softpipe/buffer: load only as many components as the the buffer resource type provides

Otherwise we risk to read past the end of the buffer.

In addition, change the loop counters to unsigned to be consistent
with the types.

Fixes: afa8707ba93a7d226a76319acda2a8dd89524db7
    softpipe: add SSBO/shader atomics support.

Signed-off-by: Gert Wollny <[email protected]>
Reviewed-by: Dave Airlie <[email protected]>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/gallium/drivers/softpipe/sp_buffer.c b/src/gallium/drivers/softpipe/sp_buffer.c
index 3ec738527af..4b0617e0bea 100644
--- a/src/gallium/drivers/softpipe/sp_buffer.c
+++ b/src/gallium/drivers/softpipe/sp_buffer.c
@@ -55,7 +55,8 @@ sp_tgsi_load(const struct tgsi_buffer *buffer,
    struct pipe_shader_buffer *bview;
    struct softpipe_resource *spr;
    unsigned width;
-   int c, j;
+   unsigned ncomp;
+   unsigned c, j;
    unsigned char *data_ptr;
    const struct util_format_description *format_desc = util_format_description(PIPE_FORMAT_R32_UINT);
 
@@ -63,6 +64,8 @@ sp_tgsi_load(const struct tgsi_buffer *buffer,
       goto fail_write_all_zero;
 
    bview = &sp_buf->sp_bview[params->unit];
+   ncomp = util_format_get_nr_components(bview->buffer->format);
+
    spr = softpipe_resource(bview->buffer);
    if (!spr)
       goto fail_write_all_zero;
@@ -88,7 +91,7 @@ sp_tgsi_load(const struct tgsi_buffer *buffer,
          continue;
       }
       data_ptr = (unsigned char *)spr->data + bview->buffer_offset + s_coord;
-      for (c = 0; c < 4; c++) {
+      for (c = 0; c < ncomp; c++) {
          format_desc->fetch_rgba_uint(sdata, data_ptr, 0, 0);
          ((uint32_t *)rgba[c])[j] = sdata[0];
          data_ptr += 4;