[Mesa-dev] [PATCH 2/2] glsl: free or reuse memory allocated for TF varying

[Gert Wollny]

Hello Tapani, 

since you wrote the original code, could you have a look at this patch?

Many thanks, 
Gert

Am Freitag, den 16.11.2018, 19:12 +0100 schrieb Gert Wollny:
> From: Gert Wollny <gert.wollny at collabora.com>
> 
> When a shader program is de-serialized the gl_shader_program passed
> in
> may actually still hold memory allocations for the transform feedback
> varyings. If that is the case, free the varying names and reallocate
> the new storage for the names array.
> 
> This fixes a memory leak:
> Direct leak of 48 byte(s) in 6 object(s) allocated from:
>  in malloc (/usr/lib64/gcc/x86_64-pc-linux-
> gnu/7.3.0/libasan.so+0xdb880)
>  in transform_feedback_varyings
> ../../samba/mesa/src/mesa/main/transformfeedback.c:875
>  in _mesa_TransformFeedbackVaryings
> ../../samba/mesa/src/mesa/main/transformfeedback.c:985
>  ...
> Indirect leak of 42 byte(s) in 6 object(s) allocated from:
>   in __interceptor_strdup (/usr/lib64/gcc/x86_64-pc-linux-
> gnu/7.3.0/libasan.so+0x761c8)
>   in transform_feedback_varyings
> ../../samba/mesa/src/mesa/main/transformfeedback.c:887
>   in _mesa_TransformFeedbackVaryings
> ../../samba/mesa/src/mesa/main/transformfeedback.c:985
> 
> Fixes: ab2643e4b06f63c93a57624003679903442634a8
>    glsl: serialize data from glTransformFeedbackVaryings
> 
> Signed-off-by: Gert Wollny <gert.wollny at collabora.com>
> ---
>  src/compiler/glsl/serialize.cpp | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/src/compiler/glsl/serialize.cpp
> b/src/compiler/glsl/serialize.cpp
> index 267700e7e7..26d8ec4b75 100644
> --- a/src/compiler/glsl/serialize.cpp
> +++ b/src/compiler/glsl/serialize.cpp
> @@ -360,13 +360,20 @@ read_xfb(struct blob_reader *metadata, struct
> gl_shader_program *shProg)
>     if (xfb_stage == ~0u)
>        return;
>  
> +   if (shProg->TransformFeedback.VaryingNames)  {
> +      for (unsigned i = 0; i < shProg->TransformFeedback.NumVarying; 
> ++i)
> +         free(shProg->TransformFeedback.VaryingNames[i]);
> +   }
> +
>     /* Data set by glTransformFeedbackVaryings. */
>     shProg->TransformFeedback.BufferMode =
> blob_read_uint32(metadata);
>     blob_copy_bytes(metadata, &shProg-
> >TransformFeedback.BufferStride,
>                     sizeof(shProg->TransformFeedback.BufferStride));
>     shProg->TransformFeedback.NumVarying =
> blob_read_uint32(metadata);
> +
>     shProg->TransformFeedback.VaryingNames = (char **)
> -      malloc(shProg->TransformFeedback.NumVarying * sizeof(GLchar
> *));
> +      realloc(shProg->TransformFeedback.VaryingNames,
> +             shProg->TransformFeedback.NumVarying * sizeof(GLchar
> *));
>     /* Note, malloc used with VaryingNames. */
>     for (unsigned i = 0; i < shProg->TransformFeedback.NumVarying;
> i++)
>        shProg->TransformFeedback.VaryingNames[i] =