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-rw-r--r--tinycc/riscv64-link.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/tinycc/riscv64-link.c b/tinycc/riscv64-link.c
new file mode 100644
index 0000000..34bfeb0
--- /dev/null
+++ b/tinycc/riscv64-link.c
@@ -0,0 +1,352 @@
+#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. */
+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_SUB6:
+ case R_RISCV_ADD16:
+ case R_RISCV_ADD32:
+ case R_RISCV_ADD64:
+ 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. */
+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_SUB6:
+ case R_RISCV_ADD16:
+ 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);
+ }
+ }
+}
+
+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_SUB16:
+ write16le(ptr, read16le(ptr) - val);
+ return;
+ case R_RISCV_SET6:
+ *ptr = (*ptr & ~0x3f) | (val & 0x3f);
+ return;
+ case R_RISCV_SUB6:
+ *ptr = (*ptr & ~0x3f) | ((*ptr - val) & 0x3f);
+ return;
+
+ case R_RISCV_32_PCREL:
+ 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
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