initgraph, whole lot of refactor

core/panic.c

@@ -1,11 +1,42 @@
+#include <zinnia/alloc.h>
 #include <zinnia/irq.h>
+#include <zinnia/ksyms.h>
 #include <zinnia/panic.h>
 #include <zinnia/percpu.h>
 #include <zinnia/print.h>
 #include <stdarg.h>
+#include <stdint.h>
 
 #define panic_log(msg, ...) kprintf("[    !!!!    ] \e[31m" msg "\e[0m", ##__VA_ARGS__)
 
+static void print_backtrace() {
+    constexpr size_t max_depth = 32;
+    void** fp = __builtin_frame_address(0);
+
+    panic_log("Backtrace:\n");
+    for (size_t i = 0; i < max_depth; i++) {
+        if (!fp || (uintptr_t)fp < mem_hhdm_base || (uintptr_t)fp % alignof(void*))
+            break;
+
+        void* ret = fp[1];
+        if (!ret)
+            break;
+
+        const char* name;
+        size_t offset;
+        // The return address may already point past the end of a noreturn call.
+        if (ksym_lookup((uintptr_t)ret - 1, &name, &offset))
+            panic_log("  #%zu [%p] %s+0x%zx\n", i, ret, name, offset + 1);
+        else
+            panic_log("  #%zu [%p] <\?\?\?>\n", i, ret);
+
+        void** next = fp[0];
+        if (next <= fp)
+            break;
+        fp = next;
+    }
+}
+
 [[noreturn]]
 void panic(const char* msg, ...) {
     // TODO: Stop all other CPUs with IPI.
@@ -15,12 +46,14 @@ void panic(const char* msg, ...) {
     struct task* current = cpu->sched.current;
     kprintf(
         "[    !!!!    ] \e[31m"
-        "Kernel panic on CPU %zu (T%zu, \"%s\"): ",
+        "Kernel panic on CPU %zu (T%zu, \"%s\"):\e[0m\n",
         cpu->id,
         current ? current->id : 0,
         current ? current->name : nullptr
     );
 
+    kprintf("[    !!!!    ] \e[31m");
+
     va_list args;
     va_start(args, msg);
     kvprintf(msg, args);
@@ -28,9 +61,10 @@ void panic(const char* msg, ...) {
 
     kprintf("\e[0m");
 
+    print_backtrace();
     panic_log("End of panic message\n");
 
-    while (1) {
+    while (true) {
         irq_wait();
     }
 }