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, 288 insertions, 0 deletions

diff --git a/drivers/mfd/bd9571mwv.c b/drivers/mfd/bd9571mwv.c
new file mode 100644
index 000000000..db8c2963f
--- /dev/null
+++ b/drivers/mfd/bd9571mwv.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ROHM BD9571MWV-M and BD9574MVF-M core driver
+ *
+ * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
+ * Copyright (C) 2020 Renesas Electronics Corporation
+ *
+ * Based on the TPS65086 driver
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rohm-generic.h>
+#include <linux/module.h>
+
+#include <linux/mfd/bd9571mwv.h>
+
+static const struct mfd_cell bd9571mwv_cells[] = {
+	{ .name = "bd9571mwv-regulator", },
+	{ .name = "bd9571mwv-gpio", },
+};
+
+static const struct regmap_range bd9571mwv_readable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_VENDOR_CODE, BD9571MWV_PRODUCT_REVISION),
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_AVS_SET_MONI, BD9571MWV_AVS_DVFS_VID(3)),
+	regmap_reg_range(BD9571MWV_VD18_VID, BD9571MWV_VD33_VID),
+	regmap_reg_range(BD9571MWV_DVFS_VINIT, BD9571MWV_DVFS_VINIT),
+	regmap_reg_range(BD9571MWV_DVFS_SETVMAX, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9571mwv_readable_table = {
+	.yes_ranges	= bd9571mwv_readable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_readable_yes_ranges),
+};
+
+static const struct regmap_range bd9571mwv_writable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_AVS_VD09_VID(0), BD9571MWV_AVS_VD09_VID(3)),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_SETVID),
+	regmap_reg_range(BD9571MWV_GPIO_DIR, BD9571MWV_GPIO_OUT),
+	regmap_reg_range(BD9571MWV_GPIO_INT_SET, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9571mwv_writable_table = {
+	.yes_ranges	= bd9571mwv_writable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_writable_yes_ranges),
+};
+
+static const struct regmap_range bd9571mwv_volatile_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_DVFS_MONIVDAC, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INT),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTREQ),
+};
+
+static const struct regmap_access_table bd9571mwv_volatile_table = {
+	.yes_ranges	= bd9571mwv_volatile_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_volatile_yes_ranges),
+};
+
+static const struct regmap_config bd9571mwv_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.cache_type	= REGCACHE_MAPLE,
+	.rd_table	= &bd9571mwv_readable_table,
+	.wr_table	= &bd9571mwv_writable_table,
+	.volatile_table	= &bd9571mwv_volatile_table,
+	.max_register	= 0xff,
+};
+
+static const struct regmap_irq bd9571mwv_irqs[] = {
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD1, 0,
+		       BD9571MWV_INT_INTREQ_MD1_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD2_E1, 0,
+		       BD9571MWV_INT_INTREQ_MD2_E1_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD2_E2, 0,
+		       BD9571MWV_INT_INTREQ_MD2_E2_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_PROT_ERR, 0,
+		       BD9571MWV_INT_INTREQ_PROT_ERR_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_GP, 0,
+		       BD9571MWV_INT_INTREQ_GP_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_128H_OF, 0,
+		       BD9571MWV_INT_INTREQ_128H_OF_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_WDT_OF, 0,
+		       BD9571MWV_INT_INTREQ_WDT_OF_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_BKUP_TRG, 0,
+		       BD9571MWV_INT_INTREQ_BKUP_TRG_INT),
+};
+
+static const struct regmap_irq_chip bd9571mwv_irq_chip = {
+	.name		= "bd9571mwv",
+	.status_base	= BD9571MWV_INT_INTREQ,
+	.mask_base	= BD9571MWV_INT_INTMASK,
+	.ack_base	= BD9571MWV_INT_INTREQ,
+	.init_ack_masked = true,
+	.num_regs	= 1,
+	.irqs		= bd9571mwv_irqs,
+	.num_irqs	= ARRAY_SIZE(bd9571mwv_irqs),
+};
+
+static const struct mfd_cell bd9574mwf_cells[] = {
+	{ .name = "bd9574mwf-regulator", },
+	{ .name = "bd9574mwf-gpio", },
+};
+
+static const struct regmap_range bd9574mwf_readable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_VENDOR_CODE, BD9571MWV_PRODUCT_REVISION),
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_DVFS_VINIT, BD9571MWV_DVFS_SETVMAX),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9574mwf_readable_table = {
+	.yes_ranges	= bd9574mwf_readable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_readable_yes_ranges),
+};
+
+static const struct regmap_range bd9574mwf_writable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_SETVID),
+	regmap_reg_range(BD9571MWV_GPIO_DIR, BD9571MWV_GPIO_OUT),
+	regmap_reg_range(BD9571MWV_GPIO_INT_SET, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9574mwf_writable_table = {
+	.yes_ranges	= bd9574mwf_writable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_writable_yes_ranges),
+};
+
+static const struct regmap_range bd9574mwf_volatile_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_DVFS_MONIVDAC, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INT),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTREQ),
+};
+
+static const struct regmap_access_table bd9574mwf_volatile_table = {
+	.yes_ranges	= bd9574mwf_volatile_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_volatile_yes_ranges),
+};
+
+static const struct regmap_config bd9574mwf_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.cache_type	= REGCACHE_MAPLE,
+	.rd_table	= &bd9574mwf_readable_table,
+	.wr_table	= &bd9574mwf_writable_table,
+	.volatile_table	= &bd9574mwf_volatile_table,
+	.max_register	= 0xff,
+};
+
+static const struct regmap_irq_chip bd9574mwf_irq_chip = {
+	.name		= "bd9574mwf",
+	.status_base	= BD9571MWV_INT_INTREQ,
+	.mask_base	= BD9571MWV_INT_INTMASK,
+	.ack_base	= BD9571MWV_INT_INTREQ,
+	.init_ack_masked = true,
+	.num_regs	= 1,
+	.irqs		= bd9571mwv_irqs,
+	.num_irqs	= ARRAY_SIZE(bd9571mwv_irqs),
+};
+
+static int bd957x_identify(struct device *dev, struct regmap *regmap)
+{
+	unsigned int value;
+	int ret;
+
+	ret = regmap_read(regmap, BD9571MWV_VENDOR_CODE, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read vendor code register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+
+	if (value != BD9571MWV_VENDOR_CODE_VAL) {
+		dev_err(dev, "Invalid vendor code ID %02x (expected %02x)\n",
+			value, BD9571MWV_VENDOR_CODE_VAL);
+		return -EINVAL;
+	}
+
+	ret = regmap_read(regmap, BD9571MWV_PRODUCT_CODE, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read product code register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+	ret = regmap_read(regmap, BD9571MWV_PRODUCT_REVISION, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read revision register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bd9571mwv_probe(struct i2c_client *client)
+{
+	const struct regmap_config *regmap_config;
+	const struct regmap_irq_chip *irq_chip;
+	const struct mfd_cell *cells;
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *irq_data;
+	int ret, num_cells, irq = client->irq;
+
+	/* Read the PMIC product code */
+	ret = i2c_smbus_read_byte_data(client, BD9571MWV_PRODUCT_CODE);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read product code\n");
+		return ret;
+	}
+
+	switch (ret) {
+	case BD9571MWV_PRODUCT_CODE_BD9571MWV:
+		regmap_config = &bd9571mwv_regmap_config;
+		irq_chip = &bd9571mwv_irq_chip;
+		cells = bd9571mwv_cells;
+		num_cells = ARRAY_SIZE(bd9571mwv_cells);
+		break;
+	case BD9571MWV_PRODUCT_CODE_BD9574MWF:
+		regmap_config = &bd9574mwf_regmap_config;
+		irq_chip = &bd9574mwf_irq_chip;
+		cells = bd9574mwf_cells;
+		num_cells = ARRAY_SIZE(bd9574mwf_cells);
+		break;
+	default:
+		dev_err(dev, "Unsupported device 0x%x\n", ret);
+		return -ENODEV;
+	}
+
+	regmap = devm_regmap_init_i2c(client, regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "Failed to initialize register map\n");
+		return PTR_ERR(regmap);
+	}
+
+	ret = bd957x_identify(dev, regmap);
+	if (ret)
+		return ret;
+
+	ret = devm_regmap_add_irq_chip(dev, regmap, irq, IRQF_ONESHOT, 0,
+				       irq_chip, &irq_data);
+	if (ret) {
+		dev_err(dev, "Failed to register IRQ chip\n");
+		return ret;
+	}
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, num_cells,
+				    NULL, 0, regmap_irq_get_domain(irq_data));
+}
+
+static const struct of_device_id bd9571mwv_of_match_table[] = {
+	{ .compatible = "rohm,bd9571mwv", },
+	{ .compatible = "rohm,bd9574mwf", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bd9571mwv_of_match_table);
+
+static const struct i2c_device_id bd9571mwv_id_table[] = {
+	{ "bd9571mwv" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, bd9571mwv_id_table);
+
+static struct i2c_driver bd9571mwv_driver = {
+	.driver		= {
+		.name	= "bd9571mwv",
+		.of_match_table = bd9571mwv_of_match_table,
+	},
+	.probe		= bd9571mwv_probe,
+	.id_table       = bd9571mwv_id_table,
+};
+module_i2c_driver(bd9571mwv_driver);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
+MODULE_DESCRIPTION("BD9571MWV PMIC Driver");
+MODULE_LICENSE("GPL v2");