elf loading and userland

src/arch/x86_64/gdt.c

@@ -35,6 +35,7 @@ static void reloadgdtr(){
 gdtr.offset = &arch_getcls()->gdt;
 gdtr.size   = sizeof(gdt_t) - 1;
 	asm("lgdt (%%rax)" : : "a"(&gdtr) : "memory");
+	asm("ltr %%ax" : : "a"(0x48));
 }
 
 void gdt_init(){

src/arch/x86_64/include/arch/ist.h

@@ -4,20 +4,22 @@
 #include <stdint.h>
 
 typedef struct{
-	uint32_t IOPB;
-	uint64_t reserved3;
-	uint64_t ist7;
-	uint64_t ist6;
-	uint64_t ist5;
-	uint64_t ist4;
-	uint64_t ist3;
-	uint64_t ist2;
-	uint64_t ist1;
-	uint64_t reserved2;
-	uint64_t rsp2;
-	uint64_t rsp1;
+	uint32_t reserved;
 	uint64_t rsp0;
-	uint64_t reserved;
+	uint64_t rsp1;
+	uint64_t rsp2;
+	uint32_t reserved2;
+	uint64_t ist1;
+	uint64_t ist2;
+	uint64_t ist3;
+	uint64_t ist4;
+	uint64_t ist5;
+	uint64_t ist6;
+	uint64_t ist7;
+	uint32_t reserved3;
+	uint32_t reserved4;
+	uint32_t reserved5;
+	uint32_t IOPB;
 } __attribute((packed)) ist_t;
 
 #endif

src/arch/x86_64/include/arch/mmu.h

@@ -24,5 +24,6 @@ void arch_mmu_init();
 void arch_mmu_apinit();
 arch_mmu_tableptr arch_mmu_newcontext();
 void arch_mmu_switchcontext(arch_mmu_tableptr);
+void arch_mmu_changeflags(arch_mmu_tableptr context, void* addr, size_t flags, size_t count);
 
 #endif

src/arch/x86_64/mmu.c

@@ -114,11 +114,13 @@ static uint64_t getmapping(arch_mmu_tableptr context, void* vaddr){
         size_t pd   = (addr >> 30) & 0b111111111;
         size_t pt   = (addr >> 21) & 0b111111111;
         size_t page = (addr >> 12) & 0b111111111;
+	
+	uint64_t* table = next(context, pdpt);
+	
+	if(!table) return 0;
+	
+	table = next(table, pd);
 
-	if(!context[pdpt]) return 0;
-	
-	uint64_t* table = next(context, pd);
-	
 	if(!table) return 0;
 
 	table = next(table, pt);
@@ -142,6 +144,20 @@ bool arch_mmu_isaccessed(arch_mmu_tableptr context, void* addr){
 	return (getmapping(context, addr) & ARCH_MMU_MAP_ACCESSED) != 0;
 }
 
+void arch_mmu_changeflags(arch_mmu_tableptr context, void* addr, size_t flags, size_t count){
+	for(size_t i = 0; i < count; ++i){
+		uint64_t mapping = getmapping(context, addr);
+		if(!mapping)
+			continue;
+		mapping &= ~(0xFFF); // get addr
+		mapping &= ~ARCH_MMU_MAP_NOEXEC;
+		mapping |= flags;
+		setpage(context, addr, mapping);
+		addr += PAGE_SIZE;
+	}
+	
+}
+
 int arch_mmu_map(arch_mmu_tableptr context, void* paddr, void* vaddr, size_t flags){
 	uint64_t entry;
 	changeentry(&entry, paddr, flags);

src/arch/x86_64/panic.c

@@ -8,7 +8,6 @@
 #define TRACE_MAXDEPTH 10
 
 static void tracestack(uint64_t** addr){
-	
 	for(size_t depth = 0; depth < TRACE_MAXDEPTH; ++depth){
 
 		uint64_t *calleeaddr = *(addr + 1);
@@ -34,8 +33,11 @@ __attribute((noreturn)) void _panic(char* reason, arch_regs *reg){
 		);
 
 		printf("Panic location: %p\n", reg->rip);
-		printf("Stack trace:\n");
-		tracestack((uint64_t**)reg->rbp);
+		
+		if(reg->rbp != 0){
+			printf("Stack trace:\n");
+			tracestack((uint64_t**)reg->rbp);
+		}
 
 	}