1010 lines
37 KiB
C++
1010 lines
37 KiB
C++
//===--------------------------- Unwind-EHABI.cpp -------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//
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// Implements ARM zero-cost C++ exceptions
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//
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//===----------------------------------------------------------------------===//
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#include "Unwind-EHABI.h"
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#if _LIBUNWIND_ARM_EHABI
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <type_traits>
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#include "config.h"
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#include "libunwind.h"
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#include "libunwind_ext.h"
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#include "unwind.h"
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namespace {
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// Strange order: take words in order, but inside word, take from most to least
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// signinficant byte.
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uint8_t getByte(const uint32_t* data, size_t offset) {
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const uint8_t* byteData = reinterpret_cast<const uint8_t*>(data);
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return byteData[(offset & ~(size_t)0x03) + (3 - (offset & (size_t)0x03))];
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}
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const char* getNextWord(const char* data, uint32_t* out) {
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*out = *reinterpret_cast<const uint32_t*>(data);
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return data + 4;
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}
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const char* getNextNibble(const char* data, uint32_t* out) {
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*out = *reinterpret_cast<const uint16_t*>(data);
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return data + 2;
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}
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struct Descriptor {
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// See # 9.2
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typedef enum {
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SU16 = 0, // Short descriptor, 16-bit entries
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LU16 = 1, // Long descriptor, 16-bit entries
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LU32 = 3, // Long descriptor, 32-bit entries
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RESERVED0 = 4, RESERVED1 = 5, RESERVED2 = 6, RESERVED3 = 7,
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RESERVED4 = 8, RESERVED5 = 9, RESERVED6 = 10, RESERVED7 = 11,
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RESERVED8 = 12, RESERVED9 = 13, RESERVED10 = 14, RESERVED11 = 15
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} Format;
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// See # 9.2
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typedef enum {
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CLEANUP = 0x0,
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FUNC = 0x1,
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CATCH = 0x2,
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INVALID = 0x4
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} Kind;
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};
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_Unwind_Reason_Code ProcessDescriptors(
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_Unwind_State state,
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_Unwind_Control_Block* ucbp,
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struct _Unwind_Context* context,
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Descriptor::Format format,
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const char* descriptorStart,
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uint32_t flags) {
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// EHT is inlined in the index using compact form. No descriptors. #5
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if (flags & 0x1)
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return _URC_CONTINUE_UNWIND;
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// TODO: We should check the state here, and determine whether we need to
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// perform phase1 or phase2 unwinding.
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(void)state;
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const char* descriptor = descriptorStart;
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uint32_t descriptorWord;
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getNextWord(descriptor, &descriptorWord);
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while (descriptorWord) {
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// Read descriptor based on # 9.2.
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uint32_t length;
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uint32_t offset;
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switch (format) {
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case Descriptor::LU32:
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descriptor = getNextWord(descriptor, &length);
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descriptor = getNextWord(descriptor, &offset);
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case Descriptor::LU16:
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descriptor = getNextNibble(descriptor, &length);
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descriptor = getNextNibble(descriptor, &offset);
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default:
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assert(false);
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return _URC_FAILURE;
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}
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// See # 9.2 table for decoding the kind of descriptor. It's a 2-bit value.
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Descriptor::Kind kind =
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static_cast<Descriptor::Kind>((length & 0x1) | ((offset & 0x1) << 1));
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// Clear off flag from last bit.
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length &= ~1u;
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offset &= ~1u;
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uintptr_t scopeStart = ucbp->pr_cache.fnstart + offset;
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uintptr_t scopeEnd = scopeStart + length;
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uintptr_t pc = _Unwind_GetIP(context);
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bool isInScope = (scopeStart <= pc) && (pc < scopeEnd);
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switch (kind) {
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case Descriptor::CLEANUP: {
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// TODO(ajwong): Handle cleanup descriptors.
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break;
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}
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case Descriptor::FUNC: {
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// TODO(ajwong): Handle function descriptors.
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break;
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}
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case Descriptor::CATCH: {
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// Catch descriptors require gobbling one more word.
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uint32_t landing_pad;
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descriptor = getNextWord(descriptor, &landing_pad);
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if (isInScope) {
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// TODO(ajwong): This is only phase1 compatible logic. Implement
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// phase2.
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landing_pad = signExtendPrel31(landing_pad & ~0x80000000);
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if (landing_pad == 0xffffffff) {
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return _URC_HANDLER_FOUND;
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} else if (landing_pad == 0xfffffffe) {
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return _URC_FAILURE;
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} else {
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/*
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bool is_reference_type = landing_pad & 0x80000000;
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void* matched_object;
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if (__cxxabiv1::__cxa_type_match(
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ucbp, reinterpret_cast<const std::type_info *>(landing_pad),
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is_reference_type,
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&matched_object) != __cxxabiv1::ctm_failed)
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return _URC_HANDLER_FOUND;
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*/
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_LIBUNWIND_ABORT("Type matching not implemented");
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}
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}
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break;
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}
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default:
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_LIBUNWIND_ABORT("Invalid descriptor kind found.");
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}
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getNextWord(descriptor, &descriptorWord);
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}
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return _URC_CONTINUE_UNWIND;
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}
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static _Unwind_Reason_Code unwindOneFrame(_Unwind_State state,
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_Unwind_Control_Block* ucbp,
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struct _Unwind_Context* context) {
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// Read the compact model EHT entry's header # 6.3
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const uint32_t* unwindingData = ucbp->pr_cache.ehtp;
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assert((*unwindingData & 0xf0000000) == 0x80000000 && "Must be a compact entry");
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Descriptor::Format format =
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static_cast<Descriptor::Format>((*unwindingData & 0x0f000000) >> 24);
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const char *lsda =
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reinterpret_cast<const char *>(_Unwind_GetLanguageSpecificData(context));
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// Handle descriptors before unwinding so they are processed in the context
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// of the correct stack frame.
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_Unwind_Reason_Code result =
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ProcessDescriptors(state, ucbp, context, format, lsda,
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ucbp->pr_cache.additional);
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if (result != _URC_CONTINUE_UNWIND)
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return result;
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if (unw_step(reinterpret_cast<unw_cursor_t*>(context)) != UNW_STEP_SUCCESS)
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return _URC_FAILURE;
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return _URC_CONTINUE_UNWIND;
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}
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// Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_CORE /
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// _UVRSD_UINT32.
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uint32_t RegisterMask(uint8_t start, uint8_t count_minus_one) {
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return ((1U << (count_minus_one + 1)) - 1) << start;
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}
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// Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_VFP /
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// _UVRSD_DOUBLE.
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uint32_t RegisterRange(uint8_t start, uint8_t count_minus_one) {
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return ((uint32_t)start << 16) | ((uint32_t)count_minus_one + 1);
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}
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} // end anonymous namespace
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/**
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* Decodes an EHT entry.
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*
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* @param data Pointer to EHT.
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* @param[out] off Offset from return value (in bytes) to begin interpretation.
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* @param[out] len Number of bytes in unwind code.
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* @return Pointer to beginning of unwind code.
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*/
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extern "C" const uint32_t*
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decode_eht_entry(const uint32_t* data, size_t* off, size_t* len) {
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if ((*data & 0x80000000) == 0) {
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// 6.2: Generic Model
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//
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// EHT entry is a prel31 pointing to the PR, followed by data understood
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// only by the personality routine. Fortunately, all existing assembler
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// implementations, including GNU assembler, LLVM integrated assembler,
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// and ARM assembler, assume that the unwind opcodes come after the
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// personality rountine address.
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*off = 1; // First byte is size data.
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*len = (((data[1] >> 24) & 0xff) + 1) * 4;
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data++; // Skip the first word, which is the prel31 offset.
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} else {
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// 6.3: ARM Compact Model
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//
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// EHT entries here correspond to the __aeabi_unwind_cpp_pr[012] PRs indeded
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// by format:
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Descriptor::Format format =
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static_cast<Descriptor::Format>((*data & 0x0f000000) >> 24);
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switch (format) {
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case Descriptor::SU16:
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*len = 4;
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*off = 1;
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break;
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case Descriptor::LU16:
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case Descriptor::LU32:
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*len = 4 + 4 * ((*data & 0x00ff0000) >> 16);
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*off = 2;
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break;
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default:
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return nullptr;
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}
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}
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return data;
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}
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_Unwind_Reason_Code _Unwind_VRS_Interpret(
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_Unwind_Context* context,
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const uint32_t* data,
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size_t offset,
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size_t len) {
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bool wrotePC = false;
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bool finish = false;
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while (offset < len && !finish) {
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uint8_t byte = getByte(data, offset++);
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if ((byte & 0x80) == 0) {
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uint32_t sp;
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_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp);
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if (byte & 0x40)
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sp -= (((uint32_t)byte & 0x3f) << 2) + 4;
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else
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sp += ((uint32_t)byte << 2) + 4;
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_Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp);
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} else {
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switch (byte & 0xf0) {
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case 0x80: {
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if (offset >= len)
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return _URC_FAILURE;
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uint32_t registers =
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(((uint32_t)byte & 0x0f) << 12) |
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(((uint32_t)getByte(data, offset++)) << 4);
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if (!registers)
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return _URC_FAILURE;
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if (registers & (1 << 15))
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wrotePC = true;
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_Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32);
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break;
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}
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case 0x90: {
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uint8_t reg = byte & 0x0f;
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if (reg == 13 || reg == 15)
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return _URC_FAILURE;
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uint32_t sp;
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_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_R0 + reg,
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_UVRSD_UINT32, &sp);
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_Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32,
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&sp);
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break;
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}
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case 0xa0: {
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uint32_t registers = RegisterMask(4, byte & 0x07);
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if (byte & 0x08)
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registers |= 1 << 14;
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_Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32);
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break;
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}
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case 0xb0: {
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switch (byte) {
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case 0xb0:
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finish = true;
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break;
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case 0xb1: {
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if (offset >= len)
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return _URC_FAILURE;
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uint8_t registers = getByte(data, offset++);
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if (registers & 0xf0 || !registers)
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return _URC_FAILURE;
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_Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32);
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break;
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}
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case 0xb2: {
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uint32_t addend = 0;
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uint32_t shift = 0;
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// This decodes a uleb128 value.
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while (true) {
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if (offset >= len)
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return _URC_FAILURE;
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uint32_t v = getByte(data, offset++);
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addend |= (v & 0x7f) << shift;
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if ((v & 0x80) == 0)
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break;
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shift += 7;
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}
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uint32_t sp;
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_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32,
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&sp);
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sp += 0x204 + (addend << 2);
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_Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32,
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&sp);
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break;
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}
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case 0xb3: {
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uint8_t v = getByte(data, offset++);
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_Unwind_VRS_Pop(context, _UVRSC_VFP,
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RegisterRange(static_cast<uint8_t>(v >> 4),
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v & 0x0f), _UVRSD_VFPX);
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break;
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}
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case 0xb4:
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case 0xb5:
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case 0xb6:
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case 0xb7:
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return _URC_FAILURE;
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default:
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_Unwind_VRS_Pop(context, _UVRSC_VFP,
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RegisterRange(8, byte & 0x07), _UVRSD_VFPX);
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break;
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}
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break;
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}
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case 0xc0: {
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switch (byte) {
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case 0xc0:
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case 0xc1:
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case 0xc2:
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case 0xc3:
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case 0xc4:
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case 0xc5:
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_Unwind_VRS_Pop(context, _UVRSC_WMMXD,
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RegisterRange(10, byte & 0x7), _UVRSD_DOUBLE);
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break;
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case 0xc6: {
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uint8_t v = getByte(data, offset++);
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uint8_t start = static_cast<uint8_t>(v >> 4);
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uint8_t count_minus_one = v & 0xf;
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if (start + count_minus_one >= 16)
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return _URC_FAILURE;
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_Unwind_VRS_Pop(context, _UVRSC_WMMXD,
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RegisterRange(start, count_minus_one),
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_UVRSD_DOUBLE);
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break;
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}
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case 0xc7: {
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uint8_t v = getByte(data, offset++);
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if (!v || v & 0xf0)
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return _URC_FAILURE;
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_Unwind_VRS_Pop(context, _UVRSC_WMMXC, v, _UVRSD_DOUBLE);
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break;
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}
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case 0xc8:
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case 0xc9: {
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uint8_t v = getByte(data, offset++);
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uint8_t start =
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static_cast<uint8_t>(((byte == 0xc8) ? 16 : 0) + (v >> 4));
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uint8_t count_minus_one = v & 0xf;
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if (start + count_minus_one >= 32)
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return _URC_FAILURE;
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_Unwind_VRS_Pop(context, _UVRSC_VFP,
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RegisterRange(start, count_minus_one),
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_UVRSD_DOUBLE);
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break;
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}
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default:
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return _URC_FAILURE;
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}
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break;
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}
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case 0xd0: {
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if (byte & 0x08)
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return _URC_FAILURE;
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_Unwind_VRS_Pop(context, _UVRSC_VFP, RegisterRange(8, byte & 0x7),
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_UVRSD_DOUBLE);
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break;
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}
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default:
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return _URC_FAILURE;
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}
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}
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}
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if (!wrotePC) {
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uint32_t lr;
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_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_LR, _UVRSD_UINT32, &lr);
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_Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_IP, _UVRSD_UINT32, &lr);
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}
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return _URC_CONTINUE_UNWIND;
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}
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extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr0(
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_Unwind_State state,
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_Unwind_Control_Block *ucbp,
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_Unwind_Context *context) {
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return unwindOneFrame(state, ucbp, context);
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}
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extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr1(
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_Unwind_State state,
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_Unwind_Control_Block *ucbp,
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_Unwind_Context *context) {
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return unwindOneFrame(state, ucbp, context);
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}
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extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr2(
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_Unwind_State state,
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_Unwind_Control_Block *ucbp,
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_Unwind_Context *context) {
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return unwindOneFrame(state, ucbp, context);
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}
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static _Unwind_Reason_Code
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unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
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// EHABI #7.3 discusses preserving the VRS in a "temporary VRS" during
|
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// phase 1 and then restoring it to the "primary VRS" for phase 2. The
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// effect is phase 2 doesn't see any of the VRS manipulations from phase 1.
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// In this implementation, the phases don't share the VRS backing store.
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// Instead, they are passed the original |uc| and they create a new VRS
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// from scratch thus achieving the same effect.
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unw_cursor_t cursor1;
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unw_init_local(&cursor1, uc);
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// Walk each frame looking for a place to stop.
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for (bool handlerNotFound = true; handlerNotFound;) {
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#if !_LIBUNWIND_ARM_EHABI
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// Ask libuwind to get next frame (skip over first which is
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// _Unwind_RaiseException).
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int stepResult = unw_step(&cursor1);
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if (stepResult == 0) {
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_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
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"bottom => _URC_END_OF_STACK\n",
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static_cast<void *>(exception_object));
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return _URC_END_OF_STACK;
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} else if (stepResult < 0) {
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_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
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"_URC_FATAL_PHASE1_ERROR\n",
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static_cast<void *>(exception_object));
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return _URC_FATAL_PHASE1_ERROR;
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}
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#endif
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// See if frame has code to run (has personality routine).
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unw_proc_info_t frameInfo;
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if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
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_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
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"failed => _URC_FATAL_PHASE1_ERROR\n",
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static_cast<void *>(exception_object));
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return _URC_FATAL_PHASE1_ERROR;
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|
}
|
|
|
|
// 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(&cursor1, functionBuf, sizeof(functionBuf),
|
|
&offset) != UNW_ESUCCESS) ||
|
|
(frameInfo.start_ip + offset > frameInfo.end_ip))
|
|
functionName = ".anonymous.";
|
|
unw_word_t pc;
|
|
unw_get_reg(&cursor1, UNW_REG_IP, &pc);
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): pc=0x%llX, start_ip=0x%llX, func=%s, "
|
|
"lsda=0x%llX, personality=0x%llX\n",
|
|
static_cast<void *>(exception_object), (long long)pc,
|
|
(long long)frameInfo.start_ip, functionName,
|
|
(long long)frameInfo.lsda, (long long)frameInfo.handler);
|
|
}
|
|
|
|
// If there is a personality routine, ask it if it will want to stop at
|
|
// this frame.
|
|
if (frameInfo.handler != 0) {
|
|
__personality_routine p =
|
|
(__personality_routine)(long)(frameInfo.handler);
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): calling personality function %p\n",
|
|
static_cast<void *>(exception_object),
|
|
reinterpret_cast<void *>(reinterpret_cast<uintptr_t>(p)));
|
|
struct _Unwind_Context *context = (struct _Unwind_Context *)(&cursor1);
|
|
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_VIRTUAL_UNWIND_FRAME, exception_object, context);
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): personality result %d start_ip %x ehtp %p "
|
|
"additional %x\n",
|
|
static_cast<void *>(exception_object), personalityResult,
|
|
exception_object->pr_cache.fnstart,
|
|
static_cast<void *>(exception_object->pr_cache.ehtp),
|
|
exception_object->pr_cache.additional);
|
|
switch (personalityResult) {
|
|
case _URC_HANDLER_FOUND:
|
|
// found a catch clause or locals that need destructing in this frame
|
|
// stop search and remember stack pointer at the frame
|
|
handlerNotFound = false;
|
|
// p should have initialized barrier_cache. EHABI #7.3.5
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND \n",
|
|
static_cast<void *>(exception_object));
|
|
return _URC_NO_REASON;
|
|
|
|
case _URC_CONTINUE_UNWIND:
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
|
|
static_cast<void *>(exception_object));
|
|
// continue unwinding
|
|
break;
|
|
|
|
// EHABI #7.3.3
|
|
case _URC_FAILURE:
|
|
return _URC_FAILURE;
|
|
|
|
default:
|
|
// something went wrong
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",
|
|
static_cast<void *>(exception_object));
|
|
return _URC_FATAL_PHASE1_ERROR;
|
|
}
|
|
}
|
|
}
|
|
return _URC_NO_REASON;
|
|
}
|
|
|
|
static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
|
|
_Unwind_Exception *exception_object,
|
|
bool resume) {
|
|
// See comment at the start of unwind_phase1 regarding VRS integrity.
|
|
unw_cursor_t cursor2;
|
|
unw_init_local(&cursor2, uc);
|
|
|
|
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n",
|
|
static_cast<void *>(exception_object));
|
|
int frame_count = 0;
|
|
|
|
// Walk each frame until we reach where search phase said to stop.
|
|
while (true) {
|
|
// Ask libuwind to get next frame (skip over first which is
|
|
// _Unwind_RaiseException or _Unwind_Resume).
|
|
//
|
|
// Resume only ever makes sense for 1 frame.
|
|
_Unwind_State state =
|
|
resume ? _US_UNWIND_FRAME_RESUME : _US_UNWIND_FRAME_STARTING;
|
|
if (resume && frame_count == 1) {
|
|
// On a resume, first unwind the _Unwind_Resume() frame. The next frame
|
|
// is now the landing pad for the cleanup from a previous execution of
|
|
// phase2. To continue unwindingly correctly, replace VRS[15] with the
|
|
// IP of the frame that the previous run of phase2 installed the context
|
|
// for. After this, continue unwinding as if normal.
|
|
//
|
|
// See #7.4.6 for details.
|
|
unw_set_reg(&cursor2, UNW_REG_IP,
|
|
exception_object->unwinder_cache.reserved2);
|
|
resume = false;
|
|
}
|
|
|
|
#if !_LIBUNWIND_ARM_EHABI
|
|
int stepResult = unw_step(&cursor2);
|
|
if (stepResult == 0) {
|
|
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
|
|
"bottom => _URC_END_OF_STACK\n",
|
|
static_cast<void *>(exception_object));
|
|
return _URC_END_OF_STACK;
|
|
} else if (stepResult < 0) {
|
|
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
|
|
"_URC_FATAL_PHASE1_ERROR\n",
|
|
static_cast<void *>(exception_object));
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
}
|
|
#endif
|
|
|
|
// Get info about this frame.
|
|
unw_word_t sp;
|
|
unw_proc_info_t frameInfo;
|
|
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
|
|
if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
|
|
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
|
|
"failed => _URC_FATAL_PHASE1_ERROR\n",
|
|
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(&cursor2, functionBuf, sizeof(functionBuf),
|
|
&offset) != UNW_ESUCCESS) ||
|
|
(frameInfo.start_ip + offset > frameInfo.end_ip))
|
|
functionName = ".anonymous.";
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase2(ex_ojb=%p): start_ip=0x%llX, func=%s, sp=0x%llX, "
|
|
"lsda=0x%llX, personality=0x%llX\n",
|
|
static_cast<void *>(exception_object), (long long)frameInfo.start_ip,
|
|
functionName, (long long)sp, (long long)frameInfo.lsda,
|
|
(long long)frameInfo.handler);
|
|
}
|
|
|
|
// 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 *)(&cursor2);
|
|
// 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)(state, exception_object, context);
|
|
switch (personalityResult) {
|
|
case _URC_CONTINUE_UNWIND:
|
|
// Continue unwinding
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
|
|
static_cast<void *>(exception_object));
|
|
// EHABI #7.2
|
|
if (sp == exception_object->barrier_cache.sp) {
|
|
// Phase 1 said we would stop at this frame, but we did not...
|
|
_LIBUNWIND_ABORT("during phase1 personality function said it would "
|
|
"stop here, but now in phase2 it did not stop here");
|
|
}
|
|
break;
|
|
case _URC_INSTALL_CONTEXT:
|
|
_LIBUNWIND_TRACE_UNWINDING(
|
|
"unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT\n",
|
|
static_cast<void *>(exception_object));
|
|
// Personality routine says to transfer control to landing pad.
|
|
// We may get control back if landing pad calls _Unwind_Resume().
|
|
if (_LIBUNWIND_TRACING_UNWINDING) {
|
|
unw_word_t pc;
|
|
unw_get_reg(&cursor2, UNW_REG_IP, &pc);
|
|
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
|
|
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
|
|
"user code with ip=0x%llX, sp=0x%llX\n",
|
|
static_cast<void *>(exception_object),
|
|
(long long)pc, (long long)sp);
|
|
}
|
|
|
|
{
|
|
// 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(&cursor2, UNW_REG_IP, &pc);
|
|
exception_object->unwinder_cache.reserved2 = (uint32_t)pc;
|
|
}
|
|
unw_resume(&cursor2);
|
|
// unw_resume() only returns if there was an error.
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
|
|
// # EHABI #7.4.3
|
|
case _URC_FAILURE:
|
|
abort();
|
|
|
|
default:
|
|
// Personality routine returned an unknown result code.
|
|
_LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
|
|
personalityResult);
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
}
|
|
}
|
|
frame_count++;
|
|
}
|
|
|
|
// Clean up phase did not resume at the frame that the search phase
|
|
// said it would...
|
|
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) {
|
|
_LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)\n",
|
|
static_cast<void *>(exception_object));
|
|
unw_context_t uc;
|
|
unw_getcontext(&uc);
|
|
|
|
// This field for is for compatibility with GCC to say this isn't a forced
|
|
// unwind. EHABI #7.2
|
|
exception_object->unwinder_cache.reserved1 = 0;
|
|
|
|
// phase 1: the search phase
|
|
_Unwind_Reason_Code phase1 = unwind_phase1(&uc, exception_object);
|
|
if (phase1 != _URC_NO_REASON)
|
|
return phase1;
|
|
|
|
// phase 2: the clean up phase
|
|
return unwind_phase2(&uc, exception_object, false);
|
|
}
|
|
|
|
_LIBUNWIND_EXPORT void _Unwind_Complete(_Unwind_Exception* exception_object) {
|
|
// This is to be called when exception handling completes to give us a chance
|
|
// to perform any housekeeping. EHABI #7.2. But we have nothing to do here.
|
|
(void)exception_object;
|
|
}
|
|
|
|
/// When _Unwind_RaiseException() is in phase2, it hands control
|
|
/// to the personality function at each frame. The personality
|
|
/// may force a jump to a landing pad in that function, the landing
|
|
/// pad code may then call _Unwind_Resume() to continue with the
|
|
/// unwinding. Note: the call to _Unwind_Resume() is from compiler
|
|
/// geneated user code. All other _Unwind_* routines are called
|
|
/// by the C++ runtime __cxa_* routines.
|
|
///
|
|
/// Note: re-throwing an exception (as opposed to continuing the unwind)
|
|
/// is implemented by having the code call __cxa_rethrow() which
|
|
/// in turn calls _Unwind_Resume_or_Rethrow().
|
|
_LIBUNWIND_EXPORT void
|
|
_Unwind_Resume(_Unwind_Exception *exception_object) {
|
|
_LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)\n",
|
|
static_cast<void *>(exception_object));
|
|
unw_context_t uc;
|
|
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, exception_object, true);
|
|
|
|
// Clients assume _Unwind_Resume() does not return, so all we can do is abort.
|
|
_LIBUNWIND_ABORT("_Unwind_Resume() can't return");
|
|
}
|
|
|
|
/// Called by personality handler during phase 2 to get LSDA for current frame.
|
|
_LIBUNWIND_EXPORT uintptr_t
|
|
_Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
|
|
unw_cursor_t *cursor = (unw_cursor_t *)context;
|
|
unw_proc_info_t frameInfo;
|
|
uintptr_t result = 0;
|
|
if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
|
|
result = (uintptr_t)frameInfo.lsda;
|
|
_LIBUNWIND_TRACE_API(
|
|
"_Unwind_GetLanguageSpecificData(context=%p) => 0x%llx\n",
|
|
static_cast<void *>(context), (long long)result);
|
|
return result;
|
|
}
|
|
|
|
static uint64_t ValueAsBitPattern(_Unwind_VRS_DataRepresentation representation,
|
|
void* valuep) {
|
|
uint64_t value = 0;
|
|
switch (representation) {
|
|
case _UVRSD_UINT32:
|
|
case _UVRSD_FLOAT:
|
|
memcpy(&value, valuep, sizeof(uint32_t));
|
|
break;
|
|
|
|
case _UVRSD_VFPX:
|
|
case _UVRSD_UINT64:
|
|
case _UVRSD_DOUBLE:
|
|
memcpy(&value, valuep, sizeof(uint64_t));
|
|
break;
|
|
}
|
|
return value;
|
|
}
|
|
|
|
_Unwind_VRS_Result
|
|
_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
|
|
uint32_t regno, _Unwind_VRS_DataRepresentation representation,
|
|
void *valuep) {
|
|
_LIBUNWIND_TRACE_API("_Unwind_VRS_Set(context=%p, regclass=%d, reg=%d, "
|
|
"rep=%d, value=0x%llX)\n",
|
|
static_cast<void *>(context), regclass, regno,
|
|
representation,
|
|
ValueAsBitPattern(representation, valuep));
|
|
unw_cursor_t *cursor = (unw_cursor_t *)context;
|
|
switch (regclass) {
|
|
case _UVRSC_CORE:
|
|
if (representation != _UVRSD_UINT32 || regno > 15)
|
|
return _UVRSR_FAILED;
|
|
return unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
|
|
*(unw_word_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_WMMXC:
|
|
if (representation != _UVRSD_UINT32 || regno > 3)
|
|
return _UVRSR_FAILED;
|
|
return unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
|
|
*(unw_word_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_VFP:
|
|
if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE)
|
|
return _UVRSR_FAILED;
|
|
if (representation == _UVRSD_VFPX) {
|
|
// Can only touch d0-15 with FSTMFDX.
|
|
if (regno > 15)
|
|
return _UVRSR_FAILED;
|
|
unw_save_vfp_as_X(cursor);
|
|
} else {
|
|
if (regno > 31)
|
|
return _UVRSR_FAILED;
|
|
}
|
|
return unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
|
|
*(unw_fpreg_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_WMMXD:
|
|
if (representation != _UVRSD_DOUBLE || regno > 31)
|
|
return _UVRSR_FAILED;
|
|
return unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
|
|
*(unw_fpreg_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
}
|
|
_LIBUNWIND_ABORT("unsupported register class");
|
|
}
|
|
|
|
static _Unwind_VRS_Result
|
|
_Unwind_VRS_Get_Internal(_Unwind_Context *context,
|
|
_Unwind_VRS_RegClass regclass, uint32_t regno,
|
|
_Unwind_VRS_DataRepresentation representation,
|
|
void *valuep) {
|
|
unw_cursor_t *cursor = (unw_cursor_t *)context;
|
|
switch (regclass) {
|
|
case _UVRSC_CORE:
|
|
if (representation != _UVRSD_UINT32 || regno > 15)
|
|
return _UVRSR_FAILED;
|
|
return unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
|
|
(unw_word_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_WMMXC:
|
|
if (representation != _UVRSD_UINT32 || regno > 3)
|
|
return _UVRSR_FAILED;
|
|
return unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
|
|
(unw_word_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_VFP:
|
|
if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE)
|
|
return _UVRSR_FAILED;
|
|
if (representation == _UVRSD_VFPX) {
|
|
// Can only touch d0-15 with FSTMFDX.
|
|
if (regno > 15)
|
|
return _UVRSR_FAILED;
|
|
unw_save_vfp_as_X(cursor);
|
|
} else {
|
|
if (regno > 31)
|
|
return _UVRSR_FAILED;
|
|
}
|
|
return unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
|
|
(unw_fpreg_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
case _UVRSC_WMMXD:
|
|
if (representation != _UVRSD_DOUBLE || regno > 31)
|
|
return _UVRSR_FAILED;
|
|
return unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
|
|
(unw_fpreg_t *)valuep) == UNW_ESUCCESS
|
|
? _UVRSR_OK
|
|
: _UVRSR_FAILED;
|
|
}
|
|
_LIBUNWIND_ABORT("unsupported register class");
|
|
}
|
|
|
|
_Unwind_VRS_Result _Unwind_VRS_Get(
|
|
_Unwind_Context *context,
|
|
_Unwind_VRS_RegClass regclass,
|
|
uint32_t regno,
|
|
_Unwind_VRS_DataRepresentation representation,
|
|
void *valuep) {
|
|
_Unwind_VRS_Result result =
|
|
_Unwind_VRS_Get_Internal(context, regclass, regno, representation,
|
|
valuep);
|
|
_LIBUNWIND_TRACE_API("_Unwind_VRS_Get(context=%p, regclass=%d, reg=%d, "
|
|
"rep=%d, value=0x%llX, result = %d)\n",
|
|
static_cast<void *>(context), regclass, regno,
|
|
representation,
|
|
ValueAsBitPattern(representation, valuep), result);
|
|
return result;
|
|
}
|
|
|
|
_Unwind_VRS_Result
|
|
_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
|
|
uint32_t discriminator,
|
|
_Unwind_VRS_DataRepresentation representation) {
|
|
_LIBUNWIND_TRACE_API("_Unwind_VRS_Pop(context=%p, regclass=%d, "
|
|
"discriminator=%d, representation=%d)\n",
|
|
static_cast<void *>(context), regclass, discriminator,
|
|
representation);
|
|
switch (regclass) {
|
|
case _UVRSC_CORE:
|
|
case _UVRSC_WMMXC: {
|
|
if (representation != _UVRSD_UINT32)
|
|
return _UVRSR_FAILED;
|
|
// When popping SP from the stack, we don't want to override it from the
|
|
// computed new stack location. See EHABI #7.5.4 table 3.
|
|
bool poppedSP = false;
|
|
uint32_t* sp;
|
|
if (_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP,
|
|
_UVRSD_UINT32, &sp) != _UVRSR_OK) {
|
|
return _UVRSR_FAILED;
|
|
}
|
|
for (uint32_t i = 0; i < 16; ++i) {
|
|
if (!(discriminator & static_cast<uint32_t>(1 << i)))
|
|
continue;
|
|
uint32_t value = *sp++;
|
|
if (regclass == _UVRSC_CORE && i == 13)
|
|
poppedSP = true;
|
|
if (_Unwind_VRS_Set(context, regclass, i,
|
|
_UVRSD_UINT32, &value) != _UVRSR_OK) {
|
|
return _UVRSR_FAILED;
|
|
}
|
|
}
|
|
if (!poppedSP) {
|
|
return _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP,
|
|
_UVRSD_UINT32, &sp);
|
|
}
|
|
return _UVRSR_OK;
|
|
}
|
|
case _UVRSC_VFP:
|
|
case _UVRSC_WMMXD: {
|
|
if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE)
|
|
return _UVRSR_FAILED;
|
|
uint32_t first = discriminator >> 16;
|
|
uint32_t count = discriminator & 0xffff;
|
|
uint32_t end = first+count;
|
|
uint32_t* sp;
|
|
if (_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP,
|
|
_UVRSD_UINT32, &sp) != _UVRSR_OK) {
|
|
return _UVRSR_FAILED;
|
|
}
|
|
// For _UVRSD_VFPX, we're assuming the data is stored in FSTMX "standard
|
|
// format 1", which is equivalent to FSTMD + a padding word.
|
|
for (uint32_t i = first; i < end; ++i) {
|
|
// SP is only 32-bit aligned so don't copy 64-bit at a time.
|
|
uint64_t value = *sp++;
|
|
value |= ((uint64_t)(*sp++)) << 32;
|
|
if (_Unwind_VRS_Set(context, regclass, i, representation, &value) !=
|
|
_UVRSR_OK)
|
|
return _UVRSR_FAILED;
|
|
}
|
|
if (representation == _UVRSD_VFPX)
|
|
++sp;
|
|
return _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32,
|
|
&sp);
|
|
}
|
|
}
|
|
_LIBUNWIND_ABORT("unsupported register class");
|
|
}
|
|
|
|
/// Called by personality handler during phase 2 to find the start of the
|
|
/// function.
|
|
_LIBUNWIND_EXPORT uintptr_t
|
|
_Unwind_GetRegionStart(struct _Unwind_Context *context) {
|
|
unw_cursor_t *cursor = (unw_cursor_t *)context;
|
|
unw_proc_info_t frameInfo;
|
|
uintptr_t result = 0;
|
|
if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
|
|
result = (uintptr_t)frameInfo.start_ip;
|
|
_LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%llX\n",
|
|
static_cast<void *>(context), (long long)result);
|
|
return result;
|
|
}
|
|
|
|
|
|
/// Called by personality handler during phase 2 if a foreign exception
|
|
// is caught.
|
|
_LIBUNWIND_EXPORT void
|
|
_Unwind_DeleteException(_Unwind_Exception *exception_object) {
|
|
_LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)\n",
|
|
static_cast<void *>(exception_object));
|
|
if (exception_object->exception_cleanup != NULL)
|
|
(*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT,
|
|
exception_object);
|
|
}
|
|
|
|
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)
|
|
return _URC_FAILURE;
|
|
return _URC_OK;
|
|
}
|
|
|
|
#endif // _LIBUNWIND_ARM_EHABI
|