ARTIQ Zynq-based core device support
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

453 lines
18 KiB

// From Current artiq firmware ksupport implementation.
// Modified to suit the case of artiq-zynq port, for ARM EHABI.
// Portions of the code in this file are derived from code by:
//
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![allow(non_camel_case_types)]
use core::mem;
use cslice::CSlice;
use unwind as uw;
use libc::{c_int, c_void, uintptr_t};
use log::{trace, error};
use crate::kernel::KERNEL_IMAGE;
use dwarf::eh::{self, EHAction, EHContext};
const EXCEPTION_CLASS: uw::_Unwind_Exception_Class = 0x4d_4c_42_53_41_52_54_51; /* 'MLBSARTQ' */
#[cfg(target_arch = "arm")]
const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1
// Note: CSlice within an exception may not be actual cslice, they may be strings that exist only
// in the host. If the length == usize:MAX, the pointer is actually a string key in the host.
#[repr(C)]
#[derive(Clone, Copy)]
pub struct Exception<'a> {
pub id: u32,
pub file: CSlice<'a, u8>,
pub line: u32,
pub column: u32,
pub function: CSlice<'a, u8>,
pub message: CSlice<'a, u8>,
pub param: [i64; 3]
}
fn str_err(_: core::str::Utf8Error) -> core::fmt::Error {
core::fmt::Error
}
fn exception_str<'a>(s: &'a CSlice<'a, u8>) -> Result<&'a str, core::str::Utf8Error> {
if s.len() == usize::MAX {
Ok("<host string>")
} else {
core::str::from_utf8(s.as_ref())
}
}
impl<'a> core::fmt::Debug for Exception<'a> {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
write!(f, "Exception {} from {} in {}:{}:{}, message: {}",
self.id,
exception_str(&self.function).map_err(str_err)?,
exception_str(&self.file).map_err(str_err)?,
self.line, self.column,
exception_str(&self.message).map_err(str_err)?)
}
}
const MAX_INFLIGHT_EXCEPTIONS: usize = 10;
const MAX_BACKTRACE_SIZE: usize = 128;
#[derive(Debug, Default)]
pub struct StackPointerBacktrace {
pub stack_pointer: usize,
pub initial_backtrace_size: usize,
pub current_backtrace_size: usize,
}
struct ExceptionBuffer {
// we need n _Unwind_Exception, because each will have their own private data
uw_exceptions: [uw::_Unwind_Exception; MAX_INFLIGHT_EXCEPTIONS],
exceptions: [Option<Exception<'static>>; MAX_INFLIGHT_EXCEPTIONS + 1],
exception_stack: [isize; MAX_INFLIGHT_EXCEPTIONS + 1],
// nested exceptions will share the backtrace buffer, treated as a tree
// backtrace contains a tuple of IP and SP
backtrace: [(usize, usize); MAX_BACKTRACE_SIZE],
backtrace_size: usize,
// stack pointers are stored to reconstruct backtrace for each exception
stack_pointers: [StackPointerBacktrace; MAX_INFLIGHT_EXCEPTIONS + 1],
// current allocated nested exceptions
exception_count: usize,
}
static mut EXCEPTION_BUFFER: ExceptionBuffer = ExceptionBuffer {
uw_exceptions: [uw::_Unwind_Exception {
exception_class: EXCEPTION_CLASS,
exception_cleanup: cleanup,
private: [0; uw::unwinder_private_data_size],
}; MAX_INFLIGHT_EXCEPTIONS],
exceptions: [None; MAX_INFLIGHT_EXCEPTIONS + 1],
exception_stack: [-1; MAX_INFLIGHT_EXCEPTIONS + 1],
backtrace: [(0, 0); MAX_BACKTRACE_SIZE],
backtrace_size: 0,
stack_pointers: [StackPointerBacktrace {
stack_pointer: 0,
initial_backtrace_size: 0,
current_backtrace_size: 0
}; MAX_INFLIGHT_EXCEPTIONS + 1],
exception_count: 0
};
pub unsafe extern fn reset_exception_buffer() {
trace!("reset exception buffer");
EXCEPTION_BUFFER.uw_exceptions = [uw::_Unwind_Exception {
exception_class: EXCEPTION_CLASS,
exception_cleanup: cleanup,
private: [0; uw::unwinder_private_data_size],
}; MAX_INFLIGHT_EXCEPTIONS];
EXCEPTION_BUFFER.exceptions = [None; MAX_INFLIGHT_EXCEPTIONS + 1];
EXCEPTION_BUFFER.exception_stack = [-1; MAX_INFLIGHT_EXCEPTIONS + 1];
EXCEPTION_BUFFER.backtrace_size = 0;
EXCEPTION_BUFFER.exception_count = 0;
}
type _Unwind_Stop_Fn = extern "C" fn(version: c_int,
actions: i32,
exception_class: uw::_Unwind_Exception_Class,
exception_object: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context,
stop_parameter: *mut c_void)
-> uw::_Unwind_Reason_Code;
extern {
// not defined in EHABI, but LLVM added it and is useful to us
fn _Unwind_ForcedUnwind(exception: *mut uw::_Unwind_Exception,
stop_fn: _Unwind_Stop_Fn,
stop_parameter: *mut c_void) -> uw::_Unwind_Reason_Code;
}
unsafe fn find_eh_action(
context: *mut uw::_Unwind_Context,
foreign_exception: bool,
id: u32,
) -> Result<EHAction, ()> {
let lsda = uw::_Unwind_GetLanguageSpecificData(context) as *const u8;
let mut ip_before_instr: c_int = 0;
let ip = uw::_Unwind_GetIPInfo(context, &mut ip_before_instr);
let eh_context = EHContext {
// The return address points 1 byte past the call instruction,
// which could be in the next IP range in LSDA range table.
ip: if ip_before_instr != 0 { ip } else { ip - 1 },
func_start: uw::_Unwind_GetRegionStart(context),
get_text_start: &|| uw::_Unwind_GetTextRelBase(context),
get_data_start: &|| uw::_Unwind_GetDataRelBase(context),
};
eh::find_eh_action(lsda, &eh_context, foreign_exception, id)
}
pub unsafe fn artiq_personality(_state: uw::_Unwind_State,
exception_object: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context)
-> uw::_Unwind_Reason_Code {
// we will only do phase 2 forced unwinding now
// The DWARF unwinder assumes that _Unwind_Context holds things like the function
// and LSDA pointers, however ARM EHABI places them into the exception object.
// To preserve signatures of functions like _Unwind_GetLanguageSpecificData(), which
// take only the context pointer, GCC personality routines stash a pointer to
// exception_object in the context, using location reserved for ARM's
// "scratch register" (r12).
uw::_Unwind_SetGR(context,
uw::UNWIND_POINTER_REG,
exception_object as uw::_Unwind_Ptr);
// ...A more principled approach would be to provide the full definition of ARM's
// _Unwind_Context in our libunwind bindings and fetch the required data from there
// directly, bypassing DWARF compatibility functions.
let exception_class = (*exception_object).exception_class;
let foreign_exception = exception_class != EXCEPTION_CLASS;
assert!(!foreign_exception, "we do not expect foreign exceptions");
let index = EXCEPTION_BUFFER.exception_stack[EXCEPTION_BUFFER.exception_count - 1];
assert!(index != -1);
let exception = EXCEPTION_BUFFER.exceptions[index as usize].as_ref().unwrap();
let id = exception.id;
let eh_action = match find_eh_action(context, foreign_exception, id) {
Ok(action) => action,
Err(_) => return uw::_URC_FAILURE,
};
match eh_action {
EHAction::None => return continue_unwind(exception_object, context),
EHAction::Cleanup(lpad) |
EHAction::Catch(lpad) => {
uw::_Unwind_SetGR(context, UNWIND_DATA_REG.0,
exception_object as uintptr_t);
uw::_Unwind_SetGR(context, UNWIND_DATA_REG.1, exception as *const _ as uw::_Unwind_Word);
uw::_Unwind_SetIP(context, lpad);
return uw::_URC_INSTALL_CONTEXT;
}
EHAction::Terminate => return uw::_URC_FAILURE,
}
// On ARM EHABI the personality routine is responsible for actually
// unwinding a single stack frame before returning (ARM EHABI Sec. 6.1).
unsafe fn continue_unwind(exception_object: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context)
-> uw::_Unwind_Reason_Code {
let reason = __gnu_unwind_frame(exception_object, context);
if reason == uw::_URC_NO_REASON {
uw::_URC_CONTINUE_UNWIND
} else {
reason
}
}
// defined in libgcc
extern "C" {
fn __gnu_unwind_frame(exception_object: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context)
-> uw::_Unwind_Reason_Code;
}
}
pub unsafe extern fn raise(exception: *const Exception) -> ! {
use cslice::AsCSlice;
let count = EXCEPTION_BUFFER.exception_count;
let stack = &mut EXCEPTION_BUFFER.exception_stack;
let diff = exception as isize - EXCEPTION_BUFFER.exceptions.as_ptr() as isize;
if 0 <= diff && diff <= (mem::size_of::<Option<Exception>>() * MAX_INFLIGHT_EXCEPTIONS) as isize {
let index = diff / (mem::size_of::<Option<Exception>>() as isize);
trace!("reraise at {}", index);
let mut found = false;
for i in 0..=MAX_INFLIGHT_EXCEPTIONS + 1 {
if found {
if stack[i] == -1 {
stack[i - 1] = index;
assert!(i == count);
break;
} else {
stack[i - 1] = stack[i];
}
} else {
if stack[i] == index {
found = true;
}
}
}
assert!(found);
let _result = _Unwind_ForcedUnwind(&mut EXCEPTION_BUFFER.uw_exceptions[stack[count - 1] as usize],
stop_fn, core::ptr::null_mut());
} else {
if count < MAX_INFLIGHT_EXCEPTIONS {
trace!("raising exception at level {}", count);
let exception = &*exception;
for (i, slot) in EXCEPTION_BUFFER.exceptions.iter_mut().enumerate() {
// we should always be able to find a slot
if slot.is_none() {
*slot = Some(
*mem::transmute::<*const Exception, *const Exception<'static>>
(exception));
EXCEPTION_BUFFER.exception_stack[count] = i as isize;
EXCEPTION_BUFFER.uw_exceptions[i].private =
[0; uw::unwinder_private_data_size];
EXCEPTION_BUFFER.stack_pointers[i] = StackPointerBacktrace {
stack_pointer: 0,
initial_backtrace_size: EXCEPTION_BUFFER.backtrace_size,
current_backtrace_size: 0,
};
EXCEPTION_BUFFER.exception_count += 1;
let _result = _Unwind_ForcedUnwind(&mut EXCEPTION_BUFFER.uw_exceptions[i],
stop_fn, core::ptr::null_mut());
}
}
} else {
error!("too many nested exceptions");
// TODO: better reporting?
let exception = Exception {
id: get_exception_id("RuntimeError"),
file: file!().as_c_slice(),
line: line!(),
column: column!(),
// https://github.com/rust-lang/rfcs/pull/1719
function: "__artiq_raise".as_c_slice(),
message: "too many nested exceptions".as_c_slice(),
param: [0, 0, 0]
};
EXCEPTION_BUFFER.exceptions[MAX_INFLIGHT_EXCEPTIONS] = Some(mem::transmute(exception));
EXCEPTION_BUFFER.stack_pointers[MAX_INFLIGHT_EXCEPTIONS] = Default::default();
EXCEPTION_BUFFER.exception_count += 1;
uncaught_exception()
}
}
unreachable!();
}
pub unsafe extern fn resume() -> ! {
trace!("resume");
assert!(EXCEPTION_BUFFER.exception_count != 0);
let i = EXCEPTION_BUFFER.exception_stack[EXCEPTION_BUFFER.exception_count - 1];
assert!(i != -1);
let _result = _Unwind_ForcedUnwind(&mut EXCEPTION_BUFFER.uw_exceptions[i as usize],
stop_fn, core::ptr::null_mut());
unreachable!()
}
pub unsafe extern fn end_catch() {
let mut count = EXCEPTION_BUFFER.exception_count;
assert!(count != 0);
// we remove all exceptions with SP <= current exception SP
// i.e. the outer exception escapes the finally block
let index = EXCEPTION_BUFFER.exception_stack[count - 1] as usize;
EXCEPTION_BUFFER.exception_stack[count - 1] = -1;
EXCEPTION_BUFFER.exceptions[index] = None;
let outer_sp = EXCEPTION_BUFFER.stack_pointers
[index].stack_pointer;
count -= 1;
for i in (0..count).rev() {
let index = EXCEPTION_BUFFER.exception_stack[i];
assert!(index != -1);
let index = index as usize;
let sp = EXCEPTION_BUFFER.stack_pointers[index].stack_pointer;
if sp >= outer_sp {
break;
}
EXCEPTION_BUFFER.exceptions[index] = None;
EXCEPTION_BUFFER.exception_stack[i] = -1;
count -= 1;
}
EXCEPTION_BUFFER.exception_count = count;
EXCEPTION_BUFFER.backtrace_size = if count > 0 {
let index = EXCEPTION_BUFFER.exception_stack[count - 1];
assert!(index != -1);
EXCEPTION_BUFFER.stack_pointers[index as usize].current_backtrace_size
} else {
0
};
}
extern fn cleanup(_unwind_code: uw::_Unwind_Reason_Code,
_uw_exception: *mut uw::_Unwind_Exception) {
unimplemented!()
}
fn uncaught_exception() -> ! {
unsafe {
// dump way to reorder the stack
for i in 0..EXCEPTION_BUFFER.exception_count {
if EXCEPTION_BUFFER.exception_stack[i] != i as isize {
// find the correct index
let index = EXCEPTION_BUFFER.exception_stack
.iter()
.position(|v| *v == i as isize).unwrap();
let a = EXCEPTION_BUFFER.exception_stack[index];
let b = EXCEPTION_BUFFER.exception_stack[i];
assert!(a != -1 && b != -1);
core::mem::swap(&mut EXCEPTION_BUFFER.exception_stack[index],
&mut EXCEPTION_BUFFER.exception_stack[i]);
core::mem::swap(&mut EXCEPTION_BUFFER.exceptions[a as usize],
&mut EXCEPTION_BUFFER.exceptions[b as usize]);
core::mem::swap(&mut EXCEPTION_BUFFER.stack_pointers[a as usize],
&mut EXCEPTION_BUFFER.stack_pointers[b as usize]);
}
}
}
unsafe {
crate::kernel::core1::terminate(
EXCEPTION_BUFFER.exceptions[..EXCEPTION_BUFFER.exception_count].as_ref(),
EXCEPTION_BUFFER.stack_pointers[..EXCEPTION_BUFFER.exception_count].as_ref(),
EXCEPTION_BUFFER.backtrace[..EXCEPTION_BUFFER.backtrace_size].as_mut())
}
}
// stop function which would be executed when we unwind each frame
extern fn stop_fn(_version: c_int,
actions: i32,
_uw_exception_class: uw::_Unwind_Exception_Class,
_uw_exception: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context,
_stop_parameter: *mut c_void) -> uw::_Unwind_Reason_Code {
unsafe {
let load_addr = KERNEL_IMAGE.as_ref().unwrap().get_load_addr();
let backtrace_size = EXCEPTION_BUFFER.backtrace_size;
// we try to remove unrelated backtrace here to save some buffer size
if backtrace_size < MAX_BACKTRACE_SIZE {
let ip = uw::_Unwind_GetIP(context);
if ip >= load_addr {
let ip = ip - load_addr;
let sp = uw::_Unwind_GetGR(context, uw::UNWIND_SP_REG);
trace!("SP: {:X}, backtrace_size: {}", sp, backtrace_size);
EXCEPTION_BUFFER.backtrace[backtrace_size] = (ip, sp);
EXCEPTION_BUFFER.backtrace_size += 1;
let last_index = EXCEPTION_BUFFER.exception_stack[EXCEPTION_BUFFER.exception_count - 1];
assert!(last_index != -1);
let sp_info = &mut EXCEPTION_BUFFER.stack_pointers[last_index as usize];
sp_info.stack_pointer = sp;
sp_info.current_backtrace_size = backtrace_size + 1;
}
} else {
trace!("backtrace size exceeded");
}
if actions as u32 & uw::_US_END_OF_STACK as u32 != 0 {
uncaught_exception()
} else {
uw::_URC_NO_REASON
}
}
}
static EXCEPTION_ID_LOOKUP: [(&str, u32); 10] = [
("RuntimeError", 0),
("RTIOUnderflow", 1),
("RTIOOverflow", 2),
("RTIODestinationUnreachable", 3),
("DMAError", 4),
("I2CError", 5),
("CacheError", 6),
("SPIError", 7),
("ZeroDivisionError", 8),
("IndexError", 9)
];
pub fn get_exception_id(name: &str) -> u32 {
for (n, id) in EXCEPTION_ID_LOOKUP.iter() {
if *n == name {
return *id
}
}
unimplemented!("unallocated internal exception id")
}
#[macro_export]
macro_rules! artiq_raise {
($name:expr, $message:expr, $param0:expr, $param1:expr, $param2:expr) => ({
use cslice::AsCSlice;
let name_id = $crate::eh_artiq::get_exception_id($name);
let exn = $crate::eh_artiq::Exception {
id: name_id,
file: file!().as_c_slice(),
line: line!(),
column: column!(),
// https://github.com/rust-lang/rfcs/pull/1719
function: "(Rust function)".as_c_slice(),
message: $message.as_c_slice(),
param: [$param0, $param1, $param2]
};
#[allow(unused_unsafe)]
unsafe {
$crate::eh_artiq::raise(&exn)
}
});
($name:expr, $message:expr) => ({
artiq_raise!($name, $message, 0, 0, 0)
});
}