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/macintosh/macio_sysfs.c | 82 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 drivers/macintosh/macio_sysfs.c (limited to 'drivers/macintosh/macio_sysfs.c') diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c new file mode 100644 index 000000000..2bbe359b2 --- /dev/null +++ b/drivers/macintosh/macio_sysfs.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +static ssize_t +compatible_show (struct device *dev, struct device_attribute *attr, char *buf) +{ + struct platform_device *of; + const char *compat; + int cplen; + int length = 0; + + of = &to_macio_device (dev)->ofdev; + compat = of_get_property(of->dev.of_node, "compatible", &cplen); + if (!compat) { + *buf = '\0'; + return 0; + } + while (cplen > 0) { + int l; + length += sprintf (buf, "%s\n", compat); + buf += length; + l = strlen (compat) + 1; + compat += l; + cplen -= l; + } + + return length; +} +static DEVICE_ATTR_RO(compatible); + +static ssize_t modalias_show (struct device *dev, struct device_attribute *attr, + char *buf) +{ + return of_device_modalias(dev, buf, PAGE_SIZE); +} + +static ssize_t devspec_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *ofdev; + + ofdev = to_platform_device(dev); + return sprintf(buf, "%pOF\n", ofdev->dev.of_node); +} +static DEVICE_ATTR_RO(modalias); +static DEVICE_ATTR_RO(devspec); + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%pOFn\n", dev->of_node); +} +static DEVICE_ATTR_RO(name); + +static ssize_t type_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", of_node_get_device_type(dev->of_node)); +} +static DEVICE_ATTR_RO(type); + +static struct attribute *macio_dev_attrs[] = { + &dev_attr_name.attr, + &dev_attr_type.attr, + &dev_attr_compatible.attr, + &dev_attr_modalias.attr, + &dev_attr_devspec.attr, + NULL, +}; + +static const struct attribute_group macio_dev_group = { + .attrs = macio_dev_attrs, +}; + +const struct attribute_group *macio_dev_groups[] = { + &macio_dev_group, + NULL, +}; -- cgit v1.3.1