[PATCH] Introduce compat_u64 and compat_s64 types

[Arnd Bergmann]

One common problem with 32 bit system call and ioctl emulation
is the different alignment rules between i386 and 64 bit machines.
A number of drivers work around this by marking the compat
structures as 'attribute((packed))', which is not the right
solution because it breaks all the non-x86 architectures that
want to use the same compat code.

Hopefully, this patch improves the situation, it introduces two
new types, compat_u64 and compat_s64. These are defined on all
architectures to have the same size and alignment as the 32 bit
version of u64 and s64.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

---

See the discussions about 'Re: drm: fix radeon setparam on
32/64 bit systems.' and 'diskquota: 32bit quota tools on
64bit architectures' about where this comes from.

Index: linux-2.6/include/asm-ia64/compat.h
===================================================================
--- linux-2.6.orig/include/asm-ia64/compat.h
+++ linux-2.6/include/asm-ia64/compat.h
@@ -31,8 +31,10 @@ typedef s32		compat_timer_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64 __attribute__((aligned(4))) compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64 __attribute__((aligned(4))) compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
Index: linux-2.6/include/asm-mips/compat.h
===================================================================
--- linux-2.6.orig/include/asm-mips/compat.h
+++ linux-2.6/include/asm-mips/compat.h
@@ -37,8 +37,10 @@ typedef s32		compat_key_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64		compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64		compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
Index: linux-2.6/include/asm-parisc/compat.h
===================================================================
--- linux-2.6.orig/include/asm-parisc/compat.h
+++ linux-2.6/include/asm-parisc/compat.h
@@ -31,8 +31,10 @@ typedef s32	compat_timer_t;
 
 typedef s32	compat_int_t;
 typedef s32	compat_long_t;
+typedef s64	compat_s64;
 typedef u32	compat_uint_t;
 typedef u32	compat_ulong_t;
+typedef u64	compat_u64;
 
 struct compat_timespec {
 	compat_time_t		tv_sec;
Index: linux-2.6/include/asm-powerpc/compat.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/compat.h
+++ linux-2.6/include/asm-powerpc/compat.h
@@ -33,8 +33,10 @@ typedef s32		compat_timer_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64		compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64		compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
Index: linux-2.6/include/asm-s390/compat.h
===================================================================
--- linux-2.6.orig/include/asm-s390/compat.h
+++ linux-2.6/include/asm-s390/compat.h
@@ -60,8 +60,10 @@ typedef s32		compat_timer_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64		compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64		compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
Index: linux-2.6/include/asm-sparc64/compat.h
===================================================================
--- linux-2.6.orig/include/asm-sparc64/compat.h
+++ linux-2.6/include/asm-sparc64/compat.h
@@ -31,8 +31,10 @@ typedef s32		compat_timer_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64		compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64		compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
Index: linux-2.6/include/asm-x86_64/compat.h
===================================================================
--- linux-2.6.orig/include/asm-x86_64/compat.h
+++ linux-2.6/include/asm-x86_64/compat.h
@@ -33,8 +33,10 @@ typedef s32		compat_key_t;
 
 typedef s32		compat_int_t;
 typedef s32		compat_long_t;
+typedef s64 __attribute__((aligned(4))) compat_s64;
 typedef u32		compat_uint_t;
 typedef u32		compat_ulong_t;
+typedef u64 __attribute__((aligned(4))) compat_u64;
 
 struct compat_timespec {
 	compat_time_t	tv_sec;
-
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