From: Daniel Borkmann <daniel@iogearbox.net>
Date: Mon, 18 Jul 2016 23:09:52 +0000 (+0200)
Subject: bpf: also check elf for official e_machine value
X-Git-Tag: v4.7.0~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e77fa41d4c78b06bdc32808212e5649cb7a37ba3;p=thirdparty%2Fiproute2.git

bpf: also check elf for official e_machine value

Use the official BPF ELF e_machine value that was assigned recently [1]
and will be propagated to glibc, libelf et al. LLVM will switch to it
in 3.9 release, therefore we need to prepare tc to check for EM_ELF as
well, older version still have the EM_NONE.

  [1] https://github.com/llvm-mirror/llvm/commit/36b9c09330bfb5e771914cfe307588f30d5510d2

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/tc/tc_bpf.c b/tc/tc_bpf.c
index 86c6069b6..7eb1cd74a 100644
--- a/tc/tc_bpf.c
+++ b/tc/tc_bpf.c
@@ -54,6 +54,10 @@
 #define AF_ALG 38
 #endif
 
+#ifndef EM_BPF
+#define EM_BPF 247
+#endif
+
 #ifdef HAVE_ELF
 static int bpf_obj_open(const char *path, enum bpf_prog_type type,
 			const char *sec, bool verbose);
@@ -1690,7 +1694,8 @@ static void bpf_hash_destroy(struct bpf_elf_ctx *ctx)
 static int bpf_elf_check_ehdr(const struct bpf_elf_ctx *ctx)
 {
 	if (ctx->elf_hdr.e_type != ET_REL ||
-	    ctx->elf_hdr.e_machine != 0 ||
+	    (ctx->elf_hdr.e_machine != EM_NONE &&
+	     ctx->elf_hdr.e_machine != EM_BPF) ||
 	    ctx->elf_hdr.e_version != EV_CURRENT) {
 		fprintf(stderr, "ELF format error, ELF file not for eBPF?\n");
 		return -EINVAL;