selftests/bpf: Reject graph kptr use after RCU unlockgrafted

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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-mt6797.c b/drivers/pinctrl/mediatek/pinctrl-mt6797.c
new file mode 100644
index 000000000..53f240491
--- /dev/null
+++ b/drivers/pinctrl/mediatek/pinctrl-mt6797.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based on pinctrl-mt6765.c
+ *
+ * Copyright (C) 2018 MediaTek Inc.
+ *
+ * Author: ZH Chen <zh.chen@mediatek.com>
+ *
+ * Copyright (C) Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ *
+ */
+
+#include "pinctrl-mtk-mt6797.h"
+#include "pinctrl-paris.h"
+
+/*
+ * MT6797 have multiple bases to program pin configuration listed as the below:
+ * gpio:0x10005000, iocfg[l]:0x10002000, iocfg[b]:0x10002400,
+ * iocfg[r]:0x10002800, iocfg[t]:0x10002C00.
+ * _i_base could be used to indicate what base the pin should be mapped into.
+ */
+
+static const struct mtk_pin_field_calc mt6797_pin_mode_range[] = {
+	PIN_FIELD(0, 261, 0x300, 0x10, 0, 4),
+};
+
+static const struct mtk_pin_field_calc mt6797_pin_dir_range[] = {
+	PIN_FIELD(0, 261, 0x0, 0x10, 0, 1),
+};
+
+static const struct mtk_pin_field_calc mt6797_pin_di_range[] = {
+	PIN_FIELD(0, 261, 0x200, 0x10, 0, 1),
+};
+
+static const struct mtk_pin_field_calc mt6797_pin_do_range[] = {
+	PIN_FIELD(0, 261, 0x100, 0x10, 0, 1),
+};
+
+static const struct mtk_pin_reg_calc mt6797_reg_cals[PINCTRL_PIN_REG_MAX] = {
+	[PINCTRL_PIN_REG_MODE] = MTK_RANGE(mt6797_pin_mode_range),
+	[PINCTRL_PIN_REG_DIR] = MTK_RANGE(mt6797_pin_dir_range),
+	[PINCTRL_PIN_REG_DI] = MTK_RANGE(mt6797_pin_di_range),
+	[PINCTRL_PIN_REG_DO] = MTK_RANGE(mt6797_pin_do_range),
+};
+
+static const char * const mt6797_pinctrl_register_base_names[] = {
+	"gpio", "iocfgl", "iocfgb", "iocfgr", "iocfgt",
+};
+
+static const struct mtk_pin_soc mt6797_data = {
+	.reg_cal = mt6797_reg_cals,
+	.pins = mtk_pins_mt6797,
+	.npins = ARRAY_SIZE(mtk_pins_mt6797),
+	.ngrps = ARRAY_SIZE(mtk_pins_mt6797),
+	.gpio_m = 0,
+	.base_names = mt6797_pinctrl_register_base_names,
+	.nbase_names = ARRAY_SIZE(mt6797_pinctrl_register_base_names),
+};
+
+static const struct of_device_id mt6797_pinctrl_of_match[] = {
+	{ .compatible = "mediatek,mt6797-pinctrl", .data = &mt6797_data },
+	{ }
+};
+
+static struct platform_driver mt6797_pinctrl_driver = {
+	.driver = {
+		.name = "mt6797-pinctrl",
+		.of_match_table = mt6797_pinctrl_of_match,
+	},
+	.probe = mtk_paris_pinctrl_probe,
+};
+
+static int __init mt6797_pinctrl_init(void)
+{
+	return platform_driver_register(&mt6797_pinctrl_driver);
+}
+arch_initcall(mt6797_pinctrl_init);