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, 116 insertions, 0 deletions

diff --git a/drivers/bus/tegra-aconnect.c b/drivers/bus/tegra-aconnect.c
new file mode 100644
index 000000000..9b2b22733
--- /dev/null
+++ b/drivers/bus/tegra-aconnect.c
@@ -0,0 +1,116 @@
+/*
+ * Tegra ACONNECT Bus Driver
+ *
+ * Copyright (C) 2016, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+struct tegra_aconnect {
+	struct clk	*ape_clk;
+	struct clk	*apb2ape_clk;
+};
+
+static int tegra_aconnect_probe(struct platform_device *pdev)
+{
+	struct tegra_aconnect *aconnect;
+
+	if (!pdev->dev.of_node)
+		return -EINVAL;
+
+	aconnect = devm_kzalloc(&pdev->dev, sizeof(struct tegra_aconnect),
+				GFP_KERNEL);
+	if (!aconnect)
+		return -ENOMEM;
+
+	aconnect->ape_clk = devm_clk_get(&pdev->dev, "ape");
+	if (IS_ERR(aconnect->ape_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(aconnect->ape_clk),
+				     "can't retrieve ape clock\n");
+
+	aconnect->apb2ape_clk = devm_clk_get(&pdev->dev, "apb2ape");
+	if (IS_ERR(aconnect->apb2ape_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(aconnect->apb2ape_clk),
+				     "can't retrieve apb2ape clock\n");
+
+	dev_set_drvdata(&pdev->dev, aconnect);
+	pm_runtime_enable(&pdev->dev);
+
+	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+
+	dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");
+
+	return 0;
+}
+
+static void tegra_aconnect_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+}
+
+static int tegra_aconnect_runtime_resume(struct device *dev)
+{
+	struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(aconnect->ape_clk);
+	if (ret) {
+		dev_err(dev, "ape clk_enable failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(aconnect->apb2ape_clk);
+	if (ret) {
+		clk_disable_unprepare(aconnect->ape_clk);
+		dev_err(dev, "apb2ape clk_enable failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int tegra_aconnect_runtime_suspend(struct device *dev)
+{
+	struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(aconnect->ape_clk);
+	clk_disable_unprepare(aconnect->apb2ape_clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tegra_aconnect_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
+			   tegra_aconnect_runtime_resume, NULL)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
+};
+
+static const struct of_device_id tegra_aconnect_of_match[] = {
+	{ .compatible = "nvidia,tegra210-aconnect", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);
+
+static struct platform_driver tegra_aconnect_driver = {
+	.probe = tegra_aconnect_probe,
+	.remove = tegra_aconnect_remove,
+	.driver = {
+		.name = "tegra-aconnect",
+		.of_match_table = tegra_aconnect_of_match,
+		.pm = &tegra_aconnect_pm_ops,
+	},
+};
+module_platform_driver(tegra_aconnect_driver);
+
+MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
+MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
+MODULE_LICENSE("GPL v2");