mirror of
https://github.com/rui314/mold.git
synced 2024-12-28 02:44:48 +03:00
433 lines
11 KiB
C++
433 lines
11 KiB
C++
#include "mold.h"
|
|
|
|
enum {
|
|
R_TLS_GOTIE = R_END + 1,
|
|
R_TLS_LE,
|
|
R_TLS_GD,
|
|
R_TLS_LD,
|
|
R_TLS_GOTDESC,
|
|
R_TLS_GOTDESC_RELAX,
|
|
R_TLS_DESC_CALL_RELAX,
|
|
R_TPOFF,
|
|
};
|
|
|
|
template <>
|
|
void PltSection<I386>::copy_buf(Context<I386> &ctx) {
|
|
u8 *buf = ctx.buf + this->shdr.sh_offset;
|
|
|
|
// Write PLT header
|
|
if (ctx.arg.pic) {
|
|
static const u8 plt0[] = {
|
|
0xff, 0xb3, 0x04, 0, 0, 0, // pushl 4(%ebx)
|
|
0xff, 0xa3, 0x08, 0, 0, 0, // jmp *8(%ebx)
|
|
0x90, 0x90, 0x90, 0x90, // nop
|
|
};
|
|
memcpy(buf, plt0, sizeof(plt0));
|
|
} else {
|
|
static const u8 plt0[] = {
|
|
0xff, 0x35, 0, 0, 0, 0, // pushl (GOTPLT+4)
|
|
0xff, 0x25, 0, 0, 0, 0, // jmp *(GOTPLT+8)
|
|
0x90, 0x90, 0x90, 0x90, // nop
|
|
};
|
|
memcpy(buf, plt0, sizeof(plt0));
|
|
*(u32 *)(buf + 2) = ctx.gotplt->shdr.sh_addr + 4;
|
|
*(u32 *)(buf + 8) = ctx.gotplt->shdr.sh_addr + 8;
|
|
}
|
|
|
|
// Write PLT entries
|
|
i64 relplt_idx = 0;
|
|
|
|
for (Symbol<I386> *sym : symbols) {
|
|
u8 *ent = buf + sym->get_plt_idx(ctx) * I386::plt_size;
|
|
|
|
if (ctx.arg.pic) {
|
|
static const u8 data[] = {
|
|
0xff, 0xa3, 0, 0, 0, 0, // jmp *foo@GOT(%ebx)
|
|
0x68, 0, 0, 0, 0, // pushl $reloc_offset
|
|
0xe9, 0, 0, 0, 0, // jmp .PLT0@PC
|
|
};
|
|
memcpy(ent, data, sizeof(data));
|
|
*(u32 *)(ent + 2) = sym->get_gotplt_addr(ctx) - sym->get_plt_addr(ctx);
|
|
} else {
|
|
static const u8 data[] = {
|
|
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOT
|
|
0x68, 0, 0, 0, 0, // pushl $reloc_offset
|
|
0xe9, 0, 0, 0, 0, // jmp .PLT0@PC
|
|
};
|
|
memcpy(ent, data, sizeof(data));
|
|
*(u32 *)(ent + 2) = sym->get_gotplt_addr(ctx);
|
|
}
|
|
|
|
*(u32 *)(ent + 7) = relplt_idx++ * sizeof(ElfRel<I386>);
|
|
*(u32 *)(ent + 12) = this->shdr.sh_addr - sym->get_plt_addr(ctx) - 16;
|
|
}
|
|
}
|
|
|
|
template <>
|
|
void PltGotSection<I386>::copy_buf(Context<I386> &ctx) {
|
|
u8 *buf = ctx.buf + this->shdr.sh_offset;
|
|
|
|
if (ctx.arg.pic) {
|
|
static const u8 data[] = {
|
|
0xff, 0xa3, 0, 0, 0, 0, // jmp *foo@GOT(%ebx)
|
|
0x66, 0x90, // nop
|
|
};
|
|
|
|
for (i64 i = 0; i < symbols.size(); i++) {
|
|
u8 *ent = buf + i * sizeof(data);
|
|
memcpy(ent, data, sizeof(data));
|
|
*(u32 *)(ent + 2) = symbols[i]->get_got_addr(ctx) - ctx.got->shdr.sh_addr;
|
|
}
|
|
} else {
|
|
static const u8 data[] = {
|
|
0xff, 0x25, 0, 0, 0, 0, // jmp *foo@GOT
|
|
0x66, 0x90, // nop
|
|
};
|
|
|
|
for (i64 i = 0; i < symbols.size(); i++) {
|
|
u8 *ent = buf + i * sizeof(data);
|
|
memcpy(ent, data, sizeof(data));
|
|
*(u32 *)(ent + 2) = symbols[i]->get_got_addr(ctx);
|
|
}
|
|
}
|
|
}
|
|
|
|
template <>
|
|
void EhFrameSection<I386>::apply_reloc(Context<I386> &ctx,
|
|
EhReloc<I386> &rel,
|
|
u64 loc, u64 val) {
|
|
u8 *base = ctx.buf + this->shdr.sh_offset;
|
|
|
|
switch (rel.type) {
|
|
case R_386_32:
|
|
*(u32 *)(base + loc) = val;
|
|
return;
|
|
case R_386_PC32:
|
|
*(u32 *)(base + loc) = val - this->shdr.sh_addr - loc;
|
|
return;
|
|
}
|
|
unreachable(ctx);
|
|
}
|
|
|
|
static void write_val(Context<I386> &ctx, u64 r_type, u8 *loc, u64 val) {
|
|
switch (r_type) {
|
|
case R_386_NONE:
|
|
return;
|
|
case R_386_8:
|
|
case R_386_PC8:
|
|
*loc += val;
|
|
return;
|
|
case R_386_16:
|
|
case R_386_PC16:
|
|
*(u16 *)loc += val;
|
|
return;
|
|
case R_386_32:
|
|
case R_386_PC32:
|
|
case R_386_GOT32:
|
|
case R_386_GOT32X:
|
|
case R_386_PLT32:
|
|
case R_386_GOTOFF:
|
|
case R_386_GOTPC:
|
|
case R_386_TLS_LDM:
|
|
case R_386_TLS_GOTIE:
|
|
case R_386_TLS_LE:
|
|
case R_386_TLS_GD:
|
|
case R_386_TLS_LDO_32:
|
|
case R_386_SIZE32:
|
|
case R_386_TLS_GOTDESC:
|
|
*(u32 *)loc += val;
|
|
return;
|
|
}
|
|
unreachable(ctx);
|
|
}
|
|
|
|
template <>
|
|
void InputSection<I386>::apply_reloc_alloc(Context<I386> &ctx, u8 *base) {
|
|
ElfRel<I386> *dynrel = nullptr;
|
|
std::span<ElfRel<I386>> rels = get_rels(ctx);
|
|
i64 frag_idx = 0;
|
|
|
|
if (ctx.reldyn)
|
|
dynrel = (ElfRel<I386> *)(ctx.buf + ctx.reldyn->shdr.sh_offset +
|
|
file.reldyn_offset + this->reldyn_offset);
|
|
|
|
for (i64 i = 0; i < rels.size(); i++) {
|
|
const ElfRel<I386> &rel = rels[i];
|
|
Symbol<I386> &sym = *file.symbols[rel.r_sym];
|
|
u8 *loc = base + rel.r_offset;
|
|
|
|
const SectionFragmentRef<I386> *ref = nullptr;
|
|
if (rel_fragments && rel_fragments[frag_idx].idx == i)
|
|
ref = &rel_fragments[frag_idx++];
|
|
|
|
auto write = [&](u64 val) {
|
|
write_val(ctx, rel.r_type, loc, val);
|
|
};
|
|
|
|
#define S (ref ? ref->frag->get_addr(ctx) : sym.get_addr(ctx))
|
|
#define A (ref ? ref->addend : 0)
|
|
#define P (output_section->shdr.sh_addr + offset + rel.r_offset)
|
|
#define G (sym.get_got_addr(ctx) - ctx.got->shdr.sh_addr)
|
|
#define GOT ctx.got->shdr.sh_addr
|
|
|
|
switch (rel_types[i]) {
|
|
case R_NONE:
|
|
break;
|
|
case R_ABS:
|
|
write(S + A);
|
|
break;
|
|
case R_BASEREL:
|
|
*dynrel++ = {P, R_386_RELATIVE, 0};
|
|
*(u32 *)loc += S + A;
|
|
break;
|
|
case R_DYN:
|
|
*dynrel++ = {P, R_386_32, (u32)sym.get_dynsym_idx(ctx)};
|
|
*(u32 *)loc += A;
|
|
break;
|
|
case R_PC:
|
|
write(S + A - P);
|
|
break;
|
|
case R_GOT:
|
|
write(G + A);
|
|
break;
|
|
case R_GOTOFF:
|
|
write(S + A - GOT);
|
|
break;
|
|
case R_GOTPC:
|
|
write(GOT + A - P);
|
|
break;
|
|
case R_GOTPCREL:
|
|
write(G + GOT + A - P);
|
|
break;
|
|
case R_TLS_GOTIE:
|
|
write(sym.get_gottp_addr(ctx) + A - GOT);
|
|
break;
|
|
case R_TLS_LE:
|
|
write(S + A - ctx.tls_end);
|
|
break;
|
|
case R_TLS_GD:
|
|
write(sym.get_tlsgd_addr(ctx) + A - GOT);
|
|
break;
|
|
case R_TLS_LD:
|
|
write(ctx.got->get_tlsld_addr(ctx) + A - GOT);
|
|
break;
|
|
case R_TPOFF:
|
|
write(S + A - ctx.tls_begin);
|
|
break;
|
|
case R_TLS_GOTDESC:
|
|
write(sym.get_tlsdesc_addr(ctx) + A - GOT);
|
|
break;
|
|
case R_TLS_GOTDESC_RELAX: {
|
|
static const u8 insn[] = {
|
|
0x8d, 0x05, 0, 0, 0, 0, // lea 0, %eax
|
|
};
|
|
memcpy(loc - 2, insn, sizeof(insn));
|
|
write(S + A - ctx.tls_end);
|
|
break;
|
|
}
|
|
case R_TLS_DESC_CALL_RELAX:
|
|
// call *(%rax) -> nop
|
|
loc[0] = 0x66;
|
|
loc[1] = 0x90;
|
|
break;
|
|
case R_SIZE:
|
|
write(sym.esym().st_size + A);
|
|
break;
|
|
default:
|
|
unreachable(ctx);
|
|
}
|
|
|
|
#undef S
|
|
#undef A
|
|
#undef P
|
|
#undef G
|
|
#undef GOT
|
|
}
|
|
}
|
|
|
|
template <>
|
|
void InputSection<I386>::apply_reloc_nonalloc(Context<I386> &ctx, u8 *base) {
|
|
std::span<ElfRel<I386>> rels = get_rels(ctx);
|
|
i64 frag_idx = 0;
|
|
|
|
for (i64 i = 0; i < rels.size(); i++) {
|
|
const ElfRel<I386> &rel = rels[i];
|
|
Symbol<I386> &sym = *file.symbols[rel.r_sym];
|
|
u8 *loc = base + rel.r_offset;
|
|
|
|
if (!sym.file) {
|
|
Error(ctx) << "undefined symbol: " << file << ": " << sym;
|
|
continue;
|
|
}
|
|
|
|
const SectionFragmentRef<I386> *ref = nullptr;
|
|
if (rel_fragments && rel_fragments[frag_idx].idx == i)
|
|
ref = &rel_fragments[frag_idx++];
|
|
|
|
auto write = [&](u64 val) {
|
|
write_val(ctx, rel.r_type, loc, val);
|
|
};
|
|
|
|
switch (rel.r_type) {
|
|
case R_386_NONE:
|
|
return;
|
|
case R_386_8:
|
|
case R_386_16:
|
|
case R_386_32:
|
|
case R_386_PC8:
|
|
case R_386_PC16:
|
|
case R_386_PC32:
|
|
if (ref)
|
|
write(ref->frag->get_addr(ctx) + ref->addend);
|
|
else
|
|
write(sym.get_addr(ctx));
|
|
break;
|
|
case R_386_GOTOFF:
|
|
write(sym.get_addr(ctx) - ctx.got->shdr.sh_addr);
|
|
break;
|
|
case R_386_TLS_LDO_32:
|
|
write(sym.get_addr(ctx) - ctx.tls_begin);
|
|
break;
|
|
case R_386_SIZE32:
|
|
write(sym.esym().st_size);
|
|
break;
|
|
default:
|
|
Fatal(ctx) << *this << ": invalid relocation for non-allocated sections: "
|
|
<< rel_to_string<I386>(rel.r_type);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <>
|
|
void InputSection<I386>::scan_relocations(Context<I386> &ctx) {
|
|
assert(shdr.sh_flags & SHF_ALLOC);
|
|
this->reldyn_offset = file.num_dynrel * sizeof(ElfRel<I386>);
|
|
std::span<ElfRel<I386>> rels = get_rels(ctx);
|
|
|
|
// Scan relocations
|
|
for (i64 i = 0; i < rels.size(); i++) {
|
|
const ElfRel<I386> &rel = rels[i];
|
|
Symbol<I386> &sym = *file.symbols[rel.r_sym];
|
|
u8 *loc = (u8 *)(contents.data() + rel.r_offset);
|
|
|
|
if (!sym.file) {
|
|
Error(ctx) << "undefined symbol: " << file << ": " << sym;
|
|
continue;
|
|
}
|
|
|
|
if (sym.get_type() == STT_GNU_IFUNC) {
|
|
sym.flags |= NEEDS_GOT;
|
|
sym.flags |= NEEDS_PLT;
|
|
}
|
|
|
|
switch (rel.r_type) {
|
|
case R_386_NONE:
|
|
rel_types[i] = R_NONE;
|
|
break;
|
|
case R_386_8:
|
|
case R_386_16: {
|
|
Action table[][4] = {
|
|
// Absolute Local Imported data Imported code
|
|
{ NONE, ERROR, ERROR, ERROR }, // DSO
|
|
{ NONE, ERROR, ERROR, ERROR }, // PIE
|
|
{ NONE, NONE, COPYREL, PLT }, // PDE
|
|
};
|
|
|
|
dispatch(ctx, table, R_ABS, i);
|
|
break;
|
|
}
|
|
case R_386_32: {
|
|
Action table[][4] = {
|
|
// Absolute Local Imported data Imported code
|
|
{ NONE, BASEREL, DYNREL, DYNREL }, // DSO
|
|
{ NONE, BASEREL, DYNREL, DYNREL }, // PIE
|
|
{ NONE, NONE, COPYREL, PLT }, // PDE
|
|
};
|
|
|
|
dispatch(ctx, table, R_ABS, i);
|
|
break;
|
|
}
|
|
case R_386_PC8:
|
|
case R_386_PC16: {
|
|
Action table[][4] = {
|
|
// Absolute Local Imported data Imported code
|
|
{ ERROR, NONE, ERROR, ERROR }, // DSO
|
|
{ ERROR, NONE, COPYREL, PLT }, // PIE
|
|
{ NONE, NONE, COPYREL, PLT }, // PDE
|
|
};
|
|
|
|
dispatch(ctx, table, R_PC, i);
|
|
break;
|
|
}
|
|
case R_386_PC32: {
|
|
Action table[][4] = {
|
|
// Absolute Local Imported data Imported code
|
|
{ BASEREL, NONE, ERROR, ERROR }, // DSO
|
|
{ BASEREL, NONE, COPYREL, PLT }, // PIE
|
|
{ NONE, NONE, COPYREL, PLT }, // PDE
|
|
};
|
|
|
|
dispatch(ctx, table, R_PC, i);
|
|
break;
|
|
}
|
|
case R_386_GOT32:
|
|
case R_386_GOT32X:
|
|
sym.flags |= NEEDS_GOT;
|
|
rel_types[i] = R_GOT;
|
|
break;
|
|
case R_386_PLT32:
|
|
if (sym.is_imported)
|
|
sym.flags |= NEEDS_PLT;
|
|
rel_types[i] = R_PC;
|
|
break;
|
|
case R_386_GOTOFF:
|
|
rel_types[i] = R_GOTOFF;
|
|
break;
|
|
case R_386_GOTPC:
|
|
sym.flags |= NEEDS_GOT;
|
|
rel_types[i] = R_GOTPC;
|
|
break;
|
|
case R_386_TLS_GOTIE:
|
|
sym.flags |= NEEDS_GOTTP;
|
|
rel_types[i] = R_TLS_GOTIE;
|
|
break;
|
|
case R_386_TLS_LE:
|
|
sym.flags |= NEEDS_GOTTP;
|
|
rel_types[i] = R_TLS_LE;
|
|
break;
|
|
case R_386_TLS_GD:
|
|
sym.flags |= NEEDS_TLSGD;
|
|
rel_types[i] = R_TLS_GD;
|
|
break;
|
|
case R_386_TLS_LDM:
|
|
sym.flags |= NEEDS_TLSLD;
|
|
rel_types[i] = R_TLS_LD;
|
|
break;
|
|
case R_386_TLS_LDO_32:
|
|
rel_types[i] = R_TPOFF;
|
|
break;
|
|
case R_386_SIZE32:
|
|
rel_types[i] = R_SIZE;
|
|
break;
|
|
case R_386_TLS_GOTDESC:
|
|
if (ctx.arg.relax && !ctx.arg.shared) {
|
|
rel_types[i] = R_TLS_GOTDESC_RELAX;
|
|
} else {
|
|
sym.flags |= NEEDS_TLSDESC;
|
|
rel_types[i] = R_TLS_GOTDESC;
|
|
}
|
|
break;
|
|
case R_386_TLS_DESC_CALL:
|
|
if (ctx.arg.relax && !ctx.arg.shared)
|
|
rel_types[i] = R_TLS_DESC_CALL_RELAX;
|
|
else
|
|
rel_types[i] = R_NONE;
|
|
break;
|
|
default:
|
|
Error(ctx) << *this << ": unknown relocation: "
|
|
<< rel_to_string<I386>(rel.r_type);
|
|
}
|
|
}
|
|
}
|