//===------------------------- AddressSpace.hpp ---------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//
// Abstracts accessing local vs remote address spaces.
//
//===----------------------------------------------------------------------===//
#ifndef __ADDRESSSPACE_HPP__
#define __ADDRESSSPACE_HPP__
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _LIBUNWIND_IS_BAREMETAL
#include <dlfcn.h>
#endif
#ifdef __APPLE__
#include <mach-o/getsect.h>
namespace libunwind {
bool checkKeyMgrRegisteredFDEs(uintptr_t targetAddr, void *&fde);
}
#endif
#include "libunwind.h"
#include "config.h"
#include "dwarf2.h"
#include "Registers.hpp"
#if LIBCXXABI_ARM_EHABI
#ifdef __linux__
typedef long unsigned int *_Unwind_Ptr;
extern "C" _Unwind_Ptr __gnu_Unwind_Find_exidx(_Unwind_Ptr addr, int *len);
// Emulate the BSD dl_unwind_find_exidx API when on a GNU libdl system.
#define dl_unwind_find_exidx __gnu_Unwind_Find_exidx
#elif !defined(_LIBUNWIND_IS_BAREMETAL)
#include <link.h>
#else // !defined(_LIBUNWIND_IS_BAREMETAL)
// When statically linked on bare-metal, the symbols for the EH table are looked
// up without going through the dynamic loader.
struct EHTEntry {
uint32_t functionOffset;
uint32_t unwindOpcodes;
};
extern EHTEntry __exidx_start;
extern EHTEntry __exidx_end;
#endif // !defined(_LIBUNWIND_IS_BAREMETAL)
#endif // LIBCXXABI_ARM_EHABI
#if defined(__linux__)
#if _LIBUNWIND_SUPPORT_DWARF_UNWIND && _LIBUNWIND_SUPPORT_DWARF_INDEX
#include <link.h>
#include "EHHeaderParser.hpp"
#endif
#endif
namespace libunwind {
/// Used by findUnwindSections() to return info about needed sections.
struct UnwindInfoSections {
#if _LIBUNWIND_SUPPORT_DWARF_UNWIND || _LIBUNWIND_SUPPORT_DWARF_INDEX || \
_LIBUNWIND_SUPPORT_COMPACT_UNWIND
// No dso_base for ARM EHABI.
uintptr_t dso_base;
#endif
#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
uintptr_t dwarf_section;
uintptr_t dwarf_section_length;
#endif
#if _LIBUNWIND_SUPPORT_DWARF_INDEX
uintptr_t dwarf_index_section;
uintptr_t dwarf_index_section_length;
#endif
#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
uintptr_t compact_unwind_section;
uintptr_t compact_unwind_section_length;
#endif
#if LIBCXXABI_ARM_EHABI
uintptr_t arm_section;
uintptr_t arm_section_length;
#endif
};
/// LocalAddressSpace is used as a template parameter to UnwindCursor when
/// unwinding a thread in the same process. The wrappers compile away,
/// making local unwinds fast.
class __attribute__((visibility("hidden"))) LocalAddressSpace {
public:
#ifdef __LP64__
typedef uint64_t pint_t;
typedef int64_t sint_t;
#else
typedef uint32_t pint_t;
typedef int32_t sint_t;
#endif
uint8_t get8(pint_t addr) {
uint8_t val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
uint16_t get16(pint_t addr) {
uint16_t val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
uint32_t get32(pint_t addr) {
uint32_t val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
uint64_t get64(pint_t addr) {
uint64_t val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
double getDouble(pint_t addr) {
double val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
v128 getVector(pint_t addr) {
v128 val;
memcpy(&val, (void *)addr, sizeof(val));
return val;
}
uintptr_t getP(pint_t addr);
static uint64_t getULEB128(pint_t &addr, pint_t end);
static int64_t getSLEB128(pint_t &addr, pint_t end);
pint_t getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
pint_t datarelBase = 0);
bool findFunctionName(pint_t addr, char *buf, size_t bufLen,
unw_word_t *offset);
bool findUnwindSections(pint_t targetAddr, UnwindInfoSections &info);
bool findOtherFDE(pint_t targetAddr, pint_t &fde);
static LocalAddressSpace sThisAddressSpace;
};
inline uintptr_t LocalAddressSpace::getP(pint_t addr) {
#ifdef __LP64__
return get64(addr);
#else
return get32(addr);
#endif
}
/// Read a ULEB128 into a 64-bit word.
inline uint64_t LocalAddressSpace::getULEB128(pint_t &addr, pint_t end) {
const uint8_t *p = (uint8_t *)addr;
const uint8_t *pend = (uint8_t *)end;
uint64_t result = 0;
int bit = 0;
do {
uint64_t b;
if (p == pend)
_LIBUNWIND_ABORT("truncated uleb128 expression");
b = *p & 0x7f;
if (bit >= 64 || b << bit >> bit != b) {
_LIBUNWIND_ABORT("malformed uleb128 expression");
} else {
result |= b << bit;
bit += 7;
}
} while (*p++ >= 0x80);
addr = (pint_t) p;
return result;
}
/// Read a SLEB128 into a 64-bit word.
inline int64_t LocalAddressSpace::getSLEB128(pint_t &addr, pint_t end) {
const uint8_t *p = (uint8_t *)addr;
const uint8_t *pend = (uint8_t *)end;
int64_t result = 0;
int bit = 0;
uint8_t byte;
do {
if (p == pend)
_LIBUNWIND_ABORT("truncated sleb128 expression");
byte = *p++;
result |= ((byte & 0x7f) << bit);
bit += 7;
} while (byte & 0x80);
// sign extend negative numbers
if ((byte & 0x40) != 0)
result |= (-1LL) << bit;
addr = (pint_t) p;
return result;
}
inline LocalAddressSpace::pint_t
LocalAddressSpace::getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
pint_t datarelBase) {
pint_t startAddr = addr;
const uint8_t *p = (uint8_t *)addr;
pint_t result;
// first get value
switch (encoding & 0x0F) {
case DW_EH_PE_ptr:
result = getP(addr);
p += sizeof(pint_t);
addr = (pint_t) p;
break;
case DW_EH_PE_uleb128:
result = (pint_t)getULEB128(addr, end);
break;
case DW_EH_PE_udata2:
result = get16(addr);
p += 2;
addr = (pint_t) p;
break;
case DW_EH_PE_udata4:
result = get32(addr);
p += 4;
addr = (pint_t) p;
break;
case DW_EH_PE_udata8:
result = (pint_t)get64(addr);
p += 8;
addr = (pint_t) p;
break;
case DW_EH_PE_sleb128:
result = (pint_t)getSLEB128(addr, end);
break;
case DW_EH_PE_sdata2:
// Sign extend from signed 16-bit value.
result = (pint_t)(int16_t)get16(addr);
p += 2;
addr = (pint_t) p;
break;
case DW_EH_PE_sdata4:
// Sign extend from signed 32-bit value.
result = (pint_t)(int32_t)get32(addr);
p += 4;
addr = (pint_t) p;
break;
case DW_EH_PE_sdata8:
result = (pint_t)get64(addr);
p += 8;
addr = (pint_t) p;
break;
default:
_LIBUNWIND_ABORT("unknown pointer encoding");
}
// then add relative offset
switch (encoding & 0x70) {
case DW_EH_PE_absptr:
// do nothing
break;
case DW_EH_PE_pcrel:
result += startAddr;
break;
case DW_EH_PE_textrel:
_LIBUNWIND_ABORT("DW_EH_PE_textrel pointer encoding not supported");
break;
case DW_EH_PE_datarel:
// DW_EH_PE_datarel is only valid in a few places, so the parameter has a
// default value of 0, and we abort in the event that someone calls this
// function with a datarelBase of 0 and DW_EH_PE_datarel encoding.
if (datarelBase == 0)
_LIBUNWIND_ABORT("DW_EH_PE_datarel is invalid with a datarelBase of 0");
result += datarelBase;
break;
case DW_EH_PE_funcrel:
_LIBUNWIND_ABORT("DW_EH_PE_funcrel pointer encoding not supported");
break;
case DW_EH_PE_aligned:
_LIBUNWIND_ABORT("DW_EH_PE_aligned pointer encoding not supported");
break;
default:
_LIBUNWIND_ABORT("unknown pointer encoding");
break;
}
if (encoding & DW_EH_PE_indirect)
result = getP(result);
return result;
}
#ifdef __APPLE__
struct dyld_unwind_sections
{
const struct mach_header* mh;
const void* dwarf_section;
uintptr_t dwarf_section_length;
const void* compact_unwind_section;
uintptr_t compact_unwind_section_length;
};
#if (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) \
&& (__MAC_OS_X_VERSION_MIN_REQUIRED >= 1070)) \
|| defined(__IPHONE_OS_VERSION_MIN_REQUIRED)
// In 10.7.0 or later, libSystem.dylib implements this function.
extern "C" bool _dyld_find_unwind_sections(void *, dyld_unwind_sections *);
#else
// In 10.6.x and earlier, we need to implement this functionality.
static inline bool _dyld_find_unwind_sections(void* addr,
dyld_unwind_sections* info) {
// Find mach-o image containing address.
Dl_info dlinfo;
if (!dladdr(addr, &dlinfo))
return false;
const mach_header *mh = (const mach_header *)dlinfo.dli_saddr;
// Find dwarf unwind section in that image.
unsigned long size;
const uint8_t *p = getsectiondata(mh, "__TEXT", "__eh_frame", &size);
if (!p)
return false;
// Fill in return struct.
info->mh = mh;
info->dwarf_section = p;
info->dwarf_section_length = size;
info->compact_unwind_section = 0;
info->compact_unwind_section_length = 0;
return true;
}
#endif
#endif
inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
UnwindInfoSections &info) {
#ifdef __APPLE__
dyld_unwind_sections dyldInfo;
if (_dyld_find_unwind_sections((void *)targetAddr, &dyldInfo)) {
info.dso_base = (uintptr_t)dyldInfo.mh;
#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
info.dwarf_section = (uintptr_t)dyldInfo.dwarf_section;
info.dwarf_section_length = dyldInfo.dwarf_section_length;
#endif
info.compact_unwind_section = (uintptr_t)dyldInfo.compact_unwind_section;
info.compact_unwind_section_length = dyldInfo.compact_unwind_section_length;
return true;
}
#elif LIBCXXABI_ARM_EHABI
#ifdef _LIBUNWIND_IS_BAREMETAL
// Bare metal is statically linked, so no need to ask the dynamic loader
info.arm_section = (uintptr_t)(&__exidx_start);
info.arm_section_length = (uintptr_t)(&__exidx_end - &__exidx_start);
#else
int length = 0;
info.arm_section = (uintptr_t) dl_unwind_find_exidx(
(_Unwind_Ptr) targetAddr, &length);
info.arm_section_length = (uintptr_t)length;
#endif
_LIBUNWIND_TRACE_UNWINDING("findUnwindSections: section %X length %x\n",
info.arm_section, info.arm_section_length);
if (info.arm_section && info.arm_section_length)
return true;
#elif _LIBUNWIND_SUPPORT_DWARF_UNWIND
#if _LIBUNWIND_SUPPORT_DWARF_INDEX
struct dl_iterate_cb_data {
LocalAddressSpace *addressSpace;
UnwindInfoSections *sects;
uintptr_t targetAddr;
};
dl_iterate_cb_data cb_data = {this, &info, targetAddr};
int found = dl_iterate_phdr(
[](struct dl_phdr_info *pinfo, size_t, void *data) -> int {
auto cbdata = static_cast<dl_iterate_cb_data *>(data);
size_t object_length;
bool found_obj = false;
bool found_hdr = false;
assert(cbdata);
assert(cbdata->sects);
if (cbdata->targetAddr < pinfo->dlpi_addr) {
return false;
}
for (ElfW(Half) i = 0; i < pinfo->dlpi_phnum; i++) {
const ElfW(Phdr) *phdr = &pinfo->dlpi_phdr[i];
if (phdr->p_type == PT_LOAD) {
uintptr_t begin = pinfo->dlpi_addr + phdr->p_vaddr;
uintptr_t end = begin + phdr->p_memsz;
if (cbdata->targetAddr >= begin && cbdata->targetAddr < end) {
cbdata->sects->dso_base = begin;
object_length = phdr->p_memsz;
found_obj = true;
}
} else if (phdr->p_type == PT_GNU_EH_FRAME) {
EHHeaderParser<LocalAddressSpace>::EHHeaderInfo hdrInfo;
uintptr_t eh_frame_hdr_start = pinfo->dlpi_addr + phdr->p_vaddr;
cbdata->sects->dwarf_index_section = eh_frame_hdr_start;
cbdata->sects->dwarf_index_section_length = phdr->p_memsz;
EHHeaderParser<LocalAddressSpace>::decodeEHHdr(
*cbdata->addressSpace, eh_frame_hdr_start, phdr->p_memsz,
hdrInfo);
cbdata->sects->dwarf_section = hdrInfo.eh_frame_ptr;
found_hdr = true;
}
}
if (found_obj && found_hdr) {
cbdata->sects->dwarf_section_length = object_length;
return true;
} else {
return false;
}
},
&cb_data);
return static_cast<bool>(found);
#else
#error "_LIBUNWIND_SUPPORT_DWARF_UNWIND requires _LIBUNWIND_SUPPORT_DWARF_INDEX on this platform."
#endif
#endif
return false;
}
inline bool LocalAddressSpace::findOtherFDE(pint_t targetAddr, pint_t &fde) {
#ifdef __APPLE__
return checkKeyMgrRegisteredFDEs(targetAddr, *((void**)&fde));
#else
// TO DO: if OS has way to dynamically register FDEs, check that.
(void)targetAddr;
(void)fde;
return false;
#endif
}
inline bool LocalAddressSpace::findFunctionName(pint_t addr, char *buf,
size_t bufLen,
unw_word_t *offset) {
#ifndef _LIBUNWIND_IS_BAREMETAL
Dl_info dyldInfo;
if (dladdr((void *)addr, &dyldInfo)) {
if (dyldInfo.dli_sname != NULL) {
snprintf(buf, bufLen, "%s", dyldInfo.dli_sname);
*offset = (addr - (pint_t) dyldInfo.dli_saddr);
return true;
}
}
#endif
return false;
}
#ifdef UNW_REMOTE
/// OtherAddressSpace is used as a template parameter to UnwindCursor when
/// unwinding a thread in the another process. The other process can be a
/// different endianness and a different pointer size which is handled by
/// the P template parameter.
template <typename P>
class OtherAddressSpace {
public:
OtherAddressSpace(task_t task) : fTask(task) {}
typedef typename P::uint_t pint_t;
uint8_t get8(pint_t addr);
uint16_t get16(pint_t addr);
uint32_t get32(pint_t addr);
uint64_t get64(pint_t addr);
pint_t getP(pint_t addr);
uint64_t getULEB128(pint_t &addr, pint_t end);
int64_t getSLEB128(pint_t &addr, pint_t end);
pint_t getEncodedP(pint_t &addr, pint_t end, uint8_t encoding,
pint_t datarelBase = 0);
bool findFunctionName(pint_t addr, char *buf, size_t bufLen,
unw_word_t *offset);
bool findUnwindSections(pint_t targetAddr, UnwindInfoSections &info);
bool findOtherFDE(pint_t targetAddr, pint_t &fde);
private:
void *localCopy(pint_t addr);
task_t fTask;
};
template <typename P> uint8_t OtherAddressSpace<P>::get8(pint_t addr) {
return *((uint8_t *)localCopy(addr));
}
template <typename P> uint16_t OtherAddressSpace<P>::get16(pint_t addr) {
return P::E::get16(*(uint16_t *)localCopy(addr));
}
template <typename P> uint32_t OtherAddressSpace<P>::get32(pint_t addr) {
return P::E::get32(*(uint32_t *)localCopy(addr));
}
template <typename P> uint64_t OtherAddressSpace<P>::get64(pint_t addr) {
return P::E::get64(*(uint64_t *)localCopy(addr));
}
template <typename P>
typename P::uint_t OtherAddressSpace<P>::getP(pint_t addr) {
return P::getP(*(uint64_t *)localCopy(addr));
}
template <typename P>
uint64_t OtherAddressSpace<P>::getULEB128(pint_t &addr, pint_t end) {
uintptr_t size = (end - addr);
LocalAddressSpace::pint_t laddr = (LocalAddressSpace::pint_t) localCopy(addr);
LocalAddressSpace::pint_t sladdr = laddr;
uint64_t result = LocalAddressSpace::getULEB128(laddr, laddr + size);
addr += (laddr - sladdr);
return result;
}
template <typename P>
int64_t OtherAddressSpace<P>::getSLEB128(pint_t &addr, pint_t end) {
uintptr_t size = (end - addr);
LocalAddressSpace::pint_t laddr = (LocalAddressSpace::pint_t) localCopy(addr);
LocalAddressSpace::pint_t sladdr = laddr;
uint64_t result = LocalAddressSpace::getSLEB128(laddr, laddr + size);
addr += (laddr - sladdr);
return result;
}
template <typename P> void *OtherAddressSpace<P>::localCopy(pint_t addr) {
// FIX ME
}
template <typename P>
bool OtherAddressSpace<P>::findFunctionName(pint_t addr, char *buf,
size_t bufLen, unw_word_t *offset) {
// FIX ME
}
/// unw_addr_space is the base class that abstract unw_addr_space_t type in
/// libunwind.h points to.
struct unw_addr_space {
cpu_type_t cpuType;
task_t taskPort;
};
/// unw_addr_space_i386 is the concrete instance that a unw_addr_space_t points
/// to when examining
/// a 32-bit intel process.
struct unw_addr_space_i386 : public unw_addr_space {
unw_addr_space_i386(task_t task) : oas(task) {}
OtherAddressSpace<Pointer32<LittleEndian> > oas;
};
/// unw_addr_space_x86_64 is the concrete instance that a unw_addr_space_t
/// points to when examining
/// a 64-bit intel process.
struct unw_addr_space_x86_64 : public unw_addr_space {
unw_addr_space_x86_64(task_t task) : oas(task) {}
OtherAddressSpace<Pointer64<LittleEndian> > oas;
};
/// unw_addr_space_ppc is the concrete instance that a unw_addr_space_t points
/// to when examining
/// a 32-bit PowerPC process.
struct unw_addr_space_ppc : public unw_addr_space {
unw_addr_space_ppc(task_t task) : oas(task) {}
OtherAddressSpace<Pointer32<BigEndian> > oas;
};
#endif // UNW_REMOTE
} // namespace libunwind
#endif // __ADDRESSSPACE_HPP__