tools: bpftool: use the kernel's instruction printer

Compile the instruction printer from kernel/bpf and use it
for disassembling "translated" eBPF code.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 8 deletions

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 421ba89ce86a..9e2681c83717 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -35,6 +35,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -46,6 +47,7 @@
 #include <bpf.h>
 
 #include "main.h"
+#include "disasm.h"
 
 static const char * const prog_type_name[] = {
         [BPF_PROG_TYPE_UNSPEC]          = "unspec",
@@ -297,11 +299,39 @@ static int do_show(int argc, char **argv)
         return 0;
 }
 
+static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
+{
+        va_list args;
+
+        va_start(args, fmt);
+        vprintf(fmt, args);
+        va_end(args);
+}
+
+static void dump_xlated(void *buf, unsigned int len, bool opcodes)
+{
+        struct bpf_insn *insn = buf;
+        unsigned int i;
+
+        for (i = 0; i < len / sizeof(*insn); i++) {
+                printf("% 4d: ", i);
+                print_bpf_insn(print_insn, NULL, insn + i, true);
+
+                if (opcodes) {
+                        printf("       ");
+                        print_hex(insn + i, 8, " ");
+                        printf("\n");
+                }
+
+                if (insn[i].code == (BPF_LD | BPF_IMM | BPF_DW))
+                        i++;
+        }
+}
+
 static int do_dump(int argc, char **argv)
 {
         struct bpf_prog_info info = {};
         __u32 len = sizeof(info);
-        bool can_disasm = false;
         unsigned int buf_size;
         char *filepath = NULL;
         bool opcodes = false;
@@ -315,7 +345,6 @@ static int do_dump(int argc, char **argv)
         if (is_prefix(*argv, "jited")) {
                 member_len = &info.jited_prog_len;
                 member_ptr = &info.jited_prog_insns;
-                can_disasm = true;
         } else if (is_prefix(*argv, "xlated")) {
                 member_len = &info.xlated_prog_len;
                 member_ptr = &info.xlated_prog_insns;
@@ -346,10 +375,6 @@ static int do_dump(int argc, char **argv)
                 NEXT_ARG();
         }
 
-        if (!filepath && !can_disasm) {
-                err("expected 'file' got %s\n", *argv);
-                return -1;
-        }
         if (argc) {
                 usage();
                 return -1;
@@ -409,7 +434,10 @@ static int do_dump(int argc, char **argv)
                         goto err_free;
                 }
         } else {
-                disasm_print_insn(buf, *member_len, opcodes);
+                if (member_len == &info.jited_prog_len)
+                        disasm_print_insn(buf, *member_len, opcodes);
+                else
+                        dump_xlated(buf, *member_len, opcodes);
         }
 
         free(buf);
@@ -430,7 +458,7 @@ static int do_help(int argc, char **argv)
 {
         fprintf(stderr,
                 "Usage: %s %s show [PROG]\n"
-                "       %s %s dump xlated PROG  file FILE\n"
+                "       %s %s dump xlated PROG [file FILE] [opcodes]\n"
                 "       %s %s dump jited  PROG [file FILE] [opcodes]\n"
                 "       %s %s pin   PROG FILE\n"
                 "       %s %s help\n"