From 548bc568f3c735e53fb5b0a5ab6473a3f1457b91 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Sun, 7 Aug 2022 14:39:19 -0700
Subject: [PATCH] check for sys/pidfd.h

This header in newer glibc defines the signatures of functions
pidfd_send_signal() and pidfd_open() and when these functions are
defined by libc then we need to include the relevant header to get
the definitions. Clang 15+ has started to error out when function
signatures are missing.

Fixes errors like
misc-utils/kill.c:402:6: error: call to undeclared function 'pidfd_send_signal'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        if (pidfd_send_signal(pfd, ctl->numsig, &info, 0) < 0)

Upstream-Status: Submitted [https://github.com/util-linux/util-linux/pull/1769]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 configure.ac          | 1 +
 include/pidfd-utils.h | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index a511e93de..fd7d9245f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -342,6 +342,7 @@ AC_CHECK_HEADERS([ \
 	sys/mkdev.h \
 	sys/mount.h \
 	sys/param.h \
+	sys/pidfd.h \
 	sys/prctl.h \
 	sys/resource.h \
 	sys/sendfile.h \
diff --git a/include/pidfd-utils.h b/include/pidfd-utils.h
index eddede976..d9e33cbc5 100644
--- a/include/pidfd-utils.h
+++ b/include/pidfd-utils.h
@@ -4,8 +4,10 @@
 #ifdef HAVE_SYS_SYSCALL_H
 # include <sys/syscall.h>
 # if defined(SYS_pidfd_send_signal) && defined(SYS_pidfd_open)
+#  ifdef HAVE_SYS_PIDFD_H
+#   include <sys/pidfd.h>
+#  endif
 #  include <sys/types.h>
-
 #  ifndef HAVE_PIDFD_SEND_SIGNAL
 static inline int pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
 				    unsigned int flags)
-- 
2.37.1