diff options
Diffstat (limited to '')
| -rw-r--r-- | library/panic_unwind/src/emcc.rs | 56 | ||||
| -rw-r--r-- | library/panic_unwind/src/gcc.rs | 292 | ||||
| -rw-r--r-- | library/panic_unwind/src/lib.rs | 8 | ||||
| -rw-r--r-- | library/panic_unwind/src/seh.rs | 45 | ||||
| -rw-r--r-- | library/std/src/personality/dwarf/eh.rs (renamed from library/panic_unwind/src/dwarf/eh.rs) | 9 | ||||
| -rw-r--r-- | library/std/src/personality/dwarf/mod.rs (renamed from library/panic_unwind/src/dwarf/mod.rs) | 0 | ||||
| -rw-r--r-- | library/std/src/personality/dwarf/tests.rs (renamed from library/panic_unwind/src/dwarf/tests.rs) | 0 |
7 files changed, 85 insertions, 325 deletions
diff --git a/library/panic_unwind/src/emcc.rs b/library/panic_unwind/src/emcc.rs index 1ee69ff9c..c6d423085 100644 --- a/library/panic_unwind/src/emcc.rs +++ b/library/panic_unwind/src/emcc.rs @@ -12,7 +12,6 @@ use core::intrinsics; use core::mem; use core::ptr; use core::sync::atomic::{AtomicBool, Ordering}; -use libc::{self, c_int}; use unwind as uw; // This matches the layout of std::type_info in C++ @@ -48,7 +47,12 @@ static EXCEPTION_TYPE_INFO: TypeInfo = TypeInfo { name: b"rust_panic\0".as_ptr(), }; +// NOTE(nbdd0121): The `canary` field will be part of stable ABI after `c_unwind` stabilization. +#[repr(C)] struct Exception { + // See `gcc.rs` on why this is present. We already have a static here so just use it. + canary: *const TypeInfo, + // This is necessary because C++ code can capture our exception with // std::exception_ptr and rethrow it multiple times, possibly even in // another thread. @@ -71,27 +75,38 @@ pub unsafe fn cleanup(ptr: *mut u8) -> Box<dyn Any + Send> { let catch_data = &*(ptr as *mut CatchData); let adjusted_ptr = __cxa_begin_catch(catch_data.ptr as *mut libc::c_void) as *mut Exception; - let out = if catch_data.is_rust_panic { - let was_caught = (*adjusted_ptr).caught.swap(true, Ordering::SeqCst); - if was_caught { - // Since cleanup() isn't allowed to panic, we just abort instead. - intrinsics::abort(); - } - (*adjusted_ptr).data.take().unwrap() - } else { + if !catch_data.is_rust_panic { + super::__rust_foreign_exception(); + } + + let canary = ptr::addr_of!((*adjusted_ptr).canary).read(); + if !ptr::eq(canary, &EXCEPTION_TYPE_INFO) { super::__rust_foreign_exception(); - }; + } + + let was_caught = (*adjusted_ptr).caught.swap(true, Ordering::SeqCst); + if was_caught { + // Since cleanup() isn't allowed to panic, we just abort instead. + intrinsics::abort(); + } + let out = (*adjusted_ptr).data.take().unwrap(); __cxa_end_catch(); out } pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 { - let sz = mem::size_of_val(&data); - let exception = __cxa_allocate_exception(sz) as *mut Exception; + let exception = __cxa_allocate_exception(mem::size_of::<Exception>()) as *mut Exception; if exception.is_null() { return uw::_URC_FATAL_PHASE1_ERROR as u32; } - ptr::write(exception, Exception { caught: AtomicBool::new(false), data: Some(data) }); + ptr::write( + exception, + Exception { + canary: &EXCEPTION_TYPE_INFO, + caught: AtomicBool::new(false), + data: Some(data), + }, + ); __cxa_throw(exception as *mut _, &EXCEPTION_TYPE_INFO, exception_cleanup); } @@ -105,21 +120,6 @@ extern "C" fn exception_cleanup(ptr: *mut libc::c_void) -> *mut libc::c_void { } } -// This is required by the compiler to exist (e.g., it's a lang item), but it's -// never actually called by the compiler. Emscripten EH doesn't use a -// personality function at all, it instead uses __cxa_find_matching_catch. -// Wasm error handling would use __gxx_personality_wasm0. -#[lang = "eh_personality"] -unsafe extern "C" fn rust_eh_personality( - _version: c_int, - _actions: uw::_Unwind_Action, - _exception_class: uw::_Unwind_Exception_Class, - _exception_object: *mut uw::_Unwind_Exception, - _context: *mut uw::_Unwind_Context, -) -> uw::_Unwind_Reason_Code { - core::intrinsics::abort() -} - extern "C" { fn __cxa_allocate_exception(thrown_size: libc::size_t) -> *mut libc::c_void; fn __cxa_begin_catch(thrown_exception: *mut libc::c_void) -> *mut libc::c_void; diff --git a/library/panic_unwind/src/gcc.rs b/library/panic_unwind/src/gcc.rs index a59659231..0b7a873a6 100644 --- a/library/panic_unwind/src/gcc.rs +++ b/library/panic_unwind/src/gcc.rs @@ -38,14 +38,23 @@ use alloc::boxed::Box; use core::any::Any; +use core::ptr; -use crate::dwarf::eh::{self, EHAction, EHContext}; -use libc::{c_int, uintptr_t}; use unwind as uw; +// In case where multiple copies of std exist in a single process, +// we use address of this static variable to distinguish an exception raised by +// this copy and some other copy (which needs to be treated as foreign exception). +static CANARY: u8 = 0; + +// NOTE(nbdd0121) +// Once `c_unwind` feature is stabilized, there will be ABI stability requirement +// on this struct. The first two field must be `_Unwind_Exception` and `canary`, +// as it may be accessed by a different version of the std with a different compiler. #[repr(C)] struct Exception { _uwe: uw::_Unwind_Exception, + canary: *const u8, cause: Box<dyn Any + Send>, } @@ -56,6 +65,7 @@ pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 { exception_cleanup, private: [0; uw::unwinder_private_data_size], }, + canary: &CANARY, cause: data, }); let exception_param = Box::into_raw(exception) as *mut uw::_Unwind_Exception; @@ -77,10 +87,22 @@ pub unsafe fn cleanup(ptr: *mut u8) -> Box<dyn Any + Send> { if (*exception).exception_class != rust_exception_class() { uw::_Unwind_DeleteException(exception); super::__rust_foreign_exception(); - } else { - let exception = Box::from_raw(exception as *mut Exception); - exception.cause } + + let exception = exception.cast::<Exception>(); + // Just access the canary field, avoid accessing the entire `Exception` as + // it can be a foreign Rust exception. + let canary = ptr::addr_of!((*exception).canary).read(); + if !ptr::eq(canary, &CANARY) { + // A foreign Rust exception, treat it slightly differently from other + // foreign exceptions, because call into `_Unwind_DeleteException` will + // call into `__rust_drop_panic` which produces a confusing + // "Rust panic must be rethrown" message. + super::__rust_foreign_exception(); + } + + let exception = Box::from_raw(exception as *mut Exception); + exception.cause } // Rust's exception class identifier. This is used by personality routines to @@ -89,263 +111,3 @@ fn rust_exception_class() -> uw::_Unwind_Exception_Class { // M O Z \0 R U S T -- vendor, language 0x4d4f5a_00_52555354 } - -// Register ids were lifted from LLVM's TargetLowering::getExceptionPointerRegister() -// and TargetLowering::getExceptionSelectorRegister() for each architecture, -// then mapped to DWARF register numbers via register definition tables -// (typically <arch>RegisterInfo.td, search for "DwarfRegNum"). -// See also https://llvm.org/docs/WritingAnLLVMBackend.html#defining-a-register. - -#[cfg(target_arch = "x86")] -const UNWIND_DATA_REG: (i32, i32) = (0, 2); // EAX, EDX - -#[cfg(target_arch = "x86_64")] -const UNWIND_DATA_REG: (i32, i32) = (0, 1); // RAX, RDX - -#[cfg(any(target_arch = "arm", target_arch = "aarch64"))] -const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1 / X0, X1 - -#[cfg(target_arch = "m68k")] -const UNWIND_DATA_REG: (i32, i32) = (0, 1); // D0, D1 - -#[cfg(any(target_arch = "mips", target_arch = "mips64"))] -const UNWIND_DATA_REG: (i32, i32) = (4, 5); // A0, A1 - -#[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))] -const UNWIND_DATA_REG: (i32, i32) = (3, 4); // R3, R4 / X3, X4 - -#[cfg(target_arch = "s390x")] -const UNWIND_DATA_REG: (i32, i32) = (6, 7); // R6, R7 - -#[cfg(any(target_arch = "sparc", target_arch = "sparc64"))] -const UNWIND_DATA_REG: (i32, i32) = (24, 25); // I0, I1 - -#[cfg(target_arch = "hexagon")] -const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1 - -#[cfg(any(target_arch = "riscv64", target_arch = "riscv32"))] -const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11 - -// The following code is based on GCC's C and C++ personality routines. For reference, see: -// https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc -// https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c - -cfg_if::cfg_if! { - if #[cfg(all(target_arch = "arm", not(target_os = "ios"), not(target_os = "watchos"), not(target_os = "netbsd")))] { - // ARM EHABI personality routine. - // https://infocenter.arm.com/help/topic/com.arm.doc.ihi0038b/IHI0038B_ehabi.pdf - // - // iOS uses the default routine instead since it uses SjLj unwinding. - #[lang = "eh_personality"] - unsafe extern "C" fn rust_eh_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; - }; - - // 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 eh_action = match find_eh_action(context) { - Ok(action) => action, - Err(_) => return uw::_URC_FAILURE, - }; - if search_phase { - match eh_action { - EHAction::None | - EHAction::Cleanup(_) => return continue_unwind(exception_object, context), - 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, 0); - 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 { - if __gnu_unwind_frame(exception_object, context) == uw::_URC_NO_REASON { - uw::_URC_CONTINUE_UNWIND - } else { - uw::_URC_FAILURE - } - } - // defined in libgcc - extern "C" { - fn __gnu_unwind_frame(exception_object: *mut uw::_Unwind_Exception, - context: *mut uw::_Unwind_Context) - -> uw::_Unwind_Reason_Code; - } - } - } else { - // Default personality routine, which is used directly on most targets - // and indirectly on Windows x86_64 via SEH. - unsafe extern "C" fn rust_eh_personality_impl(version: c_int, - actions: uw::_Unwind_Action, - _exception_class: uw::_Unwind_Exception_Class, - exception_object: *mut uw::_Unwind_Exception, - context: *mut uw::_Unwind_Context) - -> uw::_Unwind_Reason_Code { - if version != 1 { - return uw::_URC_FATAL_PHASE1_ERROR; - } - let eh_action = match find_eh_action(context) { - Ok(action) => action, - Err(_) => return uw::_URC_FATAL_PHASE1_ERROR, - }; - if actions as i32 & uw::_UA_SEARCH_PHASE as i32 != 0 { - match eh_action { - EHAction::None | - EHAction::Cleanup(_) => uw::_URC_CONTINUE_UNWIND, - EHAction::Catch(_) => uw::_URC_HANDLER_FOUND, - EHAction::Terminate => uw::_URC_FATAL_PHASE1_ERROR, - } - } else { - match eh_action { - EHAction::None => uw::_URC_CONTINUE_UNWIND, - 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, 0); - uw::_Unwind_SetIP(context, lpad); - uw::_URC_INSTALL_CONTEXT - } - EHAction::Terminate => uw::_URC_FATAL_PHASE2_ERROR, - } - } - } - - cfg_if::cfg_if! { - if #[cfg(all(windows, target_arch = "x86_64", target_env = "gnu"))] { - // On x86_64 MinGW targets, the unwinding mechanism is SEH however the unwind - // handler data (aka LSDA) uses GCC-compatible encoding. - #[lang = "eh_personality"] - #[allow(nonstandard_style)] - unsafe extern "C" fn rust_eh_personality(exceptionRecord: *mut uw::EXCEPTION_RECORD, - establisherFrame: uw::LPVOID, - contextRecord: *mut uw::CONTEXT, - dispatcherContext: *mut uw::DISPATCHER_CONTEXT) - -> uw::EXCEPTION_DISPOSITION { - uw::_GCC_specific_handler(exceptionRecord, - establisherFrame, - contextRecord, - dispatcherContext, - rust_eh_personality_impl) - } - } else { - // The personality routine for most of our targets. - #[lang = "eh_personality"] - unsafe extern "C" fn rust_eh_personality(version: c_int, - actions: uw::_Unwind_Action, - exception_class: uw::_Unwind_Exception_Class, - exception_object: *mut uw::_Unwind_Exception, - context: *mut uw::_Unwind_Context) - -> uw::_Unwind_Reason_Code { - rust_eh_personality_impl(version, - actions, - exception_class, - exception_object, - context) - } - } - } - } -} - -unsafe fn find_eh_action(context: *mut uw::_Unwind_Context) -> 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 = -1` has special meaning, so use wrapping sub to allow for that - ip: if ip_before_instr != 0 { ip } else { ip.wrapping_sub(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) -} - -// Frame unwind info registration -// -// Each module's image contains a frame unwind info section (usually -// ".eh_frame"). When a module is loaded/unloaded into the process, the -// unwinder must be informed about the location of this section in memory. The -// methods of achieving that vary by the platform. On some (e.g., Linux), the -// unwinder can discover unwind info sections on its own (by dynamically -// enumerating currently loaded modules via the dl_iterate_phdr() API and -// finding their ".eh_frame" sections); Others, like Windows, require modules -// to actively register their unwind info sections via unwinder API. -// -// This module defines two symbols which are referenced and called from -// rsbegin.rs to register our information with the GCC runtime. The -// implementation of stack unwinding is (for now) deferred to libgcc_eh, however -// Rust crates use these Rust-specific entry points to avoid potential clashes -// with any GCC runtime. -#[cfg(all(target_os = "windows", target_arch = "x86", target_env = "gnu"))] -pub mod eh_frame_registry { - extern "C" { - fn __register_frame_info(eh_frame_begin: *const u8, object: *mut u8); - fn __deregister_frame_info(eh_frame_begin: *const u8, object: *mut u8); - } - - #[rustc_std_internal_symbol] - pub unsafe extern "C" fn rust_eh_register_frames(eh_frame_begin: *const u8, object: *mut u8) { - __register_frame_info(eh_frame_begin, object); - } - - #[rustc_std_internal_symbol] - pub unsafe extern "C" fn rust_eh_unregister_frames(eh_frame_begin: *const u8, object: *mut u8) { - __deregister_frame_info(eh_frame_begin, object); - } -} diff --git a/library/panic_unwind/src/lib.rs b/library/panic_unwind/src/lib.rs index f9acb42c4..7e7180a38 100644 --- a/library/panic_unwind/src/lib.rs +++ b/library/panic_unwind/src/lib.rs @@ -42,7 +42,8 @@ cfg_if::cfg_if! { // L4Re is unix family but does not yet support unwinding. #[path = "dummy.rs"] mod real_imp; - } else if #[cfg(target_env = "msvc")] { + } else if #[cfg(all(target_env = "msvc", not(target_arch = "arm")))] { + // LLVM does not support unwinding on 32 bit ARM msvc (thumbv7a-pc-windows-msvc) #[path = "seh.rs"] mod real_imp; } else if #[cfg(any( @@ -52,9 +53,6 @@ cfg_if::cfg_if! { all(target_family = "unix", not(target_os = "espidf")), all(target_vendor = "fortanix", target_env = "sgx"), ))] { - // Rust runtime's startup objects depend on these symbols, so make them public. - #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))] - pub use real_imp::eh_frame_registry::*; #[path = "gcc.rs"] mod real_imp; } else { @@ -92,8 +90,6 @@ extern "C" { fn __rust_foreign_exception() -> !; } -mod dwarf; - #[rustc_std_internal_symbol] #[allow(improper_ctypes_definitions)] pub unsafe extern "C" fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static) { diff --git a/library/panic_unwind/src/seh.rs b/library/panic_unwind/src/seh.rs index 9f1eb411f..651115a82 100644 --- a/library/panic_unwind/src/seh.rs +++ b/library/panic_unwind/src/seh.rs @@ -49,9 +49,15 @@ use alloc::boxed::Box; use core::any::Any; use core::mem::{self, ManuallyDrop}; +use core::ptr; use libc::{c_int, c_uint, c_void}; +// NOTE(nbdd0121): The `canary` field will be part of stable ABI after `c_unwind` stabilization. +#[repr(C)] struct Exception { + // See `gcc.rs` on why this is present. We already have a static here so just use it. + canary: *const _TypeDescriptor, + // This needs to be an Option because we catch the exception by reference // and its destructor is executed by the C++ runtime. When we take the Box // out of the exception, we need to leave the exception in a valid state @@ -235,7 +241,7 @@ static mut TYPE_DESCRIPTOR: _TypeDescriptor = _TypeDescriptor { macro_rules! define_cleanup { ($abi:tt $abi2:tt) => { unsafe extern $abi fn exception_cleanup(e: *mut Exception) { - if let Exception { data: Some(b) } = e.read() { + if let Exception { data: Some(b), .. } = e.read() { drop(b); super::__rust_drop_panic(); } @@ -256,7 +262,7 @@ cfg_if::cfg_if! { } pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 { - use core::intrinsics::atomic_store; + use core::intrinsics::atomic_store_seqcst; // _CxxThrowException executes entirely on this stack frame, so there's no // need to otherwise transfer `data` to the heap. We just pass a stack @@ -265,7 +271,7 @@ pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 { // The ManuallyDrop is needed here since we don't want Exception to be // dropped when unwinding. Instead it will be dropped by exception_cleanup // which is invoked by the C++ runtime. - let mut exception = ManuallyDrop::new(Exception { data: Some(data) }); + let mut exception = ManuallyDrop::new(Exception { canary: &TYPE_DESCRIPTOR, data: Some(data) }); let throw_ptr = &mut exception as *mut _ as *mut _; // This... may seems surprising, and justifiably so. On 32-bit MSVC the @@ -288,20 +294,23 @@ pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 { // // In any case, we basically need to do something like this until we can // express more operations in statics (and we may never be able to). - atomic_store(&mut THROW_INFO.pmfnUnwind as *mut _ as *mut u32, ptr!(exception_cleanup) as u32); - atomic_store( + atomic_store_seqcst( + &mut THROW_INFO.pmfnUnwind as *mut _ as *mut u32, + ptr!(exception_cleanup) as u32, + ); + atomic_store_seqcst( &mut THROW_INFO.pCatchableTypeArray as *mut _ as *mut u32, ptr!(&CATCHABLE_TYPE_ARRAY as *const _) as u32, ); - atomic_store( + atomic_store_seqcst( &mut CATCHABLE_TYPE_ARRAY.arrayOfCatchableTypes[0] as *mut _ as *mut u32, ptr!(&CATCHABLE_TYPE as *const _) as u32, ); - atomic_store( + atomic_store_seqcst( &mut CATCHABLE_TYPE.pType as *mut _ as *mut u32, ptr!(&TYPE_DESCRIPTOR as *const _) as u32, ); - atomic_store( + atomic_store_seqcst( &mut CATCHABLE_TYPE.copyFunction as *mut _ as *mut u32, ptr!(exception_copy) as u32, ); @@ -318,18 +327,12 @@ pub unsafe fn cleanup(payload: *mut u8) -> Box<dyn Any + Send> { // __rust_try. This happens when a non-Rust foreign exception is caught. if payload.is_null() { super::__rust_foreign_exception(); - } else { - let exception = &mut *(payload as *mut Exception); - exception.data.take().unwrap() } -} - -// This is required by the compiler to exist (e.g., it's a lang item), but -// it's never actually called by the compiler because __C_specific_handler -// or _except_handler3 is the personality function that is always used. -// Hence this is just an aborting stub. -#[lang = "eh_personality"] -#[cfg(not(test))] -fn rust_eh_personality() { - core::intrinsics::abort() + let exception = payload as *mut Exception; + let canary = ptr::addr_of!((*exception).canary).read(); + if !ptr::eq(canary, &TYPE_DESCRIPTOR) { + // A foreign Rust exception. + super::__rust_foreign_exception(); + } + (*exception).data.take().unwrap() } diff --git a/library/panic_unwind/src/dwarf/eh.rs b/library/std/src/personality/dwarf/eh.rs index 7394feab8..27b50c13b 100644 --- a/library/panic_unwind/src/dwarf/eh.rs +++ b/library/std/src/personality/dwarf/eh.rs @@ -11,7 +11,7 @@ #![allow(non_upper_case_globals)] #![allow(unused)] -use crate::dwarf::DwarfReader; +use super::DwarfReader; use core::mem; pub const DW_EH_PE_omit: u8 = 0xFF; @@ -75,7 +75,7 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result let call_site_encoding = reader.read::<u8>(); let call_site_table_length = reader.read_uleb128(); - let action_table = reader.ptr.offset(call_site_table_length as isize); + let action_table = reader.ptr.add(call_site_table_length as usize); let ip = context.ip; if !USING_SJLJ_EXCEPTIONS { @@ -98,9 +98,8 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result } } } - // Ip is not present in the table. This should not happen... but it does: issue #35011. - // So rather than returning EHAction::Terminate, we do this. - Ok(EHAction::None) + // Ip is not present in the table. This indicates a nounwind call. + Ok(EHAction::Terminate) } else { // SjLj version: // The "IP" is an index into the call-site table, with two exceptions: diff --git a/library/panic_unwind/src/dwarf/mod.rs b/library/std/src/personality/dwarf/mod.rs index 652fbe95a..652fbe95a 100644 --- a/library/panic_unwind/src/dwarf/mod.rs +++ b/library/std/src/personality/dwarf/mod.rs diff --git a/library/panic_unwind/src/dwarf/tests.rs b/library/std/src/personality/dwarf/tests.rs index 1644f3708..1644f3708 100644 --- a/library/panic_unwind/src/dwarf/tests.rs +++ b/library/std/src/personality/dwarf/tests.rs |