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, 41 insertions, 0 deletions

diff --git a/arch/arm/mach-s3c/dev-uart.c b/arch/arm/mach-s3c/dev-uart.c
new file mode 100644
index 000000000..3d1f7f2fd
--- /dev/null
+++ b/arch/arm/mach-s3c/dev-uart.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+//	originally from arch/arm/plat-s3c24xx/devs.c
+//
+// Copyright (c) 2004 Simtec Electronics
+//	Ben Dooks <ben@simtec.co.uk>
+//
+// Base S3C24XX platform device definitions
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+#include "devs.h"
+
+/* uart devices */
+
+static struct platform_device s3c24xx_uart_device0 = {
+	.id		= 0,
+};
+
+static struct platform_device s3c24xx_uart_device1 = {
+	.id		= 1,
+};
+
+static struct platform_device s3c24xx_uart_device2 = {
+	.id		= 2,
+};
+
+static struct platform_device s3c24xx_uart_device3 = {
+	.id		= 3,
+};
+
+struct platform_device *s3c24xx_uart_src[4] = {
+	&s3c24xx_uart_device0,
+	&s3c24xx_uart_device1,
+	&s3c24xx_uart_device2,
+	&s3c24xx_uart_device3,
+};
+
+struct platform_device *s3c24xx_uart_devs[4] = {
+};