btw, I mentioned on irc, but someone *really* ought to go through the ioclt structs and split each struct member into it's own line, so things like '__u32 width, height' aren't so sneaky ;-)

On Mon, Jul 13, 2015 at 11:56 AM, Tvrtko Ursulin tvrtko.ursulin@linux.intel.com wrote:

From: Tvrtko Ursulin tvrtko.ursulin@intel.com

Frame buffer modifiers extensions provided in;

commit e3eb3250d84ef97b766312345774367b6a310db8 Author: Rob Clark robdclark@gmail.com Date: Thu Feb 5 14:41:52 2015 +0000

  drm: add support for tiled/compressed/etc modifier in addfb2

Missed the structure packing/alignment problem where 64-bit members were added after the odd number of 32-bit ones. This makes the compiler produce structures of different sizes under 32- and 64-bit x86 targets and makes the ioctl need explicit compat handling.

Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: dri-devel@lists.freedesktop.org Cc: Rob Clark robdclark@gmail.com Cc: Daniel Stone daniels@collabora.com Cc: Daniel Vetter daniel.vetter@intel.com

---

drivers/gpu/drm/drm_ioc32.c | 60 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+)

diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c index aa8bbb460c57..2bea11bfb3ae 100644 --- a/drivers/gpu/drm/drm_ioc32.c +++ b/drivers/gpu/drm/drm_ioc32.c @@ -70,6 +70,8 @@

#define DRM_IOCTL_WAIT_VBLANK32 DRM_IOWR(0x3a, drm_wait_vblank32_t)

+#define DRM_IOCTL_MODE_ADDFB232 DRM_IOWR(0xb8, drm_mode_fb_cmd232_t)

typedef struct drm_version_32 { int version_major; /**< Major version */ int version_minor; /**< Minor version */ @@ -1016,6 +1018,63 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd, return 0; }

+typedef struct drm_mode_fb_cmd232 {

•   u32 fb_id;
  

•   u32 width;
  

•   u32 height;
  

•   u32 pixel_format;
  

•   u32 flags;
  

•   u32 handles[4];
  

•   u32 pitches[4];
  

•   u32 offsets[4];
  

•   u64 modifier[4];
  

+} __attribute__((packed)) drm_mode_fb_cmd232_t;

+static int compat_drm_mode_addfb2(struct file *file, unsigned int cmd,

•                             unsigned long arg)
  

+{

•   drm_mode_fb_cmd232_t __user *argp = (void __user *)arg;
  

•   struct drm_mode_fb_cmd232 req32;
  

•   struct drm_mode_fb_cmd2 __user *req64;
  

•   int i;
  

•   int err;
  

•   if (copy_from_user(&req32, argp, sizeof(req32)))
  

•           return -EFAULT;
  

•   req64 = compat_alloc_user_space(sizeof(*req64));
  

•   if (!access_ok(VERIFY_WRITE, req64, sizeof(*req64))
  

•       || __put_user(req32.width, &req64->width)
  

•       || __put_user(req32.height, &req64->height)
  

•       || __put_user(req32.pixel_format, &req64->pixel_format)
  

•       || __put_user(req32.flags, &req64->flags))
  

•           return -EFAULT;
  

•   for (i = 0; i < 4; i++) {
  

•           if (__put_user(req32.handles[i], &req64->handles[i]))
  

•                   return -EFAULT;
  

•           if (__put_user(req32.pitches[i], &req64->pitches[i]))
  

•                   return -EFAULT;
  

•           if (__put_user(req32.offsets[i], &req64->offsets[i]))
  

•                   return -EFAULT;
  

•           if (__put_user(req32.modifier[i], &req64->modifier[i]))
  

•                   return -EFAULT;
  

•   }
  

•   err = drm_ioctl(file, DRM_IOCTL_MODE_ADDFB2, (unsigned long)req64);
  

•   if (err)
  

•           return err;
  

•   if (__get_user(req32.fb_id, &req64->fb_id))
  

•           return -EFAULT;
  

•   if (copy_to_user(argp, &req32, sizeof(req32)))
  

•           return -EFAULT;
  

•   return 0;
  

+}

static drm_ioctl_compat_t *drm_compat_ioctls[] = { [DRM_IOCTL_NR(DRM_IOCTL_VERSION32)] = compat_drm_version, [DRM_IOCTL_NR(DRM_IOCTL_GET_UNIQUE32)] = compat_drm_getunique, @@ -1048,6 +1107,7 @@ static drm_ioctl_compat_t *drm_compat_ioctls[] = { [DRM_IOCTL_NR(DRM_IOCTL_UPDATE_DRAW32)] = compat_drm_update_draw, #endif [DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK32)] = compat_drm_wait_vblank,

•   [DRM_IOCTL_NR(DRM_IOCTL_MODE_ADDFB232)] = compat_drm_mode_addfb2,
  

};

/**

2.4.2