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, 140 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-rt305x.c b/drivers/pinctrl/mediatek/pinctrl-rt305x.c
new file mode 100644
index 000000000..77bd4d1f6
--- /dev/null
+++ b/drivers/pinctrl/mediatek/pinctrl-rt305x.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/mach-ralink/ralink_regs.h>
+#include <asm/mach-ralink/rt305x.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include "pinctrl-mtmips.h"
+
+#define RT305X_GPIO_MODE_UART0_SHIFT	2
+#define RT305X_GPIO_MODE_UART0_MASK	0x7
+#define RT305X_GPIO_MODE_UART0(x)	((x) << RT305X_GPIO_MODE_UART0_SHIFT)
+#define RT305X_GPIO_MODE_UARTF		0
+#define RT305X_GPIO_MODE_PCM_UARTF	1
+#define RT305X_GPIO_MODE_PCM_I2S	2
+#define RT305X_GPIO_MODE_I2S_UARTF	3
+#define RT305X_GPIO_MODE_PCM_GPIO	4
+#define RT305X_GPIO_MODE_GPIO_UARTF	5
+#define RT305X_GPIO_MODE_GPIO_I2S	6
+#define RT305X_GPIO_MODE_GPIO		7
+
+#define RT305X_GPIO_MODE_I2C		0
+#define RT305X_GPIO_MODE_SPI		1
+#define RT305X_GPIO_MODE_UART1		5
+#define RT305X_GPIO_MODE_JTAG		6
+#define RT305X_GPIO_MODE_MDIO		7
+#define RT305X_GPIO_MODE_SDRAM		8
+#define RT305X_GPIO_MODE_RGMII		9
+#define RT5350_GPIO_MODE_PHY_LED	14
+#define RT5350_GPIO_MODE_SPI_CS1	21
+#define RT3352_GPIO_MODE_LNA		18
+#define RT3352_GPIO_MODE_PA		20
+
+static struct mtmips_pmx_func i2c_grp[] =  { FUNC("i2c", 0, 1, 2) };
+static struct mtmips_pmx_func spi_grp[] = { FUNC("spi", 0, 3, 4) };
+static struct mtmips_pmx_func uartf_grp[] = {
+	FUNC("uartf", RT305X_GPIO_MODE_UARTF, 7, 8),
+	FUNC("pcm uartf", RT305X_GPIO_MODE_PCM_UARTF, 7, 8),
+	FUNC("pcm i2s", RT305X_GPIO_MODE_PCM_I2S, 7, 8),
+	FUNC("i2s uartf", RT305X_GPIO_MODE_I2S_UARTF, 7, 8),
+	FUNC("pcm gpio", RT305X_GPIO_MODE_PCM_GPIO, 11, 4),
+	FUNC("gpio uartf", RT305X_GPIO_MODE_GPIO_UARTF, 7, 4),
+	FUNC("gpio i2s", RT305X_GPIO_MODE_GPIO_I2S, 7, 4),
+};
+static struct mtmips_pmx_func uartlite_grp[] = { FUNC("uartlite", 0, 15, 2) };
+static struct mtmips_pmx_func jtag_grp[] = { FUNC("jtag", 0, 17, 5) };
+static struct mtmips_pmx_func mdio_grp[] = { FUNC("mdio", 0, 22, 2) };
+static struct mtmips_pmx_func rt5350_led_grp[] = { FUNC("led", 0, 22, 5) };
+static struct mtmips_pmx_func rt5350_cs1_grp[] = {
+	FUNC("spi_cs1", 0, 27, 1),
+	FUNC("wdg_cs1", 1, 27, 1),
+};
+static struct mtmips_pmx_func sdram_grp[] = { FUNC("sdram", 0, 24, 16) };
+static struct mtmips_pmx_func rt3352_rgmii_grp[] = {
+	FUNC("rgmii", 0, 24, 12)
+};
+static struct mtmips_pmx_func rgmii_grp[] = { FUNC("rgmii", 0, 40, 12) };
+static struct mtmips_pmx_func rt3352_lna_grp[] = { FUNC("lna", 0, 36, 2) };
+static struct mtmips_pmx_func rt3352_pa_grp[] = { FUNC("pa", 0, 38, 2) };
+static struct mtmips_pmx_func rt3352_led_grp[] = { FUNC("led", 0, 40, 5) };
+static struct mtmips_pmx_func rt3352_cs1_grp[] = {
+	FUNC("spi_cs1", 0, 45, 1),
+	FUNC("wdg_cs1", 1, 45, 1),
+};
+
+static struct mtmips_pmx_group rt3050_pinmux_data[] = {
+	GRP("i2c", i2c_grp, 1, RT305X_GPIO_MODE_I2C),
+	GRP("spi", spi_grp, 1, RT305X_GPIO_MODE_SPI),
+	GRP("uartf", uartf_grp, RT305X_GPIO_MODE_UART0_MASK,
+		RT305X_GPIO_MODE_UART0_SHIFT),
+	GRP("uartlite", uartlite_grp, 1, RT305X_GPIO_MODE_UART1),
+	GRP("jtag", jtag_grp, 1, RT305X_GPIO_MODE_JTAG),
+	GRP("mdio", mdio_grp, 1, RT305X_GPIO_MODE_MDIO),
+	GRP("rgmii", rgmii_grp, 1, RT305X_GPIO_MODE_RGMII),
+	GRP("sdram", sdram_grp, 1, RT305X_GPIO_MODE_SDRAM),
+	{ 0 }
+};
+
+static struct mtmips_pmx_group rt3352_pinmux_data[] = {
+	GRP("i2c", i2c_grp, 1, RT305X_GPIO_MODE_I2C),
+	GRP("spi", spi_grp, 1, RT305X_GPIO_MODE_SPI),
+	GRP("uartf", uartf_grp, RT305X_GPIO_MODE_UART0_MASK,
+		RT305X_GPIO_MODE_UART0_SHIFT),
+	GRP("uartlite", uartlite_grp, 1, RT305X_GPIO_MODE_UART1),
+	GRP("jtag", jtag_grp, 1, RT305X_GPIO_MODE_JTAG),
+	GRP("mdio", mdio_grp, 1, RT305X_GPIO_MODE_MDIO),
+	GRP("rgmii", rt3352_rgmii_grp, 1, RT305X_GPIO_MODE_RGMII),
+	GRP("lna", rt3352_lna_grp, 1, RT3352_GPIO_MODE_LNA),
+	GRP("pa", rt3352_pa_grp, 1, RT3352_GPIO_MODE_PA),
+	GRP("led", rt3352_led_grp, 1, RT5350_GPIO_MODE_PHY_LED),
+	GRP("spi_cs1", rt3352_cs1_grp, 2, RT5350_GPIO_MODE_SPI_CS1),
+	{ 0 }
+};
+
+static struct mtmips_pmx_group rt5350_pinmux_data[] = {
+	GRP("i2c", i2c_grp, 1, RT305X_GPIO_MODE_I2C),
+	GRP("spi", spi_grp, 1, RT305X_GPIO_MODE_SPI),
+	GRP("uartf", uartf_grp, RT305X_GPIO_MODE_UART0_MASK,
+		RT305X_GPIO_MODE_UART0_SHIFT),
+	GRP("uartlite", uartlite_grp, 1, RT305X_GPIO_MODE_UART1),
+	GRP("jtag", jtag_grp, 1, RT305X_GPIO_MODE_JTAG),
+	GRP("led", rt5350_led_grp, 1, RT5350_GPIO_MODE_PHY_LED),
+	GRP("spi_cs1", rt5350_cs1_grp, 2, RT5350_GPIO_MODE_SPI_CS1),
+	{ 0 }
+};
+
+static int rt305x_pinctrl_probe(struct platform_device *pdev)
+{
+	if (soc_is_rt5350())
+		return mtmips_pinctrl_init(pdev, rt5350_pinmux_data);
+	else if (soc_is_rt305x() || soc_is_rt3350())
+		return mtmips_pinctrl_init(pdev, rt3050_pinmux_data);
+	else if (soc_is_rt3352())
+		return mtmips_pinctrl_init(pdev, rt3352_pinmux_data);
+	else
+		return -EINVAL;
+}
+
+static const struct of_device_id rt305x_pinctrl_match[] = {
+	{ .compatible = "ralink,rt305x-pinctrl" },
+	{ .compatible = "ralink,rt3352-pinctrl" },
+	{ .compatible = "ralink,rt5350-pinctrl" },
+	{ .compatible = "ralink,rt2880-pinmux" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt305x_pinctrl_match);
+
+static struct platform_driver rt305x_pinctrl_driver = {
+	.probe = rt305x_pinctrl_probe,
+	.driver = {
+		.name = "rt305x-pinctrl",
+		.of_match_table = rt305x_pinctrl_match,
+	},
+};
+
+static int __init rt305x_pinctrl_init(void)
+{
+	return platform_driver_register(&rt305x_pinctrl_driver);
+}
+core_initcall_sync(rt305x_pinctrl_init);