From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 drivers/net/phy/et1011c.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 drivers/net/phy/et1011c.c

(limited to 'drivers/net/phy/et1011c.c')

diff --git a/drivers/net/phy/et1011c.c b/drivers/net/phy/et1011c.c
new file mode 100644
index 000000000..6cd8d7758
--- /dev/null
+++ b/drivers/net/phy/et1011c.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/net/phy/et1011c.c
+ *
+ * Driver for LSI ET1011C PHYs
+ *
+ * Author: Chaithrika U S
+ *
+ * Copyright (c) 2008 Texas Instruments
+ */
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/ethtool.h>
+#include <linux/phy.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <asm/irq.h>
+
+#define ET1011C_STATUS_REG	(0x1A)
+#define ET1011C_CONFIG_REG	(0x16)
+#define ET1011C_SPEED_MASK		(0x0300)
+#define ET1011C_GIGABIT_SPEED		(0x0200)
+#define ET1011C_TX_FIFO_MASK		(0x3000)
+#define ET1011C_TX_FIFO_DEPTH_8		(0x0000)
+#define ET1011C_TX_FIFO_DEPTH_16	(0x1000)
+#define ET1011C_INTERFACE_MASK		(0x0007)
+#define ET1011C_GMII_INTERFACE		(0x0002)
+#define ET1011C_SYS_CLK_EN		(0x01 << 4)
+
+
+MODULE_DESCRIPTION("LSI ET1011C PHY driver");
+MODULE_AUTHOR("Chaithrika U S");
+MODULE_LICENSE("GPL");
+
+static int et1011c_config_aneg(struct phy_device *phydev)
+{
+	int ctl = phy_read(phydev, MII_BMCR);
+
+	if (ctl < 0)
+		return ctl;
+	ctl &= ~(BMCR_FULLDPLX | BMCR_SPEED100 | BMCR_SPEED1000 |
+		 BMCR_ANENABLE);
+	/* First clear the PHY */
+	phy_write(phydev, MII_BMCR, ctl | BMCR_RESET);
+
+	return genphy_config_aneg(phydev);
+}
+
+static int et1011c_read_status(struct phy_device *phydev)
+{
+	static int speed;
+	int ret;
+	u32 val;
+
+	ret = genphy_read_status(phydev);
+
+	if (speed != phydev->speed) {
+		speed = phydev->speed;
+		val = phy_read(phydev, ET1011C_STATUS_REG);
+		if ((val & ET1011C_SPEED_MASK) ==
+					ET1011C_GIGABIT_SPEED) {
+			val = phy_read(phydev, ET1011C_CONFIG_REG);
+			val &= ~ET1011C_TX_FIFO_MASK;
+			phy_write(phydev, ET1011C_CONFIG_REG, val |
+					  ET1011C_GMII_INTERFACE |
+					  ET1011C_SYS_CLK_EN |
+					  ET1011C_TX_FIFO_DEPTH_16);
+
+		}
+	}
+	return ret;
+}
+
+static struct phy_driver et1011c_driver[] = { {
+	.phy_id		= 0x0282f014,
+	.name		= "ET1011C",
+	.phy_id_mask	= 0xfffffff0,
+	/* PHY_GBIT_FEATURES */
+	.config_aneg	= et1011c_config_aneg,
+	.read_status	= et1011c_read_status,
+} };
+
+module_phy_driver(et1011c_driver);
+
+static const struct mdio_device_id __maybe_unused et1011c_tbl[] = {
+	{ 0x0282f014, 0xfffffff0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, et1011c_tbl);
-- 
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