Ok. So lets start again. :)
How about changing the subject to:
glsl: on UBO/SSBOs link error reset the number of active blocks to 0
On 23/02/17 19:55, Andres Gomez wrote:
Commit f1293b2f9bc3 split apart buffer block arrays but introduced
also the possibility of a recount of active
blocks (NumUniformBlocks/NumShaderStorageBlocks) which would be
incoherent with the actual amount of active
blocks (UniformBlocks/ShaderStorageBlocks) in the program.
This could cause a segmentation fault if trying to use the index of a
block in a link failed program.
How about we simplify this whole commit message to something like:
While it's legal to have an active blocks count > 0 on link failure.
Unless we actually assign memory for the blocks array we can end up
segfaulting in calls such as glUniformBlockBinding().
To avoid having to NULL check these api calls we simply reset the
block count to 0 if the array was not created.
Signed-off-by: Andres Gomez <[email protected]>
Cc: Timothy Arceri <[email protected]>
---
src/compiler/glsl/linker.cpp | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index b6f8bc4212e..bb9c101f430 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -1181,6 +1181,7 @@ interstage_cross_validate_uniform_blocks(struct
gl_shader_program *prog,
for (unsigned k = 0; k <= i; k++) {
delete[] InterfaceBlockStageIndex[k];
}
And please add a comment here:
/* Reset the block count. This will help avoid various
* segfaults from api calls that assume the array exists
* due to the count being non-zero.
*/
+ *num_blks = 0;
return false;
}
With those this is:
Reviewed-by: Timothy Arceri <[email protected]>
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