bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-regmap.c b/drivers/clk/qcom/clk-regmap.c
new file mode 100644
index 000000000..92ac4e0d7
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/device.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include <linux/export.h>
+
+#include "clk-regmap.h"
+
+/**
+ * clk_is_enabled_regmap - standard is_enabled() for regmap users
+ *
+ * @hw: clk to operate on
+ *
+ * Clocks that use regmap for their register I/O can set the
+ * enable_reg and enable_mask fields in their struct clk_regmap and then use
+ * this as their is_enabled operation, saving some code.
+ */
+int clk_is_enabled_regmap(struct clk_hw *hw)
+{
+	struct clk_regmap *rclk = to_clk_regmap(hw);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(rclk->regmap, rclk->enable_reg, &val);
+	if (ret != 0)
+		return ret;
+
+	if (rclk->enable_is_inverted)
+		return (val & rclk->enable_mask) == 0;
+	else
+		return (val & rclk->enable_mask) != 0;
+}
+EXPORT_SYMBOL_GPL(clk_is_enabled_regmap);
+
+/**
+ * clk_enable_regmap - standard enable() for regmap users
+ *
+ * @hw: clk to operate on
+ *
+ * Clocks that use regmap for their register I/O can set the
+ * enable_reg and enable_mask fields in their struct clk_regmap and then use
+ * this as their enable() operation, saving some code.
+ */
+int clk_enable_regmap(struct clk_hw *hw)
+{
+	struct clk_regmap *rclk = to_clk_regmap(hw);
+	unsigned int val;
+
+	if (rclk->enable_is_inverted)
+		val = 0;
+	else
+		val = rclk->enable_mask;
+
+	return regmap_update_bits(rclk->regmap, rclk->enable_reg,
+				  rclk->enable_mask, val);
+}
+EXPORT_SYMBOL_GPL(clk_enable_regmap);
+
+/**
+ * clk_disable_regmap - standard disable() for regmap users
+ *
+ * @hw: clk to operate on
+ *
+ * Clocks that use regmap for their register I/O can set the
+ * enable_reg and enable_mask fields in their struct clk_regmap and then use
+ * this as their disable() operation, saving some code.
+ */
+void clk_disable_regmap(struct clk_hw *hw)
+{
+	struct clk_regmap *rclk = to_clk_regmap(hw);
+	unsigned int val;
+
+	if (rclk->enable_is_inverted)
+		val = rclk->enable_mask;
+	else
+		val = 0;
+
+	regmap_update_bits(rclk->regmap, rclk->enable_reg, rclk->enable_mask,
+			   val);
+}
+EXPORT_SYMBOL_GPL(clk_disable_regmap);
+
+/**
+ * devm_clk_register_regmap - register a clk_regmap clock
+ *
+ * @dev: reference to the caller's device
+ * @rclk: clk to operate on
+ *
+ * Clocks that use regmap for their register I/O should register their
+ * clk_regmap struct via this function so that the regmap is initialized
+ * and so that the clock is registered with the common clock framework.
+ */
+int devm_clk_register_regmap(struct device *dev, struct clk_regmap *rclk)
+{
+	if (dev && dev_get_regmap(dev, NULL))
+		rclk->regmap = dev_get_regmap(dev, NULL);
+	else if (dev && dev->parent)
+		rclk->regmap = dev_get_regmap(dev->parent, NULL);
+
+	return devm_clk_hw_register(dev, &rclk->hw);
+}
+EXPORT_SYMBOL_GPL(devm_clk_register_regmap);