linux_dsm_epyc7002/tools/bpf/bpftool/jit_disasm.c
Jakub Kicinski 71bb428fe2 tools: bpf: add bpftool
Add a simple tool for querying and updating BPF objects on the system.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04 21:45:06 -07:00

88 lines
1.7 KiB
C

/*
* Based on:
*
* Minimal BPF JIT image disassembler
*
* Disassembles BPF JIT compiler emitted opcodes back to asm insn's for
* debugging or verification purposes.
*
* Copyright 2013 Daniel Borkmann <daniel@iogearbox.net>
* Licensed under the GNU General Public License, version 2.0 (GPLv2)
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <bfd.h>
#include <dis-asm.h>
#include <sys/types.h>
#include <sys/stat.h>
static void get_exec_path(char *tpath, size_t size)
{
ssize_t len;
char *path;
snprintf(tpath, size, "/proc/%d/exe", (int) getpid());
tpath[size - 1] = 0;
path = strdup(tpath);
assert(path);
len = readlink(path, tpath, size - 1);
assert(len > 0);
tpath[len] = 0;
free(path);
}
void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
{
disassembler_ftype disassemble;
struct disassemble_info info;
int count, i, pc = 0;
char tpath[256];
bfd *bfdf;
if (!len)
return;
memset(tpath, 0, sizeof(tpath));
get_exec_path(tpath, sizeof(tpath));
bfdf = bfd_openr(tpath, NULL);
assert(bfdf);
assert(bfd_check_format(bfdf, bfd_object));
init_disassemble_info(&info, stdout, (fprintf_ftype) fprintf);
info.arch = bfd_get_arch(bfdf);
info.mach = bfd_get_mach(bfdf);
info.buffer = image;
info.buffer_length = len;
disassemble_init_for_target(&info);
disassemble = disassembler(bfdf);
assert(disassemble);
do {
printf("%4x:\t", pc);
count = disassemble(pc, &info);
if (opcodes) {
printf("\n\t");
for (i = 0; i < count; ++i)
printf("%02x ", (uint8_t) image[pc + i]);
}
printf("\n");
pc += count;
} while (count > 0 && pc < len);
bfd_close(bfdf);
}