iris: fix iris_ensure_indirect_generation_shader() memory leak

This change ensures that all these allocations are using
the same memory context.

For instance, this issue is triggered with:
"piglit/bin/arb_shader_image_load_store-host-mem-barrier -auto -fbo":
Indirect leak of 32816 byte(s) in 1 object(s) allocated from:
    #0 0x7f49a35447ef in __interceptor_malloc (/usr/lib64/libasan.so.6+0xb17ef)
    waydroid#1 0x7f49998e4b4f in ralloc_size ../src/util/ralloc.c:118
    waydroid#2 0x7f49998e7521 in create_slab ../src/util/ralloc.c:801
    waydroid#3 0x7f49998e7521 in gc_alloc_size ../src/util/ralloc.c:840
    waydroid#4 0x7f49998e7d11 in gc_zalloc_size ../src/util/ralloc.c:868
    waydroid#5 0x7f49999a6126 in nir_alu_instr_create ../src/compiler/nir/nir.c:682
    waydroid#6 0x7f49999cba48 in clone_alu ../src/compiler/nir/nir_clone.c:217
    waydroid#7 0x7f49999cc85a in clone_instr ../src/compiler/nir/nir_clone.c:456
    waydroid#8 0x7f49999cee3a in clone_block ../src/compiler/nir/nir_clone.c:529
    waydroid#9 0x7f49999cee3a in clone_cf_list ../src/compiler/nir/nir_clone.c:583
    waydroid#10 0x7f49999d03be in clone_function_impl ../src/compiler/nir/nir_clone.c:660
    waydroid#11 0x7f49999d13f7 in nir_function_impl_clone ../src/compiler/nir/nir_clone.c:678
    waydroid#12 0x7f4999a0e2c5 in lower_call_function_impl ../src/compiler/nir/nir_functions.c:397
    #13 0x7f4999a0e2c5 in function_link_pass ../src/compiler/nir/nir_functions.c:430
    #14 0x7f4999a0e2c5 in function_link_pass ../src/compiler/nir/nir_functions.c:408
    #15 0x7f4999a0e2c5 in nir_function_instructions_pass ../src/compiler/nir/nir_builder.h:108
    #16 0x7f4999a0e2c5 in nir_link_shader_functions ../src/compiler/nir/nir_functions.c:452
    #17 0x7f499ca30b8f in link_libintel_shaders ../src/gallium/drivers/iris/iris_program_cache.c:329
    #18 0x7f499ca30b8f in iris_ensure_indirect_generation_shader ../src/gallium/drivers/iris/iris_program_cache.c:374
    #19 0x7f499d185267 in gfx9_emit_indirect_generate ../src/gallium/drivers/iris/iris_indirect_gen.c:593
    #20 0x7f499d119c79 in iris_upload_indirect_shader_render_state ../src/gallium/drivers/iris/iris_state.c:8744
    #21 0x7f499fe86b01 in iris_indirect_draw_vbo ../src/gallium/drivers/iris/iris_draw.c:233
    #22 0x7f499fe86b01 in iris_draw_vbo ../src/gallium/drivers/iris/iris_draw.c:343
    #23 0x7f499a174e43 in tc_call_draw_indirect ../src/gallium/auxiliary/util/u_threaded_context.c:3828
    #24 0x7f499a1557fe in batch_execute ../src/gallium/auxiliary/util/u_threaded_context.c:453
    #25 0x7f499a1557fe in tc_batch_execute ../src/gallium/auxiliary/util/u_threaded_context.c:504
    #26 0x7f499a167f26 in _tc_sync ../src/gallium/auxiliary/util/u_threaded_context.c:761
    #27 0x7f499a168888 in tc_texture_map ../src/gallium/auxiliary/util/u_threaded_context.c:2783
    #28 0x7f49986f2631 in pipe_texture_map ../src/gallium/auxiliary/util/u_inlines.h:556
    #29 0x7f49986f2631 in _mesa_map_renderbuffer ../src/mesa/main/renderbuffer.c:494
    #30 0x7f49991af7ca in readpixels_memcpy ../src/mesa/main/readpix.c:260
    #31 0x7f49991af7ca in _mesa_readpixels ../src/mesa/main/readpix.c:898
    #32 0x7f499931ee23 in st_ReadPixels ../src/mesa/state_tracker/st_cb_readpixels.c:575
    #33 0x7f49991b40b5 in read_pixels ../src/mesa/main/readpix.c:1199
    #34 0x7f49991b40b5 in _mesa_ReadnPixelsARB ../src/mesa/main/readpix.c:1216
    #35 0x7f49991b4a20 in _mesa_ReadPixels ../src/mesa/main/readpix.c:1231
...
SUMMARY: AddressSanitizer: 323648 byte(s) leaked in 201 allocation(s).

Fixes: 5438b19 ("iris: enable generated indirect draws")
Signed-off-by: Patrick Lerda <patrick9876@free.fr>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31313>
(cherry picked from commit b6b363c)

Author: Patrick Lerda

.pick_status.json

@@ -24,7 +24,7 @@
         "description": "iris: fix iris_ensure_indirect_generation_shader() memory leak",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "5438b1910464e4b17fe0248a96a6ed98f0280a20",
         "notes": null

src/gallium/drivers/iris/iris_program_cache.c

@@ -370,8 +370,7 @@ iris_ensure_indirect_generation_shader(struct iris_batch *batch)
 
    nir_shader *nir = b.shader;
 
-   void *mem_ctx = ralloc_context(NULL);
-   link_libintel_shaders(nir, screen->vtbl.load_shader_lib(screen, mem_ctx));
+   link_libintel_shaders(nir, screen->vtbl.load_shader_lib(screen, nir));
 
    NIR_PASS_V(nir, nir_lower_vars_to_ssa);
    NIR_PASS_V(nir, nir_opt_cse);
@@ -446,7 +445,7 @@ iris_ensure_indirect_generation_shader(struct iris_batch *batch)
             .log_data = &ice->dbg,
             .debug_flag = DEBUG_WM,
             .stats = stats,
-            .mem_ctx = mem_ctx,
+            .mem_ctx = nir,
          },
          .key = &prog_key.wm,
          .prog_data = prog_data,
@@ -471,7 +470,7 @@ iris_ensure_indirect_generation_shader(struct iris_batch *batch)
             .log_data = &ice->dbg,
             .debug_flag = DEBUG_WM,
             .stats = stats,
-            .mem_ctx = mem_ctx,
+            .mem_ctx = nir,
          },
          .key = &prog_key.wm,
          .prog_data = prog_data,
@@ -490,7 +489,7 @@ iris_ensure_indirect_generation_shader(struct iris_batch *batch)
                       ice->shaders.uploader_driver,
                       IRIS_CACHE_BLORP, sizeof(key), &key, program);
 
-   ralloc_free(mem_ctx);
+   ralloc_free(nir);
 
    struct iris_bo *bo = iris_resource_bo(shader->assembly.res);
    iris_use_pinned_bo(batch, bo, false, IRIS_DOMAIN_NONE);