linux-stable/tools/bpf/bpftool/xlated_dumper.c
Quentin Monnet c101189bc9 tools: bpftool: fix -Wmissing declaration warnings
Help compiler check arguments for several utility functions used to
print items to the console by adding the "printf" attribute when
declaring those functions.

Also, declare as "static" two functions that are only used in prog.c.

All of them discovered by compiling bpftool with
-Wmissing-format-attribute -Wmissing-declarations.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-15 01:31:49 +01:00

372 lines
8.7 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2018 Netronome Systems, Inc. */
#define _GNU_SOURCE
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <libbpf.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 (!feof(fp)) {
if (!fgets(buff, sizeof(buff), fp))
break;
tmp = 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];
if (sscanf(buff, "%p %*c %s", &address, sym->name) != 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)
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
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("% 4d: ", 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)
{
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn_for_graph,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
struct bpf_insn *insn_start = buf_start;
struct bpf_insn *insn_end = buf_end;
struct bpf_insn *cur = insn_start;
for (; cur <= insn_end; cur++) {
printf("% 4d: ", (int)(cur - insn_start + start_idx));
print_bpf_insn(&cbs, cur, true);
if (cur != insn_end)
printf(" | ");
}
}