tinycc/arm64-link.c
Thomas Preud'homme 0bf262864c Fix PLT creation for i386
i386 target does not have PC relative loads. Its ABI therefore require
ebx register to points to the GOT when executing a PLT entry. This means
that PLT entry cannot be used transparently, the compiler needs to
expect execution of a PLT entry to be able to use one, that is a PLT
entry should only be created if the relocation explicitely asks for it
(eg. R_386_PLT32).

This patch creates a new target macro PCRELATIVE_DLLPLT to indicate
whether a target can do a PC relative load in PLT entry when building a
dynamic library. Executable do not normally pose a problem because they
are loaded at a fixed address and thus the absolute address of GOT can
be used.

Note that in such a case, if the compiler does not use a PLT aware
relocation for external access then the code relocation will fall on the
dynamic loader since there is no PLT entry to relocate too.
2016-12-10 09:44:09 +00:00

133 lines
5.0 KiB
C

#ifdef TARGET_DEFS_ONLY
#define EM_TCC_TARGET EM_AARCH64
#define R_DATA_32 R_AARCH64_ABS32
#define R_DATA_PTR R_AARCH64_ABS64
#define R_JMP_SLOT R_AARCH64_JUMP_SLOT
#define R_GLOB_DAT R_AARCH64_GLOB_DAT
#define R_COPY R_AARCH64_COPY
#define R_NUM R_AARCH64_NUM
#define ELF_START_ADDR 0x00400000
#define ELF_PAGE_SIZE 0x1000
#define HAVE_SECTION_RELOC
#define PCRELATIVE_DLLPLT 1
#else /* !TARGET_DEFS_ONLY */
#include "tcc.h"
ST_DATA struct reloc_info relocs_info[R_NUM] = {
INIT_RELOC_INFO (R_AARCH64_ABS32, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_ABS64, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_MOVW_UABS_G0_NC, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_MOVW_UABS_G1_NC, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_MOVW_UABS_G2_NC, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_MOVW_UABS_G3, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_ADR_PREL_PG_HI21, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_ADD_ABS_LO12_NC, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_JUMP26, 1, AUTO_GOTPLT_ENTRY, 1)
INIT_RELOC_INFO (R_AARCH64_CALL26, 1, AUTO_GOTPLT_ENTRY, 1)
INIT_RELOC_INFO (R_AARCH64_ADR_GOT_PAGE, 0, ALWAYS_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_LD64_GOT_LO12_NC, 0, ALWAYS_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_GLOB_DAT, 0, NO_GOTPLT_ENTRY, 0)
INIT_RELOC_INFO (R_AARCH64_JUMP_SLOT, 1, NO_GOTPLT_ENTRY, 0)
};
void relocate_init(Section *sr) {}
void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
{
int sym_index = ELFW(R_SYM)(rel->r_info);
#ifdef DEBUG_RELOC
ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
#endif
switch(type) {
case R_AARCH64_ABS64:
write64le(ptr, val);
return;
case R_AARCH64_ABS32:
write32le(ptr, val);
return;
case R_AARCH64_MOVW_UABS_G0_NC:
write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
(val & 0xffff) << 5));
return;
case R_AARCH64_MOVW_UABS_G1_NC:
write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
(val >> 16 & 0xffff) << 5));
return;
case R_AARCH64_MOVW_UABS_G2_NC:
write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
(val >> 32 & 0xffff) << 5));
return;
case R_AARCH64_MOVW_UABS_G3:
write32le(ptr, ((read32le(ptr) & 0xffe0001f) |
(val >> 48 & 0xffff) << 5));
return;
case R_AARCH64_ADR_PREL_PG_HI21: {
uint64_t off = (val >> 12) - (addr >> 12);
if ((off + ((uint64_t)1 << 20)) >> 21)
tcc_error("R_AARCH64_ADR_PREL_PG_HI21 relocation failed");
write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
(off & 0x1ffffc) << 3 | (off & 3) << 29));
return;
}
case R_AARCH64_ADD_ABS_LO12_NC:
write32le(ptr, ((read32le(ptr) & 0xffc003ff) |
(val & 0xfff) << 10));
return;
case R_AARCH64_JUMP26:
case R_AARCH64_CALL26:
#ifdef DEBUG_RELOC
printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr, val,
(char *) symtab_section->link->data + sym->st_name);
#endif
if (((val - addr) + ((uint64_t)1 << 27)) & ~(uint64_t)0xffffffc)
tcc_error("R_AARCH64_(JUMP|CALL)26 relocation failed"
" (val=%lx, addr=%lx)", val, addr);
write32le(ptr, (0x14000000 |
(uint32_t)(type == R_AARCH64_CALL26) << 31 |
((val - addr) >> 2 & 0x3ffffff)));
return;
case R_AARCH64_ADR_GOT_PAGE: {
uint64_t off =
(((s1->got->sh_addr +
s1->sym_attrs[sym_index].got_offset) >> 12) - (addr >> 12));
if ((off + ((uint64_t)1 << 20)) >> 21)
tcc_error("R_AARCH64_ADR_GOT_PAGE relocation failed");
write32le(ptr, ((read32le(ptr) & 0x9f00001f) |
(off & 0x1ffffc) << 3 | (off & 3) << 29));
return;
}
case R_AARCH64_LD64_GOT_LO12_NC:
write32le(ptr,
((read32le(ptr) & 0xfff803ff) |
((s1->got->sh_addr +
s1->sym_attrs[sym_index].got_offset) & 0xff8) << 7));
return;
case R_AARCH64_COPY:
return;
case R_AARCH64_GLOB_DAT:
case R_AARCH64_JUMP_SLOT:
/* They don't need addend */
#ifdef DEBUG_RELOC
printf ("reloc %d @ 0x%lx: val=0x%lx name=%s\n", type, addr,
val - rel->r_addend,
(char *) symtab_section->link->data + sym->st_name);
#endif
write64le(ptr, val - rel->r_addend);
return;
default:
fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
type, (unsigned)addr, ptr, (unsigned)val);
return;
}
}
#endif /* !TARGET_DEFS_ONLY */