Commit 8f4c92f0 authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'libbpf: allow users to set kprobe/uprobe attach mode' 



Menglong Dong says:

====================

From: Menglong Dong <imagedong@tencent.com>

By default, libbpf will attach the kprobe/uprobe BPF program in the
latest mode that supported by kernel. In this series, we add the support
to let users manually attach kprobe/uprobe in legacy/perf/link mode in
the 1th patch.

And in the 2th patch, we split the testing 'attach_probe' into multi
subtests, as Andrii suggested.

In the 3th patch, we add the testings for loading kprobe/uprobe in
different mode.

Changes since v3:
- rename eBPF to BPF in the doc
- use OPTS_GET() to get the value of 'force_ioctl_attach'
- error out on attach mode is not supported
- use test_attach_probe_manual__open_and_load() directly

Changes since v2:
- fix the typo in the 2th patch

Changes since v1:
- some small changes in the 1th patch, as Andrii suggested
- split 'attach_probe' into multi subtests
====================

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents fd4cb29f c7aec81b

tools/lib/bpf/libbpf.c

+47 −1
Original line number Diff line number Diff line
@@ -9724,6 +9724,7 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p 
	char errmsg[STRERR_BUFSIZE];

	struct bpf_link_perf *link;

	int prog_fd, link_fd = -1, err;

	bool force_ioctl_attach;



	if (!OPTS_VALID(opts, bpf_perf_event_opts))

		return libbpf_err_ptr(-EINVAL);
@@ -9747,7 +9748,8 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p 
	link->link.dealloc = &bpf_link_perf_dealloc;

	link->perf_event_fd = pfd;



	if (kernel_supports(prog->obj, FEAT_PERF_LINK)) {

	force_ioctl_attach = OPTS_GET(opts, force_ioctl_attach, false);

	if (kernel_supports(prog->obj, FEAT_PERF_LINK) && !force_ioctl_attach) {

		DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts,

			.perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0));
@@ -10106,6 +10108,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 
				const struct bpf_kprobe_opts *opts)

{

	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);

	enum probe_attach_mode attach_mode;

	char errmsg[STRERR_BUFSIZE];

	char *legacy_probe = NULL;

	struct bpf_link *link;
@@ -10116,11 +10119,32 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 
	if (!OPTS_VALID(opts, bpf_kprobe_opts))

		return libbpf_err_ptr(-EINVAL);



	attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT);

	retprobe = OPTS_GET(opts, retprobe, false);

	offset = OPTS_GET(opts, offset, 0);

	pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);



	legacy = determine_kprobe_perf_type() < 0;

	switch (attach_mode) {

	case PROBE_ATTACH_MODE_LEGACY:

		legacy = true;

		pe_opts.force_ioctl_attach = true;

		break;

	case PROBE_ATTACH_MODE_PERF:

		if (legacy)

			return libbpf_err_ptr(-ENOTSUP);

		pe_opts.force_ioctl_attach = true;

		break;

	case PROBE_ATTACH_MODE_LINK:

		if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK))

			return libbpf_err_ptr(-ENOTSUP);

		break;

	case PROBE_ATTACH_MODE_DEFAULT:

		break;

	default:

		return libbpf_err_ptr(-EINVAL);

	}



	if (!legacy) {

		pfd = perf_event_open_probe(false /* uprobe */, retprobe,

					    func_name, offset,
@@ -10852,6 +10876,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 
	const char *archive_path = NULL, *archive_sep = NULL;

	char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL;

	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);

	enum probe_attach_mode attach_mode;

	char full_path[PATH_MAX];

	struct bpf_link *link;

	size_t ref_ctr_off;
@@ -10862,6 +10887,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 
	if (!OPTS_VALID(opts, bpf_uprobe_opts))

		return libbpf_err_ptr(-EINVAL);



	attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT);

	retprobe = OPTS_GET(opts, retprobe, false);

	ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);

	pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
@@ -10903,6 +10929,26 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 
	}



	legacy = determine_uprobe_perf_type() < 0;

	switch (attach_mode) {

	case PROBE_ATTACH_MODE_LEGACY:

		legacy = true;

		pe_opts.force_ioctl_attach = true;

		break;

	case PROBE_ATTACH_MODE_PERF:

		if (legacy)

			return libbpf_err_ptr(-ENOTSUP);

		pe_opts.force_ioctl_attach = true;

		break;

	case PROBE_ATTACH_MODE_LINK:

		if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK))

			return libbpf_err_ptr(-ENOTSUP);

		break;

	case PROBE_ATTACH_MODE_DEFAULT:

		break;

	default:

		return libbpf_err_ptr(-EINVAL);

	}



	if (!legacy) {

		pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,

					    func_offset, pid, ref_ctr_off);

tools/lib/bpf/libbpf.h

+37 −13
Original line number Diff line number Diff line
@@ -447,12 +447,15 @@ LIBBPF_API struct bpf_link * 
bpf_program__attach(const struct bpf_program *prog);



struct bpf_perf_event_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* custom user-provided value fetchable through bpf_get_attach_cookie() */

	__u64 bpf_cookie;

	/* don't use BPF link when attach BPF program */

	bool force_ioctl_attach;

	size_t :0;

};

#define bpf_perf_event_opts__last_field bpf_cookie

#define bpf_perf_event_opts__last_field force_ioctl_attach



LIBBPF_API struct bpf_link *

bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
@@ -461,8 +464,25 @@ LIBBPF_API struct bpf_link * 
bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,

				    const struct bpf_perf_event_opts *opts);



/**

 * enum probe_attach_mode - the mode to attach kprobe/uprobe

 *

 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will

 * be returned if it is not supported by the kernel.

 */

enum probe_attach_mode {

	/* attach probe in latest supported mode by kernel */

	PROBE_ATTACH_MODE_DEFAULT = 0,

	/* attach probe in legacy mode, using debugfs/tracefs */

	PROBE_ATTACH_MODE_LEGACY,

	/* create perf event with perf_event_open() syscall */

	PROBE_ATTACH_MODE_PERF,

	/* attach probe with BPF link */

	PROBE_ATTACH_MODE_LINK,

};



struct bpf_kprobe_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* custom user-provided value fetchable through bpf_get_attach_cookie() */

	__u64 bpf_cookie;
@@ -470,9 +490,11 @@ struct bpf_kprobe_opts { 
	size_t offset;

	/* kprobe is return probe */

	bool retprobe;

	/* kprobe attach mode */

	enum probe_attach_mode attach_mode;

	size_t :0;

};

#define bpf_kprobe_opts__last_field retprobe

#define bpf_kprobe_opts__last_field attach_mode



LIBBPF_API struct bpf_link *

bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
@@ -506,7 +528,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 
				      const struct bpf_kprobe_multi_opts *opts);



struct bpf_ksyscall_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* custom user-provided value fetchable through bpf_get_attach_cookie() */

	__u64 bpf_cookie;
@@ -552,7 +574,7 @@ bpf_program__attach_ksyscall(const struct bpf_program *prog, 
			     const struct bpf_ksyscall_opts *opts);



struct bpf_uprobe_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* offset of kernel reference counted USDT semaphore, added in

	 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
@@ -570,9 +592,11 @@ struct bpf_uprobe_opts { 
	 * binary_path.

	 */

	const char *func_name;

	/* uprobe attach mode */

	enum probe_attach_mode attach_mode;

	size_t :0;

};

#define bpf_uprobe_opts__last_field func_name

#define bpf_uprobe_opts__last_field attach_mode



/**

 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
@@ -646,7 +670,7 @@ bpf_program__attach_usdt(const struct bpf_program *prog, 
			 const struct bpf_usdt_opts *opts);



struct bpf_tracepoint_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* custom user-provided value fetchable through bpf_get_attach_cookie() */

	__u64 bpf_cookie;
@@ -1110,7 +1134,7 @@ struct user_ring_buffer; 
typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);



struct ring_buffer_opts {

	size_t sz; /* size of this struct, for forward/backward compatiblity */

	size_t sz; /* size of this struct, for forward/backward compatibility */

};



#define ring_buffer_opts__last_field sz
@@ -1475,7 +1499,7 @@ LIBBPF_API void 
bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);



struct gen_loader_opts {

	size_t sz; /* size of this struct, for forward/backward compatiblity */

	size_t sz; /* size of this struct, for forward/backward compatibility */

	const char *data;

	const char *insns;

	__u32 data_sz;
@@ -1493,13 +1517,13 @@ enum libbpf_tristate { 
};



struct bpf_linker_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

};

#define bpf_linker_opts__last_field sz



struct bpf_linker_file_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

};

#define bpf_linker_file_opts__last_field sz
@@ -1542,7 +1566,7 @@ typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cook 
				       struct bpf_link **link);



struct libbpf_prog_handler_opts {

	/* size of this struct, for forward/backward compatiblity */

	/* size of this struct, for forward/backward compatibility */

	size_t sz;

	/* User-provided value that is passed to prog_setup_fn,

	 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to

tools/testing/selftests/bpf/prog_tests/attach_probe.c

+195 −96
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <test_progs.h>

#include "test_attach_kprobe_sleepable.skel.h"

#include "test_attach_probe_manual.skel.h"

#include "test_attach_probe.skel.h"



/* this is how USDT semaphore is actually defined, except volatile modifier */
@@ -23,81 +25,54 @@ static noinline void trigger_func3(void) 
	asm volatile ("");

}



/* attach point for ref_ctr */

static noinline void trigger_func4(void)

{

	asm volatile ("");

}



static char test_data[] = "test_data";



void test_attach_probe(void)

/* manual attach kprobe/kretprobe/uprobe/uretprobe testings */

static void test_attach_probe_manual(enum probe_attach_mode attach_mode)

{

	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);

	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts);

	struct bpf_link *kprobe_link, *kretprobe_link;

	struct bpf_link *uprobe_link, *uretprobe_link;

	struct test_attach_probe* skel;

	ssize_t uprobe_offset, ref_ctr_offset;

	struct bpf_link *uprobe_err_link;

	FILE *devnull;

	bool legacy;



	/* Check if new-style kprobe/uprobe API is supported.

	 * Kernels that support new FD-based kprobe and uprobe BPF attachment

	 * through perf_event_open() syscall expose

	 * /sys/bus/event_source/devices/kprobe/type and

	 * /sys/bus/event_source/devices/uprobe/type files, respectively. They

	 * contain magic numbers that are passed as "type" field of

	 * perf_event_attr. Lack of such file in the system indicates legacy

	 * kernel with old-style kprobe/uprobe attach interface through

	 * creating per-probe event through tracefs. For such cases

	 * ref_ctr_offset feature is not supported, so we don't test it.

	 */

	legacy = access("/sys/bus/event_source/devices/kprobe/type", F_OK) != 0;



	uprobe_offset = get_uprobe_offset(&trigger_func);

	if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset"))

		return;

	struct test_attach_probe_manual *skel;

	ssize_t uprobe_offset;



	ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr);

	if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))

		return;



	skel = test_attach_probe__open();

	if (!ASSERT_OK_PTR(skel, "skel_open"))

	skel = test_attach_probe_manual__open_and_load();

	if (!ASSERT_OK_PTR(skel, "skel_kprobe_manual_open_and_load"))

		return;



	/* sleepable kprobe test case needs flags set before loading */

	if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,

		BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))

		goto cleanup;



	if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))

		goto cleanup;

	if (!ASSERT_OK_PTR(skel->bss, "check_bss"))

	uprobe_offset = get_uprobe_offset(&trigger_func);

	if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset"))

		goto cleanup;



	/* manual-attach kprobe/kretprobe */

	kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,

						 false /* retprobe */,

						 SYS_NANOSLEEP_KPROBE_NAME);

	kprobe_opts.attach_mode = attach_mode;

	kprobe_opts.retprobe = false;

	kprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe,

						      SYS_NANOSLEEP_KPROBE_NAME,

						      &kprobe_opts);

	if (!ASSERT_OK_PTR(kprobe_link, "attach_kprobe"))

		goto cleanup;

	skel->links.handle_kprobe = kprobe_link;



	kretprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kretprobe,

						    true /* retprobe */,

						    SYS_NANOSLEEP_KPROBE_NAME);

	kprobe_opts.retprobe = true;

	kretprobe_link = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe,

							 SYS_NANOSLEEP_KPROBE_NAME,

							 &kprobe_opts);

	if (!ASSERT_OK_PTR(kretprobe_link, "attach_kretprobe"))

		goto cleanup;

	skel->links.handle_kretprobe = kretprobe_link;



	/* auto-attachable kprobe and kretprobe */

	skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto);

	ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto");



	skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto);

	ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto");



	if (!legacy)

		ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before");



	/* manual-attach uprobe/uretprobe */

	uprobe_opts.attach_mode = attach_mode;

	uprobe_opts.ref_ctr_offset = 0;

	uprobe_opts.retprobe = false;

	uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;

	uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe,

						      0 /* self pid */,

						      "/proc/self/exe",
@@ -107,12 +82,7 @@ void test_attach_probe(void) 
		goto cleanup;

	skel->links.handle_uprobe = uprobe_link;



	if (!legacy)

		ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");



	/* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */

	uprobe_opts.retprobe = true;

	uprobe_opts.ref_ctr_offset = legacy ? 0 : ref_ctr_offset;

	uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe,

							 -1 /* any pid */,

							 "/proc/self/exe",
@@ -121,12 +91,7 @@ void test_attach_probe(void) 
		goto cleanup;

	skel->links.handle_uretprobe = uretprobe_link;



	/* verify auto-attach fails for old-style uprobe definition */

	uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);

	if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,

		       "auto-attach should fail for old-style name"))

		goto cleanup;



	/* attach uprobe by function name manually */

	uprobe_opts.func_name = "trigger_func2";

	uprobe_opts.retprobe = false;

	uprobe_opts.ref_ctr_offset = 0;
@@ -138,11 +103,63 @@ void test_attach_probe(void) 
	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))

		goto cleanup;



	/* trigger & validate kprobe && kretprobe */

	usleep(1);



	/* trigger & validate uprobe & uretprobe */

	trigger_func();



	/* trigger & validate uprobe attached by name */

	trigger_func2();



	ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");

	ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");

	ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");

	ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");

	ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");



cleanup:

	test_attach_probe_manual__destroy(skel);

}



static void test_attach_probe_auto(struct test_attach_probe *skel)

{

	struct bpf_link *uprobe_err_link;



	/* auto-attachable kprobe and kretprobe */

	skel->links.handle_kprobe_auto = bpf_program__attach(skel->progs.handle_kprobe_auto);

	ASSERT_OK_PTR(skel->links.handle_kprobe_auto, "attach_kprobe_auto");



	skel->links.handle_kretprobe_auto = bpf_program__attach(skel->progs.handle_kretprobe_auto);

	ASSERT_OK_PTR(skel->links.handle_kretprobe_auto, "attach_kretprobe_auto");



	/* verify auto-attach fails for old-style uprobe definition */

	uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);

	if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,

		       "auto-attach should fail for old-style name"))

		return;



	/* verify auto-attach works */

	skel->links.handle_uretprobe_byname =

			bpf_program__attach(skel->progs.handle_uretprobe_byname);

	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))

		goto cleanup;

		return;



	/* trigger & validate kprobe && kretprobe */

	usleep(1);



	/* trigger & validate uprobe attached by name */

	trigger_func2();



	ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");

	ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res");

	ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");

}



static void test_uprobe_lib(struct test_attach_probe *skel)

{

	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);

	FILE *devnull;



	/* test attach by name for a library function, using the library

	 * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
@@ -155,7 +172,7 @@ void test_attach_probe(void) 
							"libc.so.6",

							0, &uprobe_opts);

	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))

		goto cleanup;

		return;



	uprobe_opts.func_name = "fclose";

	uprobe_opts.retprobe = true;
@@ -165,62 +182,144 @@ void test_attach_probe(void) 
							"libc.so.6",

							0, &uprobe_opts);

	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))

		return;



	/* trigger & validate shared library u[ret]probes attached by name */

	devnull = fopen("/dev/null", "r");

	fclose(devnull);



	ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");

	ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");

}



static void test_uprobe_ref_ctr(struct test_attach_probe *skel)

{

	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);

	struct bpf_link *uprobe_link, *uretprobe_link;

	ssize_t uprobe_offset, ref_ctr_offset;



	uprobe_offset = get_uprobe_offset(&trigger_func4);

	if (!ASSERT_GE(uprobe_offset, 0, "uprobe_offset_ref_ctr"))

		return;



	ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr);

	if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset"))

		return;



	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before");



	uprobe_opts.retprobe = false;

	uprobe_opts.ref_ctr_offset = ref_ctr_offset;

	uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_ref_ctr,

						      0 /* self pid */,

						      "/proc/self/exe",

						      uprobe_offset,

						      &uprobe_opts);

	if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe_ref_ctr"))

		return;

	skel->links.handle_uprobe_ref_ctr = uprobe_link;



	ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after");



	/* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */

	uprobe_opts.retprobe = true;

	uprobe_opts.ref_ctr_offset = ref_ctr_offset;

	uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_ref_ctr,

							 -1 /* any pid */,

							 "/proc/self/exe",

							 uprobe_offset, &uprobe_opts);

	if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe_ref_ctr"))

		return;

	skel->links.handle_uretprobe_ref_ctr = uretprobe_link;

}



static void test_kprobe_sleepable(void)

{

	struct test_attach_kprobe_sleepable *skel;



	skel = test_attach_kprobe_sleepable__open();

	if (!ASSERT_OK_PTR(skel, "skel_kprobe_sleepable_open"))

		return;



	/* sleepable kprobe test case needs flags set before loading */

	if (!ASSERT_OK(bpf_program__set_flags(skel->progs.handle_kprobe_sleepable,

		BPF_F_SLEEPABLE), "kprobe_sleepable_flags"))

		goto cleanup;



	if (!ASSERT_OK(test_attach_kprobe_sleepable__load(skel),

		       "skel_kprobe_sleepable_load"))

		goto cleanup;



	/* sleepable kprobes should not attach successfully */

	skel->links.handle_kprobe_sleepable = bpf_program__attach(skel->progs.handle_kprobe_sleepable);

	if (!ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable"))

		goto cleanup;

	ASSERT_ERR_PTR(skel->links.handle_kprobe_sleepable, "attach_kprobe_sleepable");



cleanup:

	test_attach_kprobe_sleepable__destroy(skel);

}



static void test_uprobe_sleepable(struct test_attach_probe *skel)

{

	/* test sleepable uprobe and uretprobe variants */

	skel->links.handle_uprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uprobe_byname3_sleepable);

	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3_sleepable, "attach_uprobe_byname3_sleepable"))

		goto cleanup;

		return;



	skel->links.handle_uprobe_byname3 = bpf_program__attach(skel->progs.handle_uprobe_byname3);

	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname3, "attach_uprobe_byname3"))

		goto cleanup;

		return;



	skel->links.handle_uretprobe_byname3_sleepable = bpf_program__attach(skel->progs.handle_uretprobe_byname3_sleepable);

	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3_sleepable, "attach_uretprobe_byname3_sleepable"))

		goto cleanup;

		return;



	skel->links.handle_uretprobe_byname3 = bpf_program__attach(skel->progs.handle_uretprobe_byname3);

	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname3, "attach_uretprobe_byname3"))

		goto cleanup;

		return;



	skel->bss->user_ptr = test_data;



	/* trigger & validate kprobe && kretprobe */

	usleep(1);



	/* trigger & validate shared library u[ret]probes attached by name */

	devnull = fopen("/dev/null", "r");

	fclose(devnull);



	/* trigger & validate uprobe & uretprobe */

	trigger_func();



	/* trigger & validate uprobe attached by name */

	trigger_func2();



	/* trigger & validate sleepable uprobe attached by name */

	trigger_func3();



	ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");

	ASSERT_EQ(skel->bss->kprobe2_res, 11, "check_kprobe_auto_res");

	ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");

	ASSERT_EQ(skel->bss->kretprobe2_res, 22, "check_kretprobe_auto_res");

	ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");

	ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");

	ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");

	ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");

	ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");

	ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");

	ASSERT_EQ(skel->bss->uprobe_byname3_sleepable_res, 9, "check_uprobe_byname3_sleepable_res");

	ASSERT_EQ(skel->bss->uprobe_byname3_res, 10, "check_uprobe_byname3_res");

	ASSERT_EQ(skel->bss->uretprobe_byname3_sleepable_res, 11, "check_uretprobe_byname3_sleepable_res");

	ASSERT_EQ(skel->bss->uretprobe_byname3_res, 12, "check_uretprobe_byname3_res");

}



void test_attach_probe(void)

{

	struct test_attach_probe *skel;



	skel = test_attach_probe__open();

	if (!ASSERT_OK_PTR(skel, "skel_open"))

		return;



	if (!ASSERT_OK(test_attach_probe__load(skel), "skel_load"))

		goto cleanup;

	if (!ASSERT_OK_PTR(skel->bss, "check_bss"))

		goto cleanup;



	if (test__start_subtest("manual-default"))

		test_attach_probe_manual(PROBE_ATTACH_MODE_DEFAULT);

	if (test__start_subtest("manual-legacy"))

		test_attach_probe_manual(PROBE_ATTACH_MODE_LEGACY);

	if (test__start_subtest("manual-perf"))

		test_attach_probe_manual(PROBE_ATTACH_MODE_PERF);

	if (test__start_subtest("manual-link"))

		test_attach_probe_manual(PROBE_ATTACH_MODE_LINK);



	if (test__start_subtest("auto"))

		test_attach_probe_auto(skel);

	if (test__start_subtest("kprobe-sleepable"))

		test_kprobe_sleepable();

	if (test__start_subtest("uprobe-lib"))

		test_uprobe_lib(skel);

	if (test__start_subtest("uprobe-sleepable"))

		test_uprobe_sleepable(skel);

	if (test__start_subtest("uprobe-ref_ctr"))

		test_uprobe_ref_ctr(skel);



cleanup:

	test_attach_probe__destroy(skel);

tools/testing/selftests/bpf/progs/test_attach_kprobe_sleepable.c

0 → 100644
+23 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2017 Facebook



#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <bpf/bpf_core_read.h>

#include "bpf_misc.h"



int kprobe_res = 0;



/**

 * This program will be manually made sleepable on the userspace side

 * and should thus be unattachable.

 */

SEC("kprobe/" SYS_PREFIX "sys_nanosleep")

int handle_kprobe_sleepable(struct pt_regs *ctx)

{

	kprobe_res = 1;

	return 0;

}



char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/test_attach_probe.c

+2 −33
Original line number Diff line number Diff line
@@ -7,12 +7,8 @@ 
#include <bpf/bpf_core_read.h>

#include "bpf_misc.h"



int kprobe_res = 0;

int kprobe2_res = 0;

int kretprobe_res = 0;

int kretprobe2_res = 0;

int uprobe_res = 0;

int uretprobe_res = 0;

int uprobe_byname_res = 0;

int uretprobe_byname_res = 0;

int uprobe_byname2_res = 0;
@@ -23,13 +19,6 @@ int uretprobe_byname3_sleepable_res = 0; 
int uretprobe_byname3_res = 0;

void *user_ptr = 0;



SEC("kprobe")

int handle_kprobe(struct pt_regs *ctx)

{

	kprobe_res = 1;

	return 0;

}



SEC("ksyscall/nanosleep")

int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __kernel_timespec *rem)

{
@@ -37,24 +26,6 @@ int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __ker 
	return 0;

}



/**

 * This program will be manually made sleepable on the userspace side

 * and should thus be unattachable.

 */

SEC("kprobe/" SYS_PREFIX "sys_nanosleep")

int handle_kprobe_sleepable(struct pt_regs *ctx)

{

	kprobe_res = 2;

	return 0;

}



SEC("kretprobe")

int handle_kretprobe(struct pt_regs *ctx)

{

	kretprobe_res = 2;

	return 0;

}



SEC("kretsyscall/nanosleep")

int BPF_KRETPROBE(handle_kretprobe_auto, int ret)

{
@@ -63,16 +34,14 @@ int BPF_KRETPROBE(handle_kretprobe_auto, int ret) 
}



SEC("uprobe")

int handle_uprobe(struct pt_regs *ctx)

int handle_uprobe_ref_ctr(struct pt_regs *ctx)

{

	uprobe_res = 3;

	return 0;

}



SEC("uretprobe")

int handle_uretprobe(struct pt_regs *ctx)

int handle_uretprobe_ref_ctr(struct pt_regs *ctx)

{

	uretprobe_res = 4;

	return 0;

}