1 files changed, 57 insertions, 1 deletions

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 460c3e57fadb..f09f25eccf3c 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -68,6 +68,7 @@ struct btf_dump_data {
 	bool compact;
 	bool skip_names;
 	bool emit_zeroes;
+	bool emit_strings;
 	__u8 indent_lvl;	/* base indent level */
 	char indent_str[BTF_DATA_INDENT_STR_LEN];
 	/* below are used during iteration */
@@ -226,6 +227,9 @@ static void btf_dump_free_names(struct hashmap *map)
 	size_t bkt;
 	struct hashmap_entry *cur;
 
+	if (!map)
+		return;
+
 	hashmap__for_each_entry(map, cur, bkt)
 		free((void *)cur->pkey);
 
@@ -2028,6 +2032,52 @@ static int btf_dump_var_data(struct btf_dump *d,
 	return btf_dump_dump_type_data(d, NULL, t, type_id, data, 0, 0);
 }
 
+static int btf_dump_string_data(struct btf_dump *d,
+				const struct btf_type *t,
+				__u32 id,
+				const void *data)
+{
+	const struct btf_array *array = btf_array(t);
+	const char *chars = data;
+	__u32 i;
+
+	/* Make sure it is a NUL-terminated string. */
+	for (i = 0; i < array->nelems; i++) {
+		if ((void *)(chars + i) >= d->typed_dump->data_end)
+			return -E2BIG;
+		if (chars[i] == '\0')
+			break;
+	}
+	if (i == array->nelems) {
+		/* The caller will print this as a regular array. */
+		return -EINVAL;
+	}
+
+	btf_dump_data_pfx(d);
+	btf_dump_printf(d, "\"");
+
+	for (i = 0; i < array->nelems; i++) {
+		char c = chars[i];
+
+		if (c == '\0') {
+			/*
+			 * When printing character arrays as strings, NUL bytes
+			 * are always treated as string terminators; they are
+			 * never printed.
+			 */
+			break;
+		}
+		if (isprint(c))
+			btf_dump_printf(d, "%c", c);
+		else
+			btf_dump_printf(d, "\\x%02x", (__u8)c);
+	}
+
+	btf_dump_printf(d, "\"");
+
+	return 0;
+}
+
 static int btf_dump_array_data(struct btf_dump *d,
 			       const struct btf_type *t,
 			       __u32 id,
@@ -2055,8 +2105,13 @@ static int btf_dump_array_data(struct btf_dump *d,
 		 * char arrays, so if size is 1 and element is
 		 * printable as a char, we'll do that.
 		 */
-		if (elem_size == 1)
+		if (elem_size == 1) {
+			if (d->typed_dump->emit_strings &&
+			    btf_dump_string_data(d, t, id, data) == 0) {
+				return 0;
+			}
 			d->typed_dump->is_array_char = true;
+		}
 	}
 
 	/* note that we increment depth before calling btf_dump_print() below;
@@ -2544,6 +2599,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
 	d->typed_dump->compact = OPTS_GET(opts, compact, false);
 	d->typed_dump->skip_names = OPTS_GET(opts, skip_names, false);
 	d->typed_dump->emit_zeroes = OPTS_GET(opts, emit_zeroes, false);
+	d->typed_dump->emit_strings = OPTS_GET(opts, emit_strings, false);
 
 	ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);