nouveau: fix undefined behaviour when testing sample_count

NOTE: This is a candidate for the 9.0 branch.

3 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/drivers/nv30/nv30_screen.c b/src/gallium/drivers/nv30/nv30_screen.c
index 06f7c42bbe5..f3faf8ad18a 100644
--- a/src/gallium/drivers/nv30/nv30_screen.c
+++ b/src/gallium/drivers/nv30/nv30_screen.c
@@ -244,6 +244,8 @@ nv30_screen_is_format_supported(struct pipe_screen *pscreen,
                                 unsigned sample_count,
                                 unsigned bindings)
 {
+   if (sample_count > 4)
+      return FALSE;
    if (!(0x00000017 & (1 << sample_count)))
       return FALSE;
 
diff --git a/src/gallium/drivers/nv50/nv50_screen.c b/src/gallium/drivers/nv50/nv50_screen.c
index 1155c93e8f4..b1a9c4d6dde 100644
--- a/src/gallium/drivers/nv50/nv50_screen.c
+++ b/src/gallium/drivers/nv50/nv50_screen.c
@@ -50,6 +50,8 @@ nv50_screen_is_format_supported(struct pipe_screen *pscreen,
                                 unsigned sample_count,
                                 unsigned bindings)
 {
+   if (sample_count > 8)
+      return FALSE;
    if (!(0x117 & (1 << sample_count))) /* 0, 1, 2, 4 or 8 */
       return FALSE;
    if (sample_count == 8 && util_format_get_blocksizebits(format) >= 128)
diff --git a/src/gallium/drivers/nvc0/nvc0_screen.c b/src/gallium/drivers/nvc0/nvc0_screen.c
index de0513baff1..46bb797e53f 100644
--- a/src/gallium/drivers/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nvc0/nvc0_screen.c
@@ -39,6 +39,8 @@ nvc0_screen_is_format_supported(struct pipe_screen *pscreen,
                                 unsigned sample_count,
                                 unsigned bindings)
 {
+   if (sample_count > 8)
+      return FALSE;
    if (!(0x117 & (1 << sample_count))) /* 0, 1, 2, 4 or 8 */
       return FALSE;