• Arnd Bergmann's avatar
    Introduce compat_u64 and compat_s64 types · 4b777587
    Arnd Bergmann authored
    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: default avatarArnd Bergmann <arnd@arndb.de>
    Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
    Cc: David Woodhouse <dwmw2@infradead.org>
    Cc: Andi Kleen <ak@suse.de>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Vasily Tarasov <vtaras@openvz.org>
    Cc: <linux-arch@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    4b777587
compat.h 3.58 KB