mirror of
https://github.com/mirror/tinycc.git
synced 2024-12-26 03:50:07 +08:00
ebaa5c81f4
Allows to create dynamic executables, using the code path
for TCC_OUTPUT_DLL but add an .interp header (plus a FLAGS_1
entry in the dynamic section to make 'readelf' say "PIE")
Introduces TCC_OUTPUT_DYN as alias for TCC_OUTPUT_DLL.
There is no runtime option, only one to configure:
./configure --config-pie
100 insertions(+), 76 deletions(-)
353 lines
11 KiB
C
353 lines
11 KiB
C
#ifdef TARGET_DEFS_ONLY
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#define EM_TCC_TARGET EM_RISCV
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#define R_DATA_32 R_RISCV_32
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#define R_DATA_PTR R_RISCV_64
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#define R_JMP_SLOT R_RISCV_JUMP_SLOT
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#define R_GLOB_DAT R_RISCV_64
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#define R_COPY R_RISCV_COPY
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#define R_RELATIVE R_RISCV_RELATIVE
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#define R_NUM R_RISCV_NUM
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#define ELF_START_ADDR 0x00010000
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#define ELF_PAGE_SIZE 0x1000
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#define PCRELATIVE_DLLPLT 1
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#define RELOCATE_DLLPLT 1
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#else /* !TARGET_DEFS_ONLY */
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//#define DEBUG_RELOC
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#include "tcc.h"
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/* Returns 1 for a code relocation, 0 for a data relocation. For unknown
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relocations, returns -1. */
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int code_reloc (int reloc_type)
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{
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switch (reloc_type) {
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case R_RISCV_BRANCH:
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case R_RISCV_CALL:
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case R_RISCV_JAL:
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return 1;
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case R_RISCV_GOT_HI20:
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case R_RISCV_PCREL_HI20:
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case R_RISCV_PCREL_LO12_I:
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case R_RISCV_PCREL_LO12_S:
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case R_RISCV_32_PCREL:
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case R_RISCV_SET6:
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case R_RISCV_SUB6:
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case R_RISCV_ADD16:
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case R_RISCV_ADD32:
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case R_RISCV_ADD64:
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case R_RISCV_SUB16:
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case R_RISCV_SUB32:
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case R_RISCV_SUB64:
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case R_RISCV_32:
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case R_RISCV_64:
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return 0;
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case R_RISCV_CALL_PLT:
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return 1;
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}
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return -1;
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}
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/* Returns an enumerator to describe whether and when the relocation needs a
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GOT and/or PLT entry to be created. See tcc.h for a description of the
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different values. */
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int gotplt_entry_type (int reloc_type)
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{
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switch (reloc_type) {
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case R_RISCV_ALIGN:
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case R_RISCV_RELAX:
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case R_RISCV_RVC_BRANCH:
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case R_RISCV_RVC_JUMP:
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case R_RISCV_JUMP_SLOT:
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case R_RISCV_SET6:
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case R_RISCV_SUB6:
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case R_RISCV_ADD16:
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case R_RISCV_SUB16:
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return NO_GOTPLT_ENTRY;
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case R_RISCV_BRANCH:
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case R_RISCV_CALL:
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case R_RISCV_PCREL_HI20:
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case R_RISCV_PCREL_LO12_I:
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case R_RISCV_PCREL_LO12_S:
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case R_RISCV_32_PCREL:
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case R_RISCV_ADD32:
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case R_RISCV_ADD64:
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case R_RISCV_SUB32:
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case R_RISCV_SUB64:
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case R_RISCV_32:
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case R_RISCV_64:
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case R_RISCV_JAL:
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case R_RISCV_CALL_PLT:
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return AUTO_GOTPLT_ENTRY;
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case R_RISCV_GOT_HI20:
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return ALWAYS_GOTPLT_ENTRY;
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}
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return -1;
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}
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ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
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{
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Section *plt = s1->plt;
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uint8_t *p;
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unsigned plt_offset;
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if (plt->data_offset == 0)
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section_ptr_add(plt, 32);
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plt_offset = plt->data_offset;
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p = section_ptr_add(plt, 16);
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write64le(p, got_offset);
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return plt_offset;
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}
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/* relocate the PLT: compute addresses and offsets in the PLT now that final
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address for PLT and GOT are known (see fill_program_header) */
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ST_FUNC void relocate_plt(TCCState *s1)
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{
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uint8_t *p, *p_end;
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if (!s1->plt)
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return;
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p = s1->plt->data;
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p_end = p + s1->plt->data_offset;
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if (p < p_end) {
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uint64_t plt = s1->plt->sh_addr;
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uint64_t got = s1->got->sh_addr;
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uint64_t off = (got - plt + 0x800) >> 12;
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if ((off + ((uint32_t)1 << 20)) >> 21)
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tcc_error("Failed relocating PLT (off=0x%lx, got=0x%lx, plt=0x%lx)", (long)off, (long)got, (long)plt);
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write32le(p, 0x397 | (off << 12)); // auipc t2, %pcrel_hi(got)
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write32le(p + 4, 0x41c30333); // sub t1, t1, t3
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write32le(p + 8, 0x0003be03 // ld t3, %pcrel_lo(got)(t2)
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| (((got - plt) & 0xfff) << 20));
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write32le(p + 12, 0xfd430313); // addi t1, t1, -(32+12)
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write32le(p + 16, 0x00038293 // addi t0, t2, %pcrel_lo(got)
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| (((got - plt) & 0xfff) << 20));
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write32le(p + 20, 0x00135313); // srli t1, t1, log2(16/PTRSIZE)
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write32le(p + 24, 0x0082b283); // ld t0, PTRSIZE(t0)
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write32le(p + 28, 0x000e0067); // jr t3
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p += 32;
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while (p < p_end) {
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uint64_t pc = plt + (p - s1->plt->data);
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uint64_t addr = got + read64le(p);
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uint64_t off = (addr - pc + 0x800) >> 12;
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if ((off + ((uint32_t)1 << 20)) >> 21)
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tcc_error("Failed relocating PLT (off=0x%lx, addr=0x%lx, pc=0x%lx)", (long)off, (long)addr, (long)pc);
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write32le(p, 0xe17 | (off << 12)); // auipc t3, %pcrel_hi(func@got)
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write32le(p + 4, 0x000e3e03 // ld t3, %pcrel_lo(func@got)(t3)
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| (((addr - pc) & 0xfff) << 20));
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write32le(p + 8, 0x000e0367); // jalr t1, t3
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write32le(p + 12, 0x00000013); // nop
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p += 16;
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}
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}
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if (s1->plt->reloc) {
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ElfW_Rel *rel;
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p = s1->got->data;
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for_each_elem(s1->plt->reloc, 0, rel, ElfW_Rel) {
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write64le(p + rel->r_offset, s1->plt->sh_addr);
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}
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}
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}
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void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr,
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addr_t addr, addr_t val)
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{
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uint64_t off64;
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uint32_t off32;
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int sym_index = ELFW(R_SYM)(rel->r_info), esym_index;
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ElfW(Sym) *sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
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switch(type) {
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case R_RISCV_ALIGN:
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case R_RISCV_RELAX:
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return;
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case R_RISCV_BRANCH:
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off64 = val - addr;
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if ((off64 + (1 << 12)) & ~(uint64_t)0x1ffe)
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tcc_error("R_RISCV_BRANCH relocation failed"
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" (val=%lx, addr=%lx)", (long)val, (long)addr);
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off32 = off64 >> 1;
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write32le(ptr, (read32le(ptr) & ~0xfe000f80)
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| ((off32 & 0x800) << 20)
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| ((off32 & 0x3f0) << 21)
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| ((off32 & 0x00f) << 8)
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| ((off32 & 0x400) >> 3));
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return;
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case R_RISCV_JAL:
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off64 = val - addr;
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if ((off64 + (1 << 21)) & ~(((uint64_t)1 << 22) - 2))
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tcc_error("R_RISCV_JAL relocation failed"
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" (val=%lx, addr=%lx)", (long)val, (long)addr);
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off32 = off64;
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write32le(ptr, (read32le(ptr) & 0xfff)
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| (((off32 >> 12) & 0xff) << 12)
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| (((off32 >> 11) & 1) << 20)
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| (((off32 >> 1) & 0x3ff) << 21)
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| (((off32 >> 20) & 1) << 31));
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return;
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case R_RISCV_CALL:
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case R_RISCV_CALL_PLT:
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write32le(ptr, (read32le(ptr) & 0xfff)
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| ((val - addr + 0x800) & ~0xfff));
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write32le(ptr + 4, (read32le(ptr + 4) & 0xfffff)
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| (((val - addr) & 0xfff) << 20));
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return;
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case R_RISCV_PCREL_HI20:
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#ifdef DEBUG_RELOC
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printf("PCREL_HI20: val=%lx addr=%lx\n", (long)val, (long)addr);
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#endif
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off64 = (int64_t)(val - addr + 0x800) >> 12;
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if ((off64 + ((uint64_t)1 << 20)) >> 21)
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tcc_error("R_RISCV_PCREL_HI20 relocation failed: off=%lx cond=%lx sym=%s",
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(long)off64, (long)((int64_t)(off64 + ((uint64_t)1 << 20)) >> 21),
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symtab_section->link->data + sym->st_name);
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write32le(ptr, (read32le(ptr) & 0xfff)
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| ((off64 & 0xfffff) << 12));
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last_hi.addr = addr;
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last_hi.val = val;
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return;
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case R_RISCV_GOT_HI20:
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val = s1->got->sh_addr + get_sym_attr(s1, sym_index, 0)->got_offset;
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off64 = (int64_t)(val - addr + 0x800) >> 12;
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if ((off64 + ((uint64_t)1 << 20)) >> 21)
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tcc_error("R_RISCV_GOT_HI20 relocation failed");
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last_hi.addr = addr;
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last_hi.val = val;
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write32le(ptr, (read32le(ptr) & 0xfff)
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| ((off64 & 0xfffff) << 12));
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return;
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case R_RISCV_PCREL_LO12_I:
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#ifdef DEBUG_RELOC
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printf("PCREL_LO12_I: val=%lx addr=%lx\n", (long)val, (long)addr);
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#endif
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if (val != last_hi.addr)
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tcc_error("unsupported hi/lo pcrel reloc scheme");
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val = last_hi.val;
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addr = last_hi.addr;
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write32le(ptr, (read32le(ptr) & 0xfffff)
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| (((val - addr) & 0xfff) << 20));
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return;
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case R_RISCV_PCREL_LO12_S:
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if (val != last_hi.addr)
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tcc_error("unsupported hi/lo pcrel reloc scheme");
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val = last_hi.val;
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addr = last_hi.addr;
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off32 = val - addr;
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write32le(ptr, (read32le(ptr) & ~0xfe000f80)
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| ((off32 & 0xfe0) << 20)
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| ((off32 & 0x01f) << 7));
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return;
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case R_RISCV_RVC_BRANCH:
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off64 = (val - addr);
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if ((off64 + (1 << 8)) & ~(uint64_t)0x1fe)
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tcc_error("R_RISCV_RVC_BRANCH relocation failed"
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" (val=%lx, addr=%lx)", (long)val, (long)addr);
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off32 = off64;
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write16le(ptr, (read16le(ptr) & 0xe383)
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| (((off32 >> 5) & 1) << 2)
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| (((off32 >> 1) & 3) << 3)
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| (((off32 >> 6) & 3) << 5)
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| (((off32 >> 3) & 3) << 10)
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| (((off32 >> 8) & 1) << 12));
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return;
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case R_RISCV_RVC_JUMP:
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off64 = (val - addr);
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if ((off64 + (1 << 11)) & ~(uint64_t)0xffe)
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tcc_error("R_RISCV_RVC_BRANCH relocation failed"
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" (val=%lx, addr=%lx)", (long)val, (long)addr);
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off32 = off64;
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write16le(ptr, (read16le(ptr) & 0xe003)
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| (((off32 >> 5) & 1) << 2)
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| (((off32 >> 1) & 7) << 3)
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| (((off32 >> 7) & 1) << 6)
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| (((off32 >> 6) & 1) << 7)
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| (((off32 >> 10) & 1) << 8)
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| (((off32 >> 8) & 3) << 9)
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| (((off32 >> 4) & 1) << 11)
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| (((off32 >> 11) & 1) << 12));
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return;
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case R_RISCV_32:
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if (s1->output_type & TCC_OUTPUT_DYN) {
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/* XXX: this logic may depend on TCC's codegen
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now TCC uses R_RISCV_RELATIVE even for a 64bit pointer */
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qrel->r_offset = rel->r_offset;
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qrel->r_info = ELFW(R_INFO)(0, R_RISCV_RELATIVE);
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/* Use sign extension! */
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qrel->r_addend = (int)read32le(ptr) + val;
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qrel++;
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}
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add32le(ptr, val);
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return;
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case R_RISCV_64:
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if (s1->output_type & TCC_OUTPUT_DYN) {
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esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
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qrel->r_offset = rel->r_offset;
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if (esym_index) {
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qrel->r_info = ELFW(R_INFO)(esym_index, R_RISCV_64);
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qrel->r_addend = rel->r_addend;
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qrel++;
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break;
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} else {
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qrel->r_info = ELFW(R_INFO)(0, R_RISCV_RELATIVE);
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qrel->r_addend = read64le(ptr) + val;
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qrel++;
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}
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}
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case R_RISCV_JUMP_SLOT:
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add64le(ptr, val);
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return;
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case R_RISCV_ADD64:
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write64le(ptr, read64le(ptr) + val);
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return;
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case R_RISCV_ADD32:
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write32le(ptr, read32le(ptr) + val);
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return;
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case R_RISCV_SUB64:
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write64le(ptr, read64le(ptr) - val);
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return;
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case R_RISCV_SUB32:
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write32le(ptr, read32le(ptr) - val);
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return;
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case R_RISCV_ADD16:
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write16le(ptr, read16le(ptr) + val);
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return;
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case R_RISCV_SUB16:
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write16le(ptr, read16le(ptr) - val);
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return;
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case R_RISCV_SET6:
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*ptr = (*ptr & ~0x3f) | (val & 0x3f);
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return;
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case R_RISCV_SUB6:
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*ptr = (*ptr & ~0x3f) | ((*ptr - val) & 0x3f);
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return;
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case R_RISCV_32_PCREL:
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case R_RISCV_COPY:
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/* XXX */
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return;
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default:
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fprintf(stderr, "FIXME: handle reloc type %x at %x [%p] to %x\n",
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type, (unsigned)addr, ptr, (unsigned)val);
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return;
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}
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}
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#endif
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