[PATCHv4 bpf-next 4/6] selftests/bpf: Add uprobe context ip register change test
From: Jiri Olsa <jolsa@kernel.org>
Date: 2025-09-16 21:53:58
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
Adding test to check we can change the application execution through instruction pointer change through uprobe program. It's x86_64 specific test. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- .../testing/selftests/bpf/prog_tests/uprobe.c | 42 +++++++++++++++++++ .../testing/selftests/bpf/progs/test_uprobe.c | 14 +++++++ 2 files changed, 56 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe.c b/tools/testing/selftests/bpf/prog_tests/uprobe.c
index 19dd900df188..86404476c1da 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe.c@@ -190,10 +190,52 @@ static void regs_common(void) 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) { }
diff --git a/tools/testing/selftests/bpf/progs/test_uprobe.c b/tools/testing/selftests/bpf/progs/test_uprobe.c
index 9437bd76a437..12f4065fca20 100644
--- a/tools/testing/selftests/bpf/progs/test_uprobe.c
+++ b/tools/testing/selftests/bpf/progs/test_uprobe.c@@ -82,4 +82,18 @@ int BPF_UPROBE(test_regs_change) ctx->si = regs.si; return 0; } + +unsigned long ip; + +SEC("uprobe") +int BPF_UPROBE(test_regs_change_ip) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != my_pid) + return 0; + + ctx->ip = ip; + return 0; +} #endif
--
2.51.0