mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-15 08:44:14 +08:00
d510296d33
Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program
for skeleton generation and program loading.
"bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton"
that is similar to existing skeleton, but has one major difference:
$ bpftool gen skeleton lsm.o > lsm.skel.h
$ bpftool gen skeleton -L lsm.o > lsm.lskel.h
$ diff lsm.skel.h lsm.lskel.h
@@ -5,34 +4,34 @@
#define __LSM_SKEL_H__
#include <stdlib.h>
-#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
The light skeleton does not use majority of libbpf infrastructure.
It doesn't need libelf. It doesn't parse .o file.
It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file.
In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be
needed to work with light skeleton.
"bpftool prog load -L file.o" command is introduced for debugging of syscall/loader
program generation. Just like the same command without -L it will try to load
the programs from file.o into the kernel. It won't even try to pin them.
"bpftool prog load -L -d file.o" command will provide additional debug messages
on how syscall/loader program was generated.
Also the execution of syscall/loader program will use bpf_trace_printk() for
each step of loading BTF, creating maps, and loading programs.
The user can do "cat /.../trace_pipe" for further debug.
An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c:
struct fexit_sleep {
struct bpf_loader_ctx ctx;
struct {
struct bpf_map_desc bss;
} maps;
struct {
struct bpf_prog_desc nanosleep_fentry;
struct bpf_prog_desc nanosleep_fexit;
} progs;
struct {
int nanosleep_fentry_fd;
int nanosleep_fexit_fd;
} links;
struct fexit_sleep__bss {
int pid;
int fentry_cnt;
int fexit_cnt;
} *bss;
};
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-18-alexei.starovoitov@gmail.com
380 lines
9.1 KiB
C
380 lines
9.1 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 <bpf/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 (fgets(buff, sizeof(buff), fp)) {
|
|
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 && 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("% 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(" | ");
|
|
}
|
|
}
|