From 8e874e6a8896d976dd5cd87079770df1b2011786 Mon Sep 17 00:00:00 2001
From: Zhang Junyang <junyang@stu.pku.edu.cn>
Date: Fri, 17 May 2024 15:28:29 +0000
Subject: [PATCH] Let OSDK print source lines of the panic stack trace

---
 osdk/Cargo.lock        | 15 +++++++++++++--
 osdk/Cargo.toml        |  2 ++
 osdk/src/bundle/mod.rs | 12 ++++++++++++
 osdk/src/util.rs       | 43 +++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/osdk/Cargo.lock b/osdk/Cargo.lock
index b362d3ea8..f9801004a 100644
--- a/osdk/Cargo.lock
+++ b/osdk/Cargo.lock
@@ -132,6 +132,8 @@ dependencies = [
  "linux-bzimage-builder",
  "log",
  "quote",
+ "regex",
+ "rev_buf_reader",
  "serde",
  "serde_json",
  "sha2",
@@ -388,9 +390,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.10.3"
+version = "1.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b62dbe01f0b06f9d8dc7d49e05a0785f153b00b2c227856282f671e0318c9b15"
+checksum = "c117dbdfde9c8308975b6a18d71f3f385c89461f7b3fb054288ecf2a2058ba4c"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -415,6 +417,15 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"
 
+[[package]]
+name = "rev_buf_reader"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c0f2e47e00e29920959826e2e1784728a3780d1a784247be5257258cc75f910"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.17"
diff --git a/osdk/Cargo.toml b/osdk/Cargo.toml
index 5e8889b6d..9e6598bed 100644
--- a/osdk/Cargo.toml
+++ b/osdk/Cargo.toml
@@ -29,6 +29,8 @@ indexmap = "2.2.1"
 lazy_static = "1.4.0"
 log = "0.4.20"
 quote = "1.0.35"
+regex = "1.10.4"
+rev_buf_reader = "0.3.0"
 serde = { version = "1.0.195", features = ["derive"] }
 serde_json = "1.0.111"
 sha2 = "0.10.8"
diff --git a/osdk/src/bundle/mod.rs b/osdk/src/bundle/mod.rs
index 2513aa8a5..db8a89007 100644
--- a/osdk/src/bundle/mod.rs
+++ b/osdk/src/bundle/mod.rs
@@ -247,6 +247,18 @@ impl Bundle {
         info!("Running QEMU: {:#?}", qemu_cmd);
 
         let exit_status = qemu_cmd.status().unwrap();
+
+        // Find the QEMU output in "qemu.log", read it and check if it failed with a panic.
+        // Setting a QEMU log is required for source line stack trace because piping the output
+        // is less desirable when running QEMU with serial redirected to standard I/O.
+        let qemu_log_path = config.work_dir.join("qemu.log");
+        if let Ok(file) = std::fs::File::open(qemu_log_path) {
+            if let Some(aster_bin) = &self.manifest.aster_bin {
+                crate::util::trace_panic_from_log(file, self.path.join(aster_bin.path()));
+            }
+        }
+
+        // FIXME: When panicking it sometimes returns success, why?
         if !exit_status.success() {
             // FIXME: Exit code manipulation is not needed when using non-x86 QEMU
             let qemu_exit_code = exit_status.code().unwrap();
diff --git a/osdk/src/util.rs b/osdk/src/util.rs
index 9def7cb6b..a05aea9eb 100644
--- a/osdk/src/util.rs
+++ b/osdk/src/util.rs
@@ -2,7 +2,8 @@
 
 use std::{
     ffi::OsStr,
-    fs,
+    fs::{self, File},
+    io::{BufRead, BufReader, Write},
     path::{Path, PathBuf},
     process::Command,
 };
@@ -212,3 +213,43 @@ pub fn parse_package_id_string(package_id: &str) -> CrateInfo {
         }
     }
 }
+
+/// Print source line stack trace if a panic is detected from QEMU log.
+///
+/// The source line is produced with the `addr2line` command using the PC values in the panic
+/// stack trace.
+pub fn trace_panic_from_log(qemu_log: File, bin_path: PathBuf) {
+    // We read last 500 lines since more than 100 layers of stack trace is unlikely.
+    let reader = rev_buf_reader::RevBufReader::new(qemu_log);
+    let lines: Vec<String> = reader.lines().take(500).map(|l| l.unwrap()).collect();
+    let mut trace_exists = false;
+    let mut stack_num = 0;
+    let pc_matcher = regex::Regex::new(r" - pc (0x[0-9a-fA-F]+)").unwrap();
+    let exe = bin_path.to_string_lossy();
+    let mut addr2line = Command::new("addr2line");
+    addr2line.args(["-e", &exe]);
+    let mut addr2line_proc = addr2line
+        .stdin(std::process::Stdio::piped())
+        .stdout(std::process::Stdio::piped())
+        .spawn()
+        .unwrap();
+    for line in lines.into_iter().rev() {
+        if line.contains("printing stack trace:") {
+            println!("[OSDK] The kernel seems panicked. Parsing stack trace for source lines:");
+            trace_exists = true;
+        }
+        if trace_exists {
+            if let Some(cap) = pc_matcher.captures(&line) {
+                let pc = cap.get(1).unwrap().as_str();
+                let mut stdin = addr2line_proc.stdin.as_ref().unwrap();
+                stdin.write_all(pc.as_bytes()).unwrap();
+                stdin.write_all(b"\n").unwrap();
+                let mut line = String::new();
+                let mut stdout = BufReader::new(addr2line_proc.stdout.as_mut().unwrap());
+                stdout.read_line(&mut line).unwrap();
+                stack_num += 1;
+                println!("({: >3}) {}", stack_num, line.trim());
+            }
+        }
+    }
+}