[PATCH 1/2] tools lib bpf: Use official ELF e_machine value

Arnaldo Carvalho de Melo
2016-07-26T21:08:04Z

From: Wang Nan <wangnan0@huawei.com>

New LLVM will issue newly assigned EM_BPF machine code. The new code
will be propagated to glibc and libelf.

This patch introduces the new machine code to libbpf.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468821668-60088-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/lib/bpf/libbpf.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 32e6b6bc6f7d..b699aea9a025 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -37,6 +37,10 @@
#include "libbpf.h"
#include "bpf.h"

+#ifndef EM_BPF
+#define EM_BPF 247
+#endif
+
#define __printf(a, b) __attribute__((format(printf, a, b)))

__printf(1, 2)
@@ -439,7 +443,8 @@ static int bpf_object__elf_init(struct bpf_object *obj)
}
ep = &obj->efile.ehdr;

- if ((ep->e_type != ET_REL) || (ep->e_machine != 0)) {
+ /* Old LLVM set e_machine to EM_NONE */
+ if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) {
pr_warning("%s is not an eBPF object file\n",
obj->path);
err = -LIBBPF_ERRNO__FORMAT;
--
2.7.4