Commit 3677d0a1 authored by Daniel T. Lee's avatar Daniel T. Lee Committed by Alexei Starovoitov

samples: bpf: Refactor kprobe tracing programs with libbpf

For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing kprobe tracing programs with libbbpf
bpf loader.

    - For kprobe events pointing to system calls, the SYSCALL() macro in
    trace_common.h was used.
    - Adding a kprobe event and attaching a bpf program to it was done
    through bpf_program_attach().
    - Instead of using the existing BPF MAP definition, MAP definition
    has been refactored with the new BTF-defined MAP format.
Signed-off-by: default avatarDaniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com
parent 35a8b6dd
......@@ -71,11 +71,11 @@ tracex4-objs := tracex4_user.o
tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
tracex6-objs := tracex6_user.o
tracex7-objs := tracex7_user.o
test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o
trace_output-objs := bpf_load.o trace_output_user.o $(TRACE_HELPERS)
lathist-objs := bpf_load.o lathist_user.o
test_probe_write_user-objs := test_probe_write_user_user.o
trace_output-objs := trace_output_user.o $(TRACE_HELPERS)
lathist-objs := lathist_user.o
offwaketime-objs := bpf_load.o offwaketime_user.o $(TRACE_HELPERS)
spintest-objs := bpf_load.o spintest_user.o $(TRACE_HELPERS)
spintest-objs := spintest_user.o $(TRACE_HELPERS)
map_perf_test-objs := map_perf_test_user.o
test_overhead-objs := bpf_load.o test_overhead_user.o
test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
......@@ -86,7 +86,7 @@ xdp1-objs := xdp1_user.o
# reuse xdp1 source intentionally
xdp2-objs := xdp1_user.o
xdp_router_ipv4-objs := xdp_router_ipv4_user.o
test_current_task_under_cgroup-objs := bpf_load.o $(CGROUP_HELPERS) \
test_current_task_under_cgroup-objs := $(CGROUP_HELPERS) \
test_current_task_under_cgroup_user.o
trace_event-objs := trace_event_user.o $(TRACE_HELPERS)
sampleip-objs := sampleip_user.o $(TRACE_HELPERS)
......
......@@ -18,12 +18,12 @@
* trace_preempt_[on|off] tracepoints hooks is not supported.
*/
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u64),
.max_entries = MAX_CPU,
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, u64);
__uint(max_entries, MAX_CPU);
} my_map SEC(".maps");
SEC("kprobe/trace_preempt_off")
int bpf_prog1(struct pt_regs *ctx)
......@@ -61,12 +61,12 @@ static unsigned int log2l(unsigned long v)
return log2(v);
}
struct bpf_map_def SEC("maps") my_lat = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(long),
.max_entries = MAX_CPU * MAX_ENTRIES,
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, long);
__uint(max_entries, MAX_CPU * MAX_ENTRIES);
} my_lat SEC(".maps");
SEC("kprobe/trace_preempt_on")
int bpf_prog2(struct pt_regs *ctx)
......
......@@ -6,9 +6,8 @@
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <linux/bpf.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
#include "bpf_load.h"
#define MAX_ENTRIES 20
#define MAX_CPU 4
......@@ -81,20 +80,51 @@ static void get_data(int fd)
int main(int argc, char **argv)
{
struct bpf_link *links[2];
struct bpf_program *prog;
struct bpf_object *obj;
char filename[256];
int map_fd, i = 0;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
map_fd = bpf_object__find_map_fd_by_name(obj, "my_lat");
if (map_fd < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
bpf_object__for_each_program(prog, obj) {
links[i] = bpf_program__attach(prog);
if (libbpf_get_error(links[i])) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
links[i] = NULL;
goto cleanup;
}
i++;
}
while (1) {
get_data(map_fd[1]);
get_data(map_fd);
print_hist();
sleep(5);
}
cleanup:
for (i--; i >= 0; i--)
bpf_link__destroy(links[i]);
bpf_object__close(obj);
return 0;
}
......@@ -12,25 +12,25 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(long),
.value_size = sizeof(long),
.max_entries = 1024,
};
struct bpf_map_def SEC("maps") my_map2 = {
.type = BPF_MAP_TYPE_PERCPU_HASH,
.key_size = sizeof(long),
.value_size = sizeof(long),
.max_entries = 1024,
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, long);
__type(value, long);
__uint(max_entries, 1024);
} my_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
__uint(key_size, sizeof(long));
__uint(value_size, sizeof(long));
__uint(max_entries, 1024);
} my_map2 SEC(".maps");
struct bpf_map_def SEC("maps") stackmap = {
.type = BPF_MAP_TYPE_STACK_TRACE,
.key_size = sizeof(u32),
.value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
.max_entries = 10000,
};
struct {
__uint(type, BPF_MAP_TYPE_STACK_TRACE);
__uint(key_size, sizeof(u32));
__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
__uint(max_entries, 10000);
} stackmap SEC(".maps");
#define PROG(foo) \
int foo(struct pt_regs *ctx) \
......
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <string.h>
#include <assert.h>
#include <sys/resource.h>
#include <bpf/libbpf.h>
#include "bpf_load.h"
#include <bpf/bpf.h>
#include "trace_helpers.h"
int main(int ac, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
char filename[256], symbol[256];
struct bpf_object *obj = NULL;
struct bpf_link *links[20];
long key, next_key, value;
char filename[256];
struct bpf_program *prog;
int map_fd, i, j = 0;
const char *title;
struct ksym *sym;
int i;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
setrlimit(RLIMIT_MEMLOCK, &r);
if (setrlimit(RLIMIT_MEMLOCK, &r)) {
perror("setrlimit(RLIMIT_MEMLOCK)");
return 1;
}
if (load_kallsyms()) {
printf("failed to process /proc/kallsyms\n");
return 2;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
obj = NULL;
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
if (map_fd < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
bpf_object__for_each_program(prog, obj) {
title = bpf_program__title(prog, false);
if (sscanf(title, "kprobe/%s", symbol) != 1)
continue;
/* Attach prog only when symbol exists */
if (ksym_get_addr(symbol)) {
links[j] = bpf_program__attach(prog);
if (libbpf_get_error(links[j])) {
fprintf(stderr, "bpf_program__attach failed\n");
links[j] = NULL;
goto cleanup;
}
j++;
}
}
for (i = 0; i < 5; i++) {
key = 0;
printf("kprobing funcs:");
while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
bpf_map_lookup_elem(map_fd[0], &next_key, &value);
while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
bpf_map_lookup_elem(map_fd, &next_key, &value);
assert(next_key == value);
sym = ksym_search(value);
key = next_key;
......@@ -48,10 +85,15 @@ int main(int ac, char **argv)
if (key)
printf("\n");
key = 0;
while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0)
bpf_map_delete_elem(map_fd[0], &next_key);
while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
bpf_map_delete_elem(map_fd, &next_key);
sleep(1);
}
cleanup:
for (j--; j >= 0; j--)
bpf_link__destroy(links[j]);
bpf_object__close(obj);
return 0;
}
......@@ -10,23 +10,24 @@
#include <linux/version.h>
#include <bpf/bpf_helpers.h>
#include <uapi/linux/utsname.h>
#include "trace_common.h"
struct bpf_map_def SEC("maps") cgroup_map = {
.type = BPF_MAP_TYPE_CGROUP_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u32),
.max_entries = 1,
};
struct {
__uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
__uint(key_size, sizeof(u32));
__uint(value_size, sizeof(u32));
__uint(max_entries, 1);
} cgroup_map SEC(".maps");
struct bpf_map_def SEC("maps") perf_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u64),
.max_entries = 1,
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, u32);
__type(value, u64);
__uint(max_entries, 1);
} perf_map SEC(".maps");
/* Writes the last PID that called sync to a map at index 0 */
SEC("kprobe/sys_sync")
SEC("kprobe/" SYSCALL(sys_sync))
int bpf_prog1(struct pt_regs *ctx)
{
u64 pid = bpf_get_current_pid_tgid();
......
......@@ -4,10 +4,9 @@
#define _GNU_SOURCE
#include <stdio.h>
#include <linux/bpf.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include "bpf_load.h"
#include <bpf/libbpf.h>
#include "cgroup_helpers.h"
#define CGROUP_PATH "/my-cgroup"
......@@ -15,13 +14,44 @@
int main(int argc, char **argv)
{
pid_t remote_pid, local_pid = getpid();
int cg2, idx = 0, rc = 0;
struct bpf_link *link = NULL;
struct bpf_program *prog;
int cg2, idx = 0, rc = 1;
struct bpf_object *obj;
char filename[256];
int map_fd[2];
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
if (!prog) {
printf("finding a prog in obj file failed\n");
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd[0] = bpf_object__find_map_fd_by_name(obj, "cgroup_map");
map_fd[1] = bpf_object__find_map_fd_by_name(obj, "perf_map");
if (map_fd[0] < 0 || map_fd[1] < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
link = bpf_program__attach(prog);
if (libbpf_get_error(link)) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
link = NULL;
goto cleanup;
}
if (setup_cgroup_environment())
......@@ -70,12 +100,14 @@ int main(int argc, char **argv)
goto err;
}
goto out;
err:
rc = 1;
rc = 0;
out:
err:
close(cg2);
cleanup_cgroup_environment();
cleanup:
bpf_link__destroy(link);
bpf_object__close(obj);
return rc;
}
......@@ -13,12 +13,12 @@
#include <bpf/bpf_core_read.h>
#include "trace_common.h"
struct bpf_map_def SEC("maps") dnat_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(struct sockaddr_in),
.value_size = sizeof(struct sockaddr_in),
.max_entries = 256,
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, struct sockaddr_in);
__type(value, struct sockaddr_in);
__uint(max_entries, 256);
} dnat_map SEC(".maps");
/* kprobe is NOT a stable ABI
* kernel functions can be removed, renamed or completely change semantics.
......
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <assert.h>
#include <linux/bpf.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include "bpf_load.h"
#include <bpf/libbpf.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
int main(int ac, char **argv)
{
int serverfd, serverconnfd, clientfd;
socklen_t sockaddr_len;
struct sockaddr serv_addr, mapped_addr, tmp_addr;
struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
struct sockaddr serv_addr, mapped_addr, tmp_addr;
int serverfd, serverconnfd, clientfd, map_fd;
struct bpf_link *link = NULL;
struct bpf_program *prog;
struct bpf_object *obj;
socklen_t sockaddr_len;
char filename[256];
char *ip;
......@@ -24,10 +25,35 @@ int main(int ac, char **argv)
tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
if (libbpf_get_error(prog)) {
fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map");
if (map_fd < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
link = bpf_program__attach(prog);
if (libbpf_get_error(link)) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
link = NULL;
goto cleanup;
}
assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
......@@ -51,7 +77,7 @@ int main(int ac, char **argv)
mapped_addr_in->sin_port = htons(5555);
mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
assert(!bpf_map_update_elem(map_fd[0], &mapped_addr, &serv_addr, BPF_ANY));
assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY));
assert(listen(serverfd, 5) == 0);
......@@ -75,5 +101,8 @@ int main(int ac, char **argv)
/* Is the server's getsockname = the socket getpeername */
assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
cleanup:
bpf_link__destroy(link);
bpf_object__close(obj);
return 0;
}
......@@ -2,15 +2,16 @@
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "trace_common.h"
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = 2,
};
struct {
__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(u32));
__uint(max_entries, 2);
} my_map SEC(".maps");
SEC("kprobe/sys_write")
SEC("kprobe/" SYSCALL(sys_write))
int bpf_prog1(struct pt_regs *ctx)
{
struct S {
......
// SPDX-License-Identifier: GPL-2.0-only
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <linux/perf_event.h>
#include <linux/bpf.h>
#include <errno.h>
#include <assert.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <time.h>
#include <signal.h>
#include <bpf/libbpf.h>
#include "bpf_load.h"
#include "perf-sys.h"
static __u64 time_get_ns(void)
{
......@@ -57,20 +44,48 @@ static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
int main(int argc, char **argv)
{
struct perf_buffer_opts pb_opts = {};
struct bpf_link *link = NULL;
struct bpf_program *prog;
struct perf_buffer *pb;
struct bpf_object *obj;
int map_fd, ret = 0;
char filename[256];
FILE *f;
int ret;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
if (map_fd < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
if (libbpf_get_error(prog)) {
fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
goto cleanup;
}
link = bpf_program__attach(prog);
if (libbpf_get_error(link)) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
link = NULL;
goto cleanup;
}
pb_opts.sample_cb = print_bpf_output;
pb = perf_buffer__new(map_fd[0], 8, &pb_opts);
pb = perf_buffer__new(map_fd, 8, &pb_opts);
ret = libbpf_get_error(pb);
if (ret) {
printf("failed to setup perf_buffer: %d\n", ret);
......@@ -84,5 +99,9 @@ int main(int argc, char **argv)
while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
}
kill(0, SIGINT);
cleanup:
bpf_link__destroy(link);
bpf_object__close(obj);
return ret;
}
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