Remove kernel region pf handlers ; fix forget-to-zero-out bug.

7 files changed, 35 insertions, 38 deletions

diff --git a/src/kernel/core/kmalloc.c b/src/kernel/core/kmalloc.c
index 85e6173..c977e54 100644
--- a/src/kernel/core/kmalloc.c
+++ b/src/kernel/core/kmalloc.c
@@ -9,7 +9,7 @@
 #include <freemem.h>
 
 static void* page_alloc_fun_for_kmalloc(size_t bytes) {
-	void* addr = region_alloc(bytes, "Core kernel heap", 0);
+	void* addr = region_alloc(bytes, "Core kernel heap");
 	if (addr == 0) return 0;
 
 	// Map physical memory
diff --git a/src/kernel/core/paging.c b/src/kernel/core/paging.c
index f2289bd..eec21f6 100644
--- a/src/kernel/core/paging.c
+++ b/src/kernel/core/paging.c
@@ -8,6 +8,8 @@
 #include <malloc.h>
 #include <freemem.h>
 
+#include <string.h>
+
 #define PAGE_OF_ADDR(x)		(((size_t)(x) >> PAGE_SHIFT) % N_PAGES_IN_PT)
 #define PT_OF_ADDR(x)		((size_t)(x) >> (PAGE_SHIFT + PT_SHIFT))
 
@@ -103,18 +105,13 @@ void page_fault_handler(registers_t *regs) {
 			}
 
 			region_info_t *i = find_region(vaddr);
-			if (i == 0) {
-				dbg_printf("Kernel pagefault in non-existing region at 0x%p\n", vaddr);
-				dbg_dump_registers(regs);
-				PANIC("Unhandled kernel space page fault");
-			}
-			if (i->pf == 0) {
-				dbg_printf("Kernel pagefault in region with no handler at 0x%p (%s region)\n", vaddr, i->type);
-				dbg_dump_registers(regs);
-				dbg_print_region_info();
-				PANIC("Unhandled kernel space page fault");
-			}
-			i->pf(get_current_pagedir(), i, vaddr);
+
+			char* region = (i == 0 ? "non-exting" : i->type);
+
+			dbg_printf("Kernel pagefault in region with no handler at 0x%p (%s region)\n", vaddr, region);
+			dbg_dump_registers(regs);
+			dbg_print_region_info();
+			PANIC("Unhandled kernel space page fault");
 		}
 	}
 }
@@ -203,6 +200,7 @@ bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 	const uint32_t page = PAGE_OF_ADDR(vaddr);
 
 	ASSERT((size_t)vaddr < PD_MIRROR_ADDR);
+	ASSERT(frame_id != 0);
 	
 	bool on_kernel_pd = (size_t)vaddr >= K_HIGHHALF_ADDR || current_thread == 0;
 	
@@ -212,7 +210,6 @@ bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 	mutex_lock(&pdd->mutex);
 
 	if (!(pd->page[pt] & PTE_PRESENT)) {
-
 		uint32_t new_pt_frame;
 		int tries = 0;
 		while ((new_pt_frame = frame_alloc(1)) == 0 && (tries++) < 3) {
@@ -226,13 +223,15 @@ bool pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
 		}
 
 		current_pd->page[pt] = pd->page[pt] =
-			(new_pt_frame << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW
+			(new_pt_frame << PTE_FRAME_SHIFT)
+			| PTE_PRESENT | PTE_RW
 			| ((size_t)vaddr < K_HIGHHALF_ADDR ? PTE_USER : 0);
+
 		invlpg(&current_pt[pt]);
+		memset(&current_pt[pt], 0, PAGE_SIZE);
 	}
 	current_pt[pt].page[page] =
-		(frame_id << PTE_FRAME_SHIFT)
-			| PTE_PRESENT
+		(frame_id << PTE_FRAME_SHIFT) | PTE_PRESENT
 			| ((size_t)vaddr < K_HIGHHALF_ADDR ? PTE_USER : PTE_GLOBAL)
 			| (rw ? PTE_RW : 0);
 	invlpg(vaddr);
@@ -273,7 +272,7 @@ pagedir_t *create_pagedir(user_pf_handler_t pf, void* pfd) {
 	pd = (pagedir_t*)malloc(sizeof(pagedir_t));
 	if (pd == 0) goto error;
 
-	temp = region_alloc(PAGE_SIZE, "Temporary pagedir mapping", 0);
+	temp = region_alloc(PAGE_SIZE, "Temporary pagedir mapping");
 	if (temp == 0) goto error;
 
 	bool map_ok = pd_map_page(temp, pd_phys, true);
diff --git a/src/kernel/core/region.c b/src/kernel/core/region.c
index d22a98f..1f1958f 100644
--- a/src/kernel/core/region.c
+++ b/src/kernel/core/region.c
@@ -216,7 +216,6 @@ void region_allocator_init(void* kernel_data_end) {
 	u0->used.i.addr = (void*)K_HIGHHALF_ADDR;
 	u0->used.i.size = PAGE_ALIGN_UP(kernel_data_end) - K_HIGHHALF_ADDR;
 	u0->used.i.type = "Kernel code & data";
-	u0->used.i.pf = 0;
 	u0->used.next_by_addr = 0;
 	first_used_region = u0;
 }
@@ -238,7 +237,7 @@ void region_free(void* addr) {
 	mutex_unlock(&ra_mutex);
 }
 
-static void* region_alloc_inner(size_t size, char* type, kernel_pf_handler_t pf, bool use_reserve) {
+static void* region_alloc_inner(size_t size, char* type, bool use_reserve) {
 	size = PAGE_ALIGN_UP(size);
 
 	for (descriptor_t *i = first_free_region_by_size; i != 0; i = i->free.first_bigger) {
@@ -273,7 +272,6 @@ static void* region_alloc_inner(size_t size, char* type, kernel_pf_handler_t pf,
 			i->used.i.addr = addr;
 			i->used.i.size = size;
 			i->used.i.type = type;
-			i->used.i.pf = pf;
 			add_used_region(i);
 
 			return addr;
@@ -282,7 +280,7 @@ static void* region_alloc_inner(size_t size, char* type, kernel_pf_handler_t pf,
 	return 0;	//No big enough block found
 }
 
-void* region_alloc(size_t size, char* type, kernel_pf_handler_t pf) {
+void* region_alloc(size_t size, char* type) {
 	void* result = 0;
 	mutex_lock(&ra_mutex);
 
@@ -290,7 +288,7 @@ void* region_alloc(size_t size, char* type, kernel_pf_handler_t pf) {
 		uint32_t frame = frame_alloc(1);
 		if (frame == 0) goto try_anyway;
 
-		void* descriptor_region = region_alloc_inner(PAGE_SIZE, "Region descriptors", 0, true);
+		void* descriptor_region = region_alloc_inner(PAGE_SIZE, "Region descriptors", true);
 		ASSERT(descriptor_region != 0);
 
 		bool map_ok = pd_map_page(descriptor_region, frame, 1);
@@ -312,7 +310,7 @@ void* region_alloc(size_t size, char* type, kernel_pf_handler_t pf) {
 	// even if we don't have enough unused descriptors, we might find
 	// a free region that has exactly the right size and therefore
 	// does not require splitting, so we try the allocation in all cases
-	result = region_alloc_inner(size, type, pf, false);
+	result = region_alloc_inner(size, type, false);
 
 	mutex_unlock(&ra_mutex);
 	return result;
diff --git a/src/kernel/core/thread.c b/src/kernel/core/thread.c
index 74e5a30..1689433 100644
--- a/src/kernel/core/thread.c
+++ b/src/kernel/core/thread.c
@@ -157,7 +157,7 @@ thread_t *new_thread(entry_t entry, void* data) {
 	thread_t *t = (thread_t*)malloc(sizeof(thread_t));
 	if (t == 0) return 0;
 
-	void* stack = region_alloc(KPROC_STACK_SIZE + PAGE_SIZE, "Stack", 0);
+	void* stack = region_alloc(KPROC_STACK_SIZE + PAGE_SIZE, "Stack");
 	if (stack == 0) {
 		free(t);
 		return 0;
diff --git a/src/kernel/include/region.h b/src/kernel/include/region.h
index eb6f7e8..2593dba 100644
--- a/src/kernel/include/region.h
+++ b/src/kernel/include/region.h
@@ -8,25 +8,19 @@
 #include <paging.h>
 
 struct region_info;
-typedef void (*kernel_pf_handler_t)(pagedir_t *pd, struct region_info *r, void* addr);
 
 typedef struct region_info {
 	void* addr;
 	size_t size;
 	char* type;
-	kernel_pf_handler_t pf;
 } region_info_t;
 
 void region_allocator_init(void* kernel_data_end);
 
-void* region_alloc(size_t size, char* type, kernel_pf_handler_t pf);	// returns 0 on error
+void* region_alloc(size_t size, char* type);	// returns 0 on error
 region_info_t *find_region(void* addr);
 void region_free(void* addr);
 
-// some usefull PF handlers
-// void pf_handler_unexpected(pagedir_t *pd, struct region_info *r, void* addr);	// Expects never to be called
-// void pf_handler_stackoverflow(pagedir_t *pd, struct region_info *r, void* addr);	// Stack overflow detected
-
 // some functions for freeing regions and frames
 // region_free_unmap_free : deletes a region and frees all frames that were mapped in it
 void region_free_unmap_free(void* addr);
diff --git a/src/kernel/user/pager.c b/src/kernel/user/pager.c
index b1ce9c3..45d2970 100644
--- a/src/kernel/user/pager.c
+++ b/src/kernel/user/pager.c
@@ -47,7 +47,7 @@ error:
 void swap_page_in(pager_t *p, size_t offset, size_t len) {
 	ASSERT(PAGE_ALIGNED(offset));
 
-	void *region = region_alloc(PAGE_SIZE, "Page zeroing area", 0);
+	void *region = region_alloc(PAGE_SIZE, "Page zeroing area");
 	if (region == 0) return;
 
 	for (size_t page = offset; page < offset + len; page += PAGE_SIZE) {
@@ -92,7 +92,7 @@ bool swap_pager_resize(pager_t *p, size_t new_size) {
 	size_t last_page = PAGE_ALIGN_DOWN(new_size);
 
 	if (!PAGE_ALIGNED(new_size) && hashtbl_find(p->pages, (void*)last_page) != 0) {
-		void *region = region_alloc(PAGE_SIZE, "Page zeroing area", 0);
+		void *region = region_alloc(PAGE_SIZE, "Page zeroing area");
 		if (!region) PANIC("TODO");
 
 		uint32_t frame = (uint32_t)hashtbl_find(p->pages, (void*)last_page) >> ENT_FRAME_SHIFT;
@@ -154,7 +154,7 @@ void vfs_page_in(pager_t *p, size_t offset, size_t len) {
 	ASSERT(PAGE_ALIGNED(offset));
 	ASSERT(p->vfs_pager.ops->read != 0);
 
-	void *region = region_alloc(PAGE_SIZE, "Page loading area", 0);
+	void *region = region_alloc(PAGE_SIZE, "Page loading area");
 	if (region == 0) return;
 
 	for (size_t page = offset; page < offset + len; page += PAGE_SIZE) {
@@ -332,7 +332,7 @@ size_t pager_do_rw(pager_t *p, size_t offset, size_t len, char* buf, bool write)
 	size_t first_page = PAGE_ALIGN_DOWN(offset);
 	size_t region_len = offset + len - first_page;
 
-	region = region_alloc(PAGE_ALIGN_UP(region_len), "Temporary pager read/write zone", 0);
+	region = region_alloc(PAGE_ALIGN_UP(region_len), "Temporary pager read/write zone");
 	if (region == 0) goto end_read;
 
 	p->ops->page_in(p, first_page, region_len);
diff --git a/src/kernel/user/process.c b/src/kernel/user/process.c
index d8f1eed..4d79327 100644
--- a/src/kernel/user/process.c
+++ b/src/kernel/user/process.c
@@ -682,8 +682,14 @@ void proc_usermem_pf(void* p, registers_t *regs, void* addr) {
 		current_process_exit(PS_FAILURE, (addr < (void*)PAGE_SIZE ? FAIL_ZEROPTR : FAIL_SEGFAULT));
 	}
 
-	bool pr = ((regs->err_code & PF_PRESENT_BIT) != 0);
-	ASSERT(!pr);
+	bool pr = (regs->err_code & PF_PRESENT_BIT) != 0;
+	if (pr) {
+		uint32_t frame = pd_get_entry(addr);
+		dbg_printf("UPF 0x%p %s present %d 0x%p\n",
+			addr, (wr ? "write" : "read"),
+			frame >> PTE_FRAME_SHIFT, frame);
+		PANIC("Unexpected fault on present page.");
+	}
 
 	addr = (void*)((uint32_t)addr & PAGE_MASK);