[PATCH 1/9] KVM: selftests: Add pidfd_open syscall number fallback

From: Aqib Faruqui
Date: Fri Aug 29 2025 - 10:26:52 EST


The kselftest-harness uses pidfd_open() for test timeout handling, but
non-glibc C library headers may not define this syscall number.

Add architecture-specific fallback definitions to pidfd.h, including
support for Alpha (544) and other architectures (434). Update
kselftest_harness.h to include pidfd.h for the syscall definitions.

Signed-off-by: Aqib Faruqui <aqibaf@xxxxxxxxxx>
---
tools/testing/selftests/kselftest_harness.h | 1 +
tools/testing/selftests/pidfd/pidfd.h | 4 ++++
2 files changed, 5 insertions(+)

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index 2925e47db..1dd3e5a1b 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -69,6 +69,7 @@
#include <unistd.h>

#include "kselftest.h"
+#include "pidfd/pidfd.h"

#define TEST_TIMEOUT_DEFAULT 30

diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
index f87993def..c373ff18e 100644
--- a/tools/testing/selftests/pidfd/pidfd.h
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -45,8 +45,12 @@
#endif

#ifndef __NR_pidfd_open
+#ifdef __alpha__
+#define __NR_pidfd_open 544
+#else
#define __NR_pidfd_open 434
#endif
+#endif

#ifndef __NR_pidfd_send_signal
#define __NR_pidfd_send_signal 424
--
2.47.3