From 6bbc889d7f74f92e7947280098dffca4b2f3a7fb Mon Sep 17 00:00:00 2001
From: Paul Pan <i@0x7f.app>
Date: Fri, 23 Aug 2024 20:45:08 +0800
Subject: [PATCH] chore: kernel/arch/riscv/trap: also log sp

---
 kernel/Cargo.toml                  |  2 +-
 kernel/src/arch/riscv/backtrace.rs | 37 +++++++++++++++++++-----------
 kernel/src/arch/riscv/trap.rs      | 12 ++++++++--
 3 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/kernel/Cargo.toml b/kernel/Cargo.toml
index 7a2a61d..8fbfb40 100644
--- a/kernel/Cargo.toml
+++ b/kernel/Cargo.toml
@@ -39,4 +39,4 @@ uart_16550 = "0.3"
 
 [target.'cfg(target_arch = "riscv64")'.dependencies]
 riscv = { version = "0.11", features = ["s-mode"] }
-sbi-rt = { version = "0.0" }
+sbi-rt = { version = "0.0.3" }
diff --git a/kernel/src/arch/riscv/backtrace.rs b/kernel/src/arch/riscv/backtrace.rs
index bec0b6b..47c2c18 100644
--- a/kernel/src/arch/riscv/backtrace.rs
+++ b/kernel/src/arch/riscv/backtrace.rs
@@ -2,19 +2,28 @@ use super::layout::{BSS_END, BSS_START, TEXT_END, TEXT_START};
 use crate::plat::backtrace::FrameWalker;
 use utils::addr::{AddressOps, VirtAddr};
 
+#[inline]
+pub fn read_fp() -> usize {
+    let fp;
+    unsafe { core::arch::asm!("mv {}, fp", out(reg) fp) }
+    fp
+}
+
+#[inline]
+pub fn read_sp() -> usize {
+    let sp;
+    unsafe { core::arch::asm!("mv {}, sp", out(reg) sp) }
+    sp
+}
+
+#[inline]
+pub fn read_ra() -> usize {
+    let ra;
+    unsafe { core::arch::asm!("mv {}, ra", out(reg) ra) }
+    ra
+}
+
 impl FrameWalker {
-    fn read_fp() -> usize {
-        let fp;
-        unsafe { core::arch::asm!("mv {}, fp", out(reg) fp) }
-        fp
-    }
-
-    fn read_ra() -> usize {
-        let ra;
-        unsafe { core::arch::asm!("mv {}, ra", out(reg) ra) }
-        ra
-    }
-
     fn is_valid(&self) -> bool {
         let fp_valid = unsafe { BSS_START.as_virt_addr() <= self.current_fp && self.current_fp < BSS_END.as_virt_addr() };
         let pc_valid = unsafe { TEXT_START.as_virt_addr() <= self.current_pc && self.current_pc < TEXT_END.as_virt_addr() };
@@ -28,8 +37,8 @@ impl FrameWalker {
     pub fn new() -> Self {
         // current_{fp, pc} is deliberately missed for printing
         Self {
-            current_fp: VirtAddr::from(FrameWalker::read_fp()),
-            current_pc: VirtAddr::from(FrameWalker::read_ra()),
+            current_fp: VirtAddr::from(read_fp()),
+            current_pc: VirtAddr::from(read_ra()),
         }
     }
 }
diff --git a/kernel/src/arch/riscv/trap.rs b/kernel/src/arch/riscv/trap.rs
index 385dd2e..e4bb207 100644
--- a/kernel/src/arch/riscv/trap.rs
+++ b/kernel/src/arch/riscv/trap.rs
@@ -1,3 +1,4 @@
+use crate::arch::riscv::backtrace::read_sp;
 use crate::entry::HART_ID;
 use crate::objects::*;
 use crate::plat::console::CONSOLE;
@@ -55,12 +56,19 @@ impl TrapContextOps for TrapContext {
 
     fn configure_idle_thread(&mut self) {
         self.sepc = idle_thread as usize;
-        self.sstatus = (1 << 5) | (1 << 8); // SPIE + SPP
+        self.sstatus = (1 << 5) // SPIE: enable interrupt in idle thread
+                     | (1 << 8) // SPP:  run in kernel mode in idle thread
+                     ;
     }
 
     fn handle_trap(&mut self, from_kernel: bool) {
         let scause = riscv::register::scause::read();
-        trace!("[Trap] cpu@{} scause: {:?}", HART_ID.get(), scause.cause());
+        trace!(
+            "[Trap] cpu@{} scause: {:?} sp: {:#x}",
+            HART_ID.get(),
+            scause.cause(),
+            read_sp()
+        );
 
         macro_rules! panic_fatal {
             ($msg:expr) => {