linux/tools/bpf/bpftool/xlated_dumper.c
Jiayuan Chen 3775be3417 bpftool: Using the right format specifiers
Fixed some formatting specifiers errors, such as using %d for int and %u
for unsigned int, as well as other byte-length types.

Perform type cast using the type derived from the data type itself, for
example, if it's originally an int, it will be cast to unsigned int if
forced to unsigned.

Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250311112809.81901-3-jiayuan.chen@linux.dev
2025-03-17 13:50:56 -07:00

434 lines
10 KiB
C

// 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:%d]", insn->imm);
else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"map[id:%d][0]+%d", 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:%d]+%d", 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("| ");
}
}