tools: bpftool: improve architecture detection by using ifindex

The current architecture detection method in bpftool is designed for host
case.

For offload case, we can't use the architecture of "bpftool" itself.
Instead, we could call the existing "ifindex_to_name_ns" to get DEVNAME,
then read pci id from /sys/class/dev/DEVNAME/device/vendor, finally we map
vendor id to bfd arch name which will finally be used to select bfd backend
for the disassembler.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 15 insertions, 1 deletions

diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index 57d32e8a1391..87439320ef70 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -76,7 +76,8 @@ static int fprintf_json(void *out, const char *fmt, ...)
 	return 0;
 }
 
-void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
+void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
+		       const char *arch)
 {
 	disassembler_ftype disassemble;
 	struct disassemble_info info;
@@ -100,6 +101,19 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
 	else
 		init_disassemble_info(&info, stdout,
 				      (fprintf_ftype) fprintf);
+
+	/* Update architecture info for offload. */
+	if (arch) {
+		const bfd_arch_info_type *inf = bfd_scan_arch(arch);
+
+		if (inf) {
+			bfdf->arch_info = inf;
+		} else {
+			p_err("No libfd support for %s", arch);
+			return;
+		}
+	}
+
 	info.arch = bfd_get_arch(bfdf);
 	info.mach = bfd_get_mach(bfdf);
 	info.buffer = image;