Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c
index 96d8305..1a7a9f8 100644
--- a/tools/lib/symbol/kallsyms.c
+++ b/tools/lib/symbol/kallsyms.c
@@ -1,5 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <ctype.h>
 #include "symbol/kallsyms.h"
 #include <stdio.h>
 #include <stdlib.h>
@@ -16,6 +15,19 @@
 	return symbol_type == 'T' || symbol_type == 'W';
 }
 
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+int hex2u64(const char *ptr, u64 *long_val)
+{
+	char *p;
+
+	*long_val = strtoull(ptr, &p, 16);
+
+	return p - ptr;
+}
+
 int kallsyms__parse(const char *filename, void *arg,
 		    int (*process_symbol)(void *arg, const char *name,
 					  char type, u64 start))
diff --git a/tools/lib/symbol/kallsyms.h b/tools/lib/symbol/kallsyms.h
index 72ab987..bd988f7 100644
--- a/tools/lib/symbol/kallsyms.h
+++ b/tools/lib/symbol/kallsyms.h
@@ -18,6 +18,8 @@
 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 }
 
+int hex2u64(const char *ptr, u64 *long_val);
+
 u8 kallsyms2elf_type(char type);
 
 bool kallsyms__is_function(char symbol_type);