glsl/linker: fix output variable overlap check

Prevent an overflow caused by too many output variables. To limit the
scope of the issue, write to the assigned array only for the non-ES
fragment shader path, which is the only place where it's needed.

Since the function will bail with an error when output variables with
overlapping components are found, (max # of FS outputs) * 4 is an upper
limit to the space we need.

Found by address sanitizer.

Fixes dEQP-GLES3.functional.attribute_location.bind_aliasing.*

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
This commit is contained in:
Nicolai Hähnle 2017-09-17 18:25:39 +02:00
parent 62a8ca22cd
commit 15cae12804

View file

@ -2651,12 +2651,14 @@ assign_attribute_or_color_locations(void *mem_ctx,
} to_assign[32];
assert(max_index <= 32);
/* Temporary array for the set of attributes that have locations assigned.
/* Temporary array for the set of attributes that have locations assigned,
* for the purpose of checking overlapping slots/components of (non-ES)
* fragment shader outputs.
*/
ir_variable *assigned[16];
ir_variable *assigned[12 * 4]; /* (max # of FS outputs) * # components */
unsigned assigned_attr = 0;
unsigned num_attr = 0;
unsigned assigned_attr = 0;
foreach_in_list(ir_instruction, node, sh->ir) {
ir_variable *const var = node->as_variable();
@ -2882,6 +2884,12 @@ assign_attribute_or_color_locations(void *mem_ctx,
}
}
}
/* At most one variable per fragment output component should
* reach this. */
assert(assigned_attr < ARRAY_SIZE(assigned));
assigned[assigned_attr] = var;
assigned_attr++;
} else if (target_index == MESA_SHADER_FRAGMENT ||
(prog->IsES && prog->data->Version >= 300)) {
linker_error(prog, "overlapping location is assigned "
@ -2921,9 +2929,6 @@ assign_attribute_or_color_locations(void *mem_ctx,
double_storage_locations |= (use_mask << attr);
}
assigned[assigned_attr] = var;
assigned_attr++;
continue;
}