openwrt/target/linux/generic/patches-4.9/271-uapi-libc-compat.h-do-not-rely-on-__GLIBC__.patch

From f972afc2509eebcb00d370256c55b112a3b5ffca Mon Sep 17 00:00:00 2001
From: David Heidelberger <david.heidelberger@ixit.cz>
Date: Mon, 29 Jun 2015 16:50:40 +0200
Subject: [PATCH 2/3] uapi/libc-compat.h: do not rely on __GLIBC__

Musl provides the same structs as glibc, but does not provide a define to
allow its detection. Since the absence of __GLIBC__ also can mean that it
is included from the kernel, change the __GLIBC__ detection to
!__KERNEL__, which should always be true when included from userspace.

Signed-off-by: John Spencer <maillist-linux@barfooze.de>
Tested-by: David Heidelberger <david.heidelberger@ixit.cz>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
---
 include/uapi/linux/libc-compat.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- a/include/uapi/linux/libc-compat.h
+++ b/include/uapi/linux/libc-compat.h
@@ -48,13 +48,13 @@
 #ifndef _UAPI_LIBC_COMPAT_H
 #define _UAPI_LIBC_COMPAT_H
 
-/* We have included glibc headers... */
-#if defined(__GLIBC__)
+/* We have included libc headers... */
+#if !defined(__KERNEL__)
 
-/* Coordinate with glibc net/if.h header. */
-#if defined(_NET_IF_H) && defined(__USE_MISC)
+/* Coordinate with libc net/if.h header. */
+#if defined(_NET_IF_H) && (!defined(__GLIBC__) || defined(__USE_MISC))
 
-/* GLIBC headers included first so don't define anything
+/* LIBC headers included first so don't define anything
  * that would already be defined. */
 
 #define __UAPI_DEF_IF_IFCONF 0
@@ -65,7 +65,11 @@
 #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 0
 /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */
 #ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO
+#ifdef __GLIBC__
 #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1
+#else
+#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 0
+#endif
 #endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */
 
 #else /* _NET_IF_H */
@@ -85,10 +89,10 @@
 
 #endif /* _NET_IF_H */
 
-/* Coordinate with glibc netinet/in.h header. */
+/* Coordinate with libc netinet/in.h header. */
 #if defined(_NETINET_IN_H)
 
-/* GLIBC headers included first so don't define anything
+/* LIBC headers included first so don't define anything
  * that would already be defined. */
 #define __UAPI_DEF_IN_ADDR		0
 #define __UAPI_DEF_IN_IPPROTO		0
@@ -102,7 +106,7 @@
  * if the glibc code didn't define them. This guard matches
  * the guard in glibc/inet/netinet/in.h which defines the
  * additional in6_addr macros e.g. s6_addr16, and s6_addr32. */
-#if defined(__USE_MISC) || defined (__USE_GNU)
+#if !defined(__GLIBC__) || defined(__USE_MISC) || defined (__USE_GNU)
 #define __UAPI_DEF_IN6_ADDR_ALT		0
 #else
 #define __UAPI_DEF_IN6_ADDR_ALT		1
@@ -117,7 +121,7 @@
 #else
 
 /* Linux headers included first, and we must define everything
- * we need. The expectation is that glibc will check the
+ * we need. The expectation is that the libc will check the
  * __UAPI_DEF_* defines and adjust appropriately. */
 #define __UAPI_DEF_IN_ADDR		1
 #define __UAPI_DEF_IN_IPPROTO		1
@@ -127,7 +131,7 @@
 #define __UAPI_DEF_IN_CLASS		1
 
 #define __UAPI_DEF_IN6_ADDR		1
-/* We unconditionally define the in6_addr macros and glibc must
+/* We unconditionally define the in6_addr macros and the libc must
  * coordinate. */
 #define __UAPI_DEF_IN6_ADDR_ALT		1
 #define __UAPI_DEF_SOCKADDR_IN6		1
@@ -168,7 +172,7 @@
 /* If we did not see any headers from any supported C libraries,
  * or we are being included in the kernel, then define everything
  * that we need. */
-#else /* !defined(__GLIBC__) */
+#else /* defined(__KERNEL__) */
 
 /* Definitions for if.h */
 #define __UAPI_DEF_IF_IFCONF 1
@@ -208,6 +212,6 @@
 /* Definitions for xattr.h */
 #define __UAPI_DEF_XATTR		1
 
-#endif /* __GLIBC__ */
+#endif /* __KERNEL__ */
 
 #endif /* _UAPI_LIBC_COMPAT_H */