From cabbf335824db0df835e4c541c19d3803ce38454 Mon Sep 17 00:00:00 2001
From: Kimplul <kimi.h.kuparinen@gmail.com>
Date: Wed, 14 Sep 2022 21:30:11 +0300
Subject: add canary to kernel stack

---
 include/apos/canary.h | 27 +++++++++++++++++++++++++++
 include/apos/mem.h    | 20 ++++++++++----------
 include/apos/types.h  |  2 ++
 3 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 include/apos/canary.h

(limited to 'include')

diff --git a/include/apos/canary.h b/include/apos/canary.h
new file mode 100644
index 0000000..30a3dd2
--- /dev/null
+++ b/include/apos/canary.h
@@ -0,0 +1,27 @@
+#ifndef APOS_CANARY_H
+#define APOS_CANARY_H
+
+/**
+ * @file canary.h
+ * Kernel stack canary handling.
+ */
+
+#include <apos/tcb.h>
+#include <apos/types.h>
+
+/**
+ * Place canary at end of kernel stack.
+ *
+ * @param t \ref tcb whose kernel stack to place canary in.
+ */
+void set_canary(struct tcb *t);
+
+/**
+ * Check that canary hasn't been accidentally overwritten.
+ *
+ * @param t \ref tcb whose kernel stack canary to check.
+ * @return \ref true if overwritten, \ref false otherwise.
+ */
+bool check_canary(struct tcb *t);
+
+#endif /* APOS_CANARY_H */
diff --git a/include/apos/mem.h b/include/apos/mem.h
index 08aad1f..512f1e7 100644
--- a/include/apos/mem.h
+++ b/include/apos/mem.h
@@ -245,34 +245,34 @@ extern size_t __mm_max_order;
 /** Give names to page orders. */
 enum mm_order {
 	/** Base order. */
-	MM_O0,
+	MM_O0 = 0,
 
 	/** Order 1. */
-	MM_O1,
+	MM_O1 = 1,
 
 	/** Order 2. */
-	MM_O2,
+	MM_O2 = 2,
 
 	/** Order 3. */
-	MM_O3,
+	MM_O3 = 3,
 
 	/** Order 4. */
-	MM_O4,
+	MM_O4 = 4,
 
 	/** Order 5. */
-	MM_O5,
+	MM_O5 = 5,
 
 	/** Order 6. */
-	MM_O6,
+	MM_O6 = 6,
 
 	/** Order 7. */
-	MM_O7,
+	MM_O7 = 7,
 
 	/** Order 8. */
-	MM_O8,
+	MM_O8 = 8,
 
 	/** Order 9. */
-	MM_O9,
+	MM_O9 = 9,
 };
 
 /** Page number. */
diff --git a/include/apos/types.h b/include/apos/types.h
index 10ad80a..f249705 100644
--- a/include/apos/types.h
+++ b/include/apos/types.h
@@ -455,6 +455,8 @@ typedef uint_fast16_t vmflags_t;
  */
 /* should this enum be somewhere else? */
 enum status_codes {
+	/** Internal error, should probably halt */
+	ERR_INT = -9,
 	/** Something went wrong :/ */
 	ERR_MISC = -8,
 	/** Not initialized. */
-- 
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