From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/mfd/bcm2835-pm.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 drivers/mfd/bcm2835-pm.c (limited to 'drivers/mfd/bcm2835-pm.c') diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c new file mode 100644 index 000000000..9e8e3dcf4 --- /dev/null +++ b/drivers/mfd/bcm2835-pm.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * PM MFD driver for Broadcom BCM2835 + * + * This driver binds to the PM block and creates the MFD device for + * the WDT and power drivers. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static const struct mfd_cell bcm2835_pm_devs[] = { + { .name = "bcm2835-wdt" }, +}; + +static const struct mfd_cell bcm2835_power_devs[] = { + { .name = "bcm2835-power" }, +}; + +static int bcm2835_pm_get_pdata(struct platform_device *pdev, + struct bcm2835_pm *pm) +{ + if (of_property_present(pm->dev->of_node, "reg-names")) { + struct resource *res; + + pm->base = devm_platform_ioremap_resource_byname(pdev, "pm"); + if (IS_ERR(pm->base)) + return PTR_ERR(pm->base); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "asb"); + if (res) { + pm->asb = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pm->asb)) + pm->asb = NULL; + } + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, + "rpivid_asb"); + if (res) { + pm->rpivid_asb = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pm->rpivid_asb)) + pm->rpivid_asb = NULL; + } + + return 0; + } + + /* If no 'reg-names' property is found we can assume we're using old DTB. */ + pm->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pm->base)) + return PTR_ERR(pm->base); + + pm->asb = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(pm->asb)) + pm->asb = NULL; + + pm->rpivid_asb = devm_platform_ioremap_resource(pdev, 2); + if (IS_ERR(pm->rpivid_asb)) + pm->rpivid_asb = NULL; + + return 0; +} + +static int bcm2835_pm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bcm2835_pm *pm; + int ret; + + pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL); + if (!pm) + return -ENOMEM; + platform_set_drvdata(pdev, pm); + + pm->dev = dev; + pm->soc = (uintptr_t)device_get_match_data(dev); + + ret = bcm2835_pm_get_pdata(pdev, pm); + if (ret) + return ret; + + ret = devm_mfd_add_devices(dev, -1, + bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs), + NULL, 0, NULL); + if (ret) + return ret; + + /* + * We'll use the presence of the AXI ASB regs in the + * bcm2835-pm binding as the key for whether we can reference + * the full PM register range and support power domains. + */ + if (pm->asb || pm->soc == BCM2835_PM_SOC_BCM2712) + return devm_mfd_add_devices(dev, -1, bcm2835_power_devs, + ARRAY_SIZE(bcm2835_power_devs), + NULL, 0, NULL); + return 0; +} + +static const struct of_device_id bcm2835_pm_of_match[] = { + { .compatible = "brcm,bcm2835-pm-wdt", }, + { .compatible = "brcm,bcm2835-pm", .data = (void *)BCM2835_PM_SOC_BCM2835 }, + { .compatible = "brcm,bcm2711-pm", .data = (void *)BCM2835_PM_SOC_BCM2711 }, + { .compatible = "brcm,bcm2712-pm", .data = (void *)BCM2835_PM_SOC_BCM2712 }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match); + +static struct platform_driver bcm2835_pm_driver = { + .probe = bcm2835_pm_probe, + .driver = { + .name = "bcm2835-pm", + .of_match_table = bcm2835_pm_of_match, + }, +}; +module_platform_driver(bcm2835_pm_driver); + +MODULE_AUTHOR("Eric Anholt "); +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD"); -- cgit v1.3.1