Linux Trace Kernel
 help / color / mirror / Atom feed
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: [PATCHv2 09/11] selftests/bpf: Add reattach tests for uprobe syscall
Date: Mon, 18 May 2026 12:59:55 +0200	[thread overview]
Message-ID: <20260518105957.123445-10-jolsa@kernel.org> (raw)
In-Reply-To: <20260518105957.123445-1-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 e4a19dc9df69..e88b316a3f2c 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


  parent reply	other threads:[~2026-05-18 11:01 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-18 10:59 [PATCHv2 00/11] uprobes/x86: Fix red zone issue for optimized uprobes Jiri Olsa
2026-05-18 10:59 ` [PATCHv2 01/11] uprobes/x86: Use proper mm_struct in __in_uprobe_trampoline Jiri Olsa
2026-05-18 10:59 ` [PATCHv2 02/11] uprobes/x86: Allow to copy uprobe trampolines on fork Jiri Olsa
2026-05-18 10:59 ` [PATCHv2 03/11] uprobes/x86: Move optimized uprobe from nop5 to nop10 Jiri Olsa
2026-05-18 11:50   ` bot+bpf-ci
2026-05-18 10:59 ` [PATCHv2 04/11] libbpf: Change has_nop_combo to work on top of nop10 Jiri Olsa
2026-05-18 11:37   ` bot+bpf-ci
2026-05-18 10:59 ` [PATCHv2 05/11] libbpf: Detect uprobe syscall with new error Jiri Olsa
2026-05-18 11:37   ` bot+bpf-ci
2026-05-18 17:39   ` Andrii Nakryiko
2026-05-18 10:59 ` [PATCHv2 06/11] selftests/bpf: Emit nop,nop10 instructions combo for x86_64 arch Jiri Olsa
2026-05-18 10:59 ` [PATCHv2 07/11] selftests/bpf: Change uprobe syscall tests to use nop10 Jiri Olsa
2026-05-18 11:50   ` bot+bpf-ci
2026-05-18 10:59 ` [PATCHv2 08/11] selftests/bpf: Change uprobe/usdt trigger bench code " Jiri Olsa
2026-05-18 11:37   ` bot+bpf-ci
2026-05-18 10:59 ` Jiri Olsa [this message]
2026-05-18 10:59 ` [PATCHv2 10/11] selftests/bpf: Add tests for uprobe nop10 red zone clobbering Jiri Olsa
2026-05-18 10:59 ` [PATCHv2 11/11] selftests/bpf: Add tests for forked/cloned optimized uprobes Jiri Olsa

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260518105957.123445-10-jolsa@kernel.org \
    --to=jolsa@kernel.org \
    --cc=andrii@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox