intel/compiler: Add id parameter to shader_debug_log callback

There are two problems with the current architecture.

In OpenGL, the id is supposed to be a unique identifier for a particular
log source.  This is done so that applications can (theoretically)
filter particular log messages.  The debug callback infrastructure in
Mesa assigns a uniqe value when a value of 0 is passed in.  This causes
the id to get set once to a unique value for each message.

By passing a stack variable that is initialized to 0 on every call,
every time the same message is logged, it will have a different id.
This isn't great, but it's also not catastrophic.

When threaded shader compiles are used, the id *pointer* is saved and
dereferenced at a possibly much later time on a possibly different
thread.  This causes one thread to access the stack from a different
thread... and that stack frame might not be valid any more. :(

This fixes shader-db crashes of various kinds on Iris with threaded
shader compiles enabled.

Fixes: 42c34e1ac8d ("iris: Enable threaded shader compilation")
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12136>

1 files changed, 2 insertions, 3 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_screen.c b/src/mesa/drivers/dri/i965/brw_screen.c
index dad4bc29463..20ca5c21451 100644
--- a/src/mesa/drivers/dri/i965/brw_screen.c
+++ b/src/mesa/drivers/dri/i965/brw_screen.c
@@ -2472,14 +2472,13 @@ set_max_gl_versions(struct brw_screen *screen)
 }
 
 static void
-shader_debug_log_mesa(void *data, const char *fmt, ...)
+shader_debug_log_mesa(void *data, unsigned *msg_id, const char *fmt, ...)
 {
    struct brw_context *brw = (struct brw_context *)data;
    va_list args;
 
    va_start(args, fmt);
-   GLuint msg_id = 0;
-   _mesa_gl_vdebugf(&brw->ctx, &msg_id,
+   _mesa_gl_vdebugf(&brw->ctx, msg_id,
                     MESA_DEBUG_SOURCE_SHADER_COMPILER,
                     MESA_DEBUG_TYPE_OTHER,
                     MESA_DEBUG_SEVERITY_NOTIFICATION, fmt, args);