#ifdef TARGET_DEFS_ONLY #define EM_TCC_TARGET EM_386 /* relocation type for 32 bit data relocation */#define R_DATA_32 R_386_32#define R_DATA_PTR R_386_32#define R_JMP_SLOT R_386_JMP_SLOT#define R_GLOB_DAT R_386_GLOB_DAT#define R_COPY R_386_COPY#define R_RELATIVE R_386_RELATIVE #define R_NUM R_386_NUM #define ELF_START_ADDR 0x08048000#define ELF_PAGE_SIZE 0x1000 #define PCRELATIVE_DLLPLT 0#define RELOCATE_DLLPLT 0 #else /* !TARGET_DEFS_ONLY */ #include "tcc.h" #ifndef ELF_OBJ_ONLY/* Returns 1 for a code relocation, 0 for a data relocation. For unknown relocations, returns -1. */int code_reloc (int reloc_type){ switch (reloc_type) { case R_386_RELATIVE: case R_386_16: case R_386_32: case R_386_GOTPC: case R_386_GOTOFF: case R_386_GOT32: case R_386_GOT32X: case R_386_GLOB_DAT: case R_386_COPY: case R_386_TLS_GD: case R_386_TLS_LDM: case R_386_TLS_LDO_32: case R_386_TLS_LE: return 0; case R_386_PC16: case R_386_PC32: case R_386_PLT32: case R_386_JMP_SLOT: return 1; } return -1;} /* Returns an enumerator to describe whether and when the relocation needs a GOT and/or PLT entry to be created. See tcc.h for a description of the different values. */int gotplt_entry_type (int reloc_type){ switch (reloc_type) { case R_386_RELATIVE: case R_386_16: case R_386_GLOB_DAT: case R_386_JMP_SLOT: case R_386_COPY: return NO_GOTPLT_ENTRY; case R_386_32: /* This relocations shouldn't normally need GOT or PLT slots if it weren't for simplicity in the code generator. See our caller for comments. */ return AUTO_GOTPLT_ENTRY; case R_386_PC16: case R_386_PC32: return AUTO_GOTPLT_ENTRY; case R_386_GOTPC: case R_386_GOTOFF: return BUILD_GOT_ONLY; case R_386_GOT32: case R_386_GOT32X: case R_386_PLT32: case R_386_TLS_GD: case R_386_TLS_LDM: case R_386_TLS_LDO_32: case R_386_TLS_LE: return ALWAYS_GOTPLT_ENTRY; } return -1;} ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr){ Section *plt = s1->plt; uint8_t *p; int modrm; unsigned plt_offset, relofs; /* on i386 if we build a DLL, we add a %ebx offset */ if (s1->output_type == TCC_OUTPUT_DLL) modrm = 0xa3; else modrm = 0x25; /* empty PLT: create PLT0 entry that pushes the library identifier (GOT + PTR_SIZE) and jumps to ld.so resolution routine (GOT + 2 * PTR_SIZE) */ if (plt->data_offset == 0) { p = section_ptr_add(plt, 16); p[0] = 0xff; /* pushl got + PTR_SIZE */ p[1] = modrm + 0x10; write32le(p + 2, PTR_SIZE); p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */ p[7] = modrm; write32le(p + 8, PTR_SIZE * 2); } plt_offset = plt->data_offset; /* The PLT slot refers to the relocation entry it needs via offset. The reloc entry is created below, so its offset is the current data_offset */ relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0; /* Jump to GOT entry where ld.so initially put the address of ip + 4 */ p = section_ptr_add(plt, 16); p[0] = 0xff; /* jmp *(got + x) */ p[1] = modrm; write32le(p + 2, got_offset); p[6] = 0x68; /* push $xxx */ write32le(p + 7, relofs); p[11] = 0xe9; /* jmp plt_start */ write32le(p + 12, -(plt->data_offset)); return plt_offset;} /* relocate the PLT: compute addresses and offsets in the PLT now that final address for PLT and GOT are known (see fill_program_header) */ST_FUNC void relocate_plt(TCCState *s1){ uint8_t *p, *p_end; if (!s1->plt) return; p = s1->plt->data; p_end = p + s1->plt->data_offset; if (p < p_end) { add32le(p + 2, s1->got->sh_addr); add32le(p + 8, s1->got->sh_addr); p += 16; while (p < p_end) { add32le(p + 2, s1->got->sh_addr); p += 16; } }}#endif void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val){ int sym_index, esym_index; sym_index = ELFW(R_SYM)(rel->r_info); switch (type) { case R_386_32: if (s1->output_type == TCC_OUTPUT_DLL) { esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index; qrel->r_offset = rel->r_offset; if (esym_index) { qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32); qrel++; return; } else { qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE); qrel++; } } add32le(ptr, val); return; case R_386_PC32: if (s1->output_type == TCC_OUTPUT_DLL) { /* DLL relocation */ esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index; if (esym_index) { qrel->r_offset = rel->r_offset; qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32); qrel++; return; } } add32le(ptr, val - addr); return; case R_386_PLT32: add32le(ptr, val - addr); return; case R_386_GLOB_DAT: case R_386_JMP_SLOT: write32le(ptr, val); return; case R_386_GOTPC: add32le(ptr, s1->got->sh_addr - addr); return; case R_386_GOTOFF: add32le(ptr, val - s1->got->sh_addr); return; case R_386_GOT32: case R_386_GOT32X: /* we load the got offset */ add32le(ptr, get_sym_attr(s1, sym_index, 0)->got_offset); return; case R_386_16: if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) { output_file: tcc_error("can only produce 16-bit binary files"); } write16le(ptr, read16le(ptr) + val); return; case R_386_PC16: if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) goto output_file; write16le(ptr, read16le(ptr) + val - addr); return; case R_386_RELATIVE:#ifdef TCC_TARGET_PE add32le(ptr, val - s1->pe_imagebase);#endif /* do nothing */ return; case R_386_COPY: /* This relocation must copy initialized data from the library to the program .bss segment. Currently made like for ARM (to remove noise of default case). Is this true? */ return; case R_386_TLS_GD: { static const unsigned char expect[] = { /* lea 0(,%ebx,1),%eax */ 0x8d, 0x04, 0x1d, 0x00, 0x00, 0x00, 0x00, /* call __tls_get_addr@PLT */ 0xe8, 0xfc, 0xff, 0xff, 0xff }; static const unsigned char replace[] = { /* mov %gs:0,%eax */ 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* sub 0,%eax */ 0x81, 0xe8, 0x00, 0x00, 0x00, 0x00 }; if (memcmp (ptr-3, expect, sizeof(expect)) == 0) { ElfW(Sym) *sym; Section *sec; int32_t x; memcpy(ptr-3, replace, sizeof(replace)); rel[1].r_info = ELFW(R_INFO)(0, R_386_NONE); sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; sec = s1->sections[sym->st_shndx]; x = sym->st_value - sec->sh_addr - sec->data_offset; add32le(ptr + 5, -x); } else tcc_error("unexpected R_386_TLS_GD pattern"); } return; case R_386_TLS_LDM: { static const unsigned char expect[] = { /* lea 0(%ebx),%eax */ 0x8d, 0x83, 0x00, 0x00, 0x00, 0x00, /* call __tls_get_addr@PLT */ 0xe8, 0xfc, 0xff, 0xff, 0xff }; static const unsigned char replace[] = { /* mov %gs:0,%eax */ 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* nop */ 0x90, /* lea 0(%esi,%eiz,1),%esi */ 0x8d, 0x74, 0x26, 0x00 }; if (memcmp (ptr-2, expect, sizeof(expect)) == 0) { memcpy(ptr-2, replace, sizeof(replace)); rel[1].r_info = ELFW(R_INFO)(0, R_386_NONE); } else tcc_error("unexpected R_386_TLS_LDM pattern"); } return; case R_386_TLS_LDO_32: case R_386_TLS_LE: { ElfW(Sym) *sym; Section *sec; int32_t x; sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; sec = s1->sections[sym->st_shndx]; x = val - sec->sh_addr - sec->data_offset; add32le(ptr, x); } return; case R_386_NONE: return; default: fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n", type, (unsigned)addr, ptr, (unsigned)val); return; }} #endif /* !TARGET_DEFS_ONLY */
#ifdef TARGET_DEFS_ONLY
#define EM_TCC_TARGET EM_386
/* relocation type for 32 bit data relocation */
#define R_DATA_32 R_386_32
#define R_DATA_PTR R_386_32
#define R_JMP_SLOT R_386_JMP_SLOT
#define R_GLOB_DAT R_386_GLOB_DAT
#define R_COPY R_386_COPY
#define R_RELATIVE R_386_RELATIVE
#define R_NUM R_386_NUM
#define ELF_START_ADDR 0x08048000
#define ELF_PAGE_SIZE 0x1000
#define PCRELATIVE_DLLPLT 0
#define RELOCATE_DLLPLT 0
#else /* !TARGET_DEFS_ONLY */
#include "tcc.h"
#ifndef ELF_OBJ_ONLY
/* Returns 1 for a code relocation, 0 for a data relocation. For unknown
relocations, returns -1. */
int code_reloc (int reloc_type)
{
switch (reloc_type) {
case R_386_RELATIVE:
case R_386_16:
case R_386_32:
case R_386_GOTPC:
case R_386_GOTOFF:
case R_386_GOT32:
case R_386_GOT32X:
case R_386_GLOB_DAT:
case R_386_COPY:
case R_386_TLS_GD:
case R_386_TLS_LDM:
case R_386_TLS_LDO_32:
case R_386_TLS_LE:
return 0;
case R_386_PC16:
case R_386_PC32:
case R_386_PLT32:
case R_386_JMP_SLOT:
return 1;
}
return -1;
}
/* Returns an enumerator to describe whether and when the relocation needs a
GOT and/or PLT entry to be created. See tcc.h for a description of the
different values. */
int gotplt_entry_type (int reloc_type)
{
switch (reloc_type) {
case R_386_RELATIVE:
case R_386_16:
case R_386_GLOB_DAT:
case R_386_JMP_SLOT:
case R_386_COPY:
return NO_GOTPLT_ENTRY;
case R_386_32:
/* This relocations shouldn't normally need GOT or PLT
slots if it weren't for simplicity in the code generator.
See our caller for comments. */
return AUTO_GOTPLT_ENTRY;
case R_386_PC16:
case R_386_PC32:
return AUTO_GOTPLT_ENTRY;
case R_386_GOTPC:
case R_386_GOTOFF:
return BUILD_GOT_ONLY;
case R_386_GOT32:
case R_386_GOT32X:
case R_386_PLT32:
case R_386_TLS_GD:
case R_386_TLS_LDM:
case R_386_TLS_LDO_32:
case R_386_TLS_LE:
return ALWAYS_GOTPLT_ENTRY;
}
return -1;
}
ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
{
Section *plt = s1->plt;
uint8_t *p;
int modrm;
unsigned plt_offset, relofs;
/* on i386 if we build a DLL, we add a %ebx offset */
if (s1->output_type == TCC_OUTPUT_DLL)
modrm = 0xa3;
else
modrm = 0x25;
/* empty PLT: create PLT0 entry that pushes the library identifier
(GOT + PTR_SIZE) and jumps to ld.so resolution routine
(GOT + 2 * PTR_SIZE) */
if (plt->data_offset == 0) {
p = section_ptr_add(plt, 16);
p[0] = 0xff; /* pushl got + PTR_SIZE */
p[1] = modrm + 0x10;
write32le(p + 2, PTR_SIZE);
p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
p[7] = modrm;
write32le(p + 8, PTR_SIZE * 2);
}
plt_offset = plt->data_offset;
/* The PLT slot refers to the relocation entry it needs via offset.
The reloc entry is created below, so its offset is the current
data_offset */
relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
/* Jump to GOT entry where ld.so initially put the address of ip + 4 */
p = section_ptr_add(plt, 16);
p[0] = 0xff; /* jmp *(got + x) */
p[1] = modrm;
write32le(p + 2, got_offset);
p[6] = 0x68; /* push $xxx */
write32le(p + 7, relofs);
p[11] = 0xe9; /* jmp plt_start */
write32le(p + 12, -(plt->data_offset));
return plt_offset;
}
/* relocate the PLT: compute addresses and offsets in the PLT now that final
address for PLT and GOT are known (see fill_program_header) */
ST_FUNC void relocate_plt(TCCState *s1)
{
uint8_t *p, *p_end;
if (!s1->plt)
return;
p = s1->plt->data;
p_end = p + s1->plt->data_offset;
if (p < p_end) {
add32le(p + 2, s1->got->sh_addr);
add32le(p + 8, s1->got->sh_addr);
p += 16;
while (p < p_end) {
add32le(p + 2, s1->got->sh_addr);
p += 16;
}
}
}
#endif
void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
{
int sym_index, esym_index;
sym_index = ELFW(R_SYM)(rel->r_info);
switch (type) {
case R_386_32:
if (s1->output_type == TCC_OUTPUT_DLL) {
esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
qrel->r_offset = rel->r_offset;
if (esym_index) {
qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
qrel++;
return;
} else {
qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
qrel++;
}
}
add32le(ptr, val);
return;
case R_386_PC32:
if (s1->output_type == TCC_OUTPUT_DLL) {
/* DLL relocation */
esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
if (esym_index) {
qrel->r_offset = rel->r_offset;
qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
qrel++;
return;
}
}
add32le(ptr, val - addr);
return;
case R_386_PLT32:
add32le(ptr, val - addr);
return;
case R_386_GLOB_DAT:
case R_386_JMP_SLOT:
write32le(ptr, val);
return;
case R_386_GOTPC:
add32le(ptr, s1->got->sh_addr - addr);
return;
case R_386_GOTOFF:
add32le(ptr, val - s1->got->sh_addr);
return;
case R_386_GOT32:
case R_386_GOT32X:
/* we load the got offset */
add32le(ptr, get_sym_attr(s1, sym_index, 0)->got_offset);
return;
case R_386_16:
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
output_file:
tcc_error("can only produce 16-bit binary files");
}
write16le(ptr, read16le(ptr) + val);
return;
case R_386_PC16:
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
goto output_file;
write16le(ptr, read16le(ptr) + val - addr);
return;
case R_386_RELATIVE:
#ifdef TCC_TARGET_PE
add32le(ptr, val - s1->pe_imagebase);
#endif
/* do nothing */
return;
case R_386_COPY:
/* This relocation must copy initialized data from the library
to the program .bss segment. Currently made like for ARM
(to remove noise of default case). Is this true?
*/
return;
case R_386_TLS_GD:
{
static const unsigned char expect[] = {
/* lea 0(,%ebx,1),%eax */
0x8d, 0x04, 0x1d, 0x00, 0x00, 0x00, 0x00,
/* call __tls_get_addr@PLT */
0xe8, 0xfc, 0xff, 0xff, 0xff };
static const unsigned char replace[] = {
/* mov %gs:0,%eax */
0x65, 0xa1, 0x00, 0x00, 0x00, 0x00,
/* sub 0,%eax */
0x81, 0xe8, 0x00, 0x00, 0x00, 0x00 };
if (memcmp (ptr-3, expect, sizeof(expect)) == 0) {
ElfW(Sym) *sym;
Section *sec;
int32_t x;
memcpy(ptr-3, replace, sizeof(replace));
rel[1].r_info = ELFW(R_INFO)(0, R_386_NONE);
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
sec = s1->sections[sym->st_shndx];
x = sym->st_value - sec->sh_addr - sec->data_offset;
add32le(ptr + 5, -x);
}
else
tcc_error("unexpected R_386_TLS_GD pattern");
}
return;
case R_386_TLS_LDM:
{
static const unsigned char expect[] = {
/* lea 0(%ebx),%eax */
0x8d, 0x83, 0x00, 0x00, 0x00, 0x00,
/* call __tls_get_addr@PLT */
0xe8, 0xfc, 0xff, 0xff, 0xff };
static const unsigned char replace[] = {
/* mov %gs:0,%eax */
0x65, 0xa1, 0x00, 0x00, 0x00, 0x00,
/* nop */
0x90,
/* lea 0(%esi,%eiz,1),%esi */
0x8d, 0x74, 0x26, 0x00 };
if (memcmp (ptr-2, expect, sizeof(expect)) == 0) {
memcpy(ptr-2, replace, sizeof(replace));
rel[1].r_info = ELFW(R_INFO)(0, R_386_NONE);
}
else
tcc_error("unexpected R_386_TLS_LDM pattern");
}
return;
case R_386_TLS_LDO_32:
case R_386_TLS_LE:
{
ElfW(Sym) *sym;
Section *sec;
int32_t x;
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
sec = s1->sections[sym->st_shndx];
x = val - sec->sh_addr - sec->data_offset;
add32le(ptr, x);
}
return;
case R_386_NONE:
return;
default:
fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
type, (unsigned)addr, ptr, (unsigned)val);
return;
}
}
#endif /* !TARGET_DEFS_ONLY */