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exception fixes #162

Merged
sb10q merged 2 commits from pca006132/artiq-zynq:exception into master 2022-01-26 07:17:30 +08:00
Conversation 0 Commits 2 Files Changed 9
9 changed files with 551 additions and 219 deletions
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15
src/libdwarf/src/eh.rs
View File

@ -90,8 +90,7 @@ pub unsafe fn find_eh_action(
lsda: *const u8,
context: &EHContext<'_>,
foreign_exception: bool,
name: *const u8,
len: usize,
id: u32,
) -> Result<EHAction, ()> {
if lsda.is_null() {
return Ok(EHAction::None);
@ -164,19 +163,11 @@ pub unsafe fn find_eh_action(
ttype_base,
ttype_table,
)?;
let clause_ptr = *(catch_type as *const *const CSlice<u8>);
let clause_ptr = *(catch_type as *const *const u32);
if clause_ptr.is_null() {
return Ok(EHAction::Catch(lpad));
}
let clause_name_ptr = (*clause_ptr).as_ptr();
let clause_name_len = (*clause_ptr).len();
if (clause_name_ptr == core::ptr::null() ||
clause_name_ptr == name ||
// somehow their name pointers might differ, but the content is the
// same
core::slice::from_raw_parts(clause_name_ptr, clause_name_len) ==
core::slice::from_raw_parts(name, len))
{
if *clause_ptr == id {
return Ok(EHAction::Catch(lpad));
}
} else if ar_filter < 0 {

9
src/llvm_libunwind/include/unwind.h
View File

@ -107,9 +107,12 @@ struct _Unwind_Control_Block {
} __attribute__((__aligned__(8)));
typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
(_Unwind_State state,
_Unwind_Exception* exceptionObject,
struct _Unwind_Context* context);
(int version,
_Unwind_Action actions,
uint64_t exceptionClass,
_Unwind_Exception* exceptionObject,
struct _Unwind_Context* context,
void* stop_parameter);
typedef _Unwind_Reason_Code (*__personality_routine)
(_Unwind_State state,

170
src/llvm_libunwind/src/Unwind-EHABI.cpp
View File

@ -95,9 +95,11 @@ _Unwind_Reason_Code ProcessDescriptors(
case Descriptor::LU32:
descriptor = getNextWord(descriptor, &length);
descriptor = getNextWord(descriptor, &offset);
break;
case Descriptor::LU16:
descriptor = getNextNibble(descriptor, &length);
descriptor = getNextNibble(descriptor, &offset);
break;
default:
assert(false);
return _URC_FAILURE;
@ -183,8 +185,14 @@ static _Unwind_Reason_Code unwindOneFrame(_Unwind_State state,
if (result != _URC_CONTINUE_UNWIND)
return result;
if (__unw_step(reinterpret_cast<unw_cursor_t *>(context)) != UNW_STEP_SUCCESS)
switch (__unw_step(reinterpret_cast<unw_cursor_t *>(context))) {
case UNW_STEP_SUCCESS:
return _URC_CONTINUE_UNWIND;
case UNW_STEP_END:
return _URC_END_OF_STACK;
default:
return _URC_FAILURE;
}
return _URC_CONTINUE_UNWIND;
}
@ -677,6 +685,128 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor
return _URC_FATAL_PHASE2_ERROR;
}
static _Unwind_Reason_Code
unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
_Unwind_Exception *exception_object, _Unwind_Stop_Fn stop,
void *stop_parameter) {
// See comment at the start of unwind_phase1 regarding VRS integrity.
__unw_init_local(cursor, uc);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p)",
static_cast<void *>(exception_object));
// Walk each frame until we reach where search phase said to stop.
bool end_of_stack = false;
// TODO: why can't libunwind handle end of stack properly?
// We should fix this kind of hack.
unw_word_t forced_phase2_prev_sp = 0x0;
while (!end_of_stack) {
// Get info about this frame.
unw_word_t sp;
unw_proc_info_t frameInfo;
__unw_get_reg(cursor, UNW_REG_SP, &sp);
if (sp == forced_phase2_prev_sp) {
break;
}
forced_phase2_prev_sp = sp;
if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): __unw_get_proc_info "
"failed => _URC_FATAL_PHASE2_ERROR",
static_cast<void *>(exception_object));
return _URC_FATAL_PHASE2_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionBuf[512];
const char *functionName = functionBuf;
unw_word_t offset;
if ((__unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
&offset) != UNW_ESUCCESS) ||
(frameInfo.start_ip + offset > frameInfo.end_ip))
functionName = ".anonymous.";
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR ", func=%s, sp=0x%" PRIxPTR ", "
"lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR "",
static_cast<void *>(exception_object), frameInfo.start_ip,
functionName, sp, frameInfo.lsda,
frameInfo.handler);
}
_Unwind_Action action =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
_Unwind_Reason_Code stopResult =
(*stop)(1, action, exception_object->exception_class, exception_object,
(_Unwind_Context *)(cursor), stop_parameter);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stop function returned %d",
(void *)exception_object, stopResult);
if (stopResult != _URC_NO_REASON) {
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stopped by stop function",
(void *)exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// If there is a personality routine, tell it we are unwinding.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor);
// EHABI #7.2
exception_object->pr_cache.fnstart = frameInfo.start_ip;
exception_object->pr_cache.ehtp =
(_Unwind_EHT_Header *)frameInfo.unwind_info;
exception_object->pr_cache.additional = frameInfo.flags;
_Unwind_Reason_Code personalityResult =
(*p)(_US_FORCE_UNWIND | _US_UNWIND_FRAME_STARTING, exception_object,
context);
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
// Continue unwinding
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): _URC_CONTINUE_UNWIND",
static_cast<void *>(exception_object));
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): _URC_INSTALL_CONTEXT",
static_cast<void *>(exception_object));
{
// EHABI #7.4.1 says we need to preserve pc for when _Unwind_Resume
// is called back, to find this same frame.
unw_word_t pc;
__unw_get_reg(cursor, UNW_REG_IP, &pc);
exception_object->unwinder_cache.reserved2 = (uint32_t)pc;
}
// We may get control back if landing pad calls _Unwind_Resume().
__unw_resume(cursor);
break;
case _URC_END_OF_STACK:
end_of_stack = true;
break;
default:
// Personality routine returned an unknown result code.
_LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
}
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
"function with _UA_END_OF_STACK",
(void *)exception_object);
_Unwind_Action lastAction =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
(*stop)(1, lastAction, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(cursor), stop_parameter);
return _URC_FATAL_PHASE2_ERROR;
}
/// Called by __cxa_throw. Only returns if there is a fatal error.
_LIBUNWIND_EXPORT _Unwind_Reason_Code
_Unwind_RaiseException(_Unwind_Exception *exception_object) {
@ -724,15 +854,36 @@ _Unwind_Resume(_Unwind_Exception *exception_object) {
unw_cursor_t cursor;
__unw_getcontext(&uc);
// _Unwind_RaiseException on EHABI will always set the reserved1 field to 0,
// which is in the same position as private_1 below.
// TODO(ajwong): Who wronte the above? Why is it true?
unwind_phase2(&uc, &cursor, exception_object, true);
if (exception_object->unwinder_cache.reserved1)
unwind_phase2_forced(
&uc, &cursor, exception_object,
(_Unwind_Stop_Fn)exception_object->unwinder_cache.reserved1,
(void *)exception_object->unwinder_cache.reserved3);
else
unwind_phase2(&uc, &cursor, exception_object, true);
// Clients assume _Unwind_Resume() does not return, so all we can do is abort.
_LIBUNWIND_ABORT("_Unwind_Resume() can't return");
}
_LIBUNWIND_EXPORT _Unwind_Reason_Code
_Unwind_ForcedUnwind(_Unwind_Exception *exception_object, _Unwind_Stop_Fn stop,
void *stop_parameter) {
_LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)",
(void *)exception_object, (void *)(uintptr_t)stop);
unw_context_t uc;
unw_cursor_t cursor;
__unw_getcontext(&uc);
// Mark that this is a forced unwind, so _Unwind_Resume() can do
// the right thing.
exception_object->unwinder_cache.reserved1 = (uintptr_t)stop;
exception_object->unwinder_cache.reserved3 = (uintptr_t)stop_parameter;
return unwind_phase2_forced(&uc, &cursor, exception_object, stop,
stop_parameter);
}
/// Called by personality handler during phase 2 to get LSDA for current frame.
_LIBUNWIND_EXPORT uintptr_t
_Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
@ -1002,9 +1153,14 @@ extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code
__gnu_unwind_frame(_Unwind_Exception *exception_object,
struct _Unwind_Context *context) {
unw_cursor_t *cursor = (unw_cursor_t *)context;
if (__unw_step(cursor) != UNW_STEP_SUCCESS)
switch (__unw_step(cursor)) {
case UNW_STEP_SUCCESS:
return _URC_OK;
case UNW_STEP_END:
return _URC_END_OF_STACK;
default:
return _URC_FAILURE;
return _URC_OK;
}
}
#endif // defined(_LIBUNWIND_ARM_EHABI)

63
src/runtime/src/comms.rs
View File

@ -1,8 +1,8 @@
use core::fmt;
use core::cell::RefCell;
use core::str::Utf8Error;
use alloc::{vec, vec::Vec, string::String, collections::BTreeMap, rc::Rc};
use log::{info, warn, error};
use cslice::CSlice;
use num_derive::{FromPrimitive, ToPrimitive};
use num_traits::{FromPrimitive, ToPrimitive};
@ -39,7 +39,6 @@ pub enum Error {
UnexpectedPattern,
UnrecognizedPacket,
BufferExhausted,
Utf8Error(Utf8Error),
}
pub type Result<T> = core::result::Result<T, Error>;
@ -51,7 +50,6 @@ impl fmt::Display for Error {
Error::UnexpectedPattern => write!(f, "unexpected pattern"),
Error::UnrecognizedPacket => write!(f, "unrecognized packet"),
Error::BufferExhausted => write!(f, "buffer exhausted"),
Error::Utf8Error(error) => write!(f, "UTF-8 error: {}", error),
}
}
}
@ -122,11 +120,6 @@ async fn read_bytes(stream: &TcpStream, max_length: usize) -> Result<Vec<u8>> {
Ok(buffer)
}
async fn read_string(stream: &TcpStream, max_length: usize) -> Result<String> {
let bytes = read_bytes(stream, max_length).await?;
Ok(String::from_utf8(bytes).map_err(|err| Error::Utf8Error(err.utf8_error()))?)
}
const RETRY_LIMIT: usize = 100;
async fn fast_send(sender: &mut Sender<'_, kernel::Message>, content: kernel::Message) {
@ -156,6 +149,16 @@ async fn fast_recv(receiver: &mut Receiver<'_, kernel::Message>) -> kernel::Mess
receiver.async_recv().await
}
async fn write_exception_string(stream: &TcpStream, s: CSlice<'static, u8>) -> Result<()> {
if s.len() == usize::MAX {
write_i32(stream, -1).await?;
write_i32(stream, s.as_ptr() as i32).await?
} else {
write_chunk(stream, s.as_ref()).await?;
};
Ok(())
}
async fn handle_run_kernel(stream: Option<&TcpStream>, control: &Rc<RefCell<kernel::Control>>) -> Result<()> {
control.borrow_mut().tx.async_send(kernel::Message::StartRequest).await;
loop {
@ -204,17 +207,17 @@ async fn handle_run_kernel(stream: Option<&TcpStream>, control: &Rc<RefCell<kern
kernel::Message::RpcRecvRequest(_) => (),
other => panic!("expected (ignored) root value slot from kernel CPU, not {:?}", other),
}
let name = read_string(stream, 16384).await?;
let message = read_string(stream, 16384).await?;
let id = read_i32(stream).await? as u32;
let message = read_i32(stream).await? as u32;
let param = [read_i64(stream).await?,
read_i64(stream).await?,
read_i64(stream).await?];
let file = read_string(stream, 16384).await?;
let file = read_i32(stream).await? as u32;
let line = read_i32(stream).await?;
let column = read_i32(stream).await?;
let function = read_string(stream, 16384).await?;
let function = read_i32(stream).await? as u32;
control.tx.async_send(kernel::Message::RpcRecvReply(Err(kernel::RPCException {
name, message, param, file, line, column, function
id, message, param, file, line, column, function
}))).await;
},
_ => {
@ -231,29 +234,39 @@ async fn handle_run_kernel(stream: Option<&TcpStream>, control: &Rc<RefCell<kern
}
break;
},
kernel::Message::KernelException(exception, backtrace, async_errors) => {
kernel::Message::KernelException(exceptions, stack_pointers, backtrace, async_errors) => {
match stream {
Some(stream) => {
// only send the exception data to host if there is host,
// i.e. not idle/startup kernel.
write_header(stream, Reply::KernelException).await?;
write_chunk(stream, exception.name.as_ref()).await?;
write_chunk(stream, exception.message.as_ref()).await?;
write_i64(stream, exception.param[0] as i64).await?;
write_i64(stream, exception.param[1] as i64).await?;
write_i64(stream, exception.param[2] as i64).await?;
write_chunk(stream, exception.file.as_ref()).await?;
write_i32(stream, exception.line as i32).await?;
write_i32(stream, exception.column as i32).await?;
write_chunk(stream, exception.function.as_ref()).await?;
write_i32(stream, exceptions.len() as i32).await?;
for exception in exceptions.iter() {
let exception = exception.as_ref().unwrap();
write_i32(stream, exception.id as i32).await?;
write_exception_string(stream, exception.message).await?;
write_i64(stream, exception.param[0] as i64).await?;
write_i64(stream, exception.param[1] as i64).await?;
write_i64(stream, exception.param[2] as i64).await?;
write_exception_string(stream, exception.file).await?;
write_i32(stream, exception.line as i32).await?;
write_i32(stream, exception.column as i32).await?;
write_exception_string(stream, exception.function).await?;
}
for sp in stack_pointers.iter() {
write_i32(stream, sp.stack_pointer as i32).await?;
write_i32(stream, sp.initial_backtrace_size as i32).await?;
write_i32(stream, sp.current_backtrace_size as i32).await?;
}
write_i32(stream, backtrace.len() as i32).await?;
for &addr in backtrace {
for &(addr, sp) in backtrace {
write_i32(stream, addr as i32).await?;
write_i32(stream, sp as i32).await?;
}
write_i8(stream, async_errors as i8).await?;
},
None => {
error!("Uncaught kernel exception: {:?}", exception);
error!("Uncaught kernel exceptions: {:?}", exceptions);
}
}
break;

465
src/runtime/src/eh_artiq.rs
View File

@ -15,8 +15,9 @@
use core::mem;
use cslice::CSlice;
use unwind as uw;
use libc::{c_int, uintptr_t};
use log::trace;
use libc::{c_int, c_void, uintptr_t};
use log::{trace, error};
use crate::kernel::KERNEL_IMAGE;
use dwarf::eh::{self, EHAction, EHContext};
@ -26,10 +27,12 @@ const EXCEPTION_CLASS: uw::_Unwind_Exception_Class = 0x4d_4c_42_53_41_52_54_51;
#[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 name: CSlice<'a, u8>,
pub id: u32,
pub file: CSlice<'a, u8>,
pub line: u32,
pub column: u32,
@ -42,33 +45,100 @@ fn str_err(_: core::str::Utf8Error) -> core::fmt::Error {
core::fmt::Error
}
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: {}",
core::str::from_utf8(self.name.as_ref()).map_err(str_err)?,
core::str::from_utf8(self.function.as_ref()).map_err(str_err)?,
core::str::from_utf8(self.file.as_ref()).map_err(str_err)?,
self.line, self.column,
core::str::from_utf8(self.message.as_ref()).map_err(str_err)?)
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;
#[repr(C)]
struct ExceptionInfo {
uw_exception: uw::_Unwind_Exception,
exception: Option<Exception<'static>>,
handled: bool,
backtrace: [usize; MAX_BACKTRACE_SIZE],
backtrace_size: usize
#[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,
name: *const u8,
len: usize,
id: u32,
) -> Result<EHAction, ()> {
let lsda = uw::_Unwind_GetLanguageSpecificData(context) as *const u8;
let mut ip_before_instr: c_int = 0;
@ -81,32 +151,14 @@ unsafe fn find_eh_action(
get_text_start: &|| uw::_Unwind_GetTextRelBase(context),
get_data_start: &|| uw::_Unwind_GetDataRelBase(context),
};
eh::find_eh_action(lsda, &eh_context, foreign_exception, name, len)
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 {
let state = state as c_int;
let action = state & uw::_US_ACTION_MASK as c_int;
let search_phase = if action == uw::_US_VIRTUAL_UNWIND_FRAME as c_int {
// Backtraces on ARM will call the personality routine with
// state == _US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND. In those cases
// we want to continue unwinding the stack, otherwise all our backtraces
// would end at __rust_try
if state & uw::_US_FORCE_UNWIND as c_int != 0 {
return continue_unwind(exception_object, context);
}
true
} else if action == uw::_US_UNWIND_FRAME_STARTING as c_int {
false
} else if action == uw::_US_UNWIND_FRAME_RESUME as c_int {
return continue_unwind(exception_object, context);
} else {
return uw::_URC_FAILURE;
};
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
@ -122,52 +174,27 @@ pub unsafe fn artiq_personality(state: uw::_Unwind_State,
let exception_class = (*exception_object).exception_class;
let foreign_exception = exception_class != EXCEPTION_CLASS;
let exception_info = &mut *(exception_object as *mut ExceptionInfo);
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 (name_ptr, len) = if foreign_exception || exception_info.exception.is_none() {
(core::ptr::null(), 0)
} else {
let name = (exception_info.exception.unwrap()).name;
(name.as_ptr(), name.len())
};
let eh_action = match find_eh_action(context, foreign_exception, name_ptr, len) {
let id = exception.id;
let eh_action = match find_eh_action(context, foreign_exception, id) {
Ok(action) => action,
Err(_) => return uw::_URC_FAILURE,
};
let exception = &exception_info.exception.unwrap();
if search_phase {
match eh_action {
EHAction::None => return continue_unwind(exception_object, context),
// Actually, cleanup should not return handler found, this is to workaround
// the issue of terminating directly when no catch cause is found while
// having some cleanup routines defined by finally.
// The best way to handle this is to force unwind the stack in the raise
// function when end of stack is reached, and call terminate at the end of
// the unwind. Unfortunately, there is no forced unwind function defined
// for EHABI, and I have no idea how to implement that, so this is a hack.
EHAction::Cleanup(_) => return uw::_URC_HANDLER_FOUND,
EHAction::Catch(_) => {
// EHABI requires the personality routine to update the
// SP value in the barrier cache of the exception object.
(*exception_object).private[5] =
uw::_Unwind_GetGR(context, uw::UNWIND_SP_REG);
return uw::_URC_HANDLER_FOUND;
}
EHAction::Terminate => return uw::_URC_FAILURE,
}
} else {
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,
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
@ -175,10 +202,11 @@ pub unsafe fn artiq_personality(state: uw::_Unwind_State,
unsafe fn continue_unwind(exception_object: *mut uw::_Unwind_Exception,
context: *mut uw::_Unwind_Context)
-> uw::_Unwind_Reason_Code {
if __gnu_unwind_frame(exception_object, context) == uw::_URC_NO_REASON {
let reason = __gnu_unwind_frame(exception_object, context);
if reason == uw::_URC_NO_REASON {
uw::_URC_CONTINUE_UNWIND
} else {
uw::_URC_FAILURE
reason
}
}
// defined in libgcc
@ -189,74 +217,219 @@ pub unsafe fn artiq_personality(state: uw::_Unwind_State,
}
}
extern fn cleanup(_unwind_code: uw::_Unwind_Reason_Code,
uw_exception: *mut uw::_Unwind_Exception) {
unsafe {
let exception_info = &mut *(uw_exception as *mut ExceptionInfo);
exception_info.exception = None;
}
}
static mut INFLIGHT: ExceptionInfo = ExceptionInfo {
uw_exception: uw::_Unwind_Exception {
exception_class: EXCEPTION_CLASS,
exception_cleanup: cleanup,
private: [0; uw::unwinder_private_data_size],
},
exception: None,
handled: true,
backtrace: [0; MAX_BACKTRACE_SIZE],
backtrace_size: 0
};
pub unsafe extern fn raise(exception: *const Exception) -> ! {
trace!("Trying to raise exception");
// FIXME: unsound transmute
// This would cause stack memory corruption.
INFLIGHT.exception = Some(mem::transmute::<Exception, Exception<'static>>(*exception));
INFLIGHT.handled = false;
let result = uw::_Unwind_RaiseException(&mut INFLIGHT.uw_exception);
assert!(result == uw::_URC_FAILURE || result == uw::_URC_END_OF_STACK);
INFLIGHT.backtrace_size = 0;
// read backtrace
let _ = uw::backtrace(|ip| {
if INFLIGHT.backtrace_size < MAX_BACKTRACE_SIZE {
INFLIGHT.backtrace[INFLIGHT.backtrace_size] = ip;
INFLIGHT.backtrace_size += 1;
}
});
crate::kernel::core1::terminate(INFLIGHT.exception.as_ref().unwrap(), INFLIGHT.backtrace[..INFLIGHT.backtrace_size].as_mut());
}
pub unsafe extern fn reraise() -> ! {
use cslice::AsCSlice;
// Reraise is basically cxa_rethrow, which calls _Unwind_Resume_or_Rethrow,
// which for EHABI would always call _Unwind_RaiseException.
match INFLIGHT.exception {
Some(ref exception) => raise(exception),
None => raise(&Exception {
name: "0:artiq.coredevice.exceptions.RuntimeError".as_c_slice(),
file: file!().as_c_slice(),
line: line!(),
column: column!(),
// https://github.com/rust-lang/rfcs/pull/1719
function: "__artiq_reraise".as_c_slice(),
message: "No active exception to reraise".as_c_slice(),
param: [0, 0, 0]
})
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); 6] = [
("runtimeerror", 0),
("RTIOUnderflow", 1),
("RTIOOverflow", 2),
("RTIODestinationUnreachable", 3),
("DMAError", 4),
("I2CError", 5),
];
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 {
name: concat!("0:artiq.coredevice.exceptions.", $name).as_c_slice(),
id: name_id,
file: file!().as_c_slice(),
line: line!(),
column: column!(),
@ -266,7 +439,9 @@ macro_rules! artiq_raise {
param: [$param0, $param1, $param2]
};
#[allow(unused_unsafe)]
unsafe { $crate::eh_artiq::raise(&exn) }
unsafe {
$crate::eh_artiq::raise(&exn)
}
});
($name:expr, $message:expr) => ({
artiq_raise!($name, $message, 0, 0, 0)

3
src/runtime/src/kernel/api.rs
View File

@ -204,7 +204,8 @@ pub fn resolve(required: &[u8]) -> Option<u32> {
api!(_Unwind_Resume = unwind::_Unwind_Resume),
api!(__artiq_personality = eh_artiq::artiq_personality),
api!(__artiq_raise = eh_artiq::raise),
api!(__artiq_reraise = eh_artiq::reraise),
api!(__artiq_resume = eh_artiq::resume),
api!(__artiq_end_catch = eh_artiq::end_catch),
// Implementations for LLVM math intrinsics
api!(__powidf2),

20
src/runtime/src/kernel/core1.rs
View File

@ -182,6 +182,7 @@ pub extern "C" fn main_core1() {
info!("kernel starting");
if let Some(kernel) = loaded_kernel.take() {
unsafe {
eh_artiq::reset_exception_buffer();
KERNEL_CHANNEL_0TO1 = Some(core1_rx);
KERNEL_CHANNEL_1TO0 = Some(core1_tx);
KERNEL_IMAGE = &kernel as *const KernelImage;
@ -201,24 +202,13 @@ pub extern "C" fn main_core1() {
}
/// Called by eh_artiq
pub fn terminate(exception: &'static eh_artiq::Exception<'static>, backtrace: &'static mut [usize]) -> ! {
let load_addr = unsafe {
KERNEL_IMAGE.as_ref().unwrap().get_load_addr()
};
let mut cursor = 0;
// The address in the backtrace is relocated, so we have to convert it back to the address in
// the original python script, and remove those Rust function backtrace.
for i in 0..backtrace.len() {
if backtrace[i] >= load_addr {
backtrace[cursor] = backtrace[i] - load_addr;
cursor += 1;
}
}
pub fn terminate(exceptions: &'static [Option<eh_artiq::Exception<'static>>],
stack_pointers: &'static [eh_artiq::StackPointerBacktrace],
backtrace: &'static mut [(usize, usize)]) -> ! {
{
let core1_tx = unsafe { KERNEL_CHANNEL_1TO0.as_mut().unwrap() };
let errors = unsafe { get_async_errors() };
core1_tx.send(Message::KernelException(exception, &backtrace[..cursor], errors));
core1_tx.send(Message::KernelException(exceptions, stack_pointers, backtrace, errors));
}
loop {}
}

15
src/runtime/src/kernel/mod.rs
View File

@ -15,13 +15,13 @@ mod cache;
#[derive(Debug, Clone)]
pub struct RPCException {
pub name: String,
pub message: String,
pub id: u32,
pub message: u32,
pub param: [i64; 3],
pub file: String,
pub file: u32,
pub line: i32,
pub column: i32,
pub function: String
pub function: u32
}
#[derive(Debug, Clone)]
@ -31,7 +31,10 @@ pub enum Message {
LoadFailed,
StartRequest,
KernelFinished(u8),
KernelException(&'static eh_artiq::Exception<'static>, &'static [usize], u8),
KernelException(&'static [Option<eh_artiq::Exception<'static>>],
&'static [eh_artiq::StackPointerBacktrace],
&'static [(usize, usize)],
u8),
RpcSend { is_async: bool, data: Vec<u8> },
RpcRecvRequest(*mut ()),
RpcRecvReply(Result<usize, RPCException>),
@ -53,7 +56,7 @@ static CHANNEL_SEM: Semaphore = Semaphore::new(0, 1);
static mut KERNEL_CHANNEL_0TO1: Option<sync_channel::Receiver<'static, Message>> = None;
static mut KERNEL_CHANNEL_1TO0: Option<sync_channel::Sender<'static, Message>> = None;
static mut KERNEL_IMAGE: *const core1::KernelImage = ptr::null();
pub static mut KERNEL_IMAGE: *const core1::KernelImage = ptr::null();
static INIT_LOCK: Mutex<()> = Mutex::new(());

10
src/runtime/src/kernel/rpc.rs
View File

@ -1,7 +1,7 @@
//! Kernel-side RPC API
use alloc::vec::Vec;
use cslice::{CSlice, AsCSlice};
use cslice::CSlice;
use crate::eh_artiq;
use crate::rpc::send_args;
@ -36,12 +36,12 @@ pub extern fn rpc_recv(slot: *mut ()) -> usize {
Message::RpcRecvReply(Ok(alloc_size)) => alloc_size,
Message::RpcRecvReply(Err(exception)) => unsafe {
eh_artiq::raise(&eh_artiq::Exception {
name: exception.name.as_bytes().as_c_slice(),
file: exception.file.as_bytes().as_c_slice(),
id: exception.id,
file: CSlice::new(exception.file as *const u8, usize::MAX),
line: exception.line as u32,
column: exception.column as u32,
function: exception.function.as_bytes().as_c_slice(),
message: exception.message.as_bytes().as_c_slice(),
function: CSlice::new(exception.function as *const u8, usize::MAX),
message: CSlice::new(exception.message as *const u8, usize::MAX),
param: exception.param
})
},