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/base/physical_location.c | 144 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 drivers/base/physical_location.c (limited to 'drivers/base/physical_location.c') diff --git a/drivers/base/physical_location.c b/drivers/base/physical_location.c new file mode 100644 index 000000000..2e723fff6 --- /dev/null +++ b/drivers/base/physical_location.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Device physical location support + * + * Author: Won Chung + */ + +#include +#include +#include + +#include "physical_location.h" + +bool dev_add_physical_location(struct device *dev) +{ + struct acpi_pld_info *pld; + + if (!has_acpi_companion(dev)) + return false; + + if (!acpi_get_physical_device_location(ACPI_HANDLE(dev), &pld)) + return false; + + dev->physical_location = kzalloc_obj(*dev->physical_location); + if (!dev->physical_location) { + ACPI_FREE(pld); + return false; + } + + dev->physical_location->panel = pld->panel; + dev->physical_location->vertical_position = pld->vertical_position; + dev->physical_location->horizontal_position = pld->horizontal_position; + dev->physical_location->dock = pld->dock; + dev->physical_location->lid = pld->lid; + + ACPI_FREE(pld); + return true; +} + +static ssize_t panel_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + const char *panel; + + switch (dev->physical_location->panel) { + case DEVICE_PANEL_TOP: + panel = "top"; + break; + case DEVICE_PANEL_BOTTOM: + panel = "bottom"; + break; + case DEVICE_PANEL_LEFT: + panel = "left"; + break; + case DEVICE_PANEL_RIGHT: + panel = "right"; + break; + case DEVICE_PANEL_FRONT: + panel = "front"; + break; + case DEVICE_PANEL_BACK: + panel = "back"; + break; + default: + panel = "unknown"; + } + return sysfs_emit(buf, "%s\n", panel); +} +static DEVICE_ATTR_RO(panel); + +static ssize_t vertical_position_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const char *vertical_position; + + switch (dev->physical_location->vertical_position) { + case DEVICE_VERT_POS_UPPER: + vertical_position = "upper"; + break; + case DEVICE_VERT_POS_CENTER: + vertical_position = "center"; + break; + case DEVICE_VERT_POS_LOWER: + vertical_position = "lower"; + break; + default: + vertical_position = "unknown"; + } + return sysfs_emit(buf, "%s\n", vertical_position); +} +static DEVICE_ATTR_RO(vertical_position); + +static ssize_t horizontal_position_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const char *horizontal_position; + + switch (dev->physical_location->horizontal_position) { + case DEVICE_HORI_POS_LEFT: + horizontal_position = "left"; + break; + case DEVICE_HORI_POS_CENTER: + horizontal_position = "center"; + break; + case DEVICE_HORI_POS_RIGHT: + horizontal_position = "right"; + break; + default: + horizontal_position = "unknown"; + } + return sysfs_emit(buf, "%s\n", horizontal_position); +} +static DEVICE_ATTR_RO(horizontal_position); + +static ssize_t dock_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", + str_yes_no(dev->physical_location->dock)); +} +static DEVICE_ATTR_RO(dock); + +static ssize_t lid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", + str_yes_no(dev->physical_location->lid)); +} +static DEVICE_ATTR_RO(lid); + +static struct attribute *dev_attr_physical_location[] = { + &dev_attr_panel.attr, + &dev_attr_vertical_position.attr, + &dev_attr_horizontal_position.attr, + &dev_attr_dock.attr, + &dev_attr_lid.attr, + NULL, +}; + +const struct attribute_group dev_attr_physical_location_group = { + .name = "physical_location", + .attrs = dev_attr_physical_location, +}; + -- cgit v1.3.1