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/soc/aspeed/aspeed-lpc-ctrl.c | 356 +++++++++++++++++++++++++++++++++++ 1 file changed, 356 insertions(+) create mode 100644 drivers/soc/aspeed/aspeed-lpc-ctrl.c (limited to 'drivers/soc/aspeed/aspeed-lpc-ctrl.c') diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c new file mode 100644 index 000000000..4d8574cac --- /dev/null +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c @@ -0,0 +1,356 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2017 IBM Corporation + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define DEVICE_NAME "aspeed-lpc-ctrl" + +#define HICR5 0x80 +#define HICR5_ENL2H BIT(8) +#define HICR5_ENFWH BIT(10) + +#define HICR6 0x84 +#define SW_FWH2AHB BIT(17) + +#define HICR7 0x88 +#define HICR8 0x8c + +struct aspeed_lpc_ctrl { + struct miscdevice miscdev; + struct regmap *regmap; + struct clk *clk; + phys_addr_t mem_base; + resource_size_t mem_size; + u32 pnor_size; + u32 pnor_base; + bool fwh2ahb; + struct regmap *scu; +}; + +static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) +{ + return container_of(file->private_data, struct aspeed_lpc_ctrl, + miscdev); +} + +static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); + unsigned long vsize = vma->vm_end - vma->vm_start; + pgprot_t prot = vma->vm_page_prot; + + if (vma->vm_pgoff + vma_pages(vma) > lpc_ctrl->mem_size >> PAGE_SHIFT) + return -EINVAL; + + /* ast2400/2500 AHB accesses are not cache coherent */ + prot = pgprot_noncached(prot); + + if (remap_pfn_range(vma, vma->vm_start, + (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, + vsize, prot)) + return -EAGAIN; + + return 0; +} + +static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, + unsigned long param) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); + struct device *dev = file->private_data; + void __user *p = (void __user *)param; + struct aspeed_lpc_ctrl_mapping map; + u32 addr; + u32 size; + long rc; + + if (copy_from_user(&map, p, sizeof(map))) + return -EFAULT; + + if (map.flags != 0) + return -EINVAL; + + switch (cmd) { + case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: + /* The flash windows don't report their size */ + if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) + return -EINVAL; + + /* Support more than one window id in the future */ + if (map.window_id != 0) + return -EINVAL; + + /* If memory-region is not described in device tree */ + if (!lpc_ctrl->mem_size) { + dev_dbg(dev, "Didn't find reserved memory\n"); + return -ENXIO; + } + + map.size = lpc_ctrl->mem_size; + + return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; + case ASPEED_LPC_CTRL_IOCTL_MAP: + + /* + * The top half of HICR7 is the MSB of the BMC address of the + * mapping. + * The bottom half of HICR7 is the MSB of the HOST LPC + * firmware space address of the mapping. + * + * The 1 bits in the top of half of HICR8 represent the bits + * (in the requested address) that should be ignored and + * replaced with those from the top half of HICR7. + * The 1 bits in the bottom half of HICR8 represent the bits + * (in the requested address) that should be kept and pass + * into the BMC address space. + */ + + /* + * It doesn't make sense to talk about a size or offset with + * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 + * bits of addresses and sizes. + */ + + if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) + return -EINVAL; + + /* + * Because of the way the masks work in HICR8 offset has to + * be a multiple of size. + */ + if (map.offset & (map.size - 1)) + return -EINVAL; + + if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { + if (!lpc_ctrl->pnor_size) { + dev_dbg(dev, "Didn't find host pnor flash\n"); + return -ENXIO; + } + addr = lpc_ctrl->pnor_base; + size = lpc_ctrl->pnor_size; + } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { + /* If memory-region is not described in device tree */ + if (!lpc_ctrl->mem_size) { + dev_dbg(dev, "Didn't find reserved memory\n"); + return -ENXIO; + } + addr = lpc_ctrl->mem_base; + size = lpc_ctrl->mem_size; + } else { + return -EINVAL; + } + + /* Check overflow first! */ + if (map.offset + map.size < map.offset || + map.offset + map.size > size) + return -EINVAL; + + if (map.size == 0 || map.size > size) + return -EINVAL; + + addr += map.offset; + + /* + * addr (host lpc address) is safe regardless of values. This + * simply changes the address the host has to request on its + * side of the LPC bus. This cannot impact the hosts own + * memory space by surprise as LPC specific accessors are + * required. The only strange thing that could be done is + * setting the lower 16 bits but the shift takes care of that. + */ + + rc = regmap_write(lpc_ctrl->regmap, HICR7, + (addr | (map.addr >> 16))); + if (rc) + return rc; + + rc = regmap_write(lpc_ctrl->regmap, HICR8, + (~(map.size - 1)) | ((map.size >> 16) - 1)); + if (rc) + return rc; + + /* + * Switch to FWH2AHB mode, AST2600 only. + */ + if (lpc_ctrl->fwh2ahb) { + /* + * Enable FWH2AHB in SCU debug control register 2. This + * does not turn it on, but makes it available for it + * to be configured in HICR6. + */ + regmap_update_bits(lpc_ctrl->scu, 0x0D8, BIT(2), 0); + + /* + * The other bits in this register are interrupt status bits + * that are cleared by writing 1. As we don't want to clear + * them, set only the bit of interest. + */ + regmap_write(lpc_ctrl->regmap, HICR6, SW_FWH2AHB); + } + + /* + * Enable LPC FHW cycles. This is required for the host to + * access the regions specified. + */ + return regmap_update_bits(lpc_ctrl->regmap, HICR5, + HICR5_ENFWH | HICR5_ENL2H, + HICR5_ENFWH | HICR5_ENL2H); + } + + return -EINVAL; +} + +static const struct file_operations aspeed_lpc_ctrl_fops = { + .owner = THIS_MODULE, + .mmap = aspeed_lpc_ctrl_mmap, + .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, +}; + +static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) +{ + struct aspeed_lpc_ctrl *lpc_ctrl; + struct device_node *node; + struct resource resm; + struct device *dev; + struct device_node *np; + int rc; + + dev = &pdev->dev; + + lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); + if (!lpc_ctrl) + return -ENOMEM; + + /* If flash is described in device tree then store */ + node = of_parse_phandle(dev->of_node, "flash", 0); + if (!node) { + dev_dbg(dev, "Didn't find host pnor flash node\n"); + } else { + rc = of_address_to_resource(node, 1, &resm); + of_node_put(node); + if (rc) { + dev_err(dev, "Couldn't address to resource for flash\n"); + return rc; + } + + lpc_ctrl->pnor_size = resource_size(&resm); + lpc_ctrl->pnor_base = resm.start; + } + + + dev_set_drvdata(&pdev->dev, lpc_ctrl); + + /* If memory-region is described in device tree then store */ + rc = of_reserved_mem_region_to_resource(dev->of_node, 0, &resm); + if (!rc) { + lpc_ctrl->mem_size = resource_size(&resm); + lpc_ctrl->mem_base = resm.start; + + if (!is_power_of_2(lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory size must be a power of 2, got %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } + + if (!IS_ALIGNED(lpc_ctrl->mem_base, lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory must be naturally aligned for size %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } + } + + np = pdev->dev.parent->of_node; + if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") && + !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") && + !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) { + dev_err(dev, "unsupported LPC device binding\n"); + return -ENODEV; + } + + lpc_ctrl->regmap = syscon_node_to_regmap(np); + if (IS_ERR(lpc_ctrl->regmap)) { + dev_err(dev, "Couldn't get regmap\n"); + return -ENODEV; + } + + if (of_device_is_compatible(dev->of_node, "aspeed,ast2600-lpc-ctrl")) { + lpc_ctrl->fwh2ahb = true; + + lpc_ctrl->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2600-scu"); + if (IS_ERR(lpc_ctrl->scu)) { + dev_err(dev, "couldn't find scu\n"); + return PTR_ERR(lpc_ctrl->scu); + } + } + + lpc_ctrl->clk = devm_clk_get(dev, NULL); + if (IS_ERR(lpc_ctrl->clk)) + return dev_err_probe(dev, PTR_ERR(lpc_ctrl->clk), + "couldn't get clock\n"); + rc = clk_prepare_enable(lpc_ctrl->clk); + if (rc) { + dev_err(dev, "couldn't enable clock\n"); + return rc; + } + + lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; + lpc_ctrl->miscdev.name = DEVICE_NAME; + lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; + lpc_ctrl->miscdev.parent = dev; + rc = misc_register(&lpc_ctrl->miscdev); + if (rc) { + dev_err(dev, "Unable to register device\n"); + goto err; + } + + return 0; + +err: + clk_disable_unprepare(lpc_ctrl->clk); + return rc; +} + +static void aspeed_lpc_ctrl_remove(struct platform_device *pdev) +{ + struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); + + misc_deregister(&lpc_ctrl->miscdev); + clk_disable_unprepare(lpc_ctrl->clk); +} + +static const struct of_device_id aspeed_lpc_ctrl_match[] = { + { .compatible = "aspeed,ast2400-lpc-ctrl" }, + { .compatible = "aspeed,ast2500-lpc-ctrl" }, + { .compatible = "aspeed,ast2600-lpc-ctrl" }, + { }, +}; +MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); + +static struct platform_driver aspeed_lpc_ctrl_driver = { + .driver = { + .name = DEVICE_NAME, + .of_match_table = aspeed_lpc_ctrl_match, + }, + .probe = aspeed_lpc_ctrl_probe, + .remove = aspeed_lpc_ctrl_remove, +}; + +module_platform_driver(aspeed_lpc_ctrl_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Cyril Bur "); +MODULE_DESCRIPTION("Control for ASPEED LPC HOST to BMC mappings"); -- cgit v1.3.1