compat: consolidate the compat_flock{,64} definition

Provide a single common definition for the compat_flock and
compat_flock64 structures using the same tricks as for the native
variants.  Another extra define is added for the packing required on
x86.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Link: https://lore.kernel.org/r/20220405071314.3225832-4-guoren@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/arm64/include/asm/compat.h

@@ -65,22 +65,6 @@ struct compat_stat {
 	compat_ulong_t	__unused4[2];
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 struct compat_statfs {
 	int		f_type;
 	int		f_bsize;

arch/mips/include/asm/compat.h

@@ -55,23 +55,8 @@ struct compat_stat {
 	s32		st_pad4[14];
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	s32		l_sysid;
-	compat_pid_t	l_pid;
-	s32		pad[4];
-};
-
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
+#define __ARCH_COMPAT_FLOCK_EXTRA_SYSID		s32 l_sysid;
+#define __ARCH_COMPAT_FLOCK_PAD			s32 pad[4];
 
 struct compat_statfs {
 	int		f_type;

arch/parisc/include/asm/compat.h

@@ -53,22 +53,6 @@ struct compat_stat {
 	u32			st_spare4[3];
 };
 
-struct compat_flock {
-	short			l_type;
-	short			l_whence;
-	compat_off_t		l_start;
-	compat_off_t		l_len;
-	compat_pid_t		l_pid;
-};
-
-struct compat_flock64 {
-	short			l_type;
-	short			l_whence;
-	compat_loff_t		l_start;
-	compat_loff_t		l_len;
-	compat_pid_t		l_pid;
-};
-
 struct compat_statfs {
 	s32		f_type;
 	s32		f_bsize;

arch/powerpc/include/asm/compat.h

@@ -44,22 +44,6 @@ struct compat_stat {
 	u32		__unused4[2];
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 struct compat_statfs {
 	int		f_type;
 	int		f_bsize;

arch/s390/include/asm/compat.h

@@ -102,22 +102,6 @@ struct compat_stat {
 	u32		__unused5;
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 struct compat_statfs {
 	u32		f_type;
 	u32		f_bsize;

arch/sparc/include/asm/compat.h

@@ -75,23 +75,7 @@ struct compat_stat64 {
 	unsigned int	__unused5;
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-	short		__unused;
-};
-
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-	short		__unused;
-};
+#define __ARCH_COMPAT_FLOCK_PAD		short __unused;
 
 struct compat_statfs {
 	int		f_type;

arch/x86/include/asm/compat.h

@@ -50,25 +50,11 @@ struct compat_stat {
 	u32		__unused5;
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 /*
- * IA32 uses 4 byte alignment for 64 bit quantities,
- * so we need to pack this structure.
+ * IA32 uses 4 byte alignment for 64 bit quantities, so we need to pack the
+ * compat flock64 structure.
  */
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-} __attribute__((packed));
+#define __ARCH_NEED_COMPAT_FLOCK64_PACKED
 
 struct compat_statfs {
 	int		f_type;

include/linux/compat.h

@@ -258,6 +258,37 @@ struct compat_rlimit {
 	compat_ulong_t	rlim_max;
 };
 
+#ifdef __ARCH_NEED_COMPAT_FLOCK64_PACKED
+#define __ARCH_COMPAT_FLOCK64_PACK	__attribute__((packed))
+#else
+#define __ARCH_COMPAT_FLOCK64_PACK
+#endif
+
+struct compat_flock {
+	short			l_type;
+	short			l_whence;
+	compat_off_t		l_start;
+	compat_off_t		l_len;
+#ifdef __ARCH_COMPAT_FLOCK_EXTRA_SYSID
+	__ARCH_COMPAT_FLOCK_EXTRA_SYSID
+#endif
+	compat_pid_t		l_pid;
+#ifdef __ARCH_COMPAT_FLOCK_PAD
+	__ARCH_COMPAT_FLOCK_PAD
+#endif
+};
+
+struct compat_flock64 {
+	short		l_type;
+	short		l_whence;
+	compat_loff_t	l_start;
+	compat_loff_t	l_len;
+	compat_pid_t	l_pid;
+#ifdef __ARCH_COMPAT_FLOCK64_PAD
+	__ARCH_COMPAT_FLOCK64_PAD
+#endif
+} __ARCH_COMPAT_FLOCK64_PACK;
+
 struct compat_rusage {
 	struct old_timeval32 ru_utime;
 	struct old_timeval32 ru_stime;