include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error

When running sparse over drivers/media/v4l2-core/v4l2-ioctl.c I get these
errors:

  drivers/media/v4l2-core/v4l2-ioctl.c:2043:9: error: bad integer constant expression
  drivers/media/v4l2-core/v4l2-ioctl.c:2044:9: error: bad integer constant expression
  drivers/media/v4l2-core/v4l2-ioctl.c:2045:9: error: bad integer constant expression
  drivers/media/v4l2-core/v4l2-ioctl.c:2046:9: error: bad integer constant expression

etc.

The root cause of that turns out to be in include/asm-generic/ioctl.h:

#include <uapi/asm-generic/ioctl.h>

/* provoke compile error for invalid uses of size argument */
extern unsigned int __invalid_size_argument_for_IOC;
#define _IOC_TYPECHECK(t) \
        ((sizeof(t) == sizeof(t[1]) && \
          sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
          sizeof(t) : __invalid_size_argument_for_IOC)

If it is defined as this (as is already done if __KERNEL__ is not defined):

  #define _IOC_TYPECHECK(t) (sizeof(t))

then all is well with the world.

This patch allows sparse to work correctly.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hans Verkuil 2014-06-06 14:37:22 -07:00 committed by Linus Torvalds
parent 68a9a435e4
commit d55875f5d5
1 changed files with 5 additions and 0 deletions

View File

@ -3,10 +3,15 @@
#include <uapi/asm-generic/ioctl.h>
#ifdef __CHECKER__
#define _IOC_TYPECHECK(t) (sizeof(t))
#else
/* provoke compile error for invalid uses of size argument */
extern unsigned int __invalid_size_argument_for_IOC;
#define _IOC_TYPECHECK(t) \
((sizeof(t) == sizeof(t[1]) && \
sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
sizeof(t) : __invalid_size_argument_for_IOC)
#endif
#endif /* _ASM_GENERIC_IOCTL_H */