From 8bf40e44a06fd5a154cb04975f6fff1933e52425 Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Wed, 30 Aug 2023 13:34:23 +0200
Subject: [PATCH] misc: add syscall fallback for close_range for musl libc

Add fallback for the close_range syscall wrapper. This is needed for
musl libc, which currently does not have a close_range wrapper.
---
 meson.build       | 2 ++
 src/shared/misc.c | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/meson.build b/meson.build
index 58b7db9af..b7356b9ab 100644
--- a/meson.build
+++ b/meson.build
@@ -198,6 +198,8 @@ endif
 if cc.has_function('close_range', prefix: '#define _GNU_SOURCE\n#include <unistd.h>') and \
     cc.has_header_symbol('unistd.h', 'CLOSE_RANGE_CLOEXEC', prefix: '#define _GNU_SOURCE')
   add_project_arguments('-DHAVE_CLOSE_RANGE', language: 'c')
+elif cc.has_header('linux/close_range.h')
+  add_project_arguments('-DHAVE_LINUX_CLOSE_RANGE_H', language: 'c')
 endif
 
 if cc.has_function('strlcpy', prefix: '#define _GNU_SOURCE\n#include <string.h>')
diff --git a/src/shared/misc.c b/src/shared/misc.c
index 4c3884479..5c92a8b16 100644
--- a/src/shared/misc.c
+++ b/src/shared/misc.c
@@ -24,6 +24,9 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
+#ifdef HAVE_LINUX_CLOSE_RANGE_H
+#  include <linux/close_range.h>
+#endif
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -31,6 +34,7 @@
 #include <sys/file.h>
 #include <sys/time.h>
 #ifdef __linux__
+#  include <sys/syscall.h> /* for close_range */
 #  include <sys/sysinfo.h>
 #endif
 #include <sys/types.h>
@@ -511,7 +515,11 @@ static inline int close_range(unsigned int first RC_UNUSED,
 			      unsigned int last RC_UNUSED,
 			      unsigned int flags RC_UNUSED)
 {
+#ifdef SYS_close_range
+	return syscall(SYS_close_range, first, last, flags);
+#else
 	return -1;
+#endif
 }
 #endif
 #ifndef CLOSE_RANGE_CLOEXEC