Checks BPF syscall number, turn off libbpf building on platform doesn't
correctly support sys_bpf instead of blocking compiling.
Reported-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
---
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 062bac8..b389026 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 5bdc6ea..1f91cc9 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__)
--
1.8.3.4
--
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