From 34ff636f322c6d5e4f0a52338fa63a7dff09a495 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Sat, 18 Jul 2026 13:15:36 -0400 Subject: scftorture: Count single_rpc offline failures in statistics output scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes Signed-off-by: Paul E. McKenney --- drivers/misc/open-dice.c | 209 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 drivers/misc/open-dice.c (limited to 'drivers/misc/open-dice.c') diff --git a/drivers/misc/open-dice.c b/drivers/misc/open-dice.c new file mode 100644 index 000000000..45060fb4e --- /dev/null +++ b/drivers/misc/open-dice.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 - Google LLC + * Author: David Brazdil + * + * Driver for Open Profile for DICE. + * + * This driver takes ownership of a reserved memory region containing data + * generated by the Open Profile for DICE measured boot protocol. The memory + * contents are not interpreted by the kernel but can be mapped into a userspace + * process via a misc device. Userspace can also request a wipe of the memory. + * + * Userspace can access the data with (w/o error handling): + * + * fd = open("/dev/open-dice0", O_RDWR); + * read(fd, &size, sizeof(unsigned long)); + * data = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); + * write(fd, NULL, 0); // wipe + * close(fd); + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "open-dice" + +struct open_dice_drvdata { + struct mutex lock; + char name[16]; + struct reserved_mem *rmem; + struct miscdevice misc; +}; + +static inline struct open_dice_drvdata *to_open_dice_drvdata(struct file *filp) +{ + return container_of(filp->private_data, struct open_dice_drvdata, misc); +} + +static int open_dice_wipe(struct open_dice_drvdata *drvdata) +{ + void *kaddr; + + mutex_lock(&drvdata->lock); + kaddr = devm_memremap(drvdata->misc.this_device, drvdata->rmem->base, + drvdata->rmem->size, MEMREMAP_WC); + if (IS_ERR(kaddr)) { + mutex_unlock(&drvdata->lock); + return PTR_ERR(kaddr); + } + + memset(kaddr, 0, drvdata->rmem->size); + devm_memunmap(drvdata->misc.this_device, kaddr); + mutex_unlock(&drvdata->lock); + return 0; +} + +/* + * Copies the size of the reserved memory region to the user-provided buffer. + */ +static ssize_t open_dice_read(struct file *filp, char __user *ptr, size_t len, + loff_t *off) +{ + unsigned long val = to_open_dice_drvdata(filp)->rmem->size; + + return simple_read_from_buffer(ptr, len, off, &val, sizeof(val)); +} + +/* + * Triggers a wipe of the reserved memory region. The user-provided pointer + * is never dereferenced. + */ +static ssize_t open_dice_write(struct file *filp, const char __user *ptr, + size_t len, loff_t *off) +{ + if (open_dice_wipe(to_open_dice_drvdata(filp))) + return -EIO; + + /* Consume the input buffer. */ + return len; +} + +/* + * Creates a mapping of the reserved memory region in user address space. + */ +static int open_dice_mmap_prepare(struct vm_area_desc *desc) +{ + struct file *filp = desc->file; + struct open_dice_drvdata *drvdata = to_open_dice_drvdata(filp); + + if (vma_desc_test(desc, VMA_MAYSHARE_BIT)) { + /* Do not allow userspace to modify the underlying data. */ + if (vma_desc_test(desc, VMA_WRITE_BIT)) + return -EPERM; + /* Ensure userspace cannot acquire VM_WRITE later. */ + vma_desc_clear_flags(desc, VMA_MAYWRITE_BIT); + } + + /* Create write-combine mapping so all clients observe a wipe. */ + desc->page_prot = pgprot_writecombine(desc->page_prot); + vma_desc_set_flags(desc, VMA_DONTCOPY_BIT, VMA_DONTDUMP_BIT); + mmap_action_simple_ioremap(desc, drvdata->rmem->base, + drvdata->rmem->size); + return 0; +} + +static const struct file_operations open_dice_fops = { + .owner = THIS_MODULE, + .read = open_dice_read, + .write = open_dice_write, + .mmap_prepare = open_dice_mmap_prepare, +}; + +static int __init open_dice_probe(struct platform_device *pdev) +{ + static unsigned int dev_idx; + struct device *dev = &pdev->dev; + struct reserved_mem *rmem; + struct open_dice_drvdata *drvdata; + int ret; + + rmem = of_reserved_mem_lookup(dev->of_node); + if (!rmem) { + dev_err(dev, "failed to lookup reserved memory\n"); + return -EINVAL; + } + + if (!rmem->size || (rmem->size > ULONG_MAX)) { + dev_err(dev, "invalid memory region size\n"); + return -EINVAL; + } + + if (!PAGE_ALIGNED(rmem->base) || !PAGE_ALIGNED(rmem->size)) { + dev_err(dev, "memory region must be page-aligned\n"); + return -EINVAL; + } + + drvdata = devm_kmalloc(dev, sizeof(*drvdata), GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + *drvdata = (struct open_dice_drvdata){ + .rmem = rmem, + .misc = (struct miscdevice){ + .parent = dev, + .name = drvdata->name, + .minor = MISC_DYNAMIC_MINOR, + .fops = &open_dice_fops, + .mode = 0600, + }, + }; + mutex_init(&drvdata->lock); + + /* Index overflow check not needed, misc_register() will fail. */ + snprintf(drvdata->name, sizeof(drvdata->name), DRIVER_NAME"%u", dev_idx++); + + ret = misc_register(&drvdata->misc); + if (ret) { + dev_err(dev, "failed to register misc device '%s': %d\n", + drvdata->name, ret); + return ret; + } + + platform_set_drvdata(pdev, drvdata); + return 0; +} + +static void open_dice_remove(struct platform_device *pdev) +{ + struct open_dice_drvdata *drvdata = platform_get_drvdata(pdev); + + misc_deregister(&drvdata->misc); +} + +static const struct of_device_id open_dice_of_match[] = { + { .compatible = "google,open-dice" }, + {}, +}; + +static struct platform_driver open_dice_driver = { + .remove = open_dice_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = open_dice_of_match, + }, +}; + +static int __init open_dice_init(void) +{ + int ret = platform_driver_probe(&open_dice_driver, open_dice_probe); + + /* DICE regions are optional. Succeed even with zero instances. */ + return (ret == -ENODEV) ? 0 : ret; +} + +static void __exit open_dice_exit(void) +{ + platform_driver_unregister(&open_dice_driver); +} + +module_init(open_dice_init); +module_exit(open_dice_exit); + +MODULE_DESCRIPTION("Driver for Open Profile for DICE."); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("David Brazdil "); -- cgit v1.3.1