add patch to replace builtin strlen

backport-replace-builtin-strlen-that-appears-to-get-optimized.patch

@@ -0,0 +1,39 @@
+From eae06bdce9468d7fde263de1c53f80f2faff0c9e Mon Sep 17 00:00:00 2001
+From: Merlin Mathesius <mmathesi@redhat.com>
+Date: Wed, 13 May 2020 11:58:37 -0500
+Subject: [PATCH] Replace builtin strlen that appears to get optimized away
+ 
+---
+ dos/string.h | 12 +++++++++++-
+ 1 file changed, 11 insertions(+), 1 deletion(-)
+ 
+diff --git a/dos/string.h b/dos/string.h
+index f648de2d..407d0233 100644
+--- a/dos/string.h
++++ b/dos/string.h
+@@ -5,12 +5,22 @@
+ #ifndef _STRING_H
+ #define _STRING_H
+ 
++#include <stddef.h>
++
+ /* Standard routines */
+ #define memcpy(a,b,c)	__builtin_memcpy(a,b,c)
+ #define memmove(a,b,c)	__builtin_memmove(a,b,c)
+ #define memset(a,b,c)	__builtin_memset(a,b,c)
+ #define strcpy(a,b)	__builtin_strcpy(a,b)
+-#define strlen(a)	__builtin_strlen(a)
++#define strlen(a)	inline_strlen(a)
++
++/* replacement for builtin strlen that appears to get optimized away */
++static inline size_t inline_strlen(const char *str)
++{
++    size_t l;
++    for (l = 0; *str++; l++);
++    return l;
++}
+ 
+ /* This only returns true or false */
+ static inline int memcmp(const void *__m1, const void *__m2, unsigned int __n)
+-- 
+2.25.1

syslinux.spec

@@ -2,7 +2,7 @@
 
 Name:           syslinux
 Version:        6.04
-Release:        5
+Release:        6
 License:        GPLv2+
 Summary:        The Syslinux boot loader collection
 URL:            http://syslinux.zytor.com/wiki/index.php/The_Syslinux_Project
@@ -23,6 +23,8 @@ Patch0002:      0002-ext4-64bit-feature.patch
 # Frome: https://raw.githubusercontent.com/JeffreyALaw/Fedora-syslinux/master/0003-include-sysmacros-h.patch
 Patch0003:      0003-include-sysmacros-h.patch
 
+Patch0004:      backport-replace-builtin-strlen-that-appears-to-get-optimized.patch
+
 %description
 The Syslinux Project covers lightweight bootloaders for MS-DOS FAT filesystems (SYSLINUX),
 network booting (PXELINUX), bootable "El Torito" CD-ROMs (ISOLINUX), and Linux ext2/ext3/ext4
@@ -164,6 +166,9 @@ fi
 %{_datadir}/doc/syslinux/sample/sample.msg
 
 %changelog
+* Sun Feb 7 2021 jinzhimin<jinzhimin2@huawei.com> - 6.04-6
+- add patch to replace builtin strlen
+
 * Mon Mar 2 2020 songnannan<songnannan2@huawei.com> -6.04-5
 - change the path of file