From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/misc/phantom.c | 564 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 564 insertions(+) create mode 100644 drivers/misc/phantom.c (limited to 'drivers/misc/phantom.c') diff --git a/drivers/misc/phantom.c b/drivers/misc/phantom.c new file mode 100644 index 000000000..34a5054a6 --- /dev/null +++ b/drivers/misc/phantom.c @@ -0,0 +1,564 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2005-2007 Jiri Slaby + * + * You need a userspace library to cooperate with this driver. It (and other + * info) may be obtained here: + * http://www.fi.muni.cz/~xslaby/phantom.html + * or alternatively, you might use OpenHaptics provided by Sensable. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define PHANTOM_VERSION "n0.9.8" + +#define PHANTOM_MAX_MINORS 8 + +#define PHN_IRQCTL 0x4c /* irq control in caddr space */ + +#define PHB_RUNNING 1 +#define PHB_NOT_OH 2 + +static DEFINE_MUTEX(phantom_mutex); +static int phantom_major; + +static const struct class phantom_class = { + .name = "phantom", +}; + +struct phantom_device { + unsigned int opened; + void __iomem *caddr; + u32 __iomem *iaddr; + u32 __iomem *oaddr; + unsigned long status; + atomic_t counter; + + wait_queue_head_t wait; + struct cdev cdev; + + struct mutex open_lock; + spinlock_t regs_lock; + + /* used in NOT_OH mode */ + struct phm_regs oregs; + u32 ctl_reg; +}; + +static unsigned char phantom_devices[PHANTOM_MAX_MINORS]; + +static int phantom_status(struct phantom_device *dev, unsigned long newstat) +{ + pr_debug("phantom_status %lx %lx\n", dev->status, newstat); + + if (!(dev->status & PHB_RUNNING) && (newstat & PHB_RUNNING)) { + atomic_set(&dev->counter, 0); + iowrite32(PHN_CTL_IRQ, dev->iaddr + PHN_CONTROL); + iowrite32(0x43, dev->caddr + PHN_IRQCTL); + ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */ + } else if ((dev->status & PHB_RUNNING) && !(newstat & PHB_RUNNING)) { + iowrite32(0, dev->caddr + PHN_IRQCTL); + ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */ + } + + dev->status = newstat; + + return 0; +} + +/* + * File ops + */ + +static long phantom_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct phantom_device *dev = file->private_data; + struct phm_regs rs; + struct phm_reg r; + void __user *argp = (void __user *)arg; + unsigned long flags; + unsigned int i; + + switch (cmd) { + case PHN_SETREG: + case PHN_SET_REG: + if (copy_from_user(&r, argp, sizeof(r))) + return -EFAULT; + + if (r.reg > 7) + return -EINVAL; + + spin_lock_irqsave(&dev->regs_lock, flags); + if (r.reg == PHN_CONTROL && (r.value & PHN_CTL_IRQ) && + phantom_status(dev, dev->status | PHB_RUNNING)){ + spin_unlock_irqrestore(&dev->regs_lock, flags); + return -ENODEV; + } + + pr_debug("phantom: writing %x to %u\n", r.value, r.reg); + + /* preserve amp bit (don't allow to change it when in NOT_OH) */ + if (r.reg == PHN_CONTROL && (dev->status & PHB_NOT_OH)) { + r.value &= ~PHN_CTL_AMP; + r.value |= dev->ctl_reg & PHN_CTL_AMP; + dev->ctl_reg = r.value; + } + + iowrite32(r.value, dev->iaddr + r.reg); + ioread32(dev->iaddr); /* PCI posting */ + + if (r.reg == PHN_CONTROL && !(r.value & PHN_CTL_IRQ)) + phantom_status(dev, dev->status & ~PHB_RUNNING); + spin_unlock_irqrestore(&dev->regs_lock, flags); + break; + case PHN_SETREGS: + case PHN_SET_REGS: + if (copy_from_user(&rs, argp, sizeof(rs))) + return -EFAULT; + + pr_debug("phantom: SRS %u regs %x\n", rs.count, rs.mask); + spin_lock_irqsave(&dev->regs_lock, flags); + if (dev->status & PHB_NOT_OH) + memcpy(&dev->oregs, &rs, sizeof(rs)); + else { + u32 m = min(rs.count, 8U); + for (i = 0; i < m; i++) + if (rs.mask & BIT(i)) + iowrite32(rs.values[i], dev->oaddr + i); + ioread32(dev->iaddr); /* PCI posting */ + } + spin_unlock_irqrestore(&dev->regs_lock, flags); + break; + case PHN_GETREG: + case PHN_GET_REG: + if (copy_from_user(&r, argp, sizeof(r))) + return -EFAULT; + + if (r.reg > 7) + return -EINVAL; + + r.value = ioread32(dev->iaddr + r.reg); + + if (copy_to_user(argp, &r, sizeof(r))) + return -EFAULT; + break; + case PHN_GETREGS: + case PHN_GET_REGS: { + u32 m; + + if (copy_from_user(&rs, argp, sizeof(rs))) + return -EFAULT; + + m = min(rs.count, 8U); + + pr_debug("phantom: GRS %u regs %x\n", rs.count, rs.mask); + spin_lock_irqsave(&dev->regs_lock, flags); + for (i = 0; i < m; i++) + if (rs.mask & BIT(i)) + rs.values[i] = ioread32(dev->iaddr + i); + atomic_set(&dev->counter, 0); + spin_unlock_irqrestore(&dev->regs_lock, flags); + + if (copy_to_user(argp, &rs, sizeof(rs))) + return -EFAULT; + break; + } case PHN_NOT_OH: + spin_lock_irqsave(&dev->regs_lock, flags); + if (dev->status & PHB_RUNNING) { + printk(KERN_ERR "phantom: you need to set NOT_OH " + "before you start the device!\n"); + spin_unlock_irqrestore(&dev->regs_lock, flags); + return -EINVAL; + } + dev->status |= PHB_NOT_OH; + spin_unlock_irqrestore(&dev->regs_lock, flags); + break; + default: + return -ENOTTY; + } + + return 0; +} + +#ifdef CONFIG_COMPAT +static long phantom_compat_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + if (_IOC_NR(cmd) <= 3 && _IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { + cmd &= ~(_IOC_SIZEMASK << _IOC_SIZESHIFT); + cmd |= sizeof(void *) << _IOC_SIZESHIFT; + } + return phantom_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); +} +#else +#define phantom_compat_ioctl NULL +#endif + +static int phantom_open(struct inode *inode, struct file *file) +{ + struct phantom_device *dev = container_of(inode->i_cdev, + struct phantom_device, cdev); + + mutex_lock(&phantom_mutex); + nonseekable_open(inode, file); + + if (mutex_lock_interruptible(&dev->open_lock)) { + mutex_unlock(&phantom_mutex); + return -ERESTARTSYS; + } + + if (dev->opened) { + mutex_unlock(&dev->open_lock); + mutex_unlock(&phantom_mutex); + return -EINVAL; + } + + WARN_ON(dev->status & PHB_NOT_OH); + + file->private_data = dev; + + atomic_set(&dev->counter, 0); + dev->opened++; + mutex_unlock(&dev->open_lock); + mutex_unlock(&phantom_mutex); + return 0; +} + +static int phantom_release(struct inode *inode, struct file *file) +{ + struct phantom_device *dev = file->private_data; + + mutex_lock(&dev->open_lock); + + dev->opened = 0; + phantom_status(dev, dev->status & ~PHB_RUNNING); + dev->status &= ~PHB_NOT_OH; + + mutex_unlock(&dev->open_lock); + + return 0; +} + +static __poll_t phantom_poll(struct file *file, poll_table *wait) +{ + struct phantom_device *dev = file->private_data; + __poll_t mask = 0; + + pr_debug("phantom_poll: %d\n", atomic_read(&dev->counter)); + poll_wait(file, &dev->wait, wait); + + if (!(dev->status & PHB_RUNNING)) + mask = EPOLLERR; + else if (atomic_read(&dev->counter)) + mask = EPOLLIN | EPOLLRDNORM; + + pr_debug("phantom_poll end: %x/%d\n", mask, atomic_read(&dev->counter)); + + return mask; +} + +static const struct file_operations phantom_file_ops = { + .open = phantom_open, + .release = phantom_release, + .unlocked_ioctl = phantom_ioctl, + .compat_ioctl = phantom_compat_ioctl, + .poll = phantom_poll, +}; + +static irqreturn_t phantom_isr(int irq, void *data) +{ + struct phantom_device *dev = data; + unsigned int i; + u32 ctl; + + spin_lock(&dev->regs_lock); + ctl = ioread32(dev->iaddr + PHN_CONTROL); + if (!(ctl & PHN_CTL_IRQ)) { + spin_unlock(&dev->regs_lock); + return IRQ_NONE; + } + + iowrite32(0, dev->iaddr); + iowrite32(0xc0, dev->iaddr); + + if (dev->status & PHB_NOT_OH) { + struct phm_regs *r = &dev->oregs; + u32 m = min(r->count, 8U); + + for (i = 0; i < m; i++) + if (r->mask & BIT(i)) + iowrite32(r->values[i], dev->oaddr + i); + + dev->ctl_reg ^= PHN_CTL_AMP; + iowrite32(dev->ctl_reg, dev->iaddr + PHN_CONTROL); + } + spin_unlock(&dev->regs_lock); + + ioread32(dev->iaddr); /* PCI posting */ + + atomic_inc(&dev->counter); + wake_up_interruptible(&dev->wait); + + return IRQ_HANDLED; +} + +/* + * Init and deinit driver + */ + +static unsigned int phantom_get_free(void) +{ + unsigned int i; + + for (i = 0; i < PHANTOM_MAX_MINORS; i++) + if (phantom_devices[i] == 0) + break; + + return i; +} + +static int phantom_probe(struct pci_dev *pdev, + const struct pci_device_id *pci_id) +{ + struct phantom_device *pht; + unsigned int minor; + int retval; + + retval = pci_enable_device(pdev); + if (retval) { + dev_err(&pdev->dev, "pci_enable_device failed!\n"); + goto err; + } + + minor = phantom_get_free(); + if (minor == PHANTOM_MAX_MINORS) { + dev_err(&pdev->dev, "too many devices found!\n"); + retval = -EIO; + goto err_dis; + } + + phantom_devices[minor] = 1; + + retval = pci_request_regions(pdev, "phantom"); + if (retval) { + dev_err(&pdev->dev, "pci_request_regions failed!\n"); + goto err_null; + } + + retval = -ENOMEM; + pht = kzalloc_obj(*pht); + if (pht == NULL) { + dev_err(&pdev->dev, "unable to allocate device\n"); + goto err_reg; + } + + pht->caddr = pci_iomap(pdev, 0, 0); + if (pht->caddr == NULL) { + dev_err(&pdev->dev, "can't remap conf space\n"); + goto err_fr; + } + pht->iaddr = pci_iomap(pdev, 2, 0); + if (pht->iaddr == NULL) { + dev_err(&pdev->dev, "can't remap input space\n"); + goto err_unmc; + } + pht->oaddr = pci_iomap(pdev, 3, 0); + if (pht->oaddr == NULL) { + dev_err(&pdev->dev, "can't remap output space\n"); + goto err_unmi; + } + + mutex_init(&pht->open_lock); + spin_lock_init(&pht->regs_lock); + init_waitqueue_head(&pht->wait); + cdev_init(&pht->cdev, &phantom_file_ops); + pht->cdev.owner = THIS_MODULE; + + iowrite32(0, pht->caddr + PHN_IRQCTL); + ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */ + retval = request_irq(pdev->irq, phantom_isr, + IRQF_SHARED, "phantom", pht); + if (retval) { + dev_err(&pdev->dev, "can't establish ISR\n"); + goto err_unmo; + } + + retval = cdev_add(&pht->cdev, MKDEV(phantom_major, minor), 1); + if (retval) { + dev_err(&pdev->dev, "chardev registration failed\n"); + goto err_irq; + } + + if (IS_ERR(device_create(&phantom_class, &pdev->dev, + MKDEV(phantom_major, minor), NULL, + "phantom%u", minor))) + dev_err(&pdev->dev, "can't create device\n"); + + pci_set_drvdata(pdev, pht); + + return 0; +err_irq: + free_irq(pdev->irq, pht); +err_unmo: + pci_iounmap(pdev, pht->oaddr); +err_unmi: + pci_iounmap(pdev, pht->iaddr); +err_unmc: + pci_iounmap(pdev, pht->caddr); +err_fr: + kfree(pht); +err_reg: + pci_release_regions(pdev); +err_null: + phantom_devices[minor] = 0; +err_dis: + pci_disable_device(pdev); +err: + return retval; +} + +static void phantom_remove(struct pci_dev *pdev) +{ + struct phantom_device *pht = pci_get_drvdata(pdev); + unsigned int minor = MINOR(pht->cdev.dev); + + device_destroy(&phantom_class, MKDEV(phantom_major, minor)); + + cdev_del(&pht->cdev); + + iowrite32(0, pht->caddr + PHN_IRQCTL); + ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */ + free_irq(pdev->irq, pht); + + pci_iounmap(pdev, pht->oaddr); + pci_iounmap(pdev, pht->iaddr); + pci_iounmap(pdev, pht->caddr); + + kfree(pht); + + pci_release_regions(pdev); + + phantom_devices[minor] = 0; + + pci_disable_device(pdev); +} + +static int __maybe_unused phantom_suspend(struct device *dev_d) +{ + struct phantom_device *dev = dev_get_drvdata(dev_d); + + iowrite32(0, dev->caddr + PHN_IRQCTL); + ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */ + + synchronize_irq(to_pci_dev(dev_d)->irq); + + return 0; +} + +static int __maybe_unused phantom_resume(struct device *dev_d) +{ + struct phantom_device *dev = dev_get_drvdata(dev_d); + + iowrite32(0, dev->caddr + PHN_IRQCTL); + + return 0; +} + +static struct pci_device_id phantom_pci_tbl[] = { + { .vendor = PCI_VENDOR_ID_PLX, .device = PCI_DEVICE_ID_PLX_9050, + .subvendor = PCI_VENDOR_ID_PLX, .subdevice = PCI_DEVICE_ID_PLX_9050, + .class = PCI_CLASS_BRIDGE_OTHER << 8, .class_mask = 0xffff00 }, + { 0, } +}; +MODULE_DEVICE_TABLE(pci, phantom_pci_tbl); + +static SIMPLE_DEV_PM_OPS(phantom_pm_ops, phantom_suspend, phantom_resume); + +static struct pci_driver phantom_pci_driver = { + .name = "phantom", + .id_table = phantom_pci_tbl, + .probe = phantom_probe, + .remove = phantom_remove, + .driver.pm = &phantom_pm_ops, +}; + +static CLASS_ATTR_STRING(version, 0444, PHANTOM_VERSION); + +static int __init phantom_init(void) +{ + int retval; + dev_t dev; + + retval = class_register(&phantom_class); + if (retval) { + printk(KERN_ERR "phantom: can't register phantom class\n"); + goto err; + } + retval = class_create_file(&phantom_class, &class_attr_version.attr); + if (retval) { + printk(KERN_ERR "phantom: can't create sysfs version file\n"); + goto err_class; + } + + retval = alloc_chrdev_region(&dev, 0, PHANTOM_MAX_MINORS, "phantom"); + if (retval) { + printk(KERN_ERR "phantom: can't register character device\n"); + goto err_attr; + } + phantom_major = MAJOR(dev); + + retval = pci_register_driver(&phantom_pci_driver); + if (retval) { + printk(KERN_ERR "phantom: can't register pci driver\n"); + goto err_unchr; + } + + printk(KERN_INFO "Phantom Linux Driver, version " PHANTOM_VERSION ", " + "init OK\n"); + + return 0; +err_unchr: + unregister_chrdev_region(dev, PHANTOM_MAX_MINORS); +err_attr: + class_remove_file(&phantom_class, &class_attr_version.attr); +err_class: + class_unregister(&phantom_class); +err: + return retval; +} + +static void __exit phantom_exit(void) +{ + pci_unregister_driver(&phantom_pci_driver); + + unregister_chrdev_region(MKDEV(phantom_major, 0), PHANTOM_MAX_MINORS); + + class_remove_file(&phantom_class, &class_attr_version.attr); + class_unregister(&phantom_class); + + pr_debug("phantom: module successfully removed\n"); +} + +module_init(phantom_init); +module_exit(phantom_exit); + +MODULE_AUTHOR("Jiri Slaby "); +MODULE_DESCRIPTION("Sensable Phantom driver (PCI devices)"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(PHANTOM_VERSION); -- cgit v1.3.1