diff --git a/kernel/src/arch/riscv/backtrace.rs b/kernel/src/arch/riscv/backtrace.rs
index 8f70104..bec0b6b 100644
--- a/kernel/src/arch/riscv/backtrace.rs
+++ b/kernel/src/arch/riscv/backtrace.rs
@@ -18,7 +18,11 @@ impl FrameWalker {
     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() };
-        fp_valid && pc_valid
+
+        // pc might be 0xffff_ffff in the first frame
+        let first = self.current_pc == VirtAddr(usize::MAX);
+
+        fp_valid && (pc_valid || first)
     }
 
     pub fn new() -> Self {