From: Jiri Olsa <jolsa@kernel.org>
To: Oleg Nesterov <oleg@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: [PATCH 6/7] selftests/bpf: Add reattach tests for uprobe syscall
Date: Thu, 14 May 2026 15:53:41 +0200 [thread overview]
Message-ID: <20260514135342.22130-7-jolsa@kernel.org> (raw)
In-Reply-To: <20260514135342.22130-1-jolsa@kernel.org>
Adding reattach tests for uprobe syscall tests to make sure
we can re-attach and optimize same uprobe multiple times.
The reason is that optimized uprobe does not restore original
nop10 after detach, but instead it uses 'jmp 8' instruction.
Making sure we can still install and optimize uprobe on top
of the 'jmp 8' instruction.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/uprobe_syscall.c | 115 ++++++++++++++++--
1 file changed, 105 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
index c2e9e549c737..82b3c0ce9253 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
@@ -431,21 +431,27 @@ static void *check_attach(struct uprobe_syscall_executed *skel, trigger_t trigge
return tramp;
}
-static void check_detach(void *addr, void *tramp)
+static bool check_detach(void *addr, void *tramp)
{
+ bool ok = true;
+
/* [uprobes_trampoline] stays after detach */
- ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline");
- ASSERT_OK(memcmp(addr, jmp2B, 2), "jmp2B");
+ if (!ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline"))
+ ok = false;
+ if (!ASSERT_OK(memcmp(addr, jmp2B, 2), "jmp2B"))
+ ok = false;
+ return ok;
}
-static void check(struct uprobe_syscall_executed *skel, struct bpf_link *link,
- trigger_t trigger, void *addr, int executed)
+static void *check(struct uprobe_syscall_executed *skel, struct bpf_link *link,
+ trigger_t trigger, void *addr, int executed)
{
void *tramp;
tramp = check_attach(skel, trigger, addr, executed);
bpf_link__destroy(link);
check_detach(addr, tramp);
+ return tramp;
}
static void test_uprobe_legacy(void)
@@ -456,6 +462,7 @@ static void test_uprobe_legacy(void)
);
struct bpf_link *link;
unsigned long offset;
+ void *tramp;
offset = get_uprobe_offset(&uprobe_test);
if (!ASSERT_GE(offset, 0, "get_uprobe_offset"))
@@ -473,7 +480,28 @@ static void test_uprobe_legacy(void)
if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
goto cleanup;
- check(skel, link, uprobe_test, uprobe_test, 2);
+ tramp = check(skel, link, uprobe_test, uprobe_test, 2);
+
+ /* reattach and detach without triggering optimization */
+ link = bpf_program__attach_uprobe_opts(skel->progs.test_uprobe,
+ 0, "/proc/self/exe", offset, NULL);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
+ goto cleanup;
+
+ bpf_link__destroy(link);
+ if (!check_detach(uprobe_test, tramp))
+ goto cleanup;
+
+ uprobe_test();
+ ASSERT_EQ(skel->bss->executed, 2, "executed_no_probe");
+
+ /* reattach with triggering optimization */
+ link = bpf_program__attach_uprobe_opts(skel->progs.test_uprobe,
+ 0, "/proc/self/exe", offset, NULL);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
+ goto cleanup;
+
+ check(skel, link, uprobe_test, uprobe_test, 4);
/* uretprobe */
skel->bss->executed = 0;
@@ -495,6 +523,7 @@ static void test_uprobe_multi(void)
LIBBPF_OPTS(bpf_uprobe_multi_opts, opts);
struct bpf_link *link;
unsigned long offset;
+ void *tramp;
offset = get_uprobe_offset(&uprobe_test);
if (!ASSERT_GE(offset, 0, "get_uprobe_offset"))
@@ -515,7 +544,28 @@ static void test_uprobe_multi(void)
if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
goto cleanup;
- check(skel, link, uprobe_test, uprobe_test, 2);
+ tramp = check(skel, link, uprobe_test, uprobe_test, 2);
+
+ /* reattach and detach without triggering optimization */
+ link = bpf_program__attach_uprobe_multi(skel->progs.test_uprobe_multi,
+ 0, "/proc/self/exe", NULL, &opts);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
+ goto cleanup;
+
+ bpf_link__destroy(link);
+ if (!check_detach(uprobe_test, tramp))
+ goto cleanup;
+
+ uprobe_test();
+ ASSERT_EQ(skel->bss->executed, 2, "executed_no_probe");
+
+ /* reattach with triggering optimization */
+ link = bpf_program__attach_uprobe_multi(skel->progs.test_uprobe_multi,
+ 0, "/proc/self/exe", NULL, &opts);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
+ goto cleanup;
+
+ check(skel, link, uprobe_test, uprobe_test, 4);
/* uretprobe.multi */
skel->bss->executed = 0;
@@ -539,6 +589,7 @@ static void test_uprobe_session(void)
);
struct bpf_link *link;
unsigned long offset;
+ void *tramp;
offset = get_uprobe_offset(&uprobe_test);
if (!ASSERT_GE(offset, 0, "get_uprobe_offset"))
@@ -558,7 +609,28 @@ static void test_uprobe_session(void)
if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
goto cleanup;
- check(skel, link, uprobe_test, uprobe_test, 4);
+ tramp = check(skel, link, uprobe_test, uprobe_test, 4);
+
+ /* reattach and detach without triggering optimization */
+ link = bpf_program__attach_uprobe_multi(skel->progs.test_uprobe_session,
+ 0, "/proc/self/exe", NULL, &opts);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
+ goto cleanup;
+
+ bpf_link__destroy(link);
+ if (!check_detach(uprobe_test, tramp))
+ goto cleanup;
+
+ uprobe_test();
+ ASSERT_EQ(skel->bss->executed, 4, "executed_no_probe");
+
+ /* reattach with triggering optimization */
+ link = bpf_program__attach_uprobe_multi(skel->progs.test_uprobe_session,
+ 0, "/proc/self/exe", NULL, &opts);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi"))
+ goto cleanup;
+
+ check(skel, link, uprobe_test, uprobe_test, 8);
cleanup:
uprobe_syscall_executed__destroy(skel);
@@ -568,7 +640,7 @@ static void test_uprobe_usdt(void)
{
struct uprobe_syscall_executed *skel;
struct bpf_link *link;
- void *addr;
+ void *addr, *tramp;
errno = 0;
addr = find_nop10(usdt_test);
@@ -587,7 +659,30 @@ static void test_uprobe_usdt(void)
if (!ASSERT_OK_PTR(link, "bpf_program__attach_usdt"))
goto cleanup;
- check(skel, link, usdt_test, addr, 2);
+ tramp = check(skel, link, usdt_test, addr, 2);
+
+ /* reattach and detach without triggering optimization */
+ link = bpf_program__attach_usdt(skel->progs.test_usdt,
+ -1 /* all PIDs */, "/proc/self/exe",
+ "optimized_uprobe", "usdt", NULL);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_usdt"))
+ goto cleanup;
+
+ bpf_link__destroy(link);
+ if (!check_detach(addr, tramp))
+ goto cleanup;
+
+ usdt_test();
+ ASSERT_EQ(skel->bss->executed, 2, "executed_no_probe");
+
+ /* reattach with triggering optimization */
+ link = bpf_program__attach_usdt(skel->progs.test_usdt,
+ -1 /* all PIDs */, "/proc/self/exe",
+ "optimized_uprobe", "usdt", NULL);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach_usdt"))
+ goto cleanup;
+
+ check(skel, link, usdt_test, addr, 4);
cleanup:
uprobe_syscall_executed__destroy(skel);
--
2.53.0
next prev parent reply other threads:[~2026-05-14 13:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-14 13:53 [PATCH 0/7] uprobes/x86: Fix red zone issue for optimized uprobes Jiri Olsa
2026-05-14 13:53 ` [PATCH 1/7] uprobes/x86: Move optimized uprobe from nop5 to nop10 Jiri Olsa
2026-05-14 16:54 ` Jakub Sitnicki
2026-05-14 13:53 ` [PATCH 2/7] libbpf: Change has_nop_combo to work on top of nop10 Jiri Olsa
2026-05-14 14:55 ` bot+bpf-ci
2026-05-14 13:53 ` [PATCH 3/7] selftests/bpf: Emit nop,nop10 instructions combo for x86_64 arch Jiri Olsa
2026-05-14 13:53 ` [PATCH 4/7] selftests/bpf: Change uprobe syscall tests to use nop10 Jiri Olsa
2026-05-14 13:53 ` [PATCH 5/7] selftests/bpf: Change uprobe/usdt trigger bench code " Jiri Olsa
2026-05-14 13:53 ` Jiri Olsa [this message]
2026-05-14 13:53 ` [PATCH 7/7] selftests/bpf: Add tests for uprobe nop10 red zone clobbering Jiri Olsa
2026-05-14 14:55 ` bot+bpf-ci
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