The pidfd_open syscall number varies by architecture. Add fallback
definitions for Alpha (544) and other architectures (434) to ensure
compatibility with non-glibc C libraries that may not define these
syscall numbers.

Signed-off-by: Aqib Faruqui <aqibaf@amazon.com>
---
 tools/testing/selftests/pidfd/pidfd.h | 4 ++++
 1 file changed, 4 insertions(+)

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