Lab 6 C: Complete A1

Other changes:

- Add a workaround for a run queue corruption but that causes terminated
  threads to be scheduled.

lab6/c/Makefile

@@ -38,7 +38,7 @@ OBJS      = start main console devicetree initrd panic shell \
             xcpt/syscall/uart-write xcpt/syscall/exec xcpt/syscall/fork \
             xcpt/syscall/fork-impl xcpt/syscall/fork-child-ret \
             xcpt/syscall/exit xcpt/syscall/mbox-call xcpt/syscall/kill \
-            xcpt/syscall/signal xcpt/syscall/signal-kill \
+            xcpt/syscall/signal xcpt/syscall/signal-kill xcpt/syscall/mmap \
             xcpt/syscall/sigreturn xcpt/syscall/sigreturn-check \
             libc/ctype libc/stdio libc/stdlib/qsort libc/string \
             utils/core-id utils/fmt utils/heapq utils/rb

lab6/c/include/oscos/mem/vm.h

@@ -3,6 +3,8 @@
 
 #include "oscos/mem/types.h"
 #include "oscos/mem/vm/page-table.h"
+#include "oscos/uapi/sys/mman.h"
+#include "oscos/utils/rb.h"
 
 /// \brief Converts a kernel space virtual address into its corresponding
 ///        physical address.
@@ -24,10 +26,15 @@ typedef struct {
   mem_region_type_t type;
   const void *backing_storage_start;
   size_t backing_storage_len;
+  int prot;
 } mem_region_t;
 
 typedef struct {
-  mem_region_t text_region, stack_region, vc_region;
+  rb_node_t *root;
+} mem_regions_t;
+
+typedef struct {
+  mem_regions_t mem_regions;
   page_table_entry_t *pgd;
 } vm_addr_space_t;
 
@@ -37,11 +44,19 @@ typedef enum {
   VM_MAP_PAGE_NOMEM
 } vm_map_page_result_t;
 
-page_table_entry_t *vm_new_pgd(void);
-void vm_clone_pgd(page_table_entry_t *pgd);
-void vm_drop_pgd(page_table_entry_t *pgd);
+void vm_mem_regions_insert_region(mem_regions_t *regions,
+                                  const mem_region_t *region);
+const mem_region_t *vm_mem_regions_find_region(const mem_regions_t *regions,
+                                               void *va);
+
+vm_addr_space_t vm_new_addr_space(void);
+vm_addr_space_t vm_clone_addr_space(vm_addr_space_t addr_space);
+void vm_drop_addr_space(vm_addr_space_t pgd);
 vm_map_page_result_t vm_map_page(vm_addr_space_t *addr_space, void *va);
-vm_map_page_result_t vm_cow(vm_addr_space_t *addr_space, void *va);
+vm_map_page_result_t vm_handle_permission_fault(vm_addr_space_t *addr_space,
+                                                void *va, int access_mode);
 void vm_switch_to_addr_space(const vm_addr_space_t *addr_space);
 
+void *vm_decide_mmap_addr(vm_addr_space_t addr_space, void *va, size_t len);
+
 #endif

lab6/c/include/oscos/uapi/sys/mman.h

@@ -0,0 +1,11 @@
+#ifndef OSCOS_UAPI_SYS_MMAN_H
+#define OSCOS_UAPI_SYS_MMAN_H
+
+#define PROT_NONE 0
+#define PROT_READ 1
+#define PROT_WRITE 2
+#define PROT_EXEC 4
+
+#define MAP_FAILED ((void *)-1)
+
+#endif

lab6/c/include/oscos/uapi/sys/syscall.h

@@ -11,6 +11,7 @@
 #define SYS_kill 7
 #define SYS_signal 8
 #define SYS_signal_kill 9
-#define SYS_sigreturn 10
+#define SYS_mmap 10
+#define SYS_sigreturn 11
 
 #endif

lab6/c/include/oscos/utils/rb.h

@@ -13,14 +13,28 @@ typedef struct rb_node_t {
   alignas(16) unsigned char payload[];
 } rb_node_t;
 
+rb_node_t *rb_clone(const rb_node_t *root, size_t size,
+                    bool (*cloner)(void *dst, const void *src),
+                    void (*deleter)(void *payload));
+
 const void *rb_search(const rb_node_t *root, const void *restrict key,
                       int (*compar)(const void *, const void *, void *),
                       void *arg);
 
+const void *rb_predecessor(const rb_node_t *root, const void *restrict key,
+                           int (*compar)(const void *, const void *, void *),
+                           void *arg);
+
+const void *rb_successor(const rb_node_t *root, const void *restrict key,
+                         int (*compar)(const void *, const void *, void *),
+                         void *arg);
+
 bool rb_insert(rb_node_t **root, size_t size, const void *restrict item,
                int (*compar)(const void *, const void *, void *), void *arg);
 
 void rb_delete(rb_node_t **root, const void *restrict key,
                int (*compar)(const void *, const void *, void *), void *arg);
 
+void rb_drop(rb_node_t *root, void (*deleter)(void *payload));
+
 #endif