mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-05 03:54:35 +00:00
643 lines
18 KiB
C++
643 lines
18 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
/*
|
|
* This is an implementation of stack unwinding according to a subset
|
|
* of the ARM Exception Handling ABI, as described in:
|
|
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0038a/IHI0038A_ehabi.pdf
|
|
*
|
|
* This handles only the ARM-defined "personality routines" (chapter
|
|
* 9), and don't track the value of FP registers, because profiling
|
|
* needs only chain of PC/SP values.
|
|
*
|
|
* Because the exception handling info may not be accurate for all
|
|
* possible places where an async signal could occur (e.g., in a
|
|
* prologue or epilogue), this bounds-checks all stack accesses.
|
|
*
|
|
* This file uses "struct" for structures in the exception tables and
|
|
* "class" otherwise. We should avoid violating the C++11
|
|
* standard-layout rules in the former.
|
|
*/
|
|
|
|
#include "EHABIStackWalk.h"
|
|
|
|
#include "shared-libraries.h"
|
|
#include "platform.h"
|
|
|
|
#include "mozilla/Atomics.h"
|
|
#include "mozilla/Attributes.h"
|
|
#include "mozilla/DebugOnly.h"
|
|
#include "mozilla/Endian.h"
|
|
|
|
#include <algorithm>
|
|
#include <elf.h>
|
|
#include <stdint.h>
|
|
#include <vector>
|
|
#include <string>
|
|
|
|
#ifndef PT_ARM_EXIDX
|
|
#define PT_ARM_EXIDX 0x70000001
|
|
#endif
|
|
|
|
|
|
namespace mozilla {
|
|
|
|
struct EHEntry;
|
|
|
|
class EHState {
|
|
// Note that any core register can be used as a "frame pointer" to
|
|
// influence the unwinding process, so this must track all of them.
|
|
uint32_t mRegs[16];
|
|
public:
|
|
bool unwind(const EHEntry *aEntry, const void *stackBase);
|
|
uint32_t &operator[](int i) { return mRegs[i]; }
|
|
const uint32_t &operator[](int i) const { return mRegs[i]; }
|
|
EHState(const mcontext_t &);
|
|
};
|
|
|
|
enum {
|
|
R_SP = 13,
|
|
R_LR = 14,
|
|
R_PC = 15
|
|
};
|
|
|
|
class EHEntryHandle {
|
|
const EHEntry *mValue;
|
|
public:
|
|
EHEntryHandle(const EHEntry *aEntry) : mValue(aEntry) { }
|
|
const EHEntry *value() const { return mValue; }
|
|
};
|
|
|
|
class EHTable {
|
|
uint32_t mStartPC;
|
|
uint32_t mEndPC;
|
|
uint32_t mLoadOffset;
|
|
// In principle we should be able to binary-search the index section in
|
|
// place, but the ICS toolchain's linker is noncompliant and produces
|
|
// indices that aren't entirely sorted (e.g., libc). So we have this:
|
|
std::vector<EHEntryHandle> mEntries;
|
|
std::string mName;
|
|
public:
|
|
EHTable(const void *aELF, size_t aSize, const std::string &aName);
|
|
const EHEntry *lookup(uint32_t aPC) const;
|
|
bool isValid() const { return mEntries.size() > 0; }
|
|
const std::string &name() const { return mName; }
|
|
uint32_t startPC() const { return mStartPC; }
|
|
uint32_t endPC() const { return mEndPC; }
|
|
uint32_t loadOffset() const { return mLoadOffset; }
|
|
};
|
|
|
|
class EHAddrSpace {
|
|
std::vector<uint32_t> mStarts;
|
|
std::vector<EHTable> mTables;
|
|
static mozilla::Atomic<const EHAddrSpace*> sCurrent;
|
|
public:
|
|
explicit EHAddrSpace(const std::vector<EHTable>& aTables);
|
|
const EHTable *lookup(uint32_t aPC) const;
|
|
static void Update();
|
|
static const EHAddrSpace *Get();
|
|
};
|
|
|
|
|
|
void EHABIStackWalkInit()
|
|
{
|
|
EHAddrSpace::Update();
|
|
}
|
|
|
|
size_t EHABIStackWalk(const mcontext_t &aContext, void *stackBase,
|
|
void **aSPs, void **aPCs, const size_t aNumFrames)
|
|
{
|
|
const EHAddrSpace *space = EHAddrSpace::Get();
|
|
EHState state(aContext);
|
|
size_t count = 0;
|
|
|
|
while (count < aNumFrames) {
|
|
uint32_t pc = state[R_PC], sp = state[R_SP];
|
|
aPCs[count] = reinterpret_cast<void *>(pc);
|
|
aSPs[count] = reinterpret_cast<void *>(sp);
|
|
count++;
|
|
|
|
if (!space)
|
|
break;
|
|
// TODO: cache these lookups. Binary-searching libxul is
|
|
// expensive (possibly more expensive than doing the actual
|
|
// unwind), and even a small cache should help.
|
|
const EHTable *table = space->lookup(pc);
|
|
if (!table)
|
|
break;
|
|
const EHEntry *entry = table->lookup(pc);
|
|
if (!entry)
|
|
break;
|
|
if (!state.unwind(entry, stackBase))
|
|
break;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
|
|
struct PRel31 {
|
|
uint32_t mBits;
|
|
bool topBit() const { return mBits & 0x80000000; }
|
|
uint32_t value() const { return mBits & 0x7fffffff; }
|
|
int32_t offset() const { return (static_cast<int32_t>(mBits) << 1) >> 1; }
|
|
const void *compute() const {
|
|
return reinterpret_cast<const char *>(this) + offset();
|
|
}
|
|
private:
|
|
PRel31(const PRel31 &copied) MOZ_DELETE;
|
|
PRel31() MOZ_DELETE;
|
|
};
|
|
|
|
struct EHEntry {
|
|
PRel31 startPC;
|
|
PRel31 exidx;
|
|
private:
|
|
EHEntry(const EHEntry &copied) MOZ_DELETE;
|
|
EHEntry() MOZ_DELETE;
|
|
};
|
|
|
|
|
|
class EHInterp {
|
|
public:
|
|
// Note that stackLimit is exclusive and stackBase is inclusive
|
|
// (i.e, stackLimit < SP <= stackBase), following the convention
|
|
// set by the AAPCS spec.
|
|
EHInterp(EHState &aState, const EHEntry *aEntry,
|
|
uint32_t aStackLimit, uint32_t aStackBase)
|
|
: mState(aState),
|
|
mStackLimit(aStackLimit),
|
|
mStackBase(aStackBase),
|
|
mNextWord(0),
|
|
mWordsLeft(0),
|
|
mFailed(false)
|
|
{
|
|
const PRel31 &exidx = aEntry->exidx;
|
|
uint32_t firstWord;
|
|
|
|
if (exidx.mBits == 1) { // EXIDX_CANTUNWIND
|
|
mFailed = true;
|
|
return;
|
|
}
|
|
if (exidx.topBit()) {
|
|
firstWord = exidx.mBits;
|
|
} else {
|
|
mNextWord = reinterpret_cast<const uint32_t *>(exidx.compute());
|
|
firstWord = *mNextWord++;
|
|
}
|
|
|
|
switch (firstWord >> 24) {
|
|
case 0x80: // short
|
|
mWord = firstWord << 8;
|
|
mBytesLeft = 3;
|
|
break;
|
|
case 0x81: case 0x82: // long; catch descriptor size ignored
|
|
mWord = firstWord << 16;
|
|
mBytesLeft = 2;
|
|
mWordsLeft = (firstWord >> 16) & 0xff;
|
|
break;
|
|
default:
|
|
// unknown personality
|
|
mFailed = true;
|
|
}
|
|
}
|
|
|
|
bool unwind();
|
|
|
|
private:
|
|
// TODO: GCC has been observed not CSEing repeated reads of
|
|
// mState[R_SP] with writes to mFailed between them, suggesting that
|
|
// it hasn't determined that they can't alias and is thus missing
|
|
// optimization opportunities. So, we may want to flatten EHState
|
|
// into this class; this may also make the code simpler.
|
|
EHState &mState;
|
|
uint32_t mStackLimit;
|
|
uint32_t mStackBase;
|
|
const uint32_t *mNextWord;
|
|
uint32_t mWord;
|
|
uint8_t mWordsLeft;
|
|
uint8_t mBytesLeft;
|
|
bool mFailed;
|
|
|
|
enum {
|
|
I_ADDSP = 0x00, // 0sxxxxxx (subtract if s)
|
|
M_ADDSP = 0x80,
|
|
I_POPMASK = 0x80, // 1000iiii iiiiiiii (if any i set)
|
|
M_POPMASK = 0xf0,
|
|
I_MOVSP = 0x90, // 1001nnnn
|
|
M_MOVSP = 0xf0,
|
|
I_POPN = 0xa0, // 1010lnnn
|
|
M_POPN = 0xf0,
|
|
I_FINISH = 0xb0, // 10110000
|
|
I_POPLO = 0xb1, // 10110001 0000iiii (if any i set)
|
|
I_ADDSPBIG = 0xb2, // 10110010 uleb128
|
|
I_POPFDX = 0xb3, // 10110011 sssscccc
|
|
I_POPFDX8 = 0xb8, // 10111nnn
|
|
M_POPFDX8 = 0xf8,
|
|
// "Intel Wireless MMX" extensions omitted.
|
|
I_POPFDD = 0xc8, // 1100100h sssscccc
|
|
M_POPFDD = 0xfe,
|
|
I_POPFDD8 = 0xd0, // 11010nnn
|
|
M_POPFDD8 = 0xf8
|
|
};
|
|
|
|
uint8_t next() {
|
|
if (mBytesLeft == 0) {
|
|
if (mWordsLeft == 0) {
|
|
return I_FINISH;
|
|
}
|
|
mWordsLeft--;
|
|
mWord = *mNextWord++;
|
|
mBytesLeft = 4;
|
|
}
|
|
mBytesLeft--;
|
|
mWord = (mWord << 8) | (mWord >> 24); // rotate
|
|
return mWord;
|
|
}
|
|
|
|
uint32_t &vSP() { return mState[R_SP]; }
|
|
uint32_t *ptrSP() { return reinterpret_cast<uint32_t *>(vSP()); }
|
|
|
|
void checkStackBase() { if (vSP() > mStackBase) mFailed = true; }
|
|
void checkStackLimit() { if (vSP() <= mStackLimit) mFailed = true; }
|
|
void checkStackAlign() { if ((vSP() & 3) != 0) mFailed = true; }
|
|
void checkStack() {
|
|
checkStackBase();
|
|
checkStackLimit();
|
|
checkStackAlign();
|
|
}
|
|
|
|
void popRange(uint8_t first, uint8_t last, uint16_t mask) {
|
|
bool hasSP = false;
|
|
uint32_t tmpSP;
|
|
if (mask == 0)
|
|
mFailed = true;
|
|
for (uint8_t r = first; r <= last; ++r) {
|
|
if (mask & 1) {
|
|
if (r == R_SP) {
|
|
hasSP = true;
|
|
tmpSP = *ptrSP();
|
|
} else
|
|
mState[r] = *ptrSP();
|
|
vSP() += 4;
|
|
checkStackBase();
|
|
if (mFailed)
|
|
return;
|
|
}
|
|
mask >>= 1;
|
|
}
|
|
if (hasSP) {
|
|
vSP() = tmpSP;
|
|
checkStack();
|
|
}
|
|
}
|
|
};
|
|
|
|
|
|
bool EHState::unwind(const EHEntry *aEntry, const void *stackBasePtr) {
|
|
// The unwinding program cannot set SP to less than the initial value.
|
|
uint32_t stackLimit = mRegs[R_SP] - 4;
|
|
uint32_t stackBase = reinterpret_cast<uint32_t>(stackBasePtr);
|
|
EHInterp interp(*this, aEntry, stackLimit, stackBase);
|
|
return interp.unwind();
|
|
}
|
|
|
|
bool EHInterp::unwind() {
|
|
mState[R_PC] = 0;
|
|
checkStack();
|
|
while (!mFailed) {
|
|
uint8_t insn = next();
|
|
#if DEBUG_EHABI_UNWIND
|
|
LOGF("unwind insn = %02x", (unsigned)insn);
|
|
#endif
|
|
// Try to put the common cases first.
|
|
|
|
// 00xxxxxx: vsp = vsp + (xxxxxx << 2) + 4
|
|
// 01xxxxxx: vsp = vsp - (xxxxxx << 2) - 4
|
|
if ((insn & M_ADDSP) == I_ADDSP) {
|
|
uint32_t offset = ((insn & 0x3f) << 2) + 4;
|
|
if (insn & 0x40) {
|
|
vSP() -= offset;
|
|
checkStackLimit();
|
|
} else {
|
|
vSP() += offset;
|
|
checkStackBase();
|
|
}
|
|
continue;
|
|
}
|
|
|
|
// 10100nnn: Pop r4-r[4+nnn]
|
|
// 10101nnn: Pop r4-r[4+nnn], r14
|
|
if ((insn & M_POPN) == I_POPN) {
|
|
uint8_t n = (insn & 0x07) + 1;
|
|
bool lr = insn & 0x08;
|
|
uint32_t *ptr = ptrSP();
|
|
vSP() += (n + (lr ? 1 : 0)) * 4;
|
|
checkStackBase();
|
|
for (uint8_t r = 4; r < 4 + n; ++r)
|
|
mState[r] = *ptr++;
|
|
if (lr)
|
|
mState[R_LR] = *ptr++;
|
|
continue;
|
|
}
|
|
|
|
// 1011000: Finish
|
|
if (insn == I_FINISH) {
|
|
if (mState[R_PC] == 0) {
|
|
mState[R_PC] = mState[R_LR];
|
|
// Non-standard change (bug 916106): Prevent the caller from
|
|
// re-using LR. Since the caller is by definition not a leaf
|
|
// routine, it will have to restore LR from somewhere to
|
|
// return to its own caller, so we can safely zero it here.
|
|
// This makes a difference only if an error in unwinding
|
|
// (e.g., caused by starting from within a prologue/epilogue)
|
|
// causes us to load a pointer to a leaf routine as LR; if we
|
|
// don't do something, we'll go into an infinite loop of
|
|
// "returning" to that same function.
|
|
mState[R_LR] = 0;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// 1001nnnn: Set vsp = r[nnnn]
|
|
if ((insn & M_MOVSP) == I_MOVSP) {
|
|
vSP() = mState[insn & 0x0f];
|
|
checkStack();
|
|
continue;
|
|
}
|
|
|
|
// 11001000 sssscccc: Pop VFP regs D[16+ssss]-D[16+ssss+cccc] (as FLDMFDD)
|
|
// 11001001 sssscccc: Pop VFP regs D[ssss]-D[ssss+cccc] (as FLDMFDD)
|
|
if ((insn & M_POPFDD) == I_POPFDD) {
|
|
uint8_t n = (next() & 0x0f) + 1;
|
|
// Note: if the 16+ssss+cccc > 31, the encoding is reserved.
|
|
// As the space is currently unused, we don't try to check.
|
|
vSP() += 8 * n;
|
|
checkStackBase();
|
|
continue;
|
|
}
|
|
|
|
// 11010nnn: Pop VFP regs D[8]-D[8+nnn] (as FLDMFDD)
|
|
if ((insn & M_POPFDD8) == I_POPFDD8) {
|
|
uint8_t n = (insn & 0x07) + 1;
|
|
vSP() += 8 * n;
|
|
checkStackBase();
|
|
continue;
|
|
}
|
|
|
|
// 10110010 uleb128: vsp = vsp + 0x204 + (uleb128 << 2)
|
|
if (insn == I_ADDSPBIG) {
|
|
uint32_t acc = 0;
|
|
uint8_t shift = 0;
|
|
uint8_t byte;
|
|
do {
|
|
if (shift >= 32)
|
|
return false;
|
|
byte = next();
|
|
acc |= (byte & 0x7f) << shift;
|
|
shift += 7;
|
|
} while (byte & 0x80);
|
|
uint32_t offset = 0x204 + (acc << 2);
|
|
// The calculations above could have overflowed.
|
|
// But the one we care about is this:
|
|
if (vSP() + offset < vSP())
|
|
mFailed = true;
|
|
vSP() += offset;
|
|
// ...so that this is the only other check needed:
|
|
checkStackBase();
|
|
continue;
|
|
}
|
|
|
|
// 1000iiii iiiiiiii (i not all 0): Pop under masks {r15-r12}, {r11-r4}
|
|
if ((insn & M_POPMASK) == I_POPMASK) {
|
|
popRange(4, 15, ((insn & 0x0f) << 8) | next());
|
|
continue;
|
|
}
|
|
|
|
// 1011001 0000iiii (i not all 0): Pop under mask {r3-r0}
|
|
if (insn == I_POPLO) {
|
|
popRange(0, 3, next() & 0x0f);
|
|
continue;
|
|
}
|
|
|
|
// 10110011 sssscccc: Pop VFP regs D[ssss]-D[ssss+cccc] (as FLDMFDX)
|
|
if (insn == I_POPFDX) {
|
|
uint8_t n = (next() & 0x0f) + 1;
|
|
vSP() += 8 * n + 4;
|
|
checkStackBase();
|
|
continue;
|
|
}
|
|
|
|
// 10111nnn: Pop VFP regs D[8]-D[8+nnn] (as FLDMFDX)
|
|
if ((insn & M_POPFDX8) == I_POPFDX8) {
|
|
uint8_t n = (insn & 0x07) + 1;
|
|
vSP() += 8 * n + 4;
|
|
checkStackBase();
|
|
continue;
|
|
}
|
|
|
|
// unhandled instruction
|
|
#ifdef DEBUG_EHABI_UNWIND
|
|
LOGF("Unhandled EHABI instruction 0x%02x", insn);
|
|
#endif
|
|
mFailed = true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
bool operator<(const EHTable &lhs, const EHTable &rhs) {
|
|
return lhs.startPC() < rhs.endPC();
|
|
}
|
|
|
|
// Async signal unsafe.
|
|
EHAddrSpace::EHAddrSpace(const std::vector<EHTable>& aTables)
|
|
: mTables(aTables)
|
|
{
|
|
std::sort(mTables.begin(), mTables.end());
|
|
DebugOnly<uint32_t> lastEnd = 0;
|
|
for (std::vector<EHTable>::iterator i = mTables.begin();
|
|
i != mTables.end(); ++i) {
|
|
MOZ_ASSERT(i->startPC() >= lastEnd);
|
|
mStarts.push_back(i->startPC());
|
|
lastEnd = i->endPC();
|
|
}
|
|
}
|
|
|
|
const EHTable *EHAddrSpace::lookup(uint32_t aPC) const {
|
|
ptrdiff_t i = (std::upper_bound(mStarts.begin(), mStarts.end(), aPC)
|
|
- mStarts.begin()) - 1;
|
|
|
|
if (i < 0 || aPC >= mTables[i].endPC())
|
|
return 0;
|
|
return &mTables[i];
|
|
}
|
|
|
|
|
|
bool operator<(const EHEntryHandle &lhs, const EHEntryHandle &rhs) {
|
|
return lhs.value()->startPC.compute() < rhs.value()->startPC.compute();
|
|
}
|
|
|
|
const EHEntry *EHTable::lookup(uint32_t aPC) const {
|
|
MOZ_ASSERT(aPC >= mStartPC);
|
|
if (aPC >= mEndPC)
|
|
return nullptr;
|
|
|
|
std::vector<EHEntryHandle>::const_iterator begin = mEntries.begin();
|
|
std::vector<EHEntryHandle>::const_iterator end = mEntries.end();
|
|
MOZ_ASSERT(begin < end);
|
|
if (aPC < reinterpret_cast<uint32_t>(begin->value()->startPC.compute()))
|
|
return nullptr;
|
|
|
|
while (end - begin > 1) {
|
|
std::vector<EHEntryHandle>::const_iterator mid = begin + (end - begin) / 2;
|
|
if (aPC < reinterpret_cast<uint32_t>(mid->value()->startPC.compute()))
|
|
end = mid;
|
|
else
|
|
begin = mid;
|
|
}
|
|
return begin->value();
|
|
}
|
|
|
|
|
|
#if MOZ_LITTLE_ENDIAN
|
|
static const unsigned char hostEndian = ELFDATA2LSB;
|
|
#elif MOZ_BIG_ENDIAN
|
|
static const unsigned char hostEndian = ELFDATA2MSB;
|
|
#else
|
|
#error "No endian?"
|
|
#endif
|
|
|
|
// Async signal unsafe. (Note use of std::vector::reserve.)
|
|
EHTable::EHTable(const void *aELF, size_t aSize, const std::string &aName)
|
|
: mStartPC(~0), // largest uint32_t
|
|
mEndPC(0),
|
|
mName(aName)
|
|
{
|
|
const uint32_t base = reinterpret_cast<uint32_t>(aELF);
|
|
|
|
if (aSize < sizeof(Elf32_Ehdr))
|
|
return;
|
|
|
|
const Elf32_Ehdr &file = *(reinterpret_cast<Elf32_Ehdr *>(base));
|
|
if (memcmp(&file.e_ident[EI_MAG0], ELFMAG, SELFMAG) != 0 ||
|
|
file.e_ident[EI_CLASS] != ELFCLASS32 ||
|
|
file.e_ident[EI_DATA] != hostEndian ||
|
|
file.e_ident[EI_VERSION] != EV_CURRENT ||
|
|
file.e_ident[EI_OSABI] != ELFOSABI_SYSV ||
|
|
#ifdef EI_ABIVERSION
|
|
file.e_ident[EI_ABIVERSION] != 0 ||
|
|
#endif
|
|
file.e_machine != EM_ARM ||
|
|
file.e_version != EV_CURRENT)
|
|
// e_flags?
|
|
return;
|
|
|
|
MOZ_ASSERT(file.e_phoff + file.e_phnum * file.e_phentsize <= aSize);
|
|
const Elf32_Phdr *exidxHdr = 0, *zeroHdr = 0;
|
|
for (unsigned i = 0; i < file.e_phnum; ++i) {
|
|
const Elf32_Phdr &phdr =
|
|
*(reinterpret_cast<Elf32_Phdr *>(base + file.e_phoff
|
|
+ i * file.e_phentsize));
|
|
if (phdr.p_type == PT_ARM_EXIDX) {
|
|
exidxHdr = &phdr;
|
|
} else if (phdr.p_type == PT_LOAD) {
|
|
if (phdr.p_offset == 0) {
|
|
zeroHdr = &phdr;
|
|
}
|
|
if (phdr.p_flags & PF_X) {
|
|
mStartPC = std::min(mStartPC, phdr.p_vaddr);
|
|
mEndPC = std::max(mEndPC, phdr.p_vaddr + phdr.p_memsz);
|
|
}
|
|
}
|
|
}
|
|
if (!exidxHdr)
|
|
return;
|
|
if (!zeroHdr)
|
|
return;
|
|
mLoadOffset = base - zeroHdr->p_vaddr;
|
|
mStartPC += mLoadOffset;
|
|
mEndPC += mLoadOffset;
|
|
|
|
// Create a sorted index of the index to work around linker bugs.
|
|
const EHEntry *startTable =
|
|
reinterpret_cast<const EHEntry *>(mLoadOffset + exidxHdr->p_vaddr);
|
|
const EHEntry *endTable =
|
|
reinterpret_cast<const EHEntry *>(mLoadOffset + exidxHdr->p_vaddr
|
|
+ exidxHdr->p_memsz);
|
|
mEntries.reserve(endTable - startTable);
|
|
for (const EHEntry *i = startTable; i < endTable; ++i)
|
|
mEntries.push_back(i);
|
|
std::sort(mEntries.begin(), mEntries.end());
|
|
}
|
|
|
|
|
|
mozilla::Atomic<const EHAddrSpace*> EHAddrSpace::sCurrent(nullptr);
|
|
|
|
// Async signal safe; can fail if Update() hasn't returned yet.
|
|
const EHAddrSpace *EHAddrSpace::Get() {
|
|
return sCurrent;
|
|
}
|
|
|
|
// Collect unwinding information from loaded objects. Calls after the
|
|
// first have no effect. Async signal unsafe.
|
|
void EHAddrSpace::Update() {
|
|
const EHAddrSpace *space = sCurrent;
|
|
if (space)
|
|
return;
|
|
|
|
SharedLibraryInfo info = SharedLibraryInfo::GetInfoForSelf();
|
|
std::vector<EHTable> tables;
|
|
|
|
for (size_t i = 0; i < info.GetSize(); ++i) {
|
|
const SharedLibrary &lib = info.GetEntry(i);
|
|
if (lib.GetOffset() != 0)
|
|
// TODO: if it has a name, and we haven't seen a mapping of
|
|
// offset 0 for that file, try opening it and reading the
|
|
// headers instead. The only thing I've seen so far that's
|
|
// linked so as to need that treatment is the dynamic linker
|
|
// itself.
|
|
continue;
|
|
EHTable tab(reinterpret_cast<const void *>(lib.GetStart()),
|
|
lib.GetEnd() - lib.GetStart(), lib.GetName());
|
|
if (tab.isValid())
|
|
tables.push_back(tab);
|
|
}
|
|
space = new EHAddrSpace(tables);
|
|
|
|
if (!sCurrent.compareExchange(nullptr, space)) {
|
|
delete space;
|
|
space = sCurrent;
|
|
}
|
|
}
|
|
|
|
|
|
EHState::EHState(const mcontext_t &context) {
|
|
#ifdef linux
|
|
mRegs[0] = context.arm_r0;
|
|
mRegs[1] = context.arm_r1;
|
|
mRegs[2] = context.arm_r2;
|
|
mRegs[3] = context.arm_r3;
|
|
mRegs[4] = context.arm_r4;
|
|
mRegs[5] = context.arm_r5;
|
|
mRegs[6] = context.arm_r6;
|
|
mRegs[7] = context.arm_r7;
|
|
mRegs[8] = context.arm_r8;
|
|
mRegs[9] = context.arm_r9;
|
|
mRegs[10] = context.arm_r10;
|
|
mRegs[11] = context.arm_fp;
|
|
mRegs[12] = context.arm_ip;
|
|
mRegs[13] = context.arm_sp;
|
|
mRegs[14] = context.arm_lr;
|
|
mRegs[15] = context.arm_pc;
|
|
#else
|
|
# error "Unhandled OS for ARM EHABI unwinding"
|
|
#endif
|
|
}
|
|
|
|
} // namespace mozilla
|
|
|