Commit 9e2308c1 authored Oct 19, 2017 by Quentin Monnet Committed by David S. Miller Oct 22, 2017

tools: bpftool: print all relevant byte opcodes for "load double word"

The eBPF instruction permitting to load double words (8 bytes) into a
register need 8-byte long "immediate" field, and thus occupy twice the
space of other instructions. bpftool was aware of this and would
increment the instruction counter only once on meeting such instruction,
but it would only print the first four bytes of the immediate value to
load. Make it able to dump the whole 16 byte-long double instruction
instead (as would `llvm-objdump -d <program>`).

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d9c0b48d

tools/bpf/bpftool/prog.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -313,20 +313,29 @@ static void print_insn(struct bpf_verifier_env env, const char fmt, ...)
		static void dump_xlated(void *buf, unsigned int len, bool opcodes)
		{
		struct bpf_insn *insn = buf;
		bool double_insn = false;
		unsigned int i;

		for (i = 0; i < len / sizeof(*insn); i++) {
		if (double_insn) {
		double_insn = false;
		continue;
		}

		double_insn = insn[i].code == (BPF_LD \| BPF_IMM \| BPF_DW);

		printf("% 4d: ", i);
		print_bpf_insn(print_insn, NULL, insn + i, true);

		if (opcodes) {
		printf(" ");
		fprint_hex(stdout, insn + i, 8, " ");
		if (double_insn && i < len - 1) {
		printf(" ");
		fprint_hex(stdout, insn + i + 1, 8, " ");
		}
		printf("\n");
		}

		if (insn[i].code == (BPF_LD \| BPF_IMM \| BPF_DW))
		i++;
		}
		}

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