[PATCH 16/22] selftests/coredump: handle edge-triggered epoll correctly

From: Christian Brauner

Date: Tue Oct 28 2025 - 04:47:12 EST


by putting the file descriptor into non-blocking mode.

Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
tools/testing/selftests/coredump/coredump_test_helpers.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c b/tools/testing/selftests/coredump/coredump_test_helpers.c
index 7512a8ef73d3..116c797090a1 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.c
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.c
@@ -291,6 +291,14 @@ void process_coredump_worker(int fd_coredump, int fd_peer_pidfd, int fd_core_fil
int epfd = -1;
int exit_code = EXIT_FAILURE;
struct epoll_event ev;
+ int flags;
+
+ /* Set socket to non-blocking mode for edge-triggered epoll */
+ flags = fcntl(fd_coredump, F_GETFL, 0);
+ if (flags < 0)
+ goto out;
+ if (fcntl(fd_coredump, F_SETFL, flags | O_NONBLOCK) < 0)
+ goto out;

epfd = epoll_create1(0);
if (epfd < 0)

--
2.47.3