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Adjust ABI safety requirement
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@nbdd0121
nbdd0121 committed Aug 6, 2023
1 parent f5ef1d1 commit 7477bc5
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Showing 3 changed files with 97 additions and 88 deletions.
22 changes: 11 additions & 11 deletions src/abi.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -60,11 +60,11 @@ impl UnwindAction {

pub type UnwindExceptionCleanupFn = unsafe extern "C" fn(UnwindReasonCode, *mut UnwindException);

pub type UnwindStopFn = extern "C" fn(
pub type UnwindStopFn = unsafe extern "C" fn(
c_int,
UnwindAction,
u64,
&mut UnwindException,
*mut UnwindException,
&mut UnwindContext<'_>,
*mut c_void,
) -> UnwindReasonCode;
Expand All @@ -87,11 +87,11 @@ pub struct UnwindContext<'a> {
phantom: core::marker::PhantomData<&'a ()>,
}

pub type PersonalityRoutine = extern "C" fn(
pub type PersonalityRoutine = unsafe extern "C" fn(
c_int,
UnwindAction,
u64,
&mut UnwindException,
*mut UnwindException,
&mut UnwindContext<'_>,
) -> UnwindReasonCode;

Expand Down Expand Up @@ -134,17 +134,17 @@ binding! {
extern "C" fn _Unwind_GetTextRelBase(unwind_ctx: &UnwindContext<'_>) -> usize;
extern "C" fn _Unwind_GetDataRelBase(unwind_ctx: &UnwindContext<'_>) -> usize;
extern "C" fn _Unwind_FindEnclosingFunction(pc: *mut c_void) -> *mut c_void;
extern "C-unwind" fn _Unwind_RaiseException(
exception: &mut UnwindException,
extern "C-unwind" [unsafe] fn _Unwind_RaiseException(
exception: *mut UnwindException,
) -> UnwindReasonCode;
extern "C-unwind" fn _Unwind_ForcedUnwind(
exception: &mut UnwindException,
extern "C-unwind" [unsafe] fn _Unwind_ForcedUnwind(
exception: *mut UnwindException,
stop: UnwindStopFn,
stop_arg: *mut c_void,
) -> UnwindReasonCode;
extern "C-unwind" fn _Unwind_Resume(exception: &mut UnwindException) -> !;
extern "C-unwind" fn _Unwind_Resume_or_Rethrow(
exception: &mut UnwindException,
extern "C-unwind" [unsafe] fn _Unwind_Resume(exception: *mut UnwindException) -> !;
extern "C-unwind" [unsafe] fn _Unwind_Resume_or_Rethrow(
exception: *mut UnwindException,
) -> UnwindReasonCode;
extern "C" [unsafe] fn _Unwind_DeleteException(exception: *mut UnwindException);
extern "C-unwind" fn _Unwind_Backtrace(
Expand Down
5 changes: 1 addition & 4 deletions src/panic_handler.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,10 +59,7 @@ fn stack_trace() {
struct CallbackData {
counter: usize,
}
extern "C" fn callback(
unwind_ctx: &UnwindContext<'_>,
arg: *mut c_void,
) -> UnwindReasonCode {
extern "C" fn callback(unwind_ctx: &UnwindContext<'_>, arg: *mut c_void) -> UnwindReasonCode {
let data = unsafe { &mut *(arg as *mut CallbackData) };
data.counter += 1;
eprintln!(
Expand Down
158 changes: 85 additions & 73 deletions src/unwinder/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -149,8 +149,8 @@ macro_rules! try2 {

#[inline(never)]
#[no_mangle]
pub extern "C-unwind" fn _Unwind_RaiseException(
exception: &mut UnwindException,
pub unsafe extern "C-unwind" fn _Unwind_RaiseException(
exception: *mut UnwindException,
) -> UnwindReasonCode {
with_context(|saved_ctx| {
// Phase 1: Search for handler
Expand All @@ -159,17 +159,19 @@ pub extern "C-unwind" fn _Unwind_RaiseException(
loop {
if let Some(frame) = try1!(Frame::from_context(&ctx, signal)) {
if let Some(personality) = frame.personality() {
let result = personality(
1,
UnwindAction::SEARCH_PHASE,
exception.exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx: &mut ctx,
signal,
},
);
let result = unsafe {
personality(
1,
UnwindAction::SEARCH_PHASE,
(*exception).exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx: &mut ctx,
signal,
},
)
};

match result {
UnwindReasonCode::CONTINUE_UNWIND => (),
Expand All @@ -189,8 +191,10 @@ pub extern "C-unwind" fn _Unwind_RaiseException(

// Disambiguate normal frame and signal frame.
let handler_cfa = ctx[Arch::SP] - signal as usize;
exception.private_1 = None;
exception.private_2 = handler_cfa;
unsafe {
(*exception).private_1 = None;
(*exception).private_2 = handler_cfa;
}

let code = raise_exception_phase2(exception, saved_ctx, handler_cfa);
match code {
Expand All @@ -201,7 +205,7 @@ pub extern "C-unwind" fn _Unwind_RaiseException(
}

fn raise_exception_phase2(
exception: &mut UnwindException,
exception: *mut UnwindException,
ctx: &mut Context,
handler_cfa: usize,
) -> UnwindReasonCode {
Expand All @@ -210,22 +214,24 @@ fn raise_exception_phase2(
if let Some(frame) = try2!(Frame::from_context(ctx, signal)) {
let frame_cfa = ctx[Arch::SP] - signal as usize;
if let Some(personality) = frame.personality() {
let code = personality(
1,
UnwindAction::CLEANUP_PHASE
| if frame_cfa == handler_cfa {
UnwindAction::HANDLER_FRAME
} else {
UnwindAction::empty()
let code = unsafe {
personality(
1,
UnwindAction::CLEANUP_PHASE
| if frame_cfa == handler_cfa {
UnwindAction::HANDLER_FRAME
} else {
UnwindAction::empty()
},
(*exception).exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx,
signal,
},
exception.exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx,
signal,
},
);
)
};

match code {
UnwindReasonCode::CONTINUE_UNWIND => (),
Expand All @@ -247,14 +253,16 @@ fn raise_exception_phase2(

#[inline(never)]
#[no_mangle]
pub extern "C-unwind" fn _Unwind_ForcedUnwind(
exception: &mut UnwindException,
pub unsafe extern "C-unwind" fn _Unwind_ForcedUnwind(
exception: *mut UnwindException,
stop: UnwindStopFn,
stop_arg: *mut c_void,
) -> UnwindReasonCode {
with_context(|ctx| {
exception.private_1 = Some(stop);
exception.private_2 = stop_arg as _;
unsafe {
(*exception).private_1 = Some(stop);
(*exception).private_2 = stop_arg as _;
}

let code = force_unwind_phase2(exception, ctx, stop, stop_arg);
match code {
Expand All @@ -265,7 +273,7 @@ pub extern "C-unwind" fn _Unwind_ForcedUnwind(
}

fn force_unwind_phase2(
exception: &mut UnwindException,
exception: *mut UnwindException,
ctx: &mut Context,
stop: UnwindStopFn,
stop_arg: *mut c_void,
Expand All @@ -274,42 +282,46 @@ fn force_unwind_phase2(
loop {
let frame = try2!(Frame::from_context(ctx, signal));

let code = stop(
1,
UnwindAction::FORCE_UNWIND
| UnwindAction::END_OF_STACK
| if frame.is_none() {
UnwindAction::END_OF_STACK
} else {
UnwindAction::empty()
let code = unsafe {
stop(
1,
UnwindAction::FORCE_UNWIND
| UnwindAction::END_OF_STACK
| if frame.is_none() {
UnwindAction::END_OF_STACK
} else {
UnwindAction::empty()
},
(*exception).exception_class,
exception,
&mut UnwindContext {
frame: frame.as_ref(),
ctx,
signal,
},
exception.exception_class,
exception,
&mut UnwindContext {
frame: frame.as_ref(),
ctx,
signal,
},
stop_arg,
);
stop_arg,
)
};
match code {
UnwindReasonCode::NO_REASON => (),
_ => return UnwindReasonCode::FATAL_PHASE2_ERROR,
}

if let Some(frame) = frame {
if let Some(personality) = frame.personality() {
let code = personality(
1,
UnwindAction::FORCE_UNWIND | UnwindAction::CLEANUP_PHASE,
exception.exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx,
signal,
},
);
let code = unsafe {
personality(
1,
UnwindAction::FORCE_UNWIND | UnwindAction::CLEANUP_PHASE,
(*exception).exception_class,
exception,
&mut UnwindContext {
frame: Some(&frame),
ctx,
signal,
},
)
};

match code {
UnwindReasonCode::CONTINUE_UNWIND => (),
Expand All @@ -331,15 +343,15 @@ fn force_unwind_phase2(

#[inline(never)]
#[no_mangle]
pub extern "C-unwind" fn _Unwind_Resume(exception: &mut UnwindException) -> ! {
pub unsafe extern "C-unwind" fn _Unwind_Resume(exception: *mut UnwindException) -> ! {
with_context(|ctx| {
let code = match exception.private_1 {
let code = match unsafe { (*exception).private_1 } {
None => {
let handler_cfa = exception.private_2;
let handler_cfa = unsafe { (*exception).private_2 };
raise_exception_phase2(exception, ctx, handler_cfa)
}
Some(stop) => {
let stop_arg = exception.private_2 as _;
let stop_arg = unsafe { (*exception).private_2 as _ };
force_unwind_phase2(exception, ctx, stop, stop_arg)
}
};
Expand All @@ -351,16 +363,16 @@ pub extern "C-unwind" fn _Unwind_Resume(exception: &mut UnwindException) -> ! {

#[inline(never)]
#[no_mangle]
pub extern "C-unwind" fn _Unwind_Resume_or_Rethrow(
exception: &mut UnwindException,
pub unsafe extern "C-unwind" fn _Unwind_Resume_or_Rethrow(
exception: *mut UnwindException,
) -> UnwindReasonCode {
let stop = match exception.private_1 {
None => return _Unwind_RaiseException(exception),
let stop = match unsafe { (*exception).private_1 } {
None => return unsafe { _Unwind_RaiseException(exception) },
Some(v) => v,
};

with_context(|ctx| {
let stop_arg = exception.private_2 as _;
let stop_arg = unsafe { (*exception).private_2 as _ };
let code = force_unwind_phase2(exception, ctx, stop, stop_arg);
assert!(code == UnwindReasonCode::INSTALL_CONTEXT);

Expand Down

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