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riscv64-link.c
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riscv64-link.c
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#ifdef TARGET_DEFS_ONLY
#define EM_TCC_TARGET EM_RISCV
#define R_DATA_32 R_RISCV_32
#define R_DATA_PTR R_RISCV_64
#define R_JMP_SLOT R_RISCV_JUMP_SLOT
#define R_GLOB_DAT R_RISCV_64
#define R_COPY R_RISCV_COPY
#define R_RELATIVE R_RISCV_RELATIVE
#define R_NUM R_RISCV_NUM
#define ELF_START_ADDR 0x00010000
#define ELF_PAGE_SIZE 0x1000
#define PCRELATIVE_DLLPLT 1
#define RELOCATE_DLLPLT 1
#else /* !TARGET_DEFS_ONLY */
//#define DEBUG_RELOC
#include "tcc.h"
/* Returns 1 for a code relocation, 0 for a data relocation. For unknown
relocations, returns -1. */
ST_FUNC int code_reloc (int reloc_type)
{
switch (reloc_type) {
case R_RISCV_BRANCH:
case R_RISCV_CALL:
case R_RISCV_JAL:
return 1;
case R_RISCV_GOT_HI20:
case R_RISCV_PCREL_HI20:
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
case R_RISCV_32_PCREL:
case R_RISCV_SET6:
case R_RISCV_SET8:
case R_RISCV_SET16:
case R_RISCV_SUB6:
case R_RISCV_ADD16:
case R_RISCV_ADD32:
case R_RISCV_ADD64:
case R_RISCV_SUB8:
case R_RISCV_SUB16:
case R_RISCV_SUB32:
case R_RISCV_SUB64:
case R_RISCV_32:
case R_RISCV_64:
return 0;
case R_RISCV_CALL_PLT:
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. */
ST_FUNC int gotplt_entry_type (int reloc_type)
{
switch (reloc_type) {
case R_RISCV_ALIGN:
case R_RISCV_RELAX:
case R_RISCV_RVC_BRANCH:
case R_RISCV_RVC_JUMP:
case R_RISCV_JUMP_SLOT:
case R_RISCV_SET6:
case R_RISCV_SET8:
case R_RISCV_SET16:
case R_RISCV_SUB6:
case R_RISCV_ADD16:
case R_RISCV_SUB8:
case R_RISCV_SUB16:
return NO_GOTPLT_ENTRY;
case R_RISCV_BRANCH:
case R_RISCV_CALL:
case R_RISCV_PCREL_HI20:
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
case R_RISCV_32_PCREL:
case R_RISCV_ADD32:
case R_RISCV_ADD64:
case R_RISCV_SUB32:
case R_RISCV_SUB64:
case R_RISCV_32:
case R_RISCV_64:
case R_RISCV_JAL:
case R_RISCV_CALL_PLT:
return AUTO_GOTPLT_ENTRY;
case R_RISCV_GOT_HI20:
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;
unsigned plt_offset;
if (plt->data_offset == 0)
section_ptr_add(plt, 32);
plt_offset = plt->data_offset;
p = section_ptr_add(plt, 16);
write64le(p, got_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) {
uint64_t plt = s1->plt->sh_addr;
uint64_t got = s1->got->sh_addr;
uint64_t off = (got - plt + 0x800) >> 12;
if ((off + ((uint32_t)1 << 20)) >> 21)
tcc_error_noabort("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", (long)off, (long)got, (long)plt);
write32le(p, 0x397 | (off << 12)); // auipc t2, %pcrel_hi(got)
write32le(p + 4, 0x41c30333); // sub t1, t1, t3
write32le(p + 8, 0x0003be03 // ld t3, %pcrel_lo(got)(t2)
| (((got - plt) & 0xfff) << 20));
write32le(p + 12, 0xfd430313); // addi t1, t1, -(32+12)
write32le(p + 16, 0x00038293 // addi t0, t2, %pcrel_lo(got)
| (((got - plt) & 0xfff) << 20));
write32le(p + 20, 0x00135313); // srli t1, t1, log2(16/PTRSIZE)
write32le(p + 24, 0x0082b283); // ld t0, PTRSIZE(t0)
write32le(p + 28, 0x000e0067); // jr t3
p += 32;
while (p < p_end) {
uint64_t pc = plt + (p - s1->plt->data);
uint64_t addr = got + read64le(p);
uint64_t off = (addr - pc + 0x800) >> 12;
if ((off + ((uint32_t)1 << 20)) >> 21)
tcc_error_noabort("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", (long)off, (long)addr, (long)pc);
write32le(p, 0xe17 | (off << 12)); // auipc t3, %pcrel_hi(func@got)
write32le(p + 4, 0x000e3e03 // ld t3, %pcrel_lo(func@got)(t3)
| (((addr - pc) & 0xfff) << 20));
write32le(p + 8, 0x000e0367); // jalr t1, t3
write32le(p + 12, 0x00000013); // nop
p += 16;
}
}
if (s1->plt->reloc) {
ElfW_Rel *rel;
p = s1->got->data;
for_each_elem(s1->plt->reloc, 0, rel, ElfW_Rel) {
write64le(p + rel->r_offset, s1->plt->sh_addr);
}
}
}
ST_FUNC void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
addr_t addr, addr_t val)
{
uint64_t off64;
uint32_t off32;
int sym_index = ELFW(R_SYM)(rel->r_info), esym_index;
ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
switch(type) {
case R_RISCV_ALIGN:
case R_RISCV_RELAX:
return;
case R_RISCV_BRANCH:
off64 = val - addr;
if ((off64 + (1 << 12)) & ~(uint64_t)0x1ffe)
tcc_error_noabort("R_RISCV_BRANCH relocation failed"
" (val=%lx, addr=%lx)", (long)val, (long)addr);
off32 = off64 >> 1;
write32le(ptr, (read32le(ptr) & ~0xfe000f80)
| ((off32 & 0x800) << 20)
| ((off32 & 0x3f0) << 21)
| ((off32 & 0x00f) << 8)
| ((off32 & 0x400) >> 3));
return;
case R_RISCV_JAL:
off64 = val - addr;
if ((off64 + (1 << 21)) & ~(((uint64_t)1 << 22) - 2))
tcc_error_noabort("R_RISCV_JAL relocation failed"
" (val=%lx, addr=%lx)", (long)val, (long)addr);
off32 = off64;
write32le(ptr, (read32le(ptr) & 0xfff)
| (((off32 >> 12) & 0xff) << 12)
| (((off32 >> 11) & 1) << 20)
| (((off32 >> 1) & 0x3ff) << 21)
| (((off32 >> 20) & 1) << 31));
return;
case R_RISCV_CALL:
case R_RISCV_CALL_PLT:
write32le(ptr, (read32le(ptr) & 0xfff)
| ((val - addr + 0x800) & ~0xfff));
write32le(ptr + 4, (read32le(ptr + 4) & 0xfffff)
| (((val - addr) & 0xfff) << 20));
return;
case R_RISCV_PCREL_HI20:
#ifdef DEBUG_RELOC
printf("PCREL_HI20: val=%lx addr=%lx\n", (long)val, (long)addr);
#endif
off64 = (int64_t)(val - addr + 0x800) >> 12;
if ((off64 + ((uint64_t)1 << 20)) >> 21)
tcc_error_noabort("R_RISCV_PCREL_HI20 relocation failed: off=%lx cond=%lx sym=%s",
(long)off64, (long)((int64_t)(off64 + ((uint64_t)1 << 20)) >> 21),
symtab_section->link->data + sym->st_name);
write32le(ptr, (read32le(ptr) & 0xfff)
| ((off64 & 0xfffff) << 12));
last_hi.addr = addr;
last_hi.val = val;
return;
case R_RISCV_GOT_HI20:
val = s1->got->sh_addr + get_sym_attr(s1, sym_index, 0)->got_offset;
off64 = (int64_t)(val - addr + 0x800) >> 12;
if ((off64 + ((uint64_t)1 << 20)) >> 21)
tcc_error_noabort("R_RISCV_GOT_HI20 relocation failed");
last_hi.addr = addr;
last_hi.val = val;
write32le(ptr, (read32le(ptr) & 0xfff)
| ((off64 & 0xfffff) << 12));
return;
case R_RISCV_PCREL_LO12_I:
#ifdef DEBUG_RELOC
printf("PCREL_LO12_I: val=%lx addr=%lx\n", (long)val, (long)addr);
#endif
if (val != last_hi.addr)
tcc_error_noabort("unsupported hi/lo pcrel reloc scheme");
val = last_hi.val;
addr = last_hi.addr;
write32le(ptr, (read32le(ptr) & 0xfffff)
| (((val - addr) & 0xfff) << 20));
return;
case R_RISCV_PCREL_LO12_S:
if (val != last_hi.addr)
tcc_error_noabort("unsupported hi/lo pcrel reloc scheme");
val = last_hi.val;
addr = last_hi.addr;
off32 = val - addr;
write32le(ptr, (read32le(ptr) & ~0xfe000f80)
| ((off32 & 0xfe0) << 20)
| ((off32 & 0x01f) << 7));
return;
case R_RISCV_RVC_BRANCH:
off64 = (val - addr);
if ((off64 + (1 << 8)) & ~(uint64_t)0x1fe)
tcc_error_noabort("R_RISCV_RVC_BRANCH relocation failed"
" (val=%lx, addr=%lx)", (long)val, (long)addr);
off32 = off64;
write16le(ptr, (read16le(ptr) & 0xe383)
| (((off32 >> 5) & 1) << 2)
| (((off32 >> 1) & 3) << 3)
| (((off32 >> 6) & 3) << 5)
| (((off32 >> 3) & 3) << 10)
| (((off32 >> 8) & 1) << 12));
return;
case R_RISCV_RVC_JUMP:
off64 = (val - addr);
if ((off64 + (1 << 11)) & ~(uint64_t)0xffe)
tcc_error_noabort("R_RISCV_RVC_BRANCH relocation failed"
" (val=%lx, addr=%lx)", (long)val, (long)addr);
off32 = off64;
write16le(ptr, (read16le(ptr) & 0xe003)
| (((off32 >> 5) & 1) << 2)
| (((off32 >> 1) & 7) << 3)
| (((off32 >> 7) & 1) << 6)
| (((off32 >> 6) & 1) << 7)
| (((off32 >> 10) & 1) << 8)
| (((off32 >> 8) & 3) << 9)
| (((off32 >> 4) & 1) << 11)
| (((off32 >> 11) & 1) << 12));
return;
case R_RISCV_32:
if (s1->output_type & TCC_OUTPUT_DYN) {
/* XXX: this logic may depend on TCC's codegen
now TCC uses R_RISCV_RELATIVE even for a 64bit pointer */
qrel->r_offset = rel->r_offset;
qrel->r_info = ELFW(R_INFO)(0, R_RISCV_RELATIVE);
/* Use sign extension! */
qrel->r_addend = (int)read32le(ptr) + val;
qrel++;
}
add32le(ptr, val);
return;
case R_RISCV_64:
if (s1->output_type & TCC_OUTPUT_DYN) {
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_RISCV_64);
qrel->r_addend = rel->r_addend;
qrel++;
break;
} else {
qrel->r_info = ELFW(R_INFO)(0, R_RISCV_RELATIVE);
qrel->r_addend = read64le(ptr) + val;
qrel++;
}
}
case R_RISCV_JUMP_SLOT:
add64le(ptr, val);
return;
case R_RISCV_ADD64:
write64le(ptr, read64le(ptr) + val);
return;
case R_RISCV_ADD32:
write32le(ptr, read32le(ptr) + val);
return;
case R_RISCV_SUB64:
write64le(ptr, read64le(ptr) - val);
return;
case R_RISCV_SUB32:
write32le(ptr, read32le(ptr) - val);
return;
case R_RISCV_ADD16:
write16le(ptr, read16le(ptr) + val);
return;
case R_RISCV_SUB8:
*ptr -= val;
return;
case R_RISCV_SUB16:
write16le(ptr, read16le(ptr) - val);
return;
case R_RISCV_SET6:
*ptr = (*ptr & ~0x3f) | (val & 0x3f);
return;
case R_RISCV_SET8:
*ptr = (*ptr & ~0xff) | (val & 0xff);
return;
case R_RISCV_SET16:
*ptr = (*ptr & ~0xffff) | (val & 0xffff);
return;
case R_RISCV_SUB6:
*ptr = (*ptr & ~0x3f) | ((*ptr - val) & 0x3f);
return;
case R_RISCV_32_PCREL:
if (s1->output_type & TCC_OUTPUT_DYN) {
/* 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_RISCV_32_PCREL);
/* Use sign extension! */
qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
qrel++;
break;
}
}
add32le(ptr, val - addr);
return;
case R_RISCV_COPY:
/* XXX */
return;
default:
fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
type, (unsigned)addr, ptr, (unsigned)val);
return;
}
}
#endif