diff options
Diffstat (limited to 'lld/ELF/Arch/PPC.cpp')
| -rw-r--r-- | lld/ELF/Arch/PPC.cpp | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/lld/ELF/Arch/PPC.cpp b/lld/ELF/Arch/PPC.cpp index 1d4e80184dcd..b3cc78710e9a 100644 --- a/lld/ELF/Arch/PPC.cpp +++ b/lld/ELF/Arch/PPC.cpp @@ -67,6 +67,18 @@ static void writeFromHalf16(uint8_t *loc, uint32_t insn) { } void writePPC32GlinkSection(uint8_t *buf, size_t numEntries) { + // Create canonical PLT entries for non-PIE code. Compilers don't generate + // non-GOT-non-PLT relocations referencing external functions for -fpie/-fPIE. + uint32_t glink = in.plt->getVA(); // VA of .glink + if (!config->isPic) { + for (const Symbol *sym : in.plt->entries) + if (sym->needsPltAddr) { + writePPC32PltCallStub(buf, sym->getGotPltVA(), nullptr, 0); + buf += 16; + glink += 16; + } + } + // On PPC Secure PLT ABI, bl foo@plt jumps to a call stub, which loads an // absolute address from a specific .plt slot (usually called .got.plt on // other targets) and jumps there. @@ -85,15 +97,14 @@ void writePPC32GlinkSection(uint8_t *buf, size_t numEntries) { // computes the PLT index (by computing the distance from the landing b to // itself) and calls _dl_runtime_resolve() (in glibc). uint32_t got = in.got->getVA(); - uint32_t glink = in.plt->getVA(); // VA of .glink const uint8_t *end = buf + 64; if (config->isPic) { - uint32_t afterBcl = in.plt->getSize() - target->pltHeaderSize + 12; + uint32_t afterBcl = 4 * in.plt->getNumEntries() + 12; uint32_t gotBcl = got + 4 - (glink + afterBcl); write32(buf + 0, 0x3d6b0000 | ha(afterBcl)); // addis r11,r11,1f-glink@ha write32(buf + 4, 0x7c0802a6); // mflr r0 write32(buf + 8, 0x429f0005); // bcl 20,30,.+4 - write32(buf + 12, 0x396b0000 | lo(afterBcl)); // 1: addi r11,r11,1b-.glink@l + write32(buf + 12, 0x396b0000 | lo(afterBcl)); // 1: addi r11,r11,1b-glink@l write32(buf + 16, 0x7d8802a6); // mflr r12 write32(buf + 20, 0x7c0803a6); // mtlr r0 write32(buf + 24, 0x7d6c5850); // sub r11,r11,r12 @@ -113,16 +124,16 @@ void writePPC32GlinkSection(uint8_t *buf, size_t numEntries) { buf += 56; } else { write32(buf + 0, 0x3d800000 | ha(got + 4)); // lis r12,GOT+4@ha - write32(buf + 4, 0x3d6b0000 | ha(-glink)); // addis r11,r11,-Glink@ha + write32(buf + 4, 0x3d6b0000 | ha(-glink)); // addis r11,r11,-glink@ha if (ha(got + 4) == ha(got + 8)) write32(buf + 8, 0x800c0000 | lo(got + 4)); // lwz r0,GOT+4@l(r12) else write32(buf + 8, 0x840c0000 | lo(got + 4)); // lwzu r0,GOT+4@l(r12) - write32(buf + 12, 0x396b0000 | lo(-glink)); // addi r11,r11,-Glink@l + write32(buf + 12, 0x396b0000 | lo(-glink)); // addi r11,r11,-glink@l write32(buf + 16, 0x7c0903a6); // mtctr r0 write32(buf + 20, 0x7c0b5a14); // add r0,r11,r11 if (ha(got + 4) == ha(got + 8)) - write32(buf + 24, 0x818c0000 | lo(got + 8)); // lwz r12,GOT+8@ha(r12) + write32(buf + 24, 0x818c0000 | lo(got + 8)); // lwz r12,GOT+8@l(r12) else write32(buf + 24, 0x818c0000 | 4); // lwz r12,4(r12) write32(buf + 28, 0x7d605a14); // add r11,r0,r11 @@ -146,7 +157,7 @@ PPC::PPC() { gotBaseSymInGotPlt = false; gotHeaderEntriesNum = 3; gotPltHeaderEntriesNum = 0; - pltHeaderSize = 64; // size of PLTresolve in .glink + pltHeaderSize = 0; pltEntrySize = 4; ipltEntrySize = 16; @@ -178,25 +189,25 @@ void PPC::writeGotHeader(uint8_t *buf) const { void PPC::writeGotPlt(uint8_t *buf, const Symbol &s) const { // Address of the symbol resolver stub in .glink . - write32(buf, in.plt->getVA() + 4 * s.pltIndex); + write32(buf, in.plt->getVA() + in.plt->headerSize + 4 * s.pltIndex); } bool PPC::needsThunk(RelExpr expr, RelType type, const InputFile *file, - uint64_t branchAddr, const Symbol &s, int64_t /*a*/) const { - if (type != R_PPC_REL24 && type != R_PPC_PLTREL24) + uint64_t branchAddr, const Symbol &s, int64_t a) const { + if (type != R_PPC_LOCAL24PC && type != R_PPC_REL24 && type != R_PPC_PLTREL24) return false; if (s.isInPlt()) return true; if (s.isUndefWeak()) return false; - return !(expr == R_PC && PPC::inBranchRange(type, branchAddr, s.getVA())); + return !PPC::inBranchRange(type, branchAddr, s.getVA(a)); } uint32_t PPC::getThunkSectionSpacing() const { return 0x2000000; } bool PPC::inBranchRange(RelType type, uint64_t src, uint64_t dst) const { uint64_t offset = dst - src; - if (type == R_PPC_REL24 || type == R_PPC_PLTREL24) + if (type == R_PPC_LOCAL24PC || type == R_PPC_REL24 || type == R_PPC_PLTREL24) return isInt<26>(offset); llvm_unreachable("unsupported relocation type used in branch"); } @@ -219,13 +230,13 @@ RelExpr PPC::getRelExpr(RelType type, const Symbol &s, return R_DTPREL; case R_PPC_REL14: case R_PPC_REL32: - case R_PPC_LOCAL24PC: case R_PPC_REL16_LO: case R_PPC_REL16_HI: case R_PPC_REL16_HA: return R_PC; case R_PPC_GOT16: return R_GOT_OFF; + case R_PPC_LOCAL24PC: case R_PPC_REL24: return R_PLT_PC; case R_PPC_PLTREL24: |