From 50e1b103669a334d31bb27d7d858400c7a12e29e Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Fri, 19 Sep 2025 23:29:18 -0400
Subject: kern: proc: Keep track of mapped areas with ranges

This commit adds a virtual memory range queue to the process descriptor
in order to keep track of mapped pages and free their respective frames
upon program exit.

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/include/sys/proc.h | 18 ++++++++++++++++++
 src/sys/include/vm/vm.h    | 16 ++++++++++++++++
 2 files changed, 34 insertions(+)

(limited to 'src/sys/include')

diff --git a/src/sys/include/sys/proc.h b/src/sys/include/sys/proc.h
index 200d5ce..cf00850 100644
--- a/src/sys/include/sys/proc.h
+++ b/src/sys/include/sys/proc.h
@@ -35,6 +35,7 @@
 #include <sys/cdefs.h>
 #include <sys/param.h>
 #include <sys/queue.h>
+#include <vm/vm.h>
 #include <machine/pcb.h>    /* standard */
 
 /*
@@ -52,6 +53,7 @@
  * @flags: State flags (see PROC_*)
  * @pcb: Process control block
  * @scdom: Syscall domain
+ * @maplist: List of mapped regions
  * @link: TAILQ link
  */
 struct proc {
@@ -59,6 +61,7 @@ struct proc {
     uint32_t flags;
     struct md_pcb pcb;
     struct syscall_domain scdom;
+    TAILQ_HEAD(, vm_range) maplist;
     TAILQ_ENTRY(proc) link;
 };
 
@@ -82,6 +85,21 @@ int proc_init(struct proc *procp, int flags);
  */
 struct proc *proc_self(void);
 
+/*
+ * Allocate a range descriptor and add it to the
+ * process's range tracking list for cleanup upon
+ * exit.
+ *
+ * @procp: Process to initialize the range of
+ * @va: Virtual address to use
+ * @pa: Physical address to use
+ * @len: Length to use
+ *
+ * Returns zero on success, otherwise a less than
+ * zero value upon error.
+ */
+int proc_add_range(struct proc *procp, vaddr_t va, paddr_t pa, size_t len);
+
 /*
  * Kill a process with a specific status code
  *
diff --git a/src/sys/include/vm/vm.h b/src/sys/include/vm/vm.h
index 790fe0b..f5f7b16 100644
--- a/src/sys/include/vm/vm.h
+++ b/src/sys/include/vm/vm.h
@@ -31,6 +31,7 @@
 #define _VM_H_ 1
 
 #include <sys/types.h>
+#include <sys/queue.h>
 #include <sys/bootvars.h>
 
 #define VM_HIGHER_HALF (get_kernel_base())
@@ -42,6 +43,21 @@
 typedef uintptr_t vaddr_t;
 typedef uintptr_t paddr_t;
 
+/*
+ * Describes a virtual memory range
+ *
+ * @pa_base: Physical memory base
+ * @va_base: Virtual memory base
+ * @len: Length of region
+ * @link: Queue link
+ */
+struct vm_range {
+    paddr_t pa_base;
+    vaddr_t va_base;
+    size_t len;
+    TAILQ_ENTRY(vm_range) link;
+};
+
 void vm_init(void);
 
 #endif  /* !_VM_H_ */
-- 
cgit v1.2.3