Thread (23 messages) 23 messages, 5 authors, 3h ago

[PATCHv5 07/13] libbpf: Detect uprobe syscall with new error

From: Jiri Olsa <jolsa@kernel.org>
Date: 2026-07-01 11:14:59
Also in: bpf
Subsystem: bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), 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

In the previous optimized uprobe fix we changed the syscall
error used for its detection from ENXIO to EPROTO.

Changing related probe_uprobe_syscall detection check.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Fixes: 05738da0efa1 ("libbpf: Add uprobe syscall feature detection")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/lib/bpf/features.c                                | 4 ++--
 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
index b7e388f99d0b..e5641fa60163 100644
--- a/tools/lib/bpf/features.c
+++ b/tools/lib/bpf/features.c
@@ -577,10 +577,10 @@ static int probe_ldimm64_full_range_off(int token_fd)
 static int probe_uprobe_syscall(int token_fd)
 {
 	/*
-	 * If kernel supports uprobe() syscall, it will return -ENXIO when called
+	 * If kernel supports uprobe() syscall, it will return -EPROTO when called
 	 * from the outside of a kernel-generated uprobe trampoline.
 	 */
-	return syscall(__NR_uprobe) < 0 && errno == ENXIO;
+	return syscall(__NR_uprobe) < 0 && errno == EPROTO;
 }
 #else
 static int probe_uprobe_syscall(int token_fd)
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
index 955a37751b52..c944136252c6 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
@@ -762,7 +762,7 @@ static void test_uprobe_error(void)
 	long err = syscall(__NR_uprobe);
 
 	ASSERT_EQ(err, -1, "error");
-	ASSERT_EQ(errno, ENXIO, "errno");
+	ASSERT_EQ(errno, EPROTO, "errno");
 }
 
 static void __test_uprobe_syscall(void)
-- 
2.54.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help