Panic in exception handler

Author: bugadani

esp-backtrace/CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- `exception-handler` now panics. (#3838)
 
 ### Fixed
 

esp-backtrace/Cargo.toml

@@ -20,7 +20,7 @@ test  = false
 
 [dependencies]
 cfg-if      = "1.0.0"
-defmt       = { version = "1.0.1", optional = true }
+defmt       = { version = "1", optional = true }
 esp-config  = { version = "0.5.0", path = "../esp-config" }
 esp-println = { version = "0.15.0", optional = true, default-features = false, path = "../esp-println" }
 heapless    = "0.8"
@@ -51,17 +51,17 @@ print-float-registers = [] # TODO support esp32p4
 
 # You may optionally enable one or more of the below features to provide
 # additional functionality:
-## Print messages in red (only used for panic and exception handlers)
+## Print messages in red
 colors               = []
-## Invoke the extern function custom_halt() instead of doing a loop {} in case of a panic or exception
+## Invoke the extern function `custom_halt()` instead of doing a loop {} in case of a panic or exception
 custom-halt          = []
 ## Invoke the extern function `custom_pre_backtrace()` before handling a panic or exception
 custom-pre-backtrace = []
-## Include an exception handler, will add `esp-println` as a dependency
+## Turn unhandled exceptions into panics
 exception-handler    = []
 ## Halt both CPUs on ESP32 / ESP32-S3 instead of doing a `loop {}` in case of a panic or exception
 halt-cores           = []
-## Include a panic handler, will add `esp-println` as a dependency
+## Include a panic handler
 panic-handler        = []
 
 [lints.rust]

esp-backtrace/src/lib.rs

@@ -1,3 +1,5 @@
+//! ## Feature Flags
+#![doc = document_features::document_features!()]
 #![allow(rustdoc::bare_urls, unused_macros)]
 #![cfg_attr(target_arch = "xtensa", feature(asm_experimental_arch))]
 //! This is a lightweight crate for obtaining backtraces during panics, exceptions, and hard faults
@@ -41,12 +43,6 @@ impl Backtrace {
         arch::backtrace()
     }
 
-    #[inline]
-    #[cfg(feature = "exception-handler")]
-    fn from_sp(sp: u32) -> Self {
-        arch::backtrace_internal(sp, 0)
-    }
-
     /// Returns the backtrace frames as a slice.
     #[inline]
     pub fn frames(&self) -> &[BacktraceFrame] {
@@ -125,35 +121,21 @@ fn panic_handler(info: &core::panic::PanicInfo) -> ! {
 #[unsafe(no_mangle)]
 #[unsafe(link_section = ".rwtext")]
 unsafe fn __user_exception(cause: arch::ExceptionCause, context: arch::Context) {
-    pre_backtrace();
-
-    println!("\n\nException occurred '{}'", cause);
-    println!("{:?}", context);
-
-    let backtrace = Backtrace::from_sp(context.A1);
-    for frame in backtrace.frames() {
-        println!("0x{:x}", frame.program_counter());
-    }
-
-    abort();
+    panic!("\n\nException occurred '{}'\n{:?}", cause, context);
 }
 
 #[cfg(all(feature = "exception-handler", target_arch = "riscv32"))]
 #[unsafe(export_name = "ExceptionHandler")]
 fn exception_handler(context: &arch::TrapFrame) -> ! {
-    pre_backtrace();
-
     let mepc = context.pc;
     let code = context.mcause & 0xff;
     let mtval = context.mtval;
 
     if code == 14 {
-        println!("");
-        println!(
+        panic!(
             "Stack overflow detected at 0x{:x} called by 0x{:x}",
             mepc, context.ra
         );
-        println!("");
     } else {
         let code = match code {
             0 => "Instruction address misaligned",
@@ -175,26 +157,11 @@ fn exception_handler(context: &arch::TrapFrame) -> ! {
             _ => "UNKNOWN",
         };
 
-        println!(
+        panic!(
             "Exception '{}' mepc=0x{:08x}, mtval=0x{:08x}",
             code, mepc, mtval
         );
-
-        println!("{:?}", context);
-
-        let backtrace = Backtrace::from_sp(context.s0 as u32);
-        let frames = backtrace.frames();
-        if frames.is_empty() {
-            println!(
-                "No backtrace available - make sure to force frame-pointers. (see https://crates.io/crates/esp-backtrace)"
-            );
-        }
-        for frame in backtrace.frames() {
-            println!("0x{:x}", frame.program_counter());
-        }
     }
-
-    abort();
 }
 
 // Ensure that the address is in DRAM and that it is 16-byte aligned.

hil-test/Cargo.toml

@@ -247,7 +247,7 @@ embedded-hal-nb    = "1.0.0"
 esp-alloc          = { path = "../esp-alloc", optional = true }
 esp-backtrace      = { path = "../esp-backtrace", default-features = false, features = ["exception-handler", "defmt", "semihosting"] }
 esp-bootloader-esp-idf = { path = "../esp-bootloader-esp-idf" }
-esp-hal            = { path = "../esp-hal", optional = true }
+esp-hal            = { path = "../esp-hal" }
 esp-hal-embassy    = { path = "../esp-hal-embassy", optional = true }
 esp-storage        = { path = "../esp-storage", optional = true }
 esp-wifi           = { path = "../esp-wifi", optional = true }