chore: kernel: trap: print trace when page fault happens

.vscode/settings.json

@@ -16,5 +16,9 @@
         "**/.rustup/**": true,
         "**/.cargo/registry/**": true,
         "**/.cargo/git/**": true,
+    },
+    "[riscv]": {
+        "editor.indentSize": "tabSize",
+        "editor.tabSize": 8
     }
 }

kernel/src/arch/riscv/trap.rs

@@ -93,6 +93,10 @@ impl TrapContextOps for TrapContext {
                 if from_kernel {
                     panic_fatal!("Page Fault in Kernel");
                 }
+
+                let stval = riscv::register::stval::read();
+                trace!("Page Fault: sepc: {:#x}, stval: {:#x}", self.sepc, stval);
+
                 // TODO: handle page fault
             },
             _ => panic_fatal!("Unhandled Trap"),