From a79d109fcc5ae7d19755faf6ece411af60d56614 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sat, 6 May 2023 22:22:05 +0100
Subject: [PATCH] obj: add header-offset field to object_type

this allows the object header to be placed anywhere within the larger
object structure.

the object system now also ensures that the object is zero-initialised
during allocation.
---
 include/socks/object.h | 1 +
 kxld/kext.c            | 1 +
 obj/namespace.c        | 1 +
 obj/object.c           | 8 ++++++--
 obj/set.c              | 1 +
 sched/task.c           | 1 +
 sched/thread.c         | 1 +
 7 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/socks/object.h b/include/socks/object.h
index 3fe59af..1f0bfdc 100644
--- a/include/socks/object.h
+++ b/include/socks/object.h
@@ -48,6 +48,7 @@ struct object_type {
 	enum object_type_flags ob_flags;
 	char ob_name[32];
 	unsigned int ob_size;
+	unsigned int ob_header_offset;
 	struct vm_cache ob_cache;
 	struct queue_entry ob_list;
 	struct queue ob_attrib;
diff --git a/kxld/kext.c b/kxld/kext.c
index f921ac2..844edc8 100644
--- a/kxld/kext.c
+++ b/kxld/kext.c
@@ -34,6 +34,7 @@ static kern_status_t kext_destroy(struct object *obj)
 static struct object_type kext_type = {
 	.ob_name = "kext",
 	.ob_size = sizeof(struct kext),
+	.ob_header_offset = offsetof(struct kext, k_base),
 	.ob_ops = {
 		.query_name = kext_query_name,
 	},
diff --git a/obj/namespace.c b/obj/namespace.c
index f21b5a8..f89dce8 100644
--- a/obj/namespace.c
+++ b/obj/namespace.c
@@ -33,6 +33,7 @@ static kern_status_t ns_get_child_named(struct object *obj, const char *name, st
 static struct object_type ns_type = {
 	.ob_name = "namespace",
 	.ob_size = sizeof(struct object_namespace),
+	.ob_header_offset = offsetof(struct object_namespace, ns_base),
 	.ob_ops = {
 		.query_name = ns_query_name,
 		.get_named = ns_get_child_named,
diff --git a/obj/object.c b/obj/object.c
index 36e2916..b450a88 100644
--- a/obj/object.c
+++ b/obj/object.c
@@ -48,11 +48,15 @@ struct object *object_create(struct object_type *type)
 	}
 
 	struct vm_cache *cache = &type->ob_cache;
-	struct object *obj = vm_cache_alloc(cache, 0);
-	if (!obj) {
+	void *obj_buf = vm_cache_alloc(cache, 0);
+	if (!obj_buf) {
 		return NULL;
 	}
 
+	memset(obj_buf, 0x00, type->ob_size);
+
+	struct object *obj = (struct object *)((unsigned char *)obj_buf + type->ob_header_offset);
+
 	obj->ob_type = type;
 	obj->ob_lock = SPIN_LOCK_INIT;
 	obj->ob_magic = OBJECT_MAGIC;
diff --git a/obj/set.c b/obj/set.c
index b5f33d7..fc2836e 100644
--- a/obj/set.c
+++ b/obj/set.c
@@ -58,6 +58,7 @@ static kern_status_t set_get_child_named(struct object *obj, const char *name, s
 static struct object_type set_type = {
 	.ob_name = "set",
 	.ob_size = sizeof(struct set),
+	.ob_header_offset = offsetof(struct set, s_base),
 	.ob_ops = {
 		.query_name = set_query_name,
 		.get_named = set_get_child_named,
diff --git a/sched/task.c b/sched/task.c
index a3acbad..135734f 100644
--- a/sched/task.c
+++ b/sched/task.c
@@ -11,6 +11,7 @@
 static struct object_type task_type = {
 	.ob_name = "task",
 	.ob_size = sizeof(struct task),
+	.ob_header_offset = offsetof(struct task, t_base),
 };
 
 static struct task *__kernel_task;
diff --git a/sched/thread.c b/sched/thread.c
index afe3e4a..fa0b195 100644
--- a/sched/thread.c
+++ b/sched/thread.c
@@ -8,6 +8,7 @@
 static struct object_type thread_type = {
 	.ob_name = "thread",
 	.ob_size = sizeof(struct thread),
+	.ob_header_offset = offsetof(struct thread, thr_base),
 };
 
 kern_status_t thread_object_type_init(void)