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, 40 insertions, 0 deletions

diff --git a/drivers/input/vivaldi-fmap.c b/drivers/input/vivaldi-fmap.c
new file mode 100644
index 000000000..978949eba
--- /dev/null
+++ b/drivers/input/vivaldi-fmap.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helpers for ChromeOS Vivaldi keyboard function row mapping
+ *
+ * Copyright (C) 2022 Google, Inc
+ */
+
+#include <linux/export.h>
+#include <linux/input/vivaldi-fmap.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+/**
+ * vivaldi_function_row_physmap_show - Print vivaldi function row physmap attribute
+ * @data: The vivaldi function row map
+ * @buf: Buffer to print the function row phsymap to
+ */
+ssize_t vivaldi_function_row_physmap_show(const struct vivaldi_data *data,
+					  char *buf)
+{
+	ssize_t size = 0;
+	int i;
+	const u32 *physmap = data->function_row_physmap;
+
+	if (!data->num_function_row_keys)
+		return 0;
+
+	for (i = 0; i < data->num_function_row_keys; i++)
+		size += sysfs_emit_at(buf, size,
+				      "%s%02X", size ? " " : "", physmap[i]);
+	if (size)
+		size += sysfs_emit_at(buf, size, "\n");
+
+	return size;
+}
+EXPORT_SYMBOL_GPL(vivaldi_function_row_physmap_show);
+
+MODULE_DESCRIPTION("Helpers for ChromeOS Vivaldi keyboard function row mapping");
+MODULE_LICENSE("GPL");