From: Frédéric Bérat <fberat@redhat.com>
Date: Wed, 26 Apr 2023 09:32:04 +0000 (+0200)
Subject: misc/sys/cdefs.h: Create FORTIFY redirects for internal calls
X-Git-Tag: glibc-2.38~73
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eea000f6e69a829425fae25a7c2519f5c79551de;p=thirdparty%2Fglibc.git

misc/sys/cdefs.h: Create FORTIFY redirects for internal calls

The __REDIRECT* macros are creating aliases which may lead to unwanted
PLT entries when fortification is enabled.
To prevent these entries, the REDIRECT alias should be set to point to the
existing __GI_* aliases.
This is done transparently by creating a __REDIRECT_FORTIFY* version of
these macros, that can be overwritten internally when necessary.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---

diff --git a/include/sys/cdefs.h b/include/sys/cdefs.h
index 56adb231aa8..b84ad34a701 100644
--- a/include/sys/cdefs.h
+++ b/include/sys/cdefs.h
@@ -40,6 +40,20 @@ rtld_hidden_proto (__chk_fail)
 
 #endif
 
+#if defined SHARED
+#if IS_IN (libc) && __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
+
+#undef __REDIRECT_FORTIFY
+#define __REDIRECT_FORTIFY(name, proto, alias) \
+  __REDIRECT(name, proto, __GI_##alias)
+
+#undef __REDIRECT_FORTIFY_NTH
+#define __REDIRECT_FORTIFY_NTH(name, proto, alias) \
+  __REDIRECT_NTH(name, proto, __GI_##alias)
+
+#endif
+#endif /* defined SHARED */
+
 #endif /* !defined _ISOMAC */
 
 #endif
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 393d9091d9d..90c21e27037 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -268,6 +268,14 @@
 # define __ASMNAME(cname)  __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
 
+#ifndef __REDIRECT_FORTIFY
+#define __REDIRECT_FORTIFY __REDIRECT
+#endif
+
+#ifndef __REDIRECT_FORTIFY_NTH
+#define __REDIRECT_FORTIFY_NTH __REDIRECT_NTH
+#endif
+
 /*
 #elif __SOME_OTHER_COMPILER__