &virq);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_construct_io_irq(%d) failed.\n",
+			__func__, __LINE__, virq);
+		result = -EPERM;
+		goto fail_irq;
+	}
+
+	dummy_mask = DMA_BIT_MASK(32);
+	dev->core.dma_mask = &dummy_mask;
+	dma_set_coherent_mask(&dev->core, dummy_mask);
+
+	hcd = usb_create_hcd(&ps3_ehci_hc_driver, &dev->core, dev_name(&dev->core));
+
+	if (!hcd) {
+		dev_dbg(&dev->core, "%s:%d: usb_create_hcd failed\n", __func__,
+			__LINE__);
+		result = -ENOMEM;
+		goto fail_create_hcd;
+	}
+
+	hcd->rsrc_start = dev->m_region->lpar_addr;
+	hcd->rsrc_len = dev->m_region->len;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name))
+		dev_dbg(&dev->core, "%s:%d: request_mem_region failed\n",
+			__func__, __LINE__);
+
+	hcd->regs = ioremap(dev->m_region->lpar_addr, dev->m_region->len);
+
+	if (!hcd->regs) {
+		dev_dbg(&dev->core, "%s:%d: ioremap failed\n", __func__,
+			__LINE__);
+		result = -EPERM;
+		goto fail_ioremap;
+	}
+
+	dev_dbg(&dev->core, "%s:%d: hcd->rsrc_start %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->rsrc_start);
+	dev_dbg(&dev->core, "%s:%d: hcd->rsrc_len   %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->rsrc_len);
+	dev_dbg(&dev->core, "%s:%d: hcd->regs       %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->regs);
+	dev_dbg(&dev->core, "%s:%d: virq            %lu\n", __func__, __LINE__,
+		(unsigned long)virq);
+
+	ps3_system_bus_set_drvdata(dev, hcd);
+
+	result = usb_add_hcd(hcd, virq, 0);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: usb_add_hcd failed (%d)\n",
+			__func__, __LINE__, result);
+		goto fail_add_hcd;
+	}
+
+	device_wakeup_enable(hcd->self.controller);
+	return result;
+
+fail_add_hcd:
+	iounmap(hcd->regs);
+fail_ioremap:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	ps3_io_irq_destroy(virq);
+fail_irq:
+	ps3_free_mmio_region(dev->m_region);
+fail_mmio_region:
+	ps3_dma_region_free(dev->d_region);
+fail_dma_region:
+	ps3_close_hv_device(dev);
+fail_open:
+fail_start:
+	return result;
+}
+
+static void ps3_ehci_remove(struct ps3_system_bus_device *dev)
+{
+	unsigned int tmp;
+	struct usb_hcd *hcd = ps3_system_bus_get_drvdata(dev);
+
+	BUG_ON(!hcd);
+
+	dev_dbg(&dev->core, "%s:%d: regs %p\n", __func__, __LINE__, hcd->regs);
+	dev_dbg(&dev->core, "%s:%d: irq %u\n", __func__, __LINE__, hcd->irq);
+
+	tmp = hcd->irq;
+
+	usb_remove_hcd(hcd);
+
+	ps3_system_bus_set_drvdata(dev, NULL);
+
+	BUG_ON(!hcd->regs);
+	iounmap(hcd->regs);
+
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+
+	ps3_io_irq_destroy(tmp);
+	ps3_free_mmio_region(dev->m_region);
+
+	ps3_dma_region_free(dev->d_region);
+	ps3_close_hv_device(dev);
+}
+
+static int __init ps3_ehci_driver_register(struct ps3_system_bus_driver *drv)
+{
+	return firmware_has_feature(FW_FEATURE_PS3_LV1)
+		? ps3_system_bus_driver_register(drv)
+		: 0;
+}
+
+static void ps3_ehci_driver_unregister(struct ps3_system_bus_driver *drv)
+{
+	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
+		ps3_system_bus_driver_unregister(drv);
+}
+
+MODULE_ALIAS(PS3_MODULE_ALIAS_EHCI);
+
+static struct ps3_system_bus_driver ps3_ehci_driver = {
+	.core.name = "ps3-ehci-driver",
+	.core.owner = THIS_MODULE,
+	.match_id = PS3_MATCH_ID_EHCI,
+	.probe = ps3_ehci_probe,
+	.remove = ps3_ehci_remove,
+	.shutdown = ps3_ehci_remove,
+};