[PATCH 07/12] perf tools: Fix PowerPC native building

From: Arnaldo Carvalho de Melo
Date: Mon Jan 11 2016 - 18:33:36 EST


From: Wang Nan <wangnan0@xxxxxxxxxx>

Checks BPF syscall number, turn off libbpf building on platform doesn't
correctly support sys_bpf instead of blocking compiling.

Reported-and-Tested-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1452520124-2073-7-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/build/feature/test-bpf.c | 20 +++++++++++++++++++-
tools/lib/bpf/bpf.c | 4 ++--
2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/tools/build/feature/test-bpf.c b/tools/build/feature/test-bpf.c
index 062bac811af9..b389026839b9 100644
--- a/tools/build/feature/test-bpf.c
+++ b/tools/build/feature/test-bpf.c
@@ -1,9 +1,23 @@
+#include <asm/unistd.h>
#include <linux/bpf.h>
+#include <unistd.h>
+
+#ifndef __NR_bpf
+# if defined(__i386__)
+# define __NR_bpf 357
+# elif defined(__x86_64__)
+# define __NR_bpf 321
+# elif defined(__aarch64__)
+# define __NR_bpf 280
+# error __NR_bpf not defined. libbpf does not support your arch.
+# endif
+#endif

int main(void)
{
union bpf_attr attr;

+ /* Check fields in attr */
attr.prog_type = BPF_PROG_TYPE_KPROBE;
attr.insn_cnt = 0;
attr.insns = 0;
@@ -14,5 +28,9 @@ int main(void)
attr.kern_version = 0;

attr = attr;
- return 0;
+ /*
+ * Test existence of __NR_bpf and BPF_PROG_LOAD.
+ * This call should fail if we run the testcase.
+ */
+ return syscall(__NR_bpf, BPF_PROG_LOAD, attr, sizeof(attr));
}
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 5bdc6eab6852..1f91cc941b7c 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -14,8 +14,8 @@
#include "bpf.h"

/*
- * When building perf, unistd.h is override. Define __NR_bpf is
- * required to be defined.
+ * When building perf, unistd.h is overrided. __NR_bpf is
+ * required to be defined explicitly.
*/
#ifndef __NR_bpf
# if defined(__i386__)
--
2.1.0