From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 7 Dec 2022 17:10:42 +0000 (+0100)
Subject: fundamental: split out unaligned_{read|write}_ne{16,32,64}() helpers into unaligned... 
X-Git-Tag: v253-rc1~331^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d8007e7aacdadc57d2fd9ee3f80f620be781248e;p=thirdparty%2Fsystemd.git

fundamental: split out unaligned_{read|write}_ne{16,32,64}() helpers into unaligned-fundamental.h

Let's allow using this in code shared between userspace and EFI mode.

Also, don't implement these functions via endianness conversions given
we don't actually want to convert endianess here.
---

diff --git a/src/basic/unaligned.h b/src/basic/unaligned.h
index 4100be08031..04580cfb636 100644
--- a/src/basic/unaligned.h
+++ b/src/basic/unaligned.h
@@ -4,6 +4,8 @@
 #include <endian.h>
 #include <stdint.h>
 
+#include "unaligned-fundamental.h"
+
 /* BE */
 
 static inline uint16_t unaligned_read_be16(const void *_u) {
@@ -79,21 +81,3 @@ static inline void unaligned_write_le64(void *_u, uint64_t a) {
 
         u->x = le64toh(a);
 }
-
-#if __BYTE_ORDER == __BIG_ENDIAN
-#define unaligned_read_ne16 unaligned_read_be16
-#define unaligned_read_ne32 unaligned_read_be32
-#define unaligned_read_ne64 unaligned_read_be64
-
-#define unaligned_write_ne16 unaligned_write_be16
-#define unaligned_write_ne32 unaligned_write_be32
-#define unaligned_write_ne64 unaligned_write_be64
-#else
-#define unaligned_read_ne16 unaligned_read_le16
-#define unaligned_read_ne32 unaligned_read_le32
-#define unaligned_read_ne64 unaligned_read_le64
-
-#define unaligned_write_ne16 unaligned_write_le16
-#define unaligned_write_ne32 unaligned_write_le32
-#define unaligned_write_ne64 unaligned_write_le64
-#endif
diff --git a/src/fundamental/unaligned-fundamental.h b/src/fundamental/unaligned-fundamental.h
new file mode 100644
index 00000000000..a4c810a5fcb
--- /dev/null
+++ b/src/fundamental/unaligned-fundamental.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stdint.h>
+
+static inline uint16_t unaligned_read_ne16(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        return u->x;
+}
+
+static inline uint32_t unaligned_read_ne32(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        return u->x;
+}
+
+static inline uint64_t unaligned_read_ne64(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        return u->x;
+}
+
+static inline void unaligned_write_ne16(void *_u, uint16_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        u->x = a;
+}
+
+static inline void unaligned_write_ne32(void *_u, uint32_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        u->x = a;
+}
+
+static inline void unaligned_write_ne64(void *_u, uint64_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        u->x = a;
+}