Re: [libav-devel] [PATCH 2/3] mpegvideo_motion: Fix undefined negative shifts in mpeg_motion_internal

2016-03-02 Thread Luca Barbato 
On 03/03/16 00:52, Vittorio Giovara wrote:
> From: Michael Niedermayer 
> 
> Found-by: Clang -fsanitize=shift
> Reported-by: Thierry Foucu 
> Signed-off-by: Vittorio Giovara 
> ---
>  libavcodec/mpegvideo_motion.c | 8 +---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/mpegvideo_motion.c b/libavcodec/mpegvideo_motion.c
> index 05375a1..04f4020 100644
> --- a/libavcodec/mpegvideo_motion.c
> +++ b/libavcodec/mpegvideo_motion.c
> @@ -318,23 +318,25 @@ void mpeg_motion_internal(MpegEncContext *s,
> src_y);
>  return;
>  }
> +src_y = (unsigned)src_y << field_based;
>  s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, ptr_y,
>   s->linesize, s->linesize,
>   17, 17 + field_based,
> - src_x, src_y << field_based,
> + src_x, src_y,
>   s->h_edge_pos, s->v_edge_pos);
>  ptr_y = s->sc.edge_emu_buffer;
>  if (!CONFIG_GRAY || !(s->avctx->flags & AV_CODEC_FLAG_GRAY)) {
>  uint8_t *uvbuf = s->sc.edge_emu_buffer + 18 * s->linesize;
> +uvsrc_y = (unsigned)uvsrc_y << field_based;
>  s->vdsp.emulated_edge_mc(uvbuf, ptr_cb,
>   s->uvlinesize, s->uvlinesize,
>   9, 9 + field_based,
> - uvsrc_x, uvsrc_y << field_based,
> + uvsrc_x, uvsrc_y,
>   s->h_edge_pos >> 1, s->v_edge_pos >> 1);
>  s->vdsp.emulated_edge_mc(uvbuf + 16, ptr_cr,
>   s->uvlinesize, s->uvlinesize,
>   9, 9 + field_based,
> - uvsrc_x, uvsrc_y << field_based,
> + uvsrc_x, uvsrc_y,
>   s->h_edge_pos >> 1, s->v_edge_pos >> 1);
>  ptr_cb = uvbuf;
>  ptr_cr = uvbuf + 16;
> 

which is the range of src_y and uvsrc_y ? If it cannot be negative why
not using unsigned and be done with it?

lu
___
libav-devel mailing list
libav-devel@libav.org
https://lists.libav.org/mailman/listinfo/libav-devel

[libav-devel] [PATCH 2/3] mpegvideo_motion: Fix undefined negative shifts in mpeg_motion_internal

2016-03-02 Thread Vittorio Giovara 
From: Michael Niedermayer 

Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu 
Signed-off-by: Vittorio Giovara 
---
 libavcodec/mpegvideo_motion.c | 8 +---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavcodec/mpegvideo_motion.c b/libavcodec/mpegvideo_motion.c
index 05375a1..04f4020 100644
--- a/libavcodec/mpegvideo_motion.c
+++ b/libavcodec/mpegvideo_motion.c
@@ -318,23 +318,25 @@ void mpeg_motion_internal(MpegEncContext *s,
src_y);
 return;
 }
+src_y = (unsigned)src_y << field_based;
 s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, ptr_y,
  s->linesize, s->linesize,
  17, 17 + field_based,
- src_x, src_y << field_based,
+ src_x, src_y,
  s->h_edge_pos, s->v_edge_pos);
 ptr_y = s->sc.edge_emu_buffer;
 if (!CONFIG_GRAY || !(s->avctx->flags & AV_CODEC_FLAG_GRAY)) {
 uint8_t *uvbuf = s->sc.edge_emu_buffer + 18 * s->linesize;
+uvsrc_y = (unsigned)uvsrc_y << field_based;
 s->vdsp.emulated_edge_mc(uvbuf, ptr_cb,
  s->uvlinesize, s->uvlinesize,
  9, 9 + field_based,
- uvsrc_x, uvsrc_y << field_based,
+ uvsrc_x, uvsrc_y,
  s->h_edge_pos >> 1, s->v_edge_pos >> 1);
 s->vdsp.emulated_edge_mc(uvbuf + 16, ptr_cr,
  s->uvlinesize, s->uvlinesize,
  9, 9 + field_based,
- uvsrc_x, uvsrc_y << field_based,
+ uvsrc_x, uvsrc_y,
  s->h_edge_pos >> 1, s->v_edge_pos >> 1);
 ptr_cb = uvbuf;
 ptr_cr = uvbuf + 16;
-- 
2.7.0

___
libav-devel mailing list
libav-devel@libav.org
https://lists.libav.org/mailman/listinfo/libav-devel