From aab35b1e5907a7ac0a218b4f220c66e6d79eb39a Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 8 Oct 2021 10:46:02 +0200
Subject: [PATCH] missing: add getdents64() syscall wrapper

glibc 2.30 (Aug 2019) added a wrapper for getdents64(). For older
versions let's define our own.

(This syscall exists since Linux 2.4, hence should be safe to use for
us)
---
 meson.build                 |  1 +
 src/basic/missing_syscall.h | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/meson.build b/meson.build
index 7d97ba2fe93..6c5d4bb34cc 100644
--- a/meson.build
+++ b/meson.build
@@ -546,6 +546,7 @@ foreach ident : [
         ['mount_setattr',     '''#include <sys/mount.h>'''],
         ['move_mount',        '''#include <sys/mount.h>'''],
         ['open_tree',         '''#include <sys/mount.h>'''],
+        ['getdents64',        '''#include <dirent.h>'''],
 ]
 
         have = cc.has_function(ident[0], prefix : ident[1], args : '-D_GNU_SOURCE')
diff --git a/src/basic/missing_syscall.h b/src/basic/missing_syscall.h
index 57dae77b535..5e80fa79fd0 100644
--- a/src/basic/missing_syscall.h
+++ b/src/basic/missing_syscall.h
@@ -540,3 +540,19 @@ static inline int missing_move_mount(
 
 #  define move_mount missing_move_mount
 #endif
+
+/* ======================================================================= */
+
+#if !HAVE_GETDENTS64
+
+static inline ssize_t missing_getdents64(int fd, void *buffer, size_t length) {
+#  if defined __NR_getdents64 && __NR_getdents64 >= 0
+        return syscall(__NR_getdents64, fd, buffer, length);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define getdents64 missing_getdents64
+#endif