Print backtrace when there is uncaught panic

Cargo.lock

@@ -640,6 +640,7 @@ dependencies = [
  "bitvec",
  "buddy_system_allocator",
  "cfg-if",
+ "gimli",
  "inherit-methods-macro",
  "int-to-c-enum",
  "intrusive-collections",

framework/jinux-frame/Cargo.toml

@@ -12,6 +12,7 @@ bitflags = "1.3"
 bitvec = { version = "1.0", default-features = false, features = ["alloc"] }
 buddy_system_allocator = "0.9.0"
 cfg-if = "1.0"
+gimli = { version = "0.28", default-features = false, features = ["read-core"] }
 inherit-methods-macro = { git = "https://github.com/jinzhao-dev/inherit-methods-macro", rev = "98f7e3e" }
 int-to-c-enum = { path = "../../services/libs/int-to-c-enum" }
 intrusive-collections = "0.9.5"

framework/jinux-frame/src/panicking.rs

@@ -1,9 +1,27 @@
 //! Panic support.
 
 use alloc::{boxed::Box, string::ToString};
+use core::ffi::c_void;
 
 use crate::arch::qemu::{exit_qemu, QemuExitCode};
-use crate::println;
+use crate::{print, println};
+use log::error;
+
+extern crate cfg_if;
+extern crate gimli;
+use gimli::Register;
+
+use unwinding::{
+    abi::{
+        UnwindContext, UnwindReasonCode, _Unwind_Backtrace, _Unwind_FindEnclosingFunction,
+        _Unwind_GetGR, _Unwind_GetIP,
+    },
+    panic::begin_panic,
+};
+
+fn abort() -> ! {
+    exit_qemu(QemuExitCode::Failed);
+}
 
 #[panic_handler]
 fn panic_handler(info: &core::panic::PanicInfo) -> ! {
@@ -14,9 +32,48 @@ fn panic_handler(info: &core::panic::PanicInfo) -> ! {
         col: info.location().unwrap().column() as usize,
     };
     // Throw an exception and expecting it to be caught.
-    unwinding::panic::begin_panic(Box::new(throw_info.clone()));
-    // If the exception is not caught (e.g. by ktest), then print the information
-    // and exit failed using the debug device.
-    println!("[uncaught panic] {}", info);
-    exit_qemu(QemuExitCode::Failed);
+    begin_panic(Box::new(throw_info.clone()));
+    // If the exception is not caught (e.g. by ktest) and resumed,
+    // then print the information and abort.
+    error!("Uncaught panic!");
+    println!("{}", info);
+    println!("printing stack trace:");
+    print_stack_trace();
+    abort();
+}
+
+fn print_stack_trace() {
+    struct CallbackData {
+        counter: usize,
+    }
+    extern "C" fn callback(unwind_ctx: &UnwindContext<'_>, arg: *mut c_void) -> UnwindReasonCode {
+        let data = unsafe { &mut *(arg as *mut CallbackData) };
+        data.counter += 1;
+        let pc = _Unwind_GetIP(unwind_ctx);
+        let fde_initial_address = _Unwind_FindEnclosingFunction(pc as *mut c_void) as usize;
+        println!(
+            "{:4}: fn {:#18x} - pc {:#18x} / registers:",
+            data.counter, fde_initial_address, pc,
+        );
+        // Print the first 8 general registers for any architecture. The register number follows
+        // the DWARF standard.
+        for i in 0..8u16 {
+            let reg_i = _Unwind_GetGR(unwind_ctx, i as i32);
+            cfg_if::cfg_if! {
+                if #[cfg(target_arch = "x86_64")] {
+                    let reg_name = gimli::X86_64::register_name(Register(i)).unwrap_or("unknown");
+                } else {
+                    let reg_name = "unknown";
+                }
+            }
+            if i % 4 == 0 {
+                print!("\n    ");
+            }
+            print!(" {} {:#18x};", reg_name, reg_i);
+        }
+        print!("\n\n");
+        UnwindReasonCode::NO_REASON
+    }
+    let mut data = CallbackData { counter: 0 };
+    _Unwind_Backtrace(callback, &mut data as *mut _ as _);
 }