From ef1e0607b82e27350c2d677d649c6a0a9693fd40 Mon Sep 17 00:00:00 2001
From: Christian Brauner <brauner@kernel.org>
Date: Tue, 9 Aug 2022 16:27:40 +0200
Subject: build: detect sys/pidfd.h availability

Fixes: #4176
Signed-off-by: Christian Brauner (Microsoft) <christian.brauner@ubuntu.com>
---
 meson.build             | 1 +
 src/lxc/process_utils.h | 6 ++++++
 2 files changed, 7 insertions(+)

--- a/meson.build
+++ b/meson.build
@@ -734,6 +734,7 @@ foreach tuple: [
     ['sys/resource.h'],
     ['sys/memfd.h'],
     ['sys/personality.h'],
+    ['sys/pidfd.h'],
     ['sys/signalfd.h'],
     ['sys/timerfd.h'],
     ['pty.h'],
--- a/src/lxc/process_utils.h
+++ b/src/lxc/process_utils.h
@@ -15,6 +15,10 @@
 #include <sys/syscall.h>
 #include <unistd.h>
 
+#if HAVE_SYS_PIDFD_H
+#include <sys/pidfd.h>
+#endif
+
 #include "compiler.h"
 #include "syscall_numbers.h"
 
@@ -136,9 +140,11 @@
 #endif
 
 /* waitid */
+#if !HAVE_SYS_PIDFD_H
 #ifndef P_PIDFD
 #define P_PIDFD 3
 #endif
+#endif
 
 #ifndef CLONE_ARGS_SIZE_VER0
 #define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */