[Mesa-dev] [PATCH] softpipe: dynamically allocate space for immediate constants

[Gert Wollny]

From: Gert Wollny <gert.wollny at collabora.com>

The number of immediate constants was fixed and the size check was
only done by means of an assertion. Given this a shader that emits
more immediate constants would result in a memory corruption when
mesa is build in release mode.

Instead of using this fixed limit allocate the space dynamically, let it 
grow as needed, and also remove the unused ImmArray.

Fixes: dEQP-GLES31.functional.ssbo.layout.random.arrays_of_arrays.1

Signed-off-by: Gert Wollny <gert.wollny at collabora.com>
---
 src/gallium/auxiliary/tgsi/tgsi_exec.c | 13 ++++++++++++-
 src/gallium/auxiliary/tgsi/tgsi_exec.h |  7 +++----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 59194ebe31..5db515a075 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -1223,7 +1223,17 @@ tgsi_exec_machine_bind_shader(
          {
             uint size = parse.FullToken.FullImmediate.Immediate.NrTokens - 1;
             assert( size <= 4 );
-            assert( mach->ImmLimit + 1 <= TGSI_EXEC_NUM_IMMEDIATES );
+            if (mach->ImmLimit >= mach->ImmsReserved) {
+               unsigned newReserved = mach->ImmsReserved ? 2 * mach->ImmsReserved : 128;
+               float4 *imms = REALLOC(mach->Imms, mach->ImmsReserved, newReserved * sizeof(float4));
+               if (imms) {
+                  mach->ImmsReserved = newReserved;
+                  mach->Imms = imms;
+               } else {
+                  debug_printf("Unable to (re)allocate space for immidiate constants\n");
+                  break;
+               }
+            }
 
             for( i = 0; i < size; i++ ) {
                mach->Imms[mach->ImmLimit][i] = 
@@ -1337,6 +1347,7 @@ tgsi_exec_machine_destroy(struct tgsi_exec_machine *mach)
    if (mach) {
       FREE(mach->Instructions);
       FREE(mach->Declarations);
+      FREE(mach->Imms);
 
       align_free(mach->Inputs);
       align_free(mach->Outputs);
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h b/src/gallium/auxiliary/tgsi/tgsi_exec.h
index ed8b9e8869..6d4ac38142 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h
@@ -231,7 +231,6 @@ struct tgsi_sampler
 };
 
 #define TGSI_EXEC_NUM_TEMPS       4096
-#define TGSI_EXEC_NUM_IMMEDIATES  256
 
 /*
  * Locations of various utility registers (_I = Index, _C = Channel)
@@ -341,6 +340,7 @@ enum tgsi_break_type {
 
 #define TGSI_EXEC_MAX_BREAK_STACK (TGSI_EXEC_MAX_LOOP_NESTING + TGSI_EXEC_MAX_SWITCH_NESTING)
 
+typedef float float4[4];
 
 /**
  * Run-time virtual machine state for executing TGSI shader.
@@ -352,9 +352,8 @@ struct tgsi_exec_machine
    struct tgsi_exec_vector       Temps[TGSI_EXEC_NUM_TEMPS +
                                        TGSI_EXEC_NUM_TEMP_EXTRAS];
 
-   float                         Imms[TGSI_EXEC_NUM_IMMEDIATES][4];
-
-   float                         ImmArray[TGSI_EXEC_NUM_IMMEDIATES][4];
+   unsigned                       ImmsReserved;
+   float4                         *Imms;
 
    struct tgsi_exec_vector       *Inputs;
    struct tgsi_exec_vector       *Outputs;
-- 
2.18.0