1 files changed, 249 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe.c b/tools/testing/selftests/bpf/prog_tests/uprobe.c
new file mode 100644
index 000000000000..86404476c1da
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Hengqi Chen */
+
+#include <test_progs.h>
+#include <asm/ptrace.h>
+#include "test_uprobe.skel.h"
+
+static FILE *urand_spawn(int *pid)
+{
+	FILE *f;
+
+	/* urandom_read's stdout is wired into f */
+	f = popen("./urandom_read 1 report-pid", "r");
+	if (!f)
+		return NULL;
+
+	if (fscanf(f, "%d", pid) != 1) {
+		pclose(f);
+		errno = EINVAL;
+		return NULL;
+	}
+
+	return f;
+}
+
+static int urand_trigger(FILE **urand_pipe)
+{
+	int exit_code;
+
+	/* pclose() waits for child process to exit and returns their exit code */
+	exit_code = pclose(*urand_pipe);
+	*urand_pipe = NULL;
+
+	return exit_code;
+}
+
+static void test_uprobe_attach(void)
+{
+	LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
+	struct test_uprobe *skel;
+	FILE *urand_pipe = NULL;
+	int urand_pid = 0, err;
+
+	skel = test_uprobe__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return;
+
+	urand_pipe = urand_spawn(&urand_pid);
+	if (!ASSERT_OK_PTR(urand_pipe, "urand_spawn"))
+		goto cleanup;
+
+	skel->bss->my_pid = urand_pid;
+
+	/* Manual attach uprobe to urandlib_api
+	 * There are two `urandlib_api` symbols in .dynsym section:
+	 *   - urandlib_api@LIBURANDOM_READ_1.0.0
+	 *   - urandlib_api@@LIBURANDOM_READ_2.0.0
+	 * Both are global bind and would cause a conflict if user
+	 * specify the symbol name without a version suffix
+	 */
+	uprobe_opts.func_name = "urandlib_api";
+	skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4,
+							    urand_pid,
+							    "./liburandom_read.so",
+							    0 /* offset */,
+							    &uprobe_opts);
+	if (!ASSERT_ERR_PTR(skel->links.test4, "urandlib_api_attach_conflict"))
+		goto cleanup;
+
+	uprobe_opts.func_name = "urandlib_api@LIBURANDOM_READ_1.0.0";
+	skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4,
+							    urand_pid,
+							    "./liburandom_read.so",
+							    0 /* offset */,
+							    &uprobe_opts);
+	if (!ASSERT_OK_PTR(skel->links.test4, "urandlib_api_attach_ok"))
+		goto cleanup;
+
+	/* Auto attach 3 u[ret]probes to urandlib_api_sameoffset */
+	err = test_uprobe__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto cleanup;
+
+	/* trigger urandom_read */
+	ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code");
+
+	ASSERT_EQ(skel->bss->test1_result, 1, "urandlib_api_sameoffset");
+	ASSERT_EQ(skel->bss->test2_result, 1, "urandlib_api_sameoffset@v1");
+	ASSERT_EQ(skel->bss->test3_result, 3, "urandlib_api_sameoffset@@v2");
+	ASSERT_EQ(skel->bss->test4_result, 1, "urandlib_api");
+
+cleanup:
+	if (urand_pipe)
+		pclose(urand_pipe);
+	test_uprobe__destroy(skel);
+}
+
+#ifdef __x86_64__
+__naked __maybe_unused unsigned long uprobe_regs_change_trigger(void)
+{
+	asm volatile (
+		"ret\n"
+	);
+}
+
+static __naked void uprobe_regs_change(struct pt_regs *before, struct pt_regs *after)
+{
+	asm volatile (
+		"movq %r11,  48(%rdi)\n"
+		"movq %r10,  56(%rdi)\n"
+		"movq  %r9,  64(%rdi)\n"
+		"movq  %r8,  72(%rdi)\n"
+		"movq %rax,  80(%rdi)\n"
+		"movq %rcx,  88(%rdi)\n"
+		"movq %rdx,  96(%rdi)\n"
+		"movq %rsi, 104(%rdi)\n"
+		"movq %rdi, 112(%rdi)\n"
+
+		/* save 2nd argument */
+		"pushq %rsi\n"
+		"call uprobe_regs_change_trigger\n"
+
+		/* save  return value and load 2nd argument pointer to rax */
+		"pushq %rax\n"
+		"movq 8(%rsp), %rax\n"
+
+		"movq %r11,  48(%rax)\n"
+		"movq %r10,  56(%rax)\n"
+		"movq  %r9,  64(%rax)\n"
+		"movq  %r8,  72(%rax)\n"
+		"movq %rcx,  88(%rax)\n"
+		"movq %rdx,  96(%rax)\n"
+		"movq %rsi, 104(%rax)\n"
+		"movq %rdi, 112(%rax)\n"
+
+		/* restore return value and 2nd argument */
+		"pop %rax\n"
+		"pop %rsi\n"
+
+		"movq %rax,  80(%rsi)\n"
+		"ret\n"
+	);
+}
+
+static void regs_common(void)
+{
+	struct pt_regs before = {}, after = {}, expected = {
+		.rax = 0xc0ffe,
+		.rcx = 0xbad,
+		.rdx = 0xdead,
+		.r8  = 0x8,
+		.r9  = 0x9,
+		.r10 = 0x10,
+		.r11 = 0x11,
+		.rdi = 0x12,
+		.rsi = 0x13,
+	};
+	LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
+	struct test_uprobe *skel;
+
+	skel = test_uprobe__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return;
+
+	skel->bss->my_pid = getpid();
+	skel->bss->regs = expected;
+
+	uprobe_opts.func_name = "uprobe_regs_change_trigger";
+	skel->links.test_regs_change = bpf_program__attach_uprobe_opts(skel->progs.test_regs_change,
+							    -1,
+							    "/proc/self/exe",
+							    0 /* offset */,
+							    &uprobe_opts);
+	if (!ASSERT_OK_PTR(skel->links.test_regs_change, "bpf_program__attach_uprobe_opts"))
+		goto cleanup;
+
+	uprobe_regs_change(&before, &after);
+
+	ASSERT_EQ(after.rax, expected.rax, "ax");
+	ASSERT_EQ(after.rcx, expected.rcx, "cx");
+	ASSERT_EQ(after.rdx, expected.rdx, "dx");
+	ASSERT_EQ(after.r8,  expected.r8,  "r8");
+	ASSERT_EQ(after.r9,  expected.r9,  "r9");
+	ASSERT_EQ(after.r10, expected.r10, "r10");
+	ASSERT_EQ(after.r11, expected.r11, "r11");
+	ASSERT_EQ(after.rdi, expected.rdi, "rdi");
+	ASSERT_EQ(after.rsi, expected.rsi, "rsi");
+
+cleanup:
+	test_uprobe__destroy(skel);
+}
+
+static noinline unsigned long uprobe_regs_change_ip_1(void)
+{
+	return 0xc0ffee;
+}
+
+static noinline unsigned long uprobe_regs_change_ip_2(void)
+{
+	return 0xdeadbeef;
+}
+
+static void regs_ip(void)
+{
+	LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
+	struct test_uprobe *skel;
+	unsigned long ret;
+
+	skel = test_uprobe__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return;
+
+	skel->bss->my_pid = getpid();
+	skel->bss->ip = (unsigned long) uprobe_regs_change_ip_2;
+
+	uprobe_opts.func_name = "uprobe_regs_change_ip_1";
+	skel->links.test_regs_change_ip = bpf_program__attach_uprobe_opts(
+						skel->progs.test_regs_change_ip,
+						-1,
+						"/proc/self/exe",
+						0 /* offset */,
+						&uprobe_opts);
+	if (!ASSERT_OK_PTR(skel->links.test_regs_change_ip, "bpf_program__attach_uprobe_opts"))
+		goto cleanup;
+
+	ret = uprobe_regs_change_ip_1();
+	ASSERT_EQ(ret, 0xdeadbeef, "ret");
+
+cleanup:
+	test_uprobe__destroy(skel);
+}
+
+static void test_uprobe_regs_change(void)
+{
+	if (test__start_subtest("regs_change_common"))
+		regs_common();
+	if (test__start_subtest("regs_change_ip"))
+		regs_ip();
+}
+#else
+static void test_uprobe_regs_change(void) { }
+#endif
+
+void test_uprobe(void)
+{
+	if (test__start_subtest("attach"))
+		test_uprobe_attach();
+	test_uprobe_regs_change();
+}