llvm-project/lld/ELF/Arch/Hexagon.cpp

383 lines
11 KiB
C++

//===-- Hexagon.cpp -------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "InputFiles.h"
#include "Symbols.h"
#include "SyntheticSections.h"
#include "Target.h"
#include "lld/Common/ErrorHandler.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/Object/ELF.h"
#include "llvm/Support/Endian.h"
using namespace llvm;
using namespace llvm::object;
using namespace llvm::support::endian;
using namespace llvm::ELF;
namespace lld {
namespace elf {
namespace {
class Hexagon final : public TargetInfo {
public:
Hexagon();
uint32_t calcEFlags() const override;
RelExpr getRelExpr(RelType type, const Symbol &s,
const uint8_t *loc) const override;
RelType getDynRel(RelType type) const override;
void relocate(uint8_t *loc, const Relocation &rel,
uint64_t val) const override;
void writePltHeader(uint8_t *buf) const override;
void writePlt(uint8_t *buf, const Symbol &sym,
uint64_t pltEntryAddr) const override;
};
} // namespace
Hexagon::Hexagon() {
pltRel = R_HEX_JMP_SLOT;
relativeRel = R_HEX_RELATIVE;
gotRel = R_HEX_GLOB_DAT;
symbolicRel = R_HEX_32;
// The zero'th GOT entry is reserved for the address of _DYNAMIC. The
// next 3 are reserved for the dynamic loader.
gotPltHeaderEntriesNum = 4;
pltEntrySize = 16;
pltHeaderSize = 32;
// Hexagon Linux uses 64K pages by default.
defaultMaxPageSize = 0x10000;
noneRel = R_HEX_NONE;
tlsGotRel = R_HEX_TPREL_32;
tlsModuleIndexRel = R_HEX_DTPMOD_32;
tlsOffsetRel = R_HEX_DTPREL_32;
}
uint32_t Hexagon::calcEFlags() const {
assert(!objectFiles.empty());
// The architecture revision must always be equal to or greater than
// greatest revision in the list of inputs.
uint32_t ret = 0;
for (InputFile *f : objectFiles) {
uint32_t eflags = cast<ObjFile<ELF32LE>>(f)->getObj().getHeader()->e_flags;
if (eflags > ret)
ret = eflags;
}
return ret;
}
static uint32_t applyMask(uint32_t mask, uint32_t data) {
uint32_t result = 0;
size_t off = 0;
for (size_t bit = 0; bit != 32; ++bit) {
uint32_t valBit = (data >> off) & 1;
uint32_t maskBit = (mask >> bit) & 1;
if (maskBit) {
result |= (valBit << bit);
++off;
}
}
return result;
}
RelExpr Hexagon::getRelExpr(RelType type, const Symbol &s,
const uint8_t *loc) const {
switch (type) {
case R_HEX_NONE:
return R_NONE;
case R_HEX_6_X:
case R_HEX_8_X:
case R_HEX_9_X:
case R_HEX_10_X:
case R_HEX_11_X:
case R_HEX_12_X:
case R_HEX_16_X:
case R_HEX_32:
case R_HEX_32_6_X:
case R_HEX_HI16:
case R_HEX_LO16:
case R_HEX_DTPREL_32:
return R_ABS;
case R_HEX_B9_PCREL:
case R_HEX_B13_PCREL:
case R_HEX_B15_PCREL:
case R_HEX_6_PCREL_X:
case R_HEX_32_PCREL:
return R_PC;
case R_HEX_B9_PCREL_X:
case R_HEX_B15_PCREL_X:
case R_HEX_B22_PCREL:
case R_HEX_PLT_B22_PCREL:
case R_HEX_B22_PCREL_X:
case R_HEX_B32_PCREL_X:
return R_PLT_PC;
case R_HEX_IE_32_6_X:
case R_HEX_IE_16_X:
case R_HEX_IE_HI16:
case R_HEX_IE_LO16:
return R_GOT;
case R_HEX_GD_GOT_11_X:
case R_HEX_GD_GOT_16_X:
case R_HEX_GD_GOT_32_6_X:
return R_TLSGD_GOTPLT;
case R_HEX_GOTREL_11_X:
case R_HEX_GOTREL_16_X:
case R_HEX_GOTREL_32_6_X:
case R_HEX_GOTREL_HI16:
case R_HEX_GOTREL_LO16:
return R_GOTPLTREL;
case R_HEX_GOT_11_X:
case R_HEX_GOT_16_X:
case R_HEX_GOT_32_6_X:
return R_GOTPLT;
case R_HEX_IE_GOT_11_X:
case R_HEX_IE_GOT_16_X:
case R_HEX_IE_GOT_32_6_X:
case R_HEX_IE_GOT_HI16:
case R_HEX_IE_GOT_LO16:
config->hasStaticTlsModel = true;
return R_GOTPLT;
case R_HEX_TPREL_11_X:
case R_HEX_TPREL_16:
case R_HEX_TPREL_16_X:
case R_HEX_TPREL_32_6_X:
case R_HEX_TPREL_HI16:
case R_HEX_TPREL_LO16:
return R_TLS;
default:
error(getErrorLocation(loc) + "unknown relocation (" + Twine(type) +
") against symbol " + toString(s));
return R_NONE;
}
}
static uint32_t findMaskR6(uint32_t insn) {
// There are (arguably too) many relocation masks for the DSP's
// R_HEX_6_X type. The table below is used to select the correct mask
// for the given instruction.
struct InstructionMask {
uint32_t cmpMask;
uint32_t relocMask;
};
static const InstructionMask r6[] = {
{0x38000000, 0x0000201f}, {0x39000000, 0x0000201f},
{0x3e000000, 0x00001f80}, {0x3f000000, 0x00001f80},
{0x40000000, 0x000020f8}, {0x41000000, 0x000007e0},
{0x42000000, 0x000020f8}, {0x43000000, 0x000007e0},
{0x44000000, 0x000020f8}, {0x45000000, 0x000007e0},
{0x46000000, 0x000020f8}, {0x47000000, 0x000007e0},
{0x6a000000, 0x00001f80}, {0x7c000000, 0x001f2000},
{0x9a000000, 0x00000f60}, {0x9b000000, 0x00000f60},
{0x9c000000, 0x00000f60}, {0x9d000000, 0x00000f60},
{0x9f000000, 0x001f0100}, {0xab000000, 0x0000003f},
{0xad000000, 0x0000003f}, {0xaf000000, 0x00030078},
{0xd7000000, 0x006020e0}, {0xd8000000, 0x006020e0},
{0xdb000000, 0x006020e0}, {0xdf000000, 0x006020e0}};
// Duplex forms have a fixed mask and parse bits 15:14 are always
// zero. Non-duplex insns will always have at least one bit set in the
// parse field.
if ((0xC000 & insn) == 0x0)
return 0x03f00000;
for (InstructionMask i : r6)
if ((0xff000000 & insn) == i.cmpMask)
return i.relocMask;
error("unrecognized instruction for R_HEX_6 relocation: 0x" +
utohexstr(insn));
return 0;
}
static uint32_t findMaskR8(uint32_t insn) {
if ((0xff000000 & insn) == 0xde000000)
return 0x00e020e8;
if ((0xff000000 & insn) == 0x3c000000)
return 0x0000207f;
return 0x00001fe0;
}
static uint32_t findMaskR11(uint32_t insn) {
if ((0xff000000 & insn) == 0xa1000000)
return 0x060020ff;
return 0x06003fe0;
}
static uint32_t findMaskR16(uint32_t insn) {
if ((0xff000000 & insn) == 0x48000000)
return 0x061f20ff;
if ((0xff000000 & insn) == 0x49000000)
return 0x061f3fe0;
if ((0xff000000 & insn) == 0x78000000)
return 0x00df3fe0;
if ((0xff000000 & insn) == 0xb0000000)
return 0x0fe03fe0;
error("unrecognized instruction for R_HEX_16_X relocation: 0x" +
utohexstr(insn));
return 0;
}
static void or32le(uint8_t *p, int32_t v) { write32le(p, read32le(p) | v); }
void Hexagon::relocate(uint8_t *loc, const Relocation &rel,
uint64_t val) const {
switch (rel.type) {
case R_HEX_NONE:
break;
case R_HEX_6_PCREL_X:
case R_HEX_6_X:
or32le(loc, applyMask(findMaskR6(read32le(loc)), val));
break;
case R_HEX_8_X:
or32le(loc, applyMask(findMaskR8(read32le(loc)), val));
break;
case R_HEX_9_X:
or32le(loc, applyMask(0x00003fe0, val & 0x3f));
break;
case R_HEX_10_X:
or32le(loc, applyMask(0x00203fe0, val & 0x3f));
break;
case R_HEX_11_X:
case R_HEX_GD_GOT_11_X:
case R_HEX_IE_GOT_11_X:
case R_HEX_GOT_11_X:
case R_HEX_GOTREL_11_X:
case R_HEX_TPREL_11_X:
or32le(loc, applyMask(findMaskR11(read32le(loc)), val & 0x3f));
break;
case R_HEX_12_X:
or32le(loc, applyMask(0x000007e0, val));
break;
case R_HEX_16_X: // These relocs only have 6 effective bits.
case R_HEX_IE_16_X:
case R_HEX_IE_GOT_16_X:
case R_HEX_GD_GOT_16_X:
case R_HEX_GOT_16_X:
case R_HEX_GOTREL_16_X:
case R_HEX_TPREL_16_X:
or32le(loc, applyMask(findMaskR16(read32le(loc)), val & 0x3f));
break;
case R_HEX_TPREL_16:
or32le(loc, applyMask(findMaskR16(read32le(loc)), val & 0xffff));
break;
case R_HEX_32:
case R_HEX_32_PCREL:
case R_HEX_DTPREL_32:
or32le(loc, val);
break;
case R_HEX_32_6_X:
case R_HEX_GD_GOT_32_6_X:
case R_HEX_GOT_32_6_X:
case R_HEX_GOTREL_32_6_X:
case R_HEX_IE_GOT_32_6_X:
case R_HEX_IE_32_6_X:
case R_HEX_TPREL_32_6_X:
or32le(loc, applyMask(0x0fff3fff, val >> 6));
break;
case R_HEX_B9_PCREL:
checkInt(loc, val, 11, rel);
or32le(loc, applyMask(0x003000fe, val >> 2));
break;
case R_HEX_B9_PCREL_X:
or32le(loc, applyMask(0x003000fe, val & 0x3f));
break;
case R_HEX_B13_PCREL:
checkInt(loc, val, 15, rel);
or32le(loc, applyMask(0x00202ffe, val >> 2));
break;
case R_HEX_B15_PCREL:
checkInt(loc, val, 17, rel);
or32le(loc, applyMask(0x00df20fe, val >> 2));
break;
case R_HEX_B15_PCREL_X:
or32le(loc, applyMask(0x00df20fe, val & 0x3f));
break;
case R_HEX_B22_PCREL:
case R_HEX_PLT_B22_PCREL:
checkInt(loc, val, 22, rel);
or32le(loc, applyMask(0x1ff3ffe, val >> 2));
break;
case R_HEX_B22_PCREL_X:
or32le(loc, applyMask(0x1ff3ffe, val & 0x3f));
break;
case R_HEX_B32_PCREL_X:
or32le(loc, applyMask(0x0fff3fff, val >> 6));
break;
case R_HEX_GOTREL_HI16:
case R_HEX_HI16:
case R_HEX_IE_GOT_HI16:
case R_HEX_IE_HI16:
case R_HEX_TPREL_HI16:
or32le(loc, applyMask(0x00c03fff, val >> 16));
break;
case R_HEX_GOTREL_LO16:
case R_HEX_LO16:
case R_HEX_IE_GOT_LO16:
case R_HEX_IE_LO16:
case R_HEX_TPREL_LO16:
or32le(loc, applyMask(0x00c03fff, val));
break;
default:
llvm_unreachable("unknown relocation");
}
}
void Hexagon::writePltHeader(uint8_t *buf) const {
const uint8_t pltData[] = {
0x00, 0x40, 0x00, 0x00, // { immext (#0)
0x1c, 0xc0, 0x49, 0x6a, // r28 = add (pc, ##GOT0@PCREL) } # @GOT0
0x0e, 0x42, 0x9c, 0xe2, // { r14 -= add (r28, #16) # offset of GOTn
0x4f, 0x40, 0x9c, 0x91, // r15 = memw (r28 + #8) # object ID at GOT2
0x3c, 0xc0, 0x9c, 0x91, // r28 = memw (r28 + #4) }# dynamic link at GOT1
0x0e, 0x42, 0x0e, 0x8c, // { r14 = asr (r14, #2) # index of PLTn
0x00, 0xc0, 0x9c, 0x52, // jumpr r28 } # call dynamic linker
0x0c, 0xdb, 0x00, 0x54, // trap0(#0xdb) # bring plt0 into 16byte alignment
};
memcpy(buf, pltData, sizeof(pltData));
// Offset from PLT0 to the GOT.
uint64_t off = in.gotPlt->getVA() - in.plt->getVA();
relocateNoSym(buf, R_HEX_B32_PCREL_X, off);
relocateNoSym(buf + 4, R_HEX_6_PCREL_X, off);
}
void Hexagon::writePlt(uint8_t *buf, const Symbol &sym,
uint64_t pltEntryAddr) const {
const uint8_t inst[] = {
0x00, 0x40, 0x00, 0x00, // { immext (#0)
0x0e, 0xc0, 0x49, 0x6a, // r14 = add (pc, ##GOTn@PCREL) }
0x1c, 0xc0, 0x8e, 0x91, // r28 = memw (r14)
0x00, 0xc0, 0x9c, 0x52, // jumpr r28
};
memcpy(buf, inst, sizeof(inst));
uint64_t gotPltEntryAddr = sym.getGotPltVA();
relocateNoSym(buf, R_HEX_B32_PCREL_X, gotPltEntryAddr - pltEntryAddr);
relocateNoSym(buf + 4, R_HEX_6_PCREL_X, gotPltEntryAddr - pltEntryAddr);
}
RelType Hexagon::getDynRel(RelType type) const {
if (type == R_HEX_32)
return type;
return R_HEX_NONE;
}
TargetInfo *getHexagonTargetInfo() {
static Hexagon target;
return &target;
}
} // namespace elf
} // namespace lld