axbacktrace

This crate provides backtrace support for arceos.

Usage

Setup

There are 1 prerequisites for using this crate:

1. Unwind tables must be built into the binary, even with unwinding is set to abort. This can be done with the -C force-unwind-tables flag.

This can be done by setting RUSTFLAGS:

export RUSTFLAGS="-Cforce-unwind-tables"

Capturing backtraces

Add the axbacktrace crate as a dependency to your program:

[dependencies]
axbacktrace = { git = "https://github.com/kern-crates/axbacktrace.git" } 

You can capture a backtrace by using the dump_trace,

A sample to dump current task backtrace

use axbacktrace::{dump_backtrace, Unwind, UnwindIf, StackInfo};


// Prepare dump stack range
let stack_low = curr_task.get_kernel_stack_down().unwrap();
let stack_high = curr_task.get_kernel_stack_top().unwrap();
let stack_info = {low: stack_low,  high: stack_high};

// Init Unwind instance from current context
let mut unwind =  Unwind::new_from_cur_ctx(stack_info)
// dump current task trace
dump_trace(&mut unwind);

A sample to dump another task trace

use axbacktrace::{dump_backtrace, Unwind, UnwindIf, StackInfo};


// this excute on TaskA, and TaskB is not running
let (pc, fp) = taskb.ctx_unwind();
let stack_low = taskb.get_kernel_stack_down().unwrap();
let stack_high = taskb.get_kernel_stack_top().unwrap();
let stack_info = {low: stack_low, high: stack_high};

// Init Unwind instance from current context
let mut unwind =  Unwind::new(pc, fp, stack_info)
// dump another task trace
dump_trace(&mut unwind);

This will output:

[  1.707132 0 axbacktrace:42] Call trace: 
[  1.707929 0 axbacktrace::aarch64:71] 0xFFFF0000401F1C0C 
[  1.708731 0 axbacktrace::aarch64:71] 0xFFFF0000401EEB2C 
[  1.709370 0 axbacktrace::aarch64:71] 0xFFFF0000401F03E4 
[  1.709996 0 axbacktrace::aarch64:71] 0xFFFF000040082A08 
[  1.710619 0 axbacktrace::aarch64:71] 0xFFFF0000401D6594 
[  1.711239 0 axbacktrace::aarch64:71] 0xFFFF0000401D57D4 
[  1.711819 0 axbacktrace::aarch64:71] 0xFFFF00004008CAD0 
[  1.712394 0 axbacktrace::aarch64:71] 0x00000040080048

Resolving backtraces

The addresses generated by Backtrace can be converted to human-readable function names, filenames and line numbers by using the addr2line tool from LLVM or binutils with rustfilt to demangle Rust symbol names.

Simply run addr2line -fipe /path/to/binary | rustfilt in a terminal and then paste the addresses from the backtrace:

$ llvm-addr2line-17  -fipe ./target/aarch64-unknown-none-softfloat/debug/monolithic_userboot \
> 0xFFFF0000401F1C0C  \
> 0xFFFF0000401EEB2C  \
> 0xFFFF0000401F03E4  \
> 0xFFFF000040082A08  \
> 0xFFFF0000401D6594  \
> 0xFFFF0000401D57D4  \
> 0xFFFF00004008CAD0  \
> 0x00000040080048    \
> |rustfilt
core::ptr::drop_in_place<core::fmt::Error> at /rustc/c987ad527540e8f1565f57c31204bde33f63df76/library/core/src/ptr/mod.rs:514
core::array::<impl core::fmt::Debug for [T; N]>::fmt at /rustc/c987ad527540e8f1565f57c31204bde33f63df76/library/core/src/array/mod.rs:314
handle_el1h_64_irq_exception at /home/guoweikang/code/cicv/starry-mod/Starry/crates/axtrap/src/arch/aarch64/trap.rs:105
handle_el1h_64_irq at axstarry.17d3f64c3501fb0b-cgu.0:0
axruntime::init_interrupt at /home/guoweikang/code/cicv/starry-mod/Starry/crates/axruntime/src/lib.rs:306
rust_main at /home/guoweikang/code/cicv/starry-mod/Starry/crates/axruntime/src/lib.rs:173
arch_boot::platform::aarch64_common::rust_entry at /home/guoweikang/code/cicv/starry-mod/Starry/crates/arch_boot/src/platform/aarch64_common/mod.rs:40
_percpu_size_aligned at ??:0

License

Licensed under either of:

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)