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Merge branch 'bpf-libbpf-link-trace'

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Andrii Nakryiko says:

====================
This patchset adds the following APIs to allow attaching BPF programs to
tracing entities:
- bpf_program__attach_perf_event for attaching to any opened perf event FD,
  allowing users full control;
- bpf_program__attach_kprobe for attaching to kernel probes (both entry and
  return probes);
- bpf_program__attach_uprobe for attaching to user probes (both entry/return);
- bpf_program__attach_tracepoint for attaching to kernel tracepoints;
- bpf_program__attach_raw_tracepoint for attaching to raw kernel tracepoint
  (wrapper around bpf_raw_tracepoint_open);

This set of APIs makes libbpf more useful for tracing applications.

All attach APIs return abstract struct bpf_link that encapsulates logic of
detaching BPF program. See patch #2 for details. bpf_assoc was considered as
an alternative name for this opaque "handle", but bpf_link seems to be
appropriate semantically and is nice and short.

Pre-patch #1 makes internal libbpf_strerror_r helper function work w/ negative
error codes, lifting the burder off callers to keep track of error sign.
Patch #2 adds bpf_link abstraction.
Patch #3 adds attach_perf_event, which is the base for all other APIs.
Patch #4 adds kprobe/uprobe APIs.
Patch #5 adds tracepoint API.
Patch #6 adds raw_tracepoint API.
Patch #7 converts one existing test to use attach_perf_event.
Patch #8 adds new kprobe/uprobe tests.
Patch #9 converts some selftests currently using tracepoint to new APIs.

v4->v5:
- typo and small nits (Yonghong);
- validate pfd in attach_perf_event (Yonghong);
- parse_uint_from_file fixes (Yonghong);
- check for malloc failure in attach_raw_tracepoint (Yonghong);
- attach_probes selftests clean up fixes (Yonghong);
v3->v4:
- proper errno handling (Stanislav);
- bpf_fd -> prog_fd (Stanislav);
- switch to fprintf (Song);
v2->v3:
- added bpf_link concept (Daniel);
- didn't add generic bpf_link__attach_program for reasons described in [0];
- dropped Stanislav's Reviewed-by from patches #2-#6, in case he doesn't like
  the change;
v1->v2:
- preserve errno before close() call (Stanislav);
- use libbpf_perf_event_disable_and_close in selftest (Stanislav);
- remove unnecessary memset (Stanislav);

[0] https://lore.kernel.org/bpf/CAEf4BzZ7EM5eP2eaZn7T2Yb5QgVRiwAs+epeLR1g01TTx-6m6Q@mail.gmail.com/
====================

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Daniel Borkmann 2019-07-05 22:37:31 +02:00
commit c5f48c9276
10 changed files with 664 additions and 99 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

367
tools/lib/bpf/libbpf.c
View File

@ -32,6 +32,7 @@
#include <linux/limits.h>
#include <linux/perf_event.h>
#include <linux/ring_buffer.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/vfs.h>
@ -3941,6 +3942,372 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
return 0;
}
struct bpf_link {
int (*destroy)(struct bpf_link *link);
};
int bpf_link__destroy(struct bpf_link *link)
{
int err;
if (!link)
return 0;
err = link->destroy(link);
free(link);
return err;
}
struct bpf_link_fd {
struct bpf_link link; /* has to be at the top of struct */
int fd; /* hook FD */
};
static int bpf_link__destroy_perf_event(struct bpf_link *link)
{
struct bpf_link_fd *l = (void *)link;
int err;
err = ioctl(l->fd, PERF_EVENT_IOC_DISABLE, 0);
if (err)
err = -errno;
close(l->fd);
return err;
}
struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog,
int pfd)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link_fd *link;
int prog_fd, err;
if (pfd < 0) {
pr_warning("program '%s': invalid perf event FD %d\n",
bpf_program__title(prog, false), pfd);
return ERR_PTR(-EINVAL);
}
prog_fd = bpf_program__fd(prog);
if (prog_fd < 0) {
pr_warning("program '%s': can't attach BPF program w/o FD (did you load it?)\n",
bpf_program__title(prog, false));
return ERR_PTR(-EINVAL);
}
link = malloc(sizeof(*link));
if (!link)
return ERR_PTR(-ENOMEM);
link->link.destroy = &bpf_link__destroy_perf_event;
link->fd = pfd;
if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) {
err = -errno;
free(link);
pr_warning("program '%s': failed to attach to pfd %d: %s\n",
bpf_program__title(prog, false), pfd,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return ERR_PTR(err);
}
if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
err = -errno;
free(link);
pr_warning("program '%s': failed to enable pfd %d: %s\n",
bpf_program__title(prog, false), pfd,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return ERR_PTR(err);
}
return (struct bpf_link *)link;
}
/*
* this function is expected to parse integer in the range of [0, 2^31-1] from
* given file using scanf format string fmt. If actual parsed value is
* negative, the result might be indistinguishable from error
*/
static int parse_uint_from_file(const char *file, const char *fmt)
{
char buf[STRERR_BUFSIZE];
int err, ret;
FILE *f;
f = fopen(file, "r");
if (!f) {
err = -errno;
pr_debug("failed to open '%s': %s\n", file,
libbpf_strerror_r(err, buf, sizeof(buf)));
return err;
}
err = fscanf(f, fmt, &ret);
if (err != 1) {
err = err == EOF ? -EIO : -errno;
pr_debug("failed to parse '%s': %s\n", file,
libbpf_strerror_r(err, buf, sizeof(buf)));
fclose(f);
return err;
}
fclose(f);
return ret;
}
static int determine_kprobe_perf_type(void)
{
const char *file = "/sys/bus/event_source/devices/kprobe/type";
return parse_uint_from_file(file, "%d\n");
}
static int determine_uprobe_perf_type(void)
{
const char *file = "/sys/bus/event_source/devices/uprobe/type";
return parse_uint_from_file(file, "%d\n");
}
static int determine_kprobe_retprobe_bit(void)
{
const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe";
return parse_uint_from_file(file, "config:%d\n");
}
static int determine_uprobe_retprobe_bit(void)
{
const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
return parse_uint_from_file(file, "config:%d\n");
}
static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
uint64_t offset, int pid)
{
struct perf_event_attr attr = {};
char errmsg[STRERR_BUFSIZE];
int type, pfd, err;
type = uprobe ? determine_uprobe_perf_type()
: determine_kprobe_perf_type();
if (type < 0) {
pr_warning("failed to determine %s perf type: %s\n",
uprobe ? "uprobe" : "kprobe",
libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
return type;
}
if (retprobe) {
int bit = uprobe ? determine_uprobe_retprobe_bit()
: determine_kprobe_retprobe_bit();
if (bit < 0) {
pr_warning("failed to determine %s retprobe bit: %s\n",
uprobe ? "uprobe" : "kprobe",
libbpf_strerror_r(bit, errmsg,
sizeof(errmsg)));
return bit;
}
attr.config |= 1 << bit;
}
attr.size = sizeof(attr);
attr.type = type;
attr.config1 = (uint64_t)(void *)name; /* kprobe_func or uprobe_path */
attr.config2 = offset; /* kprobe_addr or probe_offset */
/* pid filter is meaningful only for uprobes */
pfd = syscall(__NR_perf_event_open, &attr,
pid < 0 ? -1 : pid /* pid */,
pid == -1 ? 0 : -1 /* cpu */,
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
if (pfd < 0) {
err = -errno;
pr_warning("%s perf_event_open() failed: %s\n",
uprobe ? "uprobe" : "kprobe",
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return err;
}
return pfd;
}
struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
bool retprobe,
const char *func_name)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link *link;
int pfd, err;
pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
0 /* offset */, -1 /* pid */);
if (pfd < 0) {
pr_warning("program '%s': failed to create %s '%s' perf event: %s\n",
bpf_program__title(prog, false),
retprobe ? "kretprobe" : "kprobe", func_name,
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
return ERR_PTR(pfd);
}
link = bpf_program__attach_perf_event(prog, pfd);
if (IS_ERR(link)) {
close(pfd);
err = PTR_ERR(link);
pr_warning("program '%s': failed to attach to %s '%s': %s\n",
bpf_program__title(prog, false),
retprobe ? "kretprobe" : "kprobe", func_name,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return link;
}
return link;
}
struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
bool retprobe, pid_t pid,
const char *binary_path,
size_t func_offset)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link *link;
int pfd, err;
pfd = perf_event_open_probe(true /* uprobe */, retprobe,
binary_path, func_offset, pid);
if (pfd < 0) {
pr_warning("program '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
bpf_program__title(prog, false),
retprobe ? "uretprobe" : "uprobe",
binary_path, func_offset,
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
return ERR_PTR(pfd);
}
link = bpf_program__attach_perf_event(prog, pfd);
if (IS_ERR(link)) {
close(pfd);
err = PTR_ERR(link);
pr_warning("program '%s': failed to attach to %s '%s:0x%zx': %s\n",
bpf_program__title(prog, false),
retprobe ? "uretprobe" : "uprobe",
binary_path, func_offset,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return link;
}
return link;
}
static int determine_tracepoint_id(const char *tp_category,
const char *tp_name)
{
char file[PATH_MAX];
int ret;
ret = snprintf(file, sizeof(file),
"/sys/kernel/debug/tracing/events/%s/%s/id",
tp_category, tp_name);
if (ret < 0)
return -errno;
if (ret >= sizeof(file)) {
pr_debug("tracepoint %s/%s path is too long\n",
tp_category, tp_name);
return -E2BIG;
}
return parse_uint_from_file(file, "%d\n");
}
static int perf_event_open_tracepoint(const char *tp_category,
const char *tp_name)
{
struct perf_event_attr attr = {};
char errmsg[STRERR_BUFSIZE];
int tp_id, pfd, err;
tp_id = determine_tracepoint_id(tp_category, tp_name);
if (tp_id < 0) {
pr_warning("failed to determine tracepoint '%s/%s' perf event ID: %s\n",
tp_category, tp_name,
libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg)));
return tp_id;
}
attr.type = PERF_TYPE_TRACEPOINT;
attr.size = sizeof(attr);
attr.config = tp_id;
pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */,
-1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
if (pfd < 0) {
err = -errno;
pr_warning("tracepoint '%s/%s' perf_event_open() failed: %s\n",
tp_category, tp_name,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return err;
}
return pfd;
}
struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
const char *tp_category,
const char *tp_name)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link *link;
int pfd, err;
pfd = perf_event_open_tracepoint(tp_category, tp_name);
if (pfd < 0) {
pr_warning("program '%s': failed to create tracepoint '%s/%s' perf event: %s\n",
bpf_program__title(prog, false),
tp_category, tp_name,
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
return ERR_PTR(pfd);
}
link = bpf_program__attach_perf_event(prog, pfd);
if (IS_ERR(link)) {
close(pfd);
err = PTR_ERR(link);
pr_warning("program '%s': failed to attach to tracepoint '%s/%s': %s\n",
bpf_program__title(prog, false),
tp_category, tp_name,
libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
return link;
}
return link;
}
static int bpf_link__destroy_fd(struct bpf_link *link)
{
struct bpf_link_fd *l = (void *)link;
return close(l->fd);
}
struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
const char *tp_name)
{
char errmsg[STRERR_BUFSIZE];
struct bpf_link_fd *link;
int prog_fd, pfd;
prog_fd = bpf_program__fd(prog);
if (prog_fd < 0) {
pr_warning("program '%s': can't attach before loaded\n",
bpf_program__title(prog, false));
return ERR_PTR(-EINVAL);
}
link = malloc(sizeof(*link));
if (!link)
return ERR_PTR(-ENOMEM);
link->link.destroy = &bpf_link__destroy_fd;
pfd = bpf_raw_tracepoint_open(tp_name, prog_fd);
if (pfd < 0) {
pfd = -errno;
free(link);
pr_warning("program '%s': failed to attach to raw tracepoint '%s': %s\n",
bpf_program__title(prog, false), tp_name,
libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
return ERR_PTR(pfd);
}
link->fd = pfd;
return (struct bpf_link *)link;
}
enum bpf_perf_event_ret
bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
void **copy_mem, size_t *copy_size,

21
tools/lib/bpf/libbpf.h
View File

@ -165,6 +165,27 @@ LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
struct bpf_link;
LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
LIBBPF_API struct bpf_link *
bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
const char *func_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
pid_t pid, const char *binary_path,
size_t func_offset);
LIBBPF_API struct bpf_link *
bpf_program__attach_tracepoint(struct bpf_program *prog,
const char *tp_category,
const char *tp_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
const char *tp_name);
struct bpf_insn;
/*

8
tools/lib/bpf/libbpf.map
View File

@ -167,10 +167,16 @@ LIBBPF_0.0.3 {
LIBBPF_0.0.4 {
global:
bpf_link__destroy;
bpf_object__load_xattr;
bpf_program__attach_kprobe;
bpf_program__attach_perf_event;
bpf_program__attach_raw_tracepoint;
bpf_program__attach_tracepoint;
bpf_program__attach_uprobe;
btf_dump__dump_type;
btf_dump__free;
btf_dump__new;
btf__parse_elf;
bpf_object__load_xattr;
libbpf_num_possible_cpus;
} LIBBPF_0.0.3;

2
tools/lib/bpf/str_error.c
View File

@ -11,7 +11,7 @@
*/
char *libbpf_strerror_r(int err, char *dst, int len)
{
int ret = strerror_r(err, dst, len);
int ret = strerror_r(err < 0 ? -err : err, dst, len);
if (ret)
snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret);
return dst;

166
tools/testing/selftests/bpf/prog_tests/attach_probe.c Normal file
View File

@ -0,0 +1,166 @@
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
ssize_t get_base_addr() {
size_t start;
char buf[256];
FILE *f;
f = fopen("/proc/self/maps", "r");
if (!f)
return -errno;
while (fscanf(f, "%zx-%*x %s %*s\n", &start, buf) == 2) {
if (strcmp(buf, "r-xp") == 0) {
fclose(f);
return start;
}
}
fclose(f);
return -EINVAL;
}
#ifdef __x86_64__
#define SYS_KPROBE_NAME "__x64_sys_nanosleep"
#else
#define SYS_KPROBE_NAME "sys_nanosleep"
#endif
void test_attach_probe(void)
{
const char *kprobe_name = "kprobe/sys_nanosleep";
const char *kretprobe_name = "kretprobe/sys_nanosleep";
const char *uprobe_name = "uprobe/trigger_func";
const char *uretprobe_name = "uretprobe/trigger_func";
const int kprobe_idx = 0, kretprobe_idx = 1;
const int uprobe_idx = 2, uretprobe_idx = 3;
const char *file = "./test_attach_probe.o";
struct bpf_program *kprobe_prog, *kretprobe_prog;
struct bpf_program *uprobe_prog, *uretprobe_prog;
struct bpf_object *obj;
int err, prog_fd, duration = 0, res;
struct bpf_link *kprobe_link = NULL;
struct bpf_link *kretprobe_link = NULL;
struct bpf_link *uprobe_link = NULL;
struct bpf_link *uretprobe_link = NULL;
int results_map_fd;
size_t uprobe_offset;
ssize_t base_addr;
base_addr = get_base_addr();
if (CHECK(base_addr < 0, "get_base_addr",
"failed to find base addr: %zd", base_addr))
return;
uprobe_offset = (size_t)&get_base_addr - base_addr;
/* load programs */
err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
return;
kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
if (CHECK(!kprobe_prog, "find_probe",
"prog '%s' not found\n", kprobe_name))
goto cleanup;
kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name);
if (CHECK(!kretprobe_prog, "find_probe",
"prog '%s' not found\n", kretprobe_name))
goto cleanup;
uprobe_prog = bpf_object__find_program_by_title(obj, uprobe_name);
if (CHECK(!uprobe_prog, "find_probe",
"prog '%s' not found\n", uprobe_name))
goto cleanup;
uretprobe_prog = bpf_object__find_program_by_title(obj, uretprobe_name);
if (CHECK(!uretprobe_prog, "find_probe",
"prog '%s' not found\n", uretprobe_name))
goto cleanup;
/* load maps */
results_map_fd = bpf_find_map(__func__, obj, "results_map");
if (CHECK(results_map_fd < 0, "find_results_map",
"err %d\n", results_map_fd))
goto cleanup;
kprobe_link = bpf_program__attach_kprobe(kprobe_prog,
false /* retprobe */,
SYS_KPROBE_NAME);
if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
"err %ld\n", PTR_ERR(kprobe_link))) {
kprobe_link = NULL;
goto cleanup;
}
kretprobe_link = bpf_program__attach_kprobe(kretprobe_prog,
true /* retprobe */,
SYS_KPROBE_NAME);
if (CHECK(IS_ERR(kretprobe_link), "attach_kretprobe",
"err %ld\n", PTR_ERR(kretprobe_link))) {
kretprobe_link = NULL;
goto cleanup;
}
uprobe_link = bpf_program__attach_uprobe(uprobe_prog,
false /* retprobe */,
0 /* self pid */,
"/proc/self/exe",
uprobe_offset);
if (CHECK(IS_ERR(uprobe_link), "attach_uprobe",
"err %ld\n", PTR_ERR(uprobe_link))) {
uprobe_link = NULL;
goto cleanup;
}
uretprobe_link = bpf_program__attach_uprobe(uretprobe_prog,
true /* retprobe */,
-1 /* any pid */,
"/proc/self/exe",
uprobe_offset);
if (CHECK(IS_ERR(uretprobe_link), "attach_uretprobe",
"err %ld\n", PTR_ERR(uretprobe_link))) {
uretprobe_link = NULL;
goto cleanup;
}
/* trigger & validate kprobe && kretprobe */
usleep(1);
err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res);
if (CHECK(err, "get_kprobe_res",
"failed to get kprobe res: %d\n", err))
goto cleanup;
if (CHECK(res != kprobe_idx + 1, "check_kprobe_res",
"wrong kprobe res: %d\n", res))
goto cleanup;
err = bpf_map_lookup_elem(results_map_fd, &kretprobe_idx, &res);
if (CHECK(err, "get_kretprobe_res",
"failed to get kretprobe res: %d\n", err))
goto cleanup;
if (CHECK(res != kretprobe_idx + 1, "check_kretprobe_res",
"wrong kretprobe res: %d\n", res))
goto cleanup;
/* trigger & validate uprobe & uretprobe */
get_base_addr();
err = bpf_map_lookup_elem(results_map_fd, &uprobe_idx, &res);
if (CHECK(err, "get_uprobe_res",
"failed to get uprobe res: %d\n", err))
goto cleanup;
if (CHECK(res != uprobe_idx + 1, "check_uprobe_res",
"wrong uprobe res: %d\n", res))
goto cleanup;
err = bpf_map_lookup_elem(results_map_fd, &uretprobe_idx, &res);
if (CHECK(err, "get_uretprobe_res",
"failed to get uretprobe res: %d\n", err))
goto cleanup;
if (CHECK(res != uretprobe_idx + 1, "check_uretprobe_res",
"wrong uretprobe res: %d\n", res))
goto cleanup;
cleanup:
bpf_link__destroy(kprobe_link);
bpf_link__destroy(kretprobe_link);
bpf_link__destroy(uprobe_link);
bpf_link__destroy(uretprobe_link);
bpf_object__close(obj);
}

55
tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c
View File

@ -4,11 +4,13 @@
void test_stacktrace_build_id(void)
{
int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
const char *prog_name = "tracepoint/random/urandom_read";
const char *file = "./test_stacktrace_build_id.o";
int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len;
struct perf_event_attr attr = {};
int err, prog_fd, stack_trace_len;
__u32 key, previous_key, val, duration = 0;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_link *link = NULL;
char buf[256];
int i, j;
struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
@ -18,44 +20,16 @@ void test_stacktrace_build_id(void)
retry:
err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
goto out;
return;
/* Get the ID for the sched/sched_switch tracepoint */
snprintf(buf, sizeof(buf),
"/sys/kernel/debug/tracing/events/random/urandom_read/id");
efd = open(buf, O_RDONLY, 0);
if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
goto close_prog;
bytes = read(efd, buf, sizeof(buf));
close(efd);
if (CHECK(bytes <= 0 || bytes >= sizeof(buf),
"read", "bytes %d errno %d\n", bytes, errno))
link = bpf_program__attach_tracepoint(prog, "random", "urandom_read");
if (CHECK(IS_ERR(link), "attach_tp", "err %ld\n", PTR_ERR(link)))
goto close_prog;
/* Open the perf event and attach bpf progrram */
attr.config = strtol(buf, NULL, 0);
attr.type = PERF_TYPE_TRACEPOINT;
attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
attr.sample_period = 1;
attr.wakeup_events = 1;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
pmu_fd, errno))
goto close_prog;
err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
err, errno))
goto close_pmu;
err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
err, errno))
goto disable_pmu;
/* find map fds */
control_map_fd = bpf_find_map(__func__, obj, "control_map");
if (CHECK(control_map_fd < 0, "bpf_find_map control_map",
@ -133,8 +107,7 @@ void test_stacktrace_build_id(void)
* try it one more time.
*/
if (build_id_matches < 1 && retry--) {
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close(pmu_fd);
bpf_link__destroy(link);
bpf_object__close(obj);
printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
__func__);
@ -152,14 +125,8 @@ void test_stacktrace_build_id(void)
"err %d errno %d\n", err, errno);
disable_pmu:
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close_pmu:
close(pmu_fd);
bpf_link__destroy(link);
close_prog:
bpf_object__close(obj);
out:
return;
}

31
tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
View File

@ -17,6 +17,7 @@ static __u64 read_perf_max_sample_freq(void)
void test_stacktrace_build_id_nmi(void)
{
int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
const char *prog_name = "tracepoint/random/urandom_read";
const char *file = "./test_stacktrace_build_id.o";
int err, pmu_fd, prog_fd;
struct perf_event_attr attr = {
@ -25,7 +26,9 @@ void test_stacktrace_build_id_nmi(void)
.config = PERF_COUNT_HW_CPU_CYCLES,
};
__u32 key, previous_key, val, duration = 0;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_link *link;
char buf[256];
int i, j;
struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
@ -39,6 +42,10 @@ void test_stacktrace_build_id_nmi(void)
if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
return;
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
goto close_prog;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
@ -47,15 +54,12 @@ void test_stacktrace_build_id_nmi(void)
pmu_fd, errno))
goto close_prog;
err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
err, errno))
goto close_pmu;
err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
err, errno))
goto disable_pmu;
link = bpf_program__attach_perf_event(prog, pmu_fd);
if (CHECK(IS_ERR(link), "attach_perf_event",
"err %ld\n", PTR_ERR(link))) {
close(pmu_fd);
goto close_prog;
}
/* find map fds */
control_map_fd = bpf_find_map(__func__, obj, "control_map");
@ -134,8 +138,7 @@ void test_stacktrace_build_id_nmi(void)
* try it one more time.
*/
if (build_id_matches < 1 && retry--) {
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close(pmu_fd);
bpf_link__destroy(link);
bpf_object__close(obj);
printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
__func__);
@ -154,11 +157,7 @@ void test_stacktrace_build_id_nmi(void)
*/
disable_pmu:
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close_pmu:
close(pmu_fd);
bpf_link__destroy(link);
close_prog:
bpf_object__close(obj);
}

43
tools/testing/selftests/bpf/prog_tests/stacktrace_map.c
View File

@ -4,50 +4,26 @@
void test_stacktrace_map(void)
{
int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
const char *prog_name = "tracepoint/sched/sched_switch";
int err, prog_fd, stack_trace_len;
const char *file = "./test_stacktrace_map.o";
int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len;
struct perf_event_attr attr = {};
__u32 key, val, duration = 0;
struct bpf_program *prog;
struct bpf_object *obj;
char buf[256];
struct bpf_link *link;
err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
return;
/* Get the ID for the sched/sched_switch tracepoint */
snprintf(buf, sizeof(buf),
"/sys/kernel/debug/tracing/events/sched/sched_switch/id");
efd = open(buf, O_RDONLY, 0);
if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
goto close_prog;
bytes = read(efd, buf, sizeof(buf));
close(efd);
if (bytes <= 0 || bytes >= sizeof(buf))
link = bpf_program__attach_tracepoint(prog, "sched", "sched_switch");
if (CHECK(IS_ERR(link), "attach_tp", "err %ld\n", PTR_ERR(link)))
goto close_prog;
/* Open the perf event and attach bpf progrram */
attr.config = strtol(buf, NULL, 0);
attr.type = PERF_TYPE_TRACEPOINT;
attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
attr.sample_period = 1;
attr.wakeup_events = 1;
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
pmu_fd, errno))
goto close_prog;
err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
if (err)
goto disable_pmu;
err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
if (err)
goto disable_pmu;
/* find map fds */
control_map_fd = bpf_find_map(__func__, obj, "control_map");
if (control_map_fd < 0)
@ -96,8 +72,7 @@ void test_stacktrace_map(void)
disable_pmu:
error_cnt++;
disable_pmu_noerr:
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close(pmu_fd);
bpf_link__destroy(link);
close_prog:
bpf_object__close(obj);
}

15
tools/testing/selftests/bpf/prog_tests/stacktrace_map_raw_tp.c
View File

@ -3,18 +3,25 @@
void test_stacktrace_map_raw_tp(void)
{
const char *prog_name = "tracepoint/sched/sched_switch";
int control_map_fd, stackid_hmap_fd, stackmap_fd;
const char *file = "./test_stacktrace_map.o";
int efd, err, prog_fd;
__u32 key, val, duration = 0;
int err, prog_fd;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_link *link = NULL;
err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
return;
efd = bpf_raw_tracepoint_open("sched_switch", prog_fd);
if (CHECK(efd < 0, "raw_tp_open", "err %d errno %d\n", efd, errno))
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
goto close_prog;
link = bpf_program__attach_raw_tracepoint(prog, "sched_switch");
if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
goto close_prog;
/* find map fds */
@ -55,5 +62,7 @@ void test_stacktrace_map_raw_tp(void)
close_prog:
error_cnt++;
close_prog_noerr:
if (!IS_ERR_OR_NULL(link))
bpf_link__destroy(link);
bpf_object__close(obj);
}

55
tools/testing/selftests/bpf/progs/test_attach_probe.c Normal file
View File

@ -0,0 +1,55 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Facebook
#include <linux/ptrace.h>
#include <linux/bpf.h>
#include "bpf_helpers.h"
struct {
int type;
int max_entries;
int *key;
int *value;
} results_map SEC(".maps") = {
.type = BPF_MAP_TYPE_ARRAY,
.max_entries = 4,
};
SEC("kprobe/sys_nanosleep")
int handle_sys_nanosleep_entry(struct pt_regs *ctx)
{
const int key = 0, value = 1;
bpf_map_update_elem(&results_map, &key, &value, 0);
return 0;
}
SEC("kretprobe/sys_nanosleep")
int handle_sys_getpid_return(struct pt_regs *ctx)
{
const int key = 1, value = 2;
bpf_map_update_elem(&results_map, &key, &value, 0);
return 0;
}
SEC("uprobe/trigger_func")
int handle_uprobe_entry(struct pt_regs *ctx)
{
const int key = 2, value = 3;
bpf_map_update_elem(&results_map, &key, &value, 0);
return 0;
}
SEC("uretprobe/trigger_func")
int handle_uprobe_return(struct pt_regs *ctx)
{
const int key = 3, value = 4;
bpf_map_update_elem(&results_map, &key, &value, 0);
return 0;
}
char _license[] SEC("license") = "GPL";
__u32 _version SEC("version") = 1;