1 files changed, 469 insertions, 60 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index bf6ca8e3eb13..844f6fc8487b 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -6,6 +6,8 @@
 #include "uprobe_multi.skel.h"
 #include "uprobe_multi_bench.skel.h"
 #include "uprobe_multi_usdt.skel.h"
+#include "uprobe_multi_consumers.skel.h"
+#include "uprobe_multi_pid_filter.skel.h"
 #include "bpf/libbpf_internal.h"
 #include "testing_helpers.h"
 #include "../sdt.h"
@@ -38,6 +40,7 @@ struct child {
 	int pid;
 	int tid;
 	pthread_t thread;
+	char stack[65536];
 };
 
 static void release_child(struct child *child)
@@ -67,41 +70,54 @@ static void kick_child(struct child *child)
 	fflush(NULL);
 }
 
-static struct child *spawn_child(void)
+static int child_func(void *arg)
 {
-	static struct child child;
-	int err;
-	int c;
-
-	/* pipe to notify child to execute the trigger functions */
-	if (pipe(child.go))
-		return NULL;
+	struct child *child = arg;
+	int err, c;
 
-	child.pid = child.tid = fork();
-	if (child.pid < 0) {
-		release_child(&child);
-		errno = EINVAL;
-		return NULL;
-	}
+	close(child->go[1]);
 
-	/* child */
-	if (child.pid == 0) {
-		close(child.go[1]);
+	/* wait for parent's kick */
+	err = read(child->go[0], &c, 1);
+	if (err != 1)
+		exit(err);
 
-		/* wait for parent's kick */
-		err = read(child.go[0], &c, 1);
-		if (err != 1)
-			exit(err);
+	uprobe_multi_func_1();
+	uprobe_multi_func_2();
+	uprobe_multi_func_3();
+	usdt_trigger();
 
-		uprobe_multi_func_1();
-		uprobe_multi_func_2();
-		uprobe_multi_func_3();
-		usdt_trigger();
+	exit(errno);
+}
 
-		exit(errno);
+static int spawn_child_flag(struct child *child, bool clone_vm)
+{
+	/* pipe to notify child to execute the trigger functions */
+	if (pipe(child->go))
+		return -1;
+
+	if (clone_vm) {
+		child->pid = child->tid = clone(child_func, child->stack + sizeof(child->stack)/2,
+						CLONE_VM|SIGCHLD, child);
+	} else {
+		child->pid = child->tid = fork();
+	}
+	if (child->pid < 0) {
+		release_child(child);
+		errno = EINVAL;
+		return -1;
 	}
 
-	return &child;
+	/* fork-ed child */
+	if (!clone_vm && child->pid == 0)
+		child_func(child);
+
+	return 0;
+}
+
+static int spawn_child(struct child *child)
+{
+	return spawn_child_flag(child, false);
 }
 
 static void *child_thread(void *ctx)
@@ -130,39 +146,38 @@ static void *child_thread(void *ctx)
 	pthread_exit(&err);
 }
 
-static struct child *spawn_thread(void)
+static int spawn_thread(struct child *child)
 {
-	static struct child child;
 	int c, err;
 
 	/* pipe to notify child to execute the trigger functions */
-	if (pipe(child.go))
-		return NULL;
+	if (pipe(child->go))
+		return -1;
 	/* pipe to notify parent that child thread is ready */
-	if (pipe(child.c2p)) {
-		close(child.go[0]);
-		close(child.go[1]);
-		return NULL;
+	if (pipe(child->c2p)) {
+		close(child->go[0]);
+		close(child->go[1]);
+		return -1;
 	}
 
-	child.pid = getpid();
+	child->pid = getpid();
 
-	err = pthread_create(&child.thread, NULL, child_thread, &child);
+	err = pthread_create(&child->thread, NULL, child_thread, child);
 	if (err) {
 		err = -errno;
-		close(child.go[0]);
-		close(child.go[1]);
-		close(child.c2p[0]);
-		close(child.c2p[1]);
+		close(child->go[0]);
+		close(child->go[1]);
+		close(child->c2p[0]);
+		close(child->c2p[1]);
 		errno = -err;
-		return NULL;
+		return -1;
 	}
 
-	err = read(child.c2p[0], &c, 1);
+	err = read(child->c2p[0], &c, 1);
 	if (!ASSERT_EQ(err, 1, "child_thread_ready"))
-		return NULL;
+		return -1;
 
-	return &child;
+	return 0;
 }
 
 static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child)
@@ -198,7 +213,7 @@ static void uprobe_multi_test_run(struct uprobe_multi *skel, struct child *child
 
 	/*
 	 * There are 2 entry and 2 exit probe called for each uprobe_multi_func_[123]
-	 * function and each slepable probe (6) increments uprobe_multi_sleep_result.
+	 * function and each sleepable probe (6) increments uprobe_multi_sleep_result.
 	 */
 	ASSERT_EQ(skel->bss->uprobe_multi_func_1_result, 2, "uprobe_multi_func_1_result");
 	ASSERT_EQ(skel->bss->uprobe_multi_func_2_result, 2, "uprobe_multi_func_2_result");
@@ -303,24 +318,22 @@ cleanup:
 static void
 test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_multi_opts *opts)
 {
-	struct child *child;
+	static struct child child;
 
 	/* no pid filter */
 	__test_attach_api(binary, pattern, opts, NULL);
 
 	/* pid filter */
-	child = spawn_child();
-	if (!ASSERT_OK_PTR(child, "spawn_child"))
+	if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
 		return;
 
-	__test_attach_api(binary, pattern, opts, child);
+	__test_attach_api(binary, pattern, opts, &child);
 
 	/* pid filter (thread) */
-	child = spawn_thread();
-	if (!ASSERT_OK_PTR(child, "spawn_thread"))
+	if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
 		return;
 
-	__test_attach_api(binary, pattern, opts, child);
+	__test_attach_api(binary, pattern, opts, &child);
 }
 
 static void test_attach_api_pattern(void)
@@ -516,6 +529,122 @@ cleanup:
 	uprobe_multi__destroy(skel);
 }
 
+#ifdef __x86_64__
+noinline void uprobe_multi_error_func(void)
+{
+	/*
+	 * If --fcf-protection=branch is enabled the gcc generates endbr as
+	 * first instruction, so marking the exact address of int3 with the
+	 * symbol to be used in the attach_uprobe_fail_trap test below.
+	 */
+	asm volatile (
+		".globl uprobe_multi_error_func_int3;	\n"
+		"uprobe_multi_error_func_int3:		\n"
+		"int3					\n"
+	);
+}
+
+/*
+ * Attaching uprobe on uprobe_multi_error_func results in error
+ * because it already starts with int3 instruction.
+ */
+static void attach_uprobe_fail_trap(struct uprobe_multi *skel)
+{
+	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
+	const char *syms[4] = {
+		"uprobe_multi_func_1",
+		"uprobe_multi_func_2",
+		"uprobe_multi_func_3",
+		"uprobe_multi_error_func_int3",
+	};
+
+	opts.syms = syms;
+	opts.cnt = ARRAY_SIZE(syms);
+
+	skel->links.uprobe = bpf_program__attach_uprobe_multi(skel->progs.uprobe, -1,
+							      "/proc/self/exe", NULL, &opts);
+	if (!ASSERT_ERR_PTR(skel->links.uprobe, "bpf_program__attach_uprobe_multi")) {
+		bpf_link__destroy(skel->links.uprobe);
+		skel->links.uprobe = NULL;
+	}
+}
+#else
+static void attach_uprobe_fail_trap(struct uprobe_multi *skel) { }
+#endif
+
+short sema_1 __used, sema_2 __used;
+
+static void attach_uprobe_fail_refctr(struct uprobe_multi *skel)
+{
+	unsigned long *tmp_offsets = NULL, *tmp_ref_ctr_offsets = NULL;
+	unsigned long offsets[3], ref_ctr_offsets[3];
+	LIBBPF_OPTS(bpf_link_create_opts, opts);
+	const char *path = "/proc/self/exe";
+	const char *syms[3] = {
+		"uprobe_multi_func_1",
+		"uprobe_multi_func_2",
+	};
+	const char *sema[3] = {
+		"sema_1",
+		"sema_2",
+	};
+	int prog_fd, link_fd, err;
+
+	prog_fd = bpf_program__fd(skel->progs.uprobe_extra);
+
+	err = elf_resolve_syms_offsets("/proc/self/exe", 2, (const char **) &syms,
+				       &tmp_offsets, STT_FUNC);
+	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_func"))
+		return;
+
+	err = elf_resolve_syms_offsets("/proc/self/exe", 2, (const char **) &sema,
+				       &tmp_ref_ctr_offsets, STT_OBJECT);
+	if (!ASSERT_OK(err, "elf_resolve_syms_offsets_sema"))
+		goto cleanup;
+
+	/*
+	 * We attach to 3 uprobes on 2 functions, so 2 uprobes share single function,
+	 * but with different ref_ctr_offset which is not allowed and results in fail.
+	 */
+	offsets[0] = tmp_offsets[0]; /* uprobe_multi_func_1 */
+	offsets[1] = tmp_offsets[1]; /* uprobe_multi_func_2 */
+	offsets[2] = tmp_offsets[1]; /* uprobe_multi_func_2 */
+
+	ref_ctr_offsets[0] = tmp_ref_ctr_offsets[0]; /* sema_1 */
+	ref_ctr_offsets[1] = tmp_ref_ctr_offsets[1]; /* sema_2 */
+	ref_ctr_offsets[2] = tmp_ref_ctr_offsets[0]; /* sema_1, error */
+
+	opts.uprobe_multi.path = path;
+	opts.uprobe_multi.offsets = (const unsigned long *) &offsets;
+	opts.uprobe_multi.ref_ctr_offsets = (const unsigned long *) &ref_ctr_offsets;
+	opts.uprobe_multi.cnt = 3;
+
+	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
+	if (!ASSERT_ERR(link_fd, "link_fd"))
+		close(link_fd);
+
+cleanup:
+	free(tmp_ref_ctr_offsets);
+	free(tmp_offsets);
+}
+
+static void test_attach_uprobe_fails(void)
+{
+	struct uprobe_multi *skel = NULL;
+
+	skel = uprobe_multi__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "uprobe_multi__open_and_load"))
+		return;
+
+	/* attach fails due to adding uprobe on trap instruction, x86_64 only */
+	attach_uprobe_fail_trap(skel);
+
+	/* attach fail due to wrong ref_ctr_offs on one of the uprobes */
+	attach_uprobe_fail_refctr(skel);
+
+	uprobe_multi__destroy(skel);
+}
+
 static void __test_link_api(struct child *child)
 {
 	int prog_fd, link1_fd = -1, link2_fd = -1, link3_fd = -1, link4_fd = -1;
@@ -595,24 +724,296 @@ cleanup:
 
 static void test_link_api(void)
 {
-	struct child *child;
+	static struct child child;
 
 	/* no pid filter */
 	__test_link_api(NULL);
 
 	/* pid filter */
-	child = spawn_child();
-	if (!ASSERT_OK_PTR(child, "spawn_child"))
+	if (!ASSERT_OK(spawn_child(&child), "spawn_child"))
 		return;
 
-	__test_link_api(child);
+	__test_link_api(&child);
 
 	/* pid filter (thread) */
-	child = spawn_thread();
-	if (!ASSERT_OK_PTR(child, "spawn_thread"))
+	if (!ASSERT_OK(spawn_thread(&child), "spawn_thread"))
+		return;
+
+	__test_link_api(&child);
+}
+
+static struct bpf_program *
+get_program(struct uprobe_multi_consumers *skel, int prog)
+{
+	switch (prog) {
+	case 0:
+		return skel->progs.uprobe_0;
+	case 1:
+		return skel->progs.uprobe_1;
+	case 2:
+		return skel->progs.uprobe_2;
+	case 3:
+		return skel->progs.uprobe_3;
+	default:
+		ASSERT_FAIL("get_program");
+		return NULL;
+	}
+}
+
+static struct bpf_link **
+get_link(struct uprobe_multi_consumers *skel, int link)
+{
+	switch (link) {
+	case 0:
+		return &skel->links.uprobe_0;
+	case 1:
+		return &skel->links.uprobe_1;
+	case 2:
+		return &skel->links.uprobe_2;
+	case 3:
+		return &skel->links.uprobe_3;
+	default:
+		ASSERT_FAIL("get_link");
+		return NULL;
+	}
+}
+
+static int uprobe_attach(struct uprobe_multi_consumers *skel, int idx)
+{
+	struct bpf_program *prog = get_program(skel, idx);
+	struct bpf_link **link = get_link(skel, idx);
+	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
+
+	if (!prog || !link)
+		return -1;
+
+	/*
+	 * bit/prog: 0,1 uprobe entry
+	 * bit/prog: 2,3 uprobe return
+	 */
+	opts.retprobe = idx == 2 || idx == 3;
+
+	*link = bpf_program__attach_uprobe_multi(prog, 0, "/proc/self/exe",
+						"uprobe_consumer_test",
+						&opts);
+	if (!ASSERT_OK_PTR(*link, "bpf_program__attach_uprobe_multi"))
+		return -1;
+	return 0;
+}
+
+static void uprobe_detach(struct uprobe_multi_consumers *skel, int idx)
+{
+	struct bpf_link **link = get_link(skel, idx);
+
+	bpf_link__destroy(*link);
+	*link = NULL;
+}
+
+static bool test_bit(int bit, unsigned long val)
+{
+	return val & (1 << bit);
+}
+
+noinline int
+uprobe_consumer_test(struct uprobe_multi_consumers *skel,
+		     unsigned long before, unsigned long after)
+{
+	int idx;
+
+	/* detach uprobe for each unset programs in 'before' state ... */
+	for (idx = 0; idx < 4; idx++) {
+		if (test_bit(idx, before) && !test_bit(idx, after))
+			uprobe_detach(skel, idx);
+	}
+
+	/* ... and attach all new programs in 'after' state */
+	for (idx = 0; idx < 4; idx++) {
+		if (!test_bit(idx, before) && test_bit(idx, after)) {
+			if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_after"))
+				return -1;
+		}
+	}
+	return 0;
+}
+
+static void consumer_test(struct uprobe_multi_consumers *skel,
+			  unsigned long before, unsigned long after)
+{
+	int err, idx;
+
+	printf("consumer_test before %lu after %lu\n", before, after);
+
+	/* 'before' is each, we attach uprobe for every set idx */
+	for (idx = 0; idx < 4; idx++) {
+		if (test_bit(idx, before)) {
+			if (!ASSERT_OK(uprobe_attach(skel, idx), "uprobe_attach_before"))
+				goto cleanup;
+		}
+	}
+
+	err = uprobe_consumer_test(skel, before, after);
+	if (!ASSERT_EQ(err, 0, "uprobe_consumer_test"))
+		goto cleanup;
+
+	for (idx = 0; idx < 4; idx++) {
+		const char *fmt = "BUG";
+		__u64 val = 0;
+
+		if (idx < 2) {
+			/*
+			 * uprobe entry
+			 *   +1 if define in 'before'
+			 */
+			if (test_bit(idx, before))
+				val++;
+			fmt = "prog 0/1: uprobe";
+		} else {
+			/*
+			 * uprobe return is tricky ;-)
+			 *
+			 * to trigger uretprobe consumer, the uretprobe needs to be installed,
+			 * which means one of the 'return' uprobes was alive when probe was hit:
+			 *
+			 *   idxs: 2/3 uprobe return in 'installed' mask
+			 *
+			 * in addition if 'after' state removes everything that was installed in
+			 * 'before' state, then uprobe kernel object goes away and return uprobe
+			 * is not installed and we won't hit it even if it's in 'after' state.
+			 */
+			unsigned long had_uretprobes  = before & 0b1100; /* is uretprobe installed */
+			unsigned long probe_preserved = before & after;  /* did uprobe go away */
+
+			if (had_uretprobes && probe_preserved && test_bit(idx, after))
+				val++;
+			fmt = "idx 2/3: uretprobe";
+		}
+
+		ASSERT_EQ(skel->bss->uprobe_result[idx], val, fmt);
+		skel->bss->uprobe_result[idx] = 0;
+	}
+
+cleanup:
+	for (idx = 0; idx < 4; idx++)
+		uprobe_detach(skel, idx);
+}
+
+static void test_consumers(void)
+{
+	struct uprobe_multi_consumers *skel;
+	int before, after;
+
+	skel = uprobe_multi_consumers__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "uprobe_multi_consumers__open_and_load"))
+		return;
+
+	/*
+	 * The idea of this test is to try all possible combinations of
+	 * uprobes consumers attached on single function.
+	 *
+	 *  - 2 uprobe entry consumer
+	 *  - 2 uprobe exit consumers
+	 *
+	 * The test uses 4 uprobes attached on single function, but that
+	 * translates into single uprobe with 4 consumers in kernel.
+	 *
+	 * The before/after values present the state of attached consumers
+	 * before and after the probed function:
+	 *
+	 *  bit/prog 0,1 : uprobe entry
+	 *  bit/prog 2,3 : uprobe return
+	 *
+	 * For example for:
+	 *
+	 *   before = 0b0101
+	 *   after  = 0b0110
+	 *
+	 * it means that before we call 'uprobe_consumer_test' we attach
+	 * uprobes defined in 'before' value:
+	 *
+	 *   - bit/prog 0: uprobe entry
+	 *   - bit/prog 2: uprobe return
+	 *
+	 * uprobe_consumer_test is called and inside it we attach and detach
+	 * uprobes based on 'after' value:
+	 *
+	 *   - bit/prog 0: stays untouched
+	 *   - bit/prog 2: uprobe return is detached
+	 *
+	 * uprobe_consumer_test returns and we check counters values increased
+	 * by bpf programs on each uprobe to match the expected count based on
+	 * before/after bits.
+	 */
+
+	for (before = 0; before < 16; before++) {
+		for (after = 0; after < 16; after++)
+			consumer_test(skel, before, after);
+	}
+
+	uprobe_multi_consumers__destroy(skel);
+}
+
+static struct bpf_program *uprobe_multi_program(struct uprobe_multi_pid_filter *skel, int idx)
+{
+	switch (idx) {
+	case 0: return skel->progs.uprobe_multi_0;
+	case 1: return skel->progs.uprobe_multi_1;
+	case 2: return skel->progs.uprobe_multi_2;
+	}
+	return NULL;
+}
+
+#define TASKS 3
+
+static void run_pid_filter(struct uprobe_multi_pid_filter *skel, bool clone_vm, bool retprobe)
+{
+	LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .retprobe = retprobe);
+	struct bpf_link *link[TASKS] = {};
+	struct child child[TASKS] = {};
+	int i;
+
+	memset(skel->bss->test, 0, sizeof(skel->bss->test));
+
+	for (i = 0; i < TASKS; i++) {
+		if (!ASSERT_OK(spawn_child_flag(&child[i], clone_vm), "spawn_child"))
+			goto cleanup;
+		skel->bss->pids[i] = child[i].pid;
+	}
+
+	for (i = 0; i < TASKS; i++) {
+		link[i] = bpf_program__attach_uprobe_multi(uprobe_multi_program(skel, i),
+							   child[i].pid, "/proc/self/exe",
+							   "uprobe_multi_func_1", &opts);
+		if (!ASSERT_OK_PTR(link[i], "bpf_program__attach_uprobe_multi"))
+			goto cleanup;
+	}
+
+	for (i = 0; i < TASKS; i++)
+		kick_child(&child[i]);
+
+	for (i = 0; i < TASKS; i++) {
+		ASSERT_EQ(skel->bss->test[i][0], 1, "pid");
+		ASSERT_EQ(skel->bss->test[i][1], 0, "unknown");
+	}
+
+cleanup:
+	for (i = 0; i < TASKS; i++)
+		bpf_link__destroy(link[i]);
+	for (i = 0; i < TASKS; i++)
+		release_child(&child[i]);
+}
+
+static void test_pid_filter_process(bool clone_vm)
+{
+	struct uprobe_multi_pid_filter *skel;
+
+	skel = uprobe_multi_pid_filter__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "uprobe_multi_pid_filter__open_and_load"))
 		return;
 
-	__test_link_api(child);
+	run_pid_filter(skel, clone_vm, false);
+	run_pid_filter(skel, clone_vm, true);
+
+	uprobe_multi_pid_filter__destroy(skel);
 }
 
 static void test_bench_attach_uprobe(void)
@@ -703,4 +1104,12 @@ void test_uprobe_multi_test(void)
 		test_bench_attach_usdt();
 	if (test__start_subtest("attach_api_fails"))
 		test_attach_api_fails();
+	if (test__start_subtest("attach_uprobe_fails"))
+		test_attach_uprobe_fails();
+	if (test__start_subtest("consumers"))
+		test_consumers();
+	if (test__start_subtest("filter_fork"))
+		test_pid_filter_process(false);
+	if (test__start_subtest("filter_clone_vm"))
+		test_pid_filter_process(true);
 }