more bpf samples build breakage...

Inlcuding bpf_util.h into test_pkt_access.c et al. broke the build even
more so than it already is on sparc.

The problem is we end up including all the stdio.h bits and eventually
hit things like:

In file included from /usr/include/stdio.h:933:
/usr/include/bits/stdio-ldbl.h:28:20: error: cannot apply asm label to function after its first use
__LDBL_REDIR_DECL (vfprintf)
~~~~~~~~~~~~~~~~~~~^~~~~~~~~
/usr/include/sys/cdefs.h:373:26: note: expanded from macro '__LDBL_REDIR_DECL'
  extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));

So please let's put CLANG compiled helpers into header files
specifically meant to be included by CLANG compiled BPF programs
rather than the host build environment.

From: David Miller <davem@davemloft.net>
Date: Mon, 01 May 2017 15:30:05 -0400 (EDT)

Inlcuding bpf_util.h into test_pkt_access.c et al. broke the build even
more so than it already is on sparc.

The problem is we end up including all the stdio.h bits and eventually
hit things like:

In file included from /usr/include/stdio.h:933:
/usr/include/bits/stdio-ldbl.h:28:20: error: cannot apply asm label to function after its first use
__LDBL_REDIR_DECL (vfprintf)
~~~~~~~~~~~~~~~~~~~^~~~~~~~~
/usr/include/sys/cdefs.h:373:26: note: expanded from macro '__LDBL_REDIR_DECL'
  extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));

So please let's put CLANG compiled helpers into header files
specifically meant to be included by CLANG compiled BPF programs
rather than the host build environment.

I'm pushing the following quick fix for this for now:

From bc1bafbbe9b3558d7789ff151ef4f185b6ad21f3 Mon Sep 17 00:00:00 2001

From: "David S. Miller" <davem@davemloft.net>
Date: Mon, 1 May 2017 12:43:49 -0700
Subject: [PATCH] bpf: Move endianness BPF helpers out of bpf_util.h

We do not want to include things like stdio.h and friends into
eBPF program builds.  bpf_util.h is for host compiled programs,
so eBPF C-code helpers don't really belong there.

Add a new bpf_endian.h as a quick fix for this for now.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 tools/testing/selftests/bpf/bpf_endian.h      | 23 +++++++++++++++++++++++
 tools/testing/selftests/bpf/bpf_util.h        | 19 -------------------
 tools/testing/selftests/bpf/test_l4lb.c       |  2 +-
 tools/testing/selftests/bpf/test_pkt_access.c |  2 +-
 4 files changed, 25 insertions(+), 21 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/bpf_endian.h

diff --git a/tools/testing/selftests/bpf/bpf_endian.h b/tools/testing/selftests/bpf/bpf_endian.h
new file mode 100644
index 0000000..19d0604
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_endian.h

@@ -0,0 +1,23 @@
+#ifndef __BPF_ENDIAN__
+#define __BPF_ENDIAN__
+
+#include <asm/byteorder.h>
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# define __bpf_ntohs(x)		__builtin_bswap16(x)
+# define __bpf_htons(x)		__builtin_bswap16(x)
+#elif __BYTE_ORDER == __BIG_ENDIAN
+# define __bpf_ntohs(x)		(x)
+# define __bpf_htons(x)		(x)
+#else
+# error "Fix your __BYTE_ORDER?!"
+#endif
+
+#define bpf_htons(x)				\
+	(__builtin_constant_p(x) ?		\
+	 __constant_htons(x) : __bpf_htons(x))
+#define bpf_ntohs(x)				\
+	(__builtin_constant_p(x) ?		\
+	 __constant_ntohs(x) : __bpf_ntohs(x))
+
+#endif

diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
index 369e7d7..20ecbaa 100644
--- a/tools/testing/selftests/bpf/bpf_util.h
+++ b/tools/testing/selftests/bpf/bpf_util.h

@@ -6,25 +6,6 @@
 #include <string.h>
 #include <errno.h>
 
-#include <asm/byteorder.h>
-
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-# define __bpf_ntohs(x)		__builtin_bswap16(x)
-# define __bpf_htons(x)		__builtin_bswap16(x)
-#elif __BYTE_ORDER == __BIG_ENDIAN
-# define __bpf_ntohs(x)		(x)
-# define __bpf_htons(x)		(x)
-#else
-# error "Fix your __BYTE_ORDER?!"
-#endif
-
-#define bpf_htons(x)				\
-	(__builtin_constant_p(x) ?		\
-	 __constant_htons(x) : __bpf_htons(x))
-#define bpf_ntohs(x)				\
-	(__builtin_constant_p(x) ?		\
-	 __constant_ntohs(x) : __bpf_ntohs(x))
-
 static inline unsigned int bpf_num_possible_cpus(void)
 {
 	static const char *fcpu = "/sys/devices/system/cpu/possible";

diff --git a/tools/testing/selftests/bpf/test_l4lb.c b/tools/testing/selftests/bpf/test_l4lb.c
index b68b212..1e10c95 100644
--- a/tools/testing/selftests/bpf/test_l4lb.c
+++ b/tools/testing/selftests/bpf/test_l4lb.c

@@ -19,7 +19,7 @@
 #include <linux/udp.h>
 #include "bpf_helpers.h"
 #include "test_iptunnel_common.h"
-#include "bpf_util.h"
+#include "bpf_endian.h"
 
 int _version SEC("version") = 1;
 

diff --git a/tools/testing/selftests/bpf/test_pkt_access.c b/tools/testing/selftests/bpf/test_pkt_access.c
index 7113005..39387bb 100644
--- a/tools/testing/selftests/bpf/test_pkt_access.c
+++ b/tools/testing/selftests/bpf/test_pkt_access.c

@@ -14,7 +14,7 @@
 #include <linux/tcp.h>
 #include <linux/pkt_cls.h>
 #include "bpf_helpers.h"
-#include "bpf_util.h"
+#include "bpf_endian.h"
 
 #define barrier() __asm__ __volatile__("": : :"memory")
 int _version SEC("version") = 1;

-- 
2.1.2.532.g19b5d50

On 05/01/2017 09:30 PM, David Miller wrote:

Inlcuding bpf_util.h into test_pkt_access.c et al. broke the build even
more so than it already is on sparc.

The problem is we end up including all the stdio.h bits and eventually
hit things like:

In file included from /usr/include/stdio.h:933:
/usr/include/bits/stdio-ldbl.h:28:20: error: cannot apply asm label to function after its first use
__LDBL_REDIR_DECL (vfprintf)
~~~~~~~~~~~~~~~~~~~^~~~~~~~~
/usr/include/sys/cdefs.h:373:26: note: expanded from macro '__LDBL_REDIR_DECL'
   extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));

So please let's put CLANG compiled helpers into header files
specifically meant to be included by CLANG compiled BPF programs
rather than the host build environment.

Argh, sorry for that and thanks for the quick fix. When I tested
this on x86_64, I didn't hit a compilation issue.

BPF selftests:

[root@apoc bpf]# make > /dev/null
Warning: tools/include/uapi/linux/bpf.h differs from kernel
[root@apoc bpf]# ./test_progs
test_pkt_access:PASS:ipv4 401 nsec
test_pkt_access:PASS:ipv6 271 nsec
test_xdp:PASS:ipv4 4617 nsec
test_xdp:PASS:ipv6 2979 nsec
test_l4lb:PASS:ipv4 921 nsec
test_l4lb:PASS:ipv6 717 nsec
Summary: 6 PASSED, 0 FAILED
[root@apoc bpf]#

BPF samples:

[root@apoc bpf]# make > /dev/null
In file included from /root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:54:0:
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c: In function ‘prog_load’:
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:119:5: warning: overflow in implicit constant conversion [-Woverflow]
      -32 + offsetof(struct stats, uid)),
      ^
/root/cilium/net-next/samples/bpf/libbpf.h:135:12: note: in definition of macro ‘BPF_STX_MEM’
    .off   = OFF,     \
             ^
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:121:5: warning: overflow in implicit constant conversion [-Woverflow]
      -32 + offsetof(struct stats, packets), 1),
      ^
/root/cilium/net-next/samples/bpf/libbpf.h:155:12: note: in definition of macro ‘BPF_ST_MEM’
    .off   = OFF,     \
             ^
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:129:5: warning: overflow in implicit constant conversion [-Woverflow]
      -32 + offsetof(struct stats, bytes)),
      ^
/root/cilium/net-next/samples/bpf/libbpf.h:135:12: note: in definition of macro ‘BPF_STX_MEM’
    .off   = OFF,     \
             ^
[root@apoc bpf]#

Above warning is from 51570a5ab2b7 ("A Sample of using socket
cookie and uid for traffic monitoring"). I can see to send a
fix for it.

Thanks,
Daniel

From: Daniel Borkmann <daniel@iogearbox.net>
Date: Mon, 01 May 2017 22:38:58 +0200

BPF samples:

[root@apoc bpf]# make > /dev/null
In file included from
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:54:0:
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c: In
function ‘prog_load’:
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:119:5:
warning: overflow in implicit constant conversion [-Woverflow]
     -32 + offsetof(struct stats, uid)),
     ^
/root/cilium/net-next/samples/bpf/libbpf.h:135:12: note: in definition
of macro ‘BPF_STX_MEM’
   .off   = OFF,     \
            ^
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:121:5:
warning: overflow in implicit constant conversion [-Woverflow]
     -32 + offsetof(struct stats, packets), 1),
     ^
/root/cilium/net-next/samples/bpf/libbpf.h:155:12: note: in definition
of macro ‘BPF_ST_MEM’
   .off   = OFF,     \
            ^
/root/cilium/net-next/samples/bpf/cookie_uid_helper_example.c:129:5:
warning: overflow in implicit constant conversion [-Woverflow]
     -32 + offsetof(struct stats, bytes)),
     ^
/root/cilium/net-next/samples/bpf/libbpf.h:135:12: note: in definition
of macro ‘BPF_STX_MEM’
   .off   = OFF,     \
            ^
[root@apoc bpf]#

Above warning is from 51570a5ab2b7 ("A Sample of using socket
cookie and uid for traffic monitoring"). I can see to send a
fix for it.

Please do, thanks.