1 files changed, 75 insertions, 11 deletions

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 60c20f301a6b..ba351dfa109b 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -187,26 +187,90 @@ static bool cleanup_symbol_name(char *s)
 	return false;
 }
 
+static int compare_symbol_name(const char *name, char *namebuf)
+{
+	int ret;
+
+	ret = strcmp(name, namebuf);
+	if (!ret)
+		return ret;
+
+	if (cleanup_symbol_name(namebuf) && !strcmp(name, namebuf))
+		return 0;
+
+	return ret;
+}
+
+static int kallsyms_lookup_names(const char *name,
+				 unsigned int *start,
+				 unsigned int *end)
+{
+	int ret;
+	int low, mid, high;
+	unsigned int seq, off;
+	char namebuf[KSYM_NAME_LEN];
+
+	low = 0;
+	high = kallsyms_num_syms - 1;
+
+	while (low <= high) {
+		mid = low + (high - low) / 2;
+		seq = kallsyms_seqs_of_names[mid];
+		off = get_symbol_offset(seq);
+		kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
+		ret = compare_symbol_name(name, namebuf);
+		if (ret > 0)
+			low = mid + 1;
+		else if (ret < 0)
+			high = mid - 1;
+		else
+			break;
+	}
+
+	if (low > high)
+		return -ESRCH;
+
+	low = mid;
+	while (low) {
+		seq = kallsyms_seqs_of_names[low - 1];
+		off = get_symbol_offset(seq);
+		kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
+		if (compare_symbol_name(name, namebuf))
+			break;
+		low--;
+	}
+	*start = low;
+
+	if (end) {
+		high = mid;
+		while (high < kallsyms_num_syms - 1) {
+			seq = kallsyms_seqs_of_names[high + 1];
+			off = get_symbol_offset(seq);
+			kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
+			if (compare_symbol_name(name, namebuf))
+				break;
+			high++;
+		}
+		*end = high;
+	}
+
+	return 0;
+}
+
 /* Lookup the address for this symbol. Returns 0 if not found. */
 unsigned long kallsyms_lookup_name(const char *name)
 {
-	char namebuf[KSYM_NAME_LEN];
-	unsigned long i;
-	unsigned int off;
+	int ret;
+	unsigned int i;
 
 	/* Skip the search for empty string. */
 	if (!*name)
 		return 0;
 
-	for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
-		off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
-
-		if (strcmp(namebuf, name) == 0)
-			return kallsyms_sym_address(i);
+	ret = kallsyms_lookup_names(name, &i, NULL);
+	if (!ret)
+		return kallsyms_sym_address(kallsyms_seqs_of_names[i]);
 
-		if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0)
-			return kallsyms_sym_address(i);
-	}
 	return module_kallsyms_lookup_name(name);
 }