[PATCH v3 1/2] Loongarch: adapt for the re-introduction of fstat and newfstatat in 6.11

[Miao Wang via B4 Relay]

From: Miao Wang <shankerwangmiao@gmail.com>

In Linux 6.11, fstat and newfstatat are added back. We need to include
this change in kernel-features.h to avoid producing libraries
incompatible with previous linux versions with new headers.

The definition of the two syscalls will be removed when the targeted
kernel version is below 6.10.6 in loongarch/sysdep.h, since the feature
has already been backported to 6.10.6 in the stable tree.

Signed-off-by: Miao Wang <shankerwangmiao@gmail.com>
---
 .../unix/sysv/linux/loongarch/kernel-features.h    | 27 ++++++++++++++++++++++
 sysdeps/unix/sysv/linux/loongarch/sysdep.h         |  5 ++++
 2 files changed, 32 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/loongarch/kernel-features.h b/sysdeps/unix/sysv/linux/loongarch/kernel-features.h
new file mode 100644
index 0000000000..8e2927c501
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/loongarch/kernel-features.h
@@ -0,0 +1,27 @@
+/* Set flags signalling availability of kernel features based on given
+   kernel version number.  Loongarch version.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include_next <kernel-features.h>
+
+#define __ASSUME_LOONGARCH_NEWSTAT 1
+
+/* No support for fstat or newfstatat before 6.10.6.  */
+#if __LINUX_KERNEL_VERSION < 0x060a06
+# undef __ASSUME_LOONGARCH_NEWSTAT
+#endif
diff --git a/sysdeps/unix/sysv/linux/loongarch/sysdep.h b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
index eb0ba790da..1fdf18197f 100644
--- a/sysdeps/unix/sysv/linux/loongarch/sysdep.h
+++ b/sysdeps/unix/sysv/linux/loongarch/sysdep.h
@@ -109,6 +109,11 @@
 #undef SYS_ify
 #define SYS_ify(syscall_name) __NR_##syscall_name
 
+#ifndef __ASSUME_LOONGARCH_NEWSTAT
+#undef __NR_fstat
+#undef __NR_newfstatat
+#endif
+
 #ifndef __ASSEMBLER__
 
 #define VDSO_NAME "LINUX_5.10"

-- 
2.43.0