Change semantics of pd_map_page to return true on success, false on error.

4 files changed, 14 insertions, 11 deletions

diff --git a/src/kernel/core/paging.c b/src/kernel/core/paging.c
index e60ca53..25113ca 100644
--- a/src/kernel/core/paging.c
+++ b/src/kernel/core/paging.c
@@ -171,7 +171,7 @@ uint32_t pd_get_frame(void* vaddr) {
 	return current_pt[pt].page[page] >> PTE_FRAME_SHIFT;
 }
 
-int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
+bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 	uint32_t pt = PT_OF_ADDR(vaddr);
 	uint32_t page = PAGE_OF_ADDR(vaddr);
 
@@ -186,7 +186,7 @@ int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 		uint32_t new_pt_frame = frame_alloc(1);
 		if (new_pt_frame == 0) {
 			mutex_unlock(&pdd->mutex);
-			return 1;	// OOM
+			return false;	// OOM
 		}
 
 		current_pd->page[pt] = pd->page[pt] =
@@ -201,7 +201,7 @@ int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 	invlpg(vaddr);
 
 	mutex_unlock(&pdd->mutex);
-	return 0;
+	return true;
 } 
 
 void pd_unmap_page(void* vaddr) {
@@ -239,8 +239,8 @@ pagedir_t *create_pagedir() {
 	temp = region_alloc(PAGE_SIZE, 0, 0);
 	if (temp == 0) goto error;
 
-	int error = pd_map_page(temp, pd_phys, true);
-	if (error) goto error;
+	bool map_ok = pd_map_page(temp, pd_phys, true);
+	if (!map_ok) goto error;
 
 	pd->phys_addr = pd_phys * PAGE_SIZE;
 	pd->mutex = MUTEX_UNLOCKED;
diff --git a/src/kernel/core/region.c b/src/kernel/core/region.c
index 3127048..c14f129 100644
--- a/src/kernel/core/region.c
+++ b/src/kernel/core/region.c
@@ -293,8 +293,8 @@ void* region_alloc(size_t size, char* type, page_fault_handler_t pf) {
 		void* descriptor_region = region_alloc_inner(PAGE_SIZE, "Region descriptors", 0, true);
 		ASSERT(descriptor_region != 0);
 
-		int error = pd_map_page(descriptor_region, frame, 1);
-		if (error) {
+		bool map_ok = pd_map_page(descriptor_region, frame, 1);
+		if (!map_ok) {
 			// this can happen if we weren't able to allocate a frame for
 			// a new pagetable
 			frame_free(frame, 1);
@@ -339,8 +339,8 @@ void default_allocator_pf_handler(pagedir_t *pd, struct region_info *r, void* ad
 	uint32_t f = frame_alloc(1);
 	if (f == 0) PANIC("Out Of Memory");
 
-	int error = pd_map_page(addr, f, 1);
-	if (error) PANIC("Could not map frame (OOM)");
+	bool map_ok = pd_map_page(addr, f, 1);
+	if (!map_ok) PANIC("Could not map frame (OOM)");
 }
 
 void region_free_unmap_free(void* ptr) {
diff --git a/src/kernel/core/thread.c b/src/kernel/core/thread.c
index 7f0bb5b..3f25add 100644
--- a/src/kernel/core/thread.c
+++ b/src/kernel/core/thread.c
@@ -129,7 +129,10 @@ thread_t *new_thread(entry_t entry, void* data) {
 			free(t);
 			return 0;
 		}
-		pd_map_page(i, f, true);
+		bool map_ok = pd_map_page(i, f, true);
+		if (!map_ok) {
+			PANIC("TODO");
+		}
 	}
 
 	t->stack_region = find_region(stack);
diff --git a/src/kernel/include/paging.h b/src/kernel/include/paging.h
index 44014a2..d42ec52 100644
--- a/src/kernel/include/paging.h
+++ b/src/kernel/include/paging.h
@@ -16,7 +16,7 @@ void switch_pagedir(pagedir_t *pd);
 
 // these functions are always relative to the currently mapped page directory
 uint32_t pd_get_frame(void* vaddr);		// get physical frame for virtual address
-int pd_map_page(void* vaddr, uint32_t frame_id, bool rw);		// returns nonzero on error
+bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw);		// returns true on success, false on failure
 void pd_unmap_page(void* vaddr);	// does nothing if page not mapped
 
 // Note on concurrency : we expect that multiple threads will not try to map/unmap