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x86_64: Use addend on relocs

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Traditional behaviour on x86-64 is to encode the relocation
addend in r_addend, not in the relocated field (after all,
that's the reason to use RELA relocs to begin with).  Our
linker can deal with both, other linkers as well.  But using
e.g. the GNU assembler one can detect differences (equivalent
code in the end, but still a difference).

Now there's only a trivial difference in tests/asmtest.S
(having to do with ordering of prefixes).
This commit is contained in:
Michael Matz 2016-05-09 23:09:55 +02:00
parent 5e47b08dc8
commit 9645b62a65
2 changed files with 14 additions and 19 deletions
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2
tccelf.c
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@ -927,7 +927,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s)
qrel->r_offset = rel->r_offset;
qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
/* Use sign extension! */
qrel->r_addend = (int)read32le(ptr);
qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
qrel++;
break;
}

31
x86_64-gen.c
View File

@ -256,7 +256,7 @@ ST_FUNC int oad(int c, int s)
ST_FUNC void gen_addr32(int r, Sym *sym, int c)
{
if (r & VT_SYM)
greloc(cur_text_section, sym, ind, R_X86_64_32);
greloca(cur_text_section, sym, ind, R_X86_64_32, c), c=0;
gen_le32(c);
}
@ -264,7 +264,7 @@ ST_FUNC void gen_addr32(int r, Sym *sym, int c)
ST_FUNC void gen_addr64(int r, Sym *sym, int64_t c)
{
if (r & VT_SYM)
greloc(cur_text_section, sym, ind, R_X86_64_64);
greloca(cur_text_section, sym, ind, R_X86_64_64, c), c=0;
gen_le64(c);
}
@ -272,7 +272,7 @@ ST_FUNC void gen_addr64(int r, Sym *sym, int64_t c)
ST_FUNC void gen_addrpc32(int r, Sym *sym, int c)
{
if (r & VT_SYM)
greloc(cur_text_section, sym, ind, R_X86_64_PC32);
greloca(cur_text_section, sym, ind, R_X86_64_PC32, c-4), c=4;
gen_le32(c-4);
}
@ -280,12 +280,7 @@ ST_FUNC void gen_addrpc32(int r, Sym *sym, int c)
static void gen_gotpcrel(int r, Sym *sym, int c)
{
#ifndef TCC_TARGET_PE
Section *sr;
ElfW(Rela) *rel;
greloc(cur_text_section, sym, ind, R_X86_64_GOTPCREL);
sr = cur_text_section->reloc;
rel = (ElfW(Rela) *)(sr->data + sr->data_offset - sizeof(ElfW(Rela)));
rel->r_addend = -4;
greloca(cur_text_section, sym, ind, R_X86_64_GOTPCREL, -4);
#else
tcc_error("internal error: no GOT on PE: %s %x %x | %02x %02x %02x\n",
get_tok_str(sym->v, NULL), c, r,
@ -608,16 +603,16 @@ static void gcall_or_jmp(int is_jmp)
if (vtop->r & VT_SYM) {
/* relocation case */
#ifdef TCC_TARGET_PE
greloc(cur_text_section, vtop->sym, ind + 1, R_X86_64_PC32);
greloca(cur_text_section, vtop->sym, ind + 1, R_X86_64_PC32, (int)(vtop->c.i-4));
#else
greloc(cur_text_section, vtop->sym, ind + 1, R_X86_64_PLT32);
greloca(cur_text_section, vtop->sym, ind + 1, R_X86_64_PLT32, (int)(vtop->c.i-4));
#endif
} else {
/* put an empty PC32 relocation */
put_elf_reloc(symtab_section, cur_text_section,
ind + 1, R_X86_64_PC32, 0);
put_elf_reloca(symtab_section, cur_text_section,
ind + 1, R_X86_64_PC32, 0, (int)(vtop->c.i-4));
}
oad(0xe8 + is_jmp, vtop->c.i - 4); /* call/jmp im */
oad(0xe8 + is_jmp, 0); /* call/jmp im */
} else {
/* otherwise, indirect call */
r = TREG_R11;
@ -637,8 +632,8 @@ static unsigned long func_bound_ind;
static void gen_static_call(int v)
{
Sym *sym = external_global_sym(v, &func_old_type, 0);
oad(0xe8, -4);
greloc(cur_text_section, sym, ind-4, R_X86_64_PC32);
oad(0xe8, 0);
greloca(cur_text_section, sym, ind-4, R_X86_64_PC32, -4);
}
/* generate a bounded pointer addition */
@ -991,8 +986,8 @@ void gfunc_epilog(void)
if (v >= 4096) {
Sym *sym = external_global_sym(TOK___chkstk, &func_old_type, 0);
oad(0xb8, v); /* mov stacksize, %eax */
oad(0xe8, -4); /* call __chkstk, (does the stackframe too) */
greloc(cur_text_section, sym, ind-4, R_X86_64_PC32);
oad(0xe8, 0); /* call __chkstk, (does the stackframe too) */
greloca(cur_text_section, sym, ind-4, R_X86_64_PC32, -4);
o(0x90); /* fill for FUNC_PROLOG_SIZE = 11 bytes */
} else {
o(0xe5894855); /* push %rbp, mov %rsp, %rbp */