// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2018 Netronome Systems, Inc. */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <bpf/libbpf.h>
#include <bpf/libbpf_internal.h>
#include "disasm.h"
#include "json_writer.h"
#include "main.h"
#include "xlated_dumper.h"
static int kernel_syms_cmp(const void *sym_a, const void *sym_b)
{
return ((struct kernel_sym *)sym_a)->address -
((struct kernel_sym *)sym_b)->address;
}
void kernel_syms_load(struct dump_data *dd)
{
struct kernel_sym *sym;
char buff[256];
void *tmp, *address;
FILE *fp;
fp = fopen("/proc/kallsyms", "r");
if (!fp)
return;
while (fgets(buff, sizeof(buff), fp)) {
tmp = libbpf_reallocarray(dd->sym_mapping, dd->sym_count + 1,
sizeof(*dd->sym_mapping));
if (!tmp) {
out:
free(dd->sym_mapping);
dd->sym_mapping = NULL;
fclose(fp);
return;
}
dd->sym_mapping = tmp;
sym = &dd->sym_mapping[dd->sym_count];
/* module is optional */
sym->module[0] = '\0';
/* trim the square brackets around the module name */
if (sscanf(buff, "%p %*c %s [%[^]]s", &address, sym->name, sym->module) < 2)
continue;
sym->address = (unsigned long)address;
if (!strcmp(sym->name, "__bpf_call_base")) {
dd->address_call_base = sym->address;
/* sysctl kernel.kptr_restrict was set */
if (!sym->address)
goto out;
}
if (sym->address)
dd->sym_count++;
}
fclose(fp);
qsort(dd->sym_mapping, dd->sym_count,
sizeof(*dd->sym_mapping), kernel_syms_cmp);
}
void kernel_syms_destroy(struct dump_data *dd)
{
free(dd->sym_mapping);
}
struct kernel_sym *kernel_syms_search(struct dump_data *dd,
unsigned long key)
{
struct kernel_sym sym = {
.address = key,
};
return dd->sym_mapping ?
bsearch(&sym, dd->sym_mapping, dd->sym_count,
sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL;
}
static void __printf(2, 3) print_insn(void *private_data, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vprintf(fmt, args);
va_end(args);
}
static void __printf(2, 3)
print_insn_for_graph(void *private_data, const char *fmt, ...)
{
char buf[64], *p;
va_list args;
va_start(args, fmt);
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
p = buf;
while (*p != '\0') {
if (*p == '\n') {
memmove(p + 3, p, strlen(buf) + 1 - (p - buf));
/* Align each instruction dump row left. */
*p++ = '\\';
*p++ = 'l';
/* Output multiline concatenation. */
*p++ = '\\';
} else if (*p == '<' || *p == '>' || *p == '|' || *p == '&') {
memmove(p + 1, p, strlen(buf) + 1 - (p - buf));
/* Escape special character. */
*p++ = '\\';
}
p++;
}
printf("%s", buf);
}
static void __printf(2, 3)
print_insn_json(void *private_data, const char *fmt, ...)
{
unsigned int l = strlen(fmt);
char chomped_fmt[l];
va_list args;
va_start(args, fmt);
if (l > 0) {
strncpy(chomped_fmt, fmt, l - 1);
chomped_fmt[l - 1] = '\0';
}
jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
va_end(args);
}
static const char *print_call_pcrel(struct dump_data *dd,
struct kernel_sym *sym,
unsigned long address,
const struct bpf_insn *insn)
{
if (!dd->nr_jited_ksyms)
/* Do not show address for interpreted programs */
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%+d", insn->off);
else if (sym)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%+d#%s", insn->off, sym->name);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%+d#0x%lx", insn->off, address);
return dd->scratch_buff;
}
static const char *print_call_helper(struct dump_data *dd,
struct kernel_sym *sym,
unsigned long address)
{
if (sym)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%s", sym->name);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"0x%lx", address);
return dd->scratch_buff;
}
static const char *print_call(void *private_data,
const struct bpf_insn *insn)
{
struct dump_data *dd = private_data;
unsigned long address = dd->address_call_base + insn->imm;
struct kernel_sym *sym;
if (insn->src_reg == BPF_PSEUDO_CALL &&
(__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
address = dd->jited_ksyms[insn->imm];
sym = kernel_syms_search(dd, address);
if (insn->src_reg == BPF_PSEUDO_CALL)
return print_call_pcrel(dd, sym, address, insn);
else
return print_call_helper(dd, sym, address);
}
static const char *print_imm(void *private_data,
const struct bpf_insn *insn,
__u64 full_imm)
{
struct dump_data *dd = private_data;
if (insn->src_reg == BPF_PSEUDO_MAP_FD)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"map[id:%u]", insn->imm);
else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"map[id:%u][0]+%u", insn->imm, (insn + 1)->imm);
else if (insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"map[idx:%u]+%u", insn->imm, (insn + 1)->imm);
else if (insn->src_reg == BPF_PSEUDO_FUNC)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"subprog[%+d]", insn->imm);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"0x%llx", (unsigned long long)full_imm);
return dd->scratch_buff;
}
void dump_xlated_json(struct dump_data *dd, void *buf, unsigned int len,
bool opcodes, bool linum)
{
const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn_json,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
struct bpf_func_info *record;
struct bpf_insn *insn = buf;
struct btf *btf = dd->btf;
bool double_insn = false;
unsigned int nr_skip = 0;
char func_sig[1024];
unsigned int i;
jsonw_start_array(json_wtr);
record = dd->func_info;
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);
jsonw_start_object(json_wtr);
if (btf && record) {
if (record->insn_off == i) {
btf_dumper_type_only(btf, record->type_id,
func_sig,
sizeof(func_sig));
if (func_sig[0] != '\0') {
jsonw_name(json_wtr, "proto");
jsonw_string(json_wtr, func_sig);
}
record = (void *)record + dd->finfo_rec_size;
}
}
if (prog_linfo) {
const struct bpf_line_info *linfo;
linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
if (linfo) {
btf_dump_linfo_json(btf, linfo, linum);
nr_skip++;
}
}
jsonw_name(json_wtr, "disasm");
print_bpf_insn(&cbs, insn + i, true);
if (opcodes) {
jsonw_name(json_wtr, "opcodes");
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "code");
jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
jsonw_name(json_wtr, "src_reg");
jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
jsonw_name(json_wtr, "dst_reg");
jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
jsonw_name(json_wtr, "off");
print_hex_data_json((uint8_t *)(&insn[i].off), 2);
jsonw_name(json_wtr, "imm");
if (double_insn && i < len - 1)
print_hex_data_json((uint8_t *)(&insn[i].imm),
12);
else
print_hex_data_json((uint8_t *)(&insn[i].imm),
4);
jsonw_end_object(json_wtr);
}
jsonw_end_object(json_wtr);
}
jsonw_end_array(json_wtr);
}
void dump_xlated_plain(struct dump_data *dd, void *buf, unsigned int len,
bool opcodes, bool linum)
{
const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
struct bpf_func_info *record;
struct bpf_insn *insn = buf;
struct btf *btf = dd->btf;
unsigned int nr_skip = 0;
bool double_insn = false;
char func_sig[1024];
unsigned int i;
record = dd->func_info;
for (i = 0; i < len / sizeof(*insn); i++) {
if (double_insn) {
double_insn = false;
continue;
}
if (btf && record) {
if (record->insn_off == i) {
btf_dumper_type_only(btf, record->type_id,
func_sig,
sizeof(func_sig));
if (func_sig[0] != '\0')
printf("%s:\n", func_sig);
record = (void *)record + dd->finfo_rec_size;
}
}
if (prog_linfo) {
const struct bpf_line_info *linfo;
linfo = bpf_prog_linfo__lfind(prog_linfo, i, nr_skip);
if (linfo) {
btf_dump_linfo_plain(btf, linfo, "; ",
linum);
nr_skip++;
}
}
double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
printf("%4u: ", i);
print_bpf_insn(&cbs, 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");
}
}
}
void dump_xlated_for_graph(struct dump_data *dd, void *buf_start, void *buf_end,
unsigned int start_idx,
bool opcodes, bool linum)
{
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn_for_graph,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
const struct bpf_prog_linfo *prog_linfo = dd->prog_linfo;
const struct bpf_line_info *last_linfo = NULL;
struct bpf_func_info *record = dd->func_info;
struct bpf_insn *insn_start = buf_start;
struct bpf_insn *insn_end = buf_end;
struct bpf_insn *cur = insn_start;
struct btf *btf = dd->btf;
bool double_insn = false;
char func_sig[1024];
for (; cur <= insn_end; cur++) {
unsigned int insn_off;
if (double_insn) {
double_insn = false;
continue;
}
double_insn = cur->code == (BPF_LD | BPF_IMM | BPF_DW);
insn_off = (unsigned int)(cur - insn_start + start_idx);
if (btf && record) {
if (record->insn_off == insn_off) {
btf_dumper_type_only(btf, record->type_id,
func_sig,
sizeof(func_sig));
if (func_sig[0] != '\0')
printf("; %s:\\l\\\n", func_sig);
record = (void *)record + dd->finfo_rec_size;
}
}
if (prog_linfo) {
const struct bpf_line_info *linfo;
linfo = bpf_prog_linfo__lfind(prog_linfo, insn_off, 0);
if (linfo && linfo != last_linfo) {
btf_dump_linfo_dotlabel(btf, linfo, linum);
last_linfo = linfo;
}
}
printf("%u: ", insn_off);
print_bpf_insn(&cbs, cur, true);
if (opcodes) {
printf("\\ \\ \\ \\ ");
fprint_hex(stdout, cur, 8, " ");
if (double_insn && cur <= insn_end - 1) {
printf(" ");
fprint_hex(stdout, cur + 1, 8, " ");
}
printf("\\l\\\n");
}
if (cur != insn_end)
printf("| ");
}
}
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