Re: [PATCH] drm mode: fix drmIoctl wrapper

[Marcin Slusarz <marcin.slusarz@gmail.com>]

On Sun, Jun 05, 2011 at 07:28:20PM +0200, Marcin Slusarz wrote:
> Both drmIoctl and ioctl define second argument as unigned long, but
> DRM_IOCTL do not.
> 
> Debugging/tracing tools (like strace or valgrind) on 64-bit machines see
> different request value for ioctls with 32nd bit set, because casting
> signed int to unsigned long extends 32nd bit to upper word, so 0x80000000
> becomes 0xFFFFFFFF80000000)
> 
> Nobody noticed because higher 32 bits are chopped off on their way to kernel.
> ---
>  xf86drmMode.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/xf86drmMode.c b/xf86drmMode.c
> index 0d268fc..f08e648 100644
> --- a/xf86drmMode.c
> +++ b/xf86drmMode.c
> @@ -52,7 +52,7 @@
>  #define U642VOID(x) ((void *)(unsigned long)(x))
>  #define VOID2U64(x) ((uint64_t)(unsigned long)(x))
>  
> -static inline DRM_IOCTL(int fd, int cmd, void *arg)
> +static inline int DRM_IOCTL(int fd, unsigned long cmd, void *arg)
>  {
>  	int ret = drmIoctl(fd, cmd, arg);
>  	return ret < 0 ? -errno : ret;
> -- 


Hi Chris,

Can you take a look a this patch?
Commit b803918f3f77c62edf22e78cb2095be399753423 "drm mode: Return -errno
on drmIoctl() failure" reveals you are the author of DRM_IOCTL :).

Thanks,
Marcin