Added free page count to panic()

kernel/include/pmm.h

@@ -3,6 +3,9 @@
 
 #include <kernel.h>
 
+extern size_t pmm_total_pages;
+extern size_t pmm_free_pages;
+
 int pmm_init(void);
 void* pmm_alloc(void);
 int pmm_free(void*);

kernel/src/kmain.c

@@ -8,6 +8,8 @@
 #include <isr.h>
 #include <pmm.h>
 
+void a(void) { *(char*)(1234) = 0; } 
+
 __noreturn
 void _start(void) {
 	int err = 0;
@@ -35,6 +37,8 @@ void _start(void) {
 	// The most important function in the world.
 	splash();
 
+	a();
+
 	// Patiently wait for things to do :)
 	while (1);
 };

kernel/src/panic.c

@@ -2,9 +2,28 @@
 #include <kernel.h>
 #include <stdarg.h>
 #include <system.h>
+#include <pmm.h>
 
 static int crashing = 0;
 
+void panic_call_trace(void) {
+	uintptr_t* rbp;
+	__asm__ volatile ("movq %%rbp, %0" : "=r"(rbp));
+
+	pr_emerg("Call trace:\n");
+	for (size_t i = 0; i < 16 && (uintptr_t)rbp > 0x1000; i++) {
+		uintptr_t retaddr = rbp[1];
+		offset_t offset = 0;
+
+		// TODO: Parse ELF and print function names
+		char* fname = "???";
+
+		pr_emerg("  [<%p>] %s+0x%x\n", retaddr, fname, offset);
+
+		rbp = (uintptr_t*)*rbp;
+	}
+}
+
 void panic(const char *fmt, ...) {
 	va_list ap;
 	va_start(ap, fmt);
@@ -24,8 +43,12 @@ void vpanic(const char *fmt, va_list ap) {
 	len = vsnprintf(buf, sizeof(buf), fmt, ap);
 	if (len && buf[len - 1] == '\n') buf[len - 1] = '\0';
 
-	pr_emerg("--- [ Kernel panic: %s ] ---\n", buf);	
+	pr_emerg("--- [ Kernel panic: %s ] ---\n\n", buf);	
-	//pr_emerg("--- [ End kernel panic: %s ] ---\n", buf);
+
+	pr_emerg("%d / %d pages free.\n\n", pmm_free_pages, pmm_total_pages);
+	panic_call_trace();
+
+	pr_emerg("\n--- [ End kernel panic: %s ] ---\n", buf);
 
 	// We can add some kind of LED blink or smth later :)
 	for (;;) __asm__ volatile ("hlt");

kernel/src/pmm.c

@@ -7,7 +7,8 @@
 #include <pmm.h>
 
 uint64_t* pmm_head = NULL;
-size_t pmm_total_mem = 0;
+size_t pmm_total_pages = 0;
+size_t pmm_free_pages = 0;
 
 int pmm_init(void) {
 	pr_info("[pmm] Physical memory map:\n"); // We're gonna use the loop to also print the memmap
@@ -33,12 +34,13 @@ int pmm_init(void) {
 			uint64_t* addr = TO_VIRT(entry->base) + offset;
 			*addr = (uint64_t)pmm_head;
 			pmm_head = addr;
-			pmm_total_mem += PAGE_SIZE;
+			pmm_total_pages++;
 		}
 	}
 
-	pr_info("[pmm] %d bytes of available memory.\n", pmm_total_mem);
+	pr_info("[pmm] %d free pages.\n", pmm_total_pages);
-	if (pmm_total_mem == 0) return -ENOMEM;
+	if (pmm_total_pages == 0) return -ENOMEM;
+	pmm_free_pages = pmm_total_pages;
 
 	return SUCCESS;
 }
@@ -49,6 +51,7 @@ void* pmm_alloc() {
 	uint64_t* addr = pmm_head;
 	if ((uintptr_t)addr % PAGE_SIZE != 0) panic("pmm_head corrupted.");
 	pmm_head = (uint64_t*)(*addr);
+	pmm_free_pages--;
 
 	return TO_PHYS(addr);
 }
@@ -60,6 +63,7 @@ int pmm_free(void* page) {
 	uint64_t* addr = TO_VIRT(page);
 	*addr = (uint64_t)pmm_head;
 	pmm_head = addr;
+	pmm_free_pages++;
 
 	return SUCCESS;
 }