tools/testing/selftests/bpf/prog_tests/attach_probe.c - linux - Git at Google


            
            // SPDX-License-Identifier: GPL-2.0

            
            #include <test_progs.h>

            
            #include "test_attach_probe.skel.h"


            /* this is how USDT semaphore is actually defined, except volatile modifier */

            
            volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes")));


            /* uprobe attach point */

            
            static void trigger_func(void)

            
            {

            
            	asm volatile ("");

            
            }


            /* attach point for byname uprobe */

            
            static void trigger_func2(void)

            
            {

            
            	asm volatile ("");

            
            }


            /* attach point for byname sleepable uprobe */

            
            static void trigger_func3(void)

            
            {

            
            	asm volatile ("");

            
            }


            static char test_data[] = "test_data";


            void test_attach_probe(void)

            
            {

            
            	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_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;

            
            	bool legacy;

            
            	char *mem;


            	/* 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;


            	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"))

            
            		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"))

            
            		goto cleanup;


            	/* manual-attach kprobe/kretprobe */

            
            	kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,

            
            						 false /* retprobe */,

            
            						 SYS_NANOSLEEP_KPROBE_NAME);

            
            	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);

            
            	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");


            	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",

            
            						      uprobe_offset,

            
            						      &uprobe_opts);

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

            
            		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",

            
            							 uprobe_offset, &uprobe_opts);

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

            
            		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;


            	uprobe_opts.func_name = "trigger_func2";

            
            	uprobe_opts.retprobe = false;

            
            	uprobe_opts.ref_ctr_offset = 0;

            
            	skel->links.handle_uprobe_byname =

            
            			bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,

            
            							0 /* this pid */,

            
            							"/proc/self/exe",

            
            							0, &uprobe_opts);

            
            	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))

            
            		goto cleanup;


            	/* 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;


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

            
            	 * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().

            
            	 */

            
            	uprobe_opts.func_name = "malloc";

            
            	uprobe_opts.retprobe = false;

            
            	skel->links.handle_uprobe_byname2 =

            
            			bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,

            
            							0 /* this pid */,

            
            							"libc.so.6",

            
            							0, &uprobe_opts);

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

            
            		goto cleanup;


            	uprobe_opts.func_name = "free";

            
            	uprobe_opts.retprobe = true;

            
            	skel->links.handle_uretprobe_byname2 =

            
            			bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,

            
            							-1 /* any pid */,

            
            							"libc.so.6",

            
            							0, &uprobe_opts);

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

            
            		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;


            	/* 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;


            	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;


            	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;


            	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;


            	skel->bss->user_ptr = test_data;


            	/* trigger & validate kprobe && kretprobe */

            
            	usleep(1);


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

            
            	mem = malloc(1);

            
            	free(mem);


            	/* 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");


            cleanup:

            
            	test_attach_probe__destroy(skel);

            
            	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");

            
            }
	// SPDX-License-Identifier: GPL-2.0
	#include <test_progs.h>
	#include "test_attach_probe.skel.h"

	/* this is how USDT semaphore is actually defined, except volatile modifier */
	volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes")));

	/* uprobe attach point */
	static void trigger_func(void)
	{
	asm volatile ("");
	}

	/* attach point for byname uprobe */
	static void trigger_func2(void)
	{
	asm volatile ("");
	}

	/* attach point for byname sleepable uprobe */
	static void trigger_func3(void)
	{
	asm volatile ("");
	}

	static char test_data[] = "test_data";

	void test_attach_probe(void)
	{
	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_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;
	bool legacy;
	char *mem;

	/* 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;

	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"))
	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"))
	goto cleanup;

	/* manual-attach kprobe/kretprobe */
	kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,
	false /* retprobe */,
	SYS_NANOSLEEP_KPROBE_NAME);
	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);
	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");

	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",
	uprobe_offset,
	&uprobe_opts);
	if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe"))
	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",
	uprobe_offset, &uprobe_opts);
	if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe"))
	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;

	uprobe_opts.func_name = "trigger_func2";
	uprobe_opts.retprobe = false;
	uprobe_opts.ref_ctr_offset = 0;
	skel->links.handle_uprobe_byname =
	bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
	0 /* this pid */,
	"/proc/self/exe",
	0, &uprobe_opts);
	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
	goto cleanup;

	/* 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;

	/* test attach by name for a library function, using the library
	* as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
	*/
	uprobe_opts.func_name = "malloc";
	uprobe_opts.retprobe = false;
	skel->links.handle_uprobe_byname2 =
	bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
	0 /* this pid */,
	"libc.so.6",
	0, &uprobe_opts);
	if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
	goto cleanup;

	uprobe_opts.func_name = "free";
	uprobe_opts.retprobe = true;
	skel->links.handle_uretprobe_byname2 =
	bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
	-1 /* any pid */,
	"libc.so.6",
	0, &uprobe_opts);
	if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
	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;

	/* 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;

	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;

	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;

	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;

	skel->bss->user_ptr = test_data;

	/* trigger & validate kprobe && kretprobe */
	usleep(1);

	/* trigger & validate shared library u[ret]probes attached by name */
	mem = malloc(1);
	free(mem);

	/* 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");

	cleanup:
	test_attach_probe__destroy(skel);
	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
	}