dyngen.c

qemu虚拟机代码

                        }
                    }
#endif                    
                    if (val >= start_offset && val <= start_offset + copy_size) {
                        n = strtol(p, NULL, 10);
                        fprintf(outfile, "    label_offsets[%d] = %ld + (gen_code_ptr - gen_code_buf);\n", n, (long)(val - start_offset));
                    }
                }
            }
        }

        /* load parameres in variables */
        for(i = 0; i < nb_args; i++) {
            fprintf(outfile, "    param%d = *opparam_ptr++;\n", i + 1);
        }

        /* patch relocations */
#if defined(HOST_I386)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset >= start_offset &&
		    rel->r_offset < start_offset + copy_size) {
                    sym_name = get_rel_sym_name(rel);
                    if (!sym_name)
                        continue;
                    reloc_offset = rel->r_offset - start_offset;
                    if (strstart(sym_name, "__op_jmp", &p)) {
                        int n;
                        n = strtol(p, NULL, 10);
                        /* __op_jmp relocations are done at
                           runtime to do translated block
                           chaining: the offset of the instruction
                           needs to be stored */
                        fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
                                n, reloc_offset);
                        continue;
                    }

                    get_reloc_expr(name, sizeof(name), sym_name);
                    addend = get32((uint32_t *)(text + rel->r_offset));
#ifdef CONFIG_FORMAT_ELF
                    type = ELF32_R_TYPE(rel->r_info);
                    switch(type) {
                    case R_386_32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_386_PC32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
                    default:
                        error("unsupported i386 relocation (%d)", type);
                    }
#elif defined(CONFIG_FORMAT_COFF)
                    {
                        char *temp_name;
                        int j;
                        EXE_SYM *sym;
                        temp_name = get_sym_name(symtab + *(uint32_t *)(rel->r_reloc->r_symndx));
                        if (!strcmp(temp_name, ".data")) {
                            for (j = 0, sym = symtab; j < nb_syms; j++, sym++) {
                                if (strstart(sym->st_name, sym_name, NULL)) {
                                    addend -= sym->st_value;
                                }
                            }
                        }
                    }
                    type = rel->r_type;
                    switch(type) {
                    case DIR32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case DISP32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d -4;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
                    default:
                        error("unsupported i386 relocation (%d)", type);
                    }
#else
#error unsupport object format
#endif
                }
                }
            }
#elif defined(HOST_X86_64)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset >= start_offset &&
		    rel->r_offset < start_offset + copy_size) {
                    sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                    get_reloc_expr(name, sizeof(name), sym_name);
                    type = ELF32_R_TYPE(rel->r_info);
                    addend = rel->r_addend;
                    reloc_offset = rel->r_offset - start_offset;
                    switch(type) {
                    case R_X86_64_32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (uint32_t)%s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_X86_64_32S:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (int32_t)%s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_X86_64_PC32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
                    default:
                        error("unsupported X86_64 relocation (%d)", type);
                    }
                }
                }
            }
#elif defined(HOST_PPC)
            {
#ifdef CONFIG_FORMAT_ELF
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
			rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                        reloc_offset = rel->r_offset - start_offset;
                        if (strstart(sym_name, "__op_jmp", &p)) {
                            int n;
                            n = strtol(p, NULL, 10);
                            /* __op_jmp relocations are done at
                               runtime to do translated block
                               chaining: the offset of the instruction
                               needs to be stored */
                            fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
                                    n, reloc_offset);
                            continue;
                        }
                        
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        switch(type) {
                        case R_PPC_ADDR32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_LO:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d);\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_HI:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d) >> 16;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_HA:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d + 0x8000) >> 16;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_REL24:
                            /* warning: must be at 32 MB distancy */
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((%s - (long)(gen_code_ptr + %d) + %d) & 0x03fffffc);\n", 
                                    reloc_offset, reloc_offset, name, reloc_offset, addend);
                            break;
                        default:
                            error("unsupported powerpc relocation (%d)", type);
                        }
                    }
                }
#elif defined(CONFIG_FORMAT_MACH)
				struct scattered_relocation_info *scarel;
				struct relocation_info * rel;
				char final_sym_name[256];
				const char *sym_name;
				const char *p;
				int slide, sslide;
				int i;
	
				for(i = 0, rel = relocs; i < nb_relocs; i++, rel++) {
					unsigned int offset, length, value = 0;
					unsigned int type, pcrel, isym = 0;
					unsigned int usesym = 0;
				
					if(R_SCATTERED & rel->r_address) {
						scarel = (struct scattered_relocation_info*)rel;
						offset = (unsigned int)scarel->r_address;
						length = scarel->r_length;
						pcrel = scarel->r_pcrel;
						type = scarel->r_type;
						value = scarel->r_value;
					} else {
						value = isym = rel->r_symbolnum;
						usesym = (rel->r_extern);
						offset = rel->r_address;
						length = rel->r_length;
						pcrel = rel->r_pcrel;
						type = rel->r_type;
					}
				
					slide = offset - start_offset;
		
					if (!(offset >= start_offset && offset < start_offset + size)) 
						continue;  /* not in our range */

					sym_name = get_reloc_name(rel, &sslide);
					
					if(usesym && symtab[isym].n_type & N_STAB)
						continue; /* don't handle STAB (debug sym) */
					
					if (sym_name && strstart(sym_name, "__op_jmp", &p)) {
						int n;
						n = strtol(p, NULL, 10);
						fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
							n, slide);
						continue; /* Nothing more to do */
					}
					
					if(!sym_name)
					{
						fprintf(outfile, "/* #warning relocation not handled in %s (value 0x%x, %s, offset 0x%x, length 0x%x, %s, type 0x%x) */\n",
						           name, value, usesym ? "use sym" : "don't use sym", offset, length, pcrel ? "pcrel":"", type);
						continue; /* dunno how to handle without final_sym_name */
					}
													   
                                        get_reloc_expr(final_sym_name, sizeof(final_sym_name), 
                                                       sym_name);
					switch(type) {
					case PPC_RELOC_BR24:
					    if (!strstart(sym_name,"__op_gen_label",&p)) {
    						fprintf(outfile, "{\n");
    						fprintf(outfile, "    uint32_t imm = *(uint32_t *)(gen_code_ptr + %d) & 0x3fffffc;\n", slide);
    						fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((imm + ((long)%s - (long)gen_code_ptr) + %d) & 0x03fffffc);\n", 
											slide, slide, name, sslide );
    						fprintf(outfile, "}\n");
    					} else {
							fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | (((long)%s - (long)gen_code_ptr - %d) & 0x03fffffc);\n",
											slide, slide, final_sym_name, slide);
    					}
						break;
					case PPC_RELOC_HI16:
						fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d) >> 16;\n", 
							slide, final_sym_name, sslide);
						break;
					case PPC_RELOC_LO16:
						fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d);\n", 
					slide, final_sym_name, sslide);
                            break;
					case PPC_RELOC_HA16:
						fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d + 0x8000) >> 16;\n", 
							slide, final_sym_name, sslide);
						break;
				default:
					error("unsupported powerpc relocation (%d)", type);
				}
			}
#else
#error unsupport object format
#endif
            }
#elif defined(HOST_S390)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
			rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        reloc_offset = rel->r_offset - start_offset;
                        switch(type) {
                        case R_390_32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_390_16:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_390_8:
                            fprintf(outfile, "    *(uint8_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        default:
                            error("unsupported s390 relocation (%d)", type);
                        }
                    }
                }
            }
#elif defined(HOST_ALPHA)
            {
                for (i = 0, rel = relocs; i < nb_relocs; i++, rel++) {
		    if (rel->r_offset >= start_offset && rel->r_offset < start_offset + copy_size) {
			int type;
                        long reloc_offset;

			type = ELF64_R_TYPE(rel->r_info);
			sym_name = strtab + symtab[ELF64_R_SYM(rel->r_info)].st_name;
                        reloc_offset = rel->r_offset - start_offset;
			switch (type) {
			case R_ALPHA_GPDISP:
			    /* The gp is just 32 bit, and never changes, so it's easiest to emit it
			       as an immediate instead of constructing it from the pv or ra.  */
			    fprintf(outfile, "    immediate_ldah(gen_code_ptr + %ld, gp);\n",
				    reloc_offset);
			    fprintf(outfile, "    immediate_lda(gen_code_ptr + %ld, gp);\n",
				    reloc_offset + (int)rel->r_addend);
			    break;
			case R_ALPHA_LITUSE:
			    /* jsr to literal hint. Could be used to optimize to bsr. Ignore for
			       now, since some called functions (libc) need pv to be set up.  */
			    break;
			case R_ALPHA_HINT:
			    /* Branch target prediction hint. Ignore for now.  Should be already
			       correct for in-function jumps.  */
			    break;
			case R_ALPHA_LITERAL:
			    /* Load a literal from the GOT relative to the gp.  Since there's only a
			       single gp, nothing is to be done.  */
			    break;
			case R_ALPHA_GPRELHIGH:
			    /* Handle fake relocations against __op_param symbol.  Need to emit the
			       high part of the immediate value instead.  Other symbols need no
			       special treatment.  */
			    if (strstart(sym_name, "__op_param", &p))
				fprintf(outfile, "    immediate_ldah(gen_code_ptr + %ld, param%s);\n",
					reloc_offset, p);
			    break;
			case R_ALPHA_GPRELLOW:
			    if (strstart(sym_name, "__op_param", &p))
				fprintf(outfile, "    immediate_lda(gen_code_ptr + %ld, param%s);\n",
					reloc_offset, p);
			    break;
			case R_ALPHA_BRSGP:
			    /* PC-relative jump. Tweak offset to skip the two instructions that try to
			       set up the gp from the pv.  */
			    fprintf(outfile, "    fix_bsr(gen_code_ptr + %ld, (uint8_t *) &%s - (gen_code_ptr + %ld + 4) + 8);\n",
				    reloc_offset, sym_name, reloc_offset);
			    break;
			default:
			    error("unsupported Alpha relocation (%d)", type);
			}
		    }
                }
            }
#elif defined(HOST_IA64)
            {
		unsigned long sym_idx;
		long code_offset;
                char name[256];
                int type;
                long addend;

                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
		    sym_idx = ELF64_R_SYM(rel->r_info);
                    if (rel->r_offset < start_offset
			|| rel->r_offset >= start_offset + copy_size)
			continue;
		    sym_name = (strtab + symtab[sym_idx].st_name);
		    code_offset = rel->r_offset - start_offset;
		    if (strstart(sym_name, "__op_jmp", &p)) {
			int n;
			n = strtol(p, NULL, 10);
			/* __op_jmp relocations are done at
			   runtime to do translated block
			   chaining: the offset of the instruction
			   needs to be stored */
			fprintf(outfile, "    jmp_offsets[%d] ="
				"%ld + (gen_code_ptr - gen_code_buf);\n",
				n, code_offset);
			continue;
		    }
		    get_reloc_expr(name, sizeof(name), sym_name);
		    type = ELF64_R_TYPE(rel->r_info);
		    addend = rel->r_addend;
		    switch(type) {
		      case R_IA64_IMM64:
			  fprintf(outfile,
				  "    ia64_imm64(gen_code_ptr + %ld, "
				  "%s + %ld);\n",
				  code_offset, name, addend);
			  break;
		      case R_IA64_LTOFF22X:
		      case R_IA64_LTOFF22:
			  fprintf(outfile, "    IA64_LTOFF(gen_code_ptr + %ld,"
				  " %s + %ld, %d);\n",
				  code_offset, name, addend,
				  (type == R_IA64_LTOFF22X));
			  break;
		      case R_IA64_LDXMOV:
			  fprintf(outfile,
				  "    ia64_ldxmov(gen_code_ptr + %ld,"
				  " %s + %ld);\n", code_offset, name, addend);
			  break;

		      case R_IA64_PCREL21B:
			  if (strstart(sym_name, "__op_gen_label", NULL)) {
			      fprintf(outfile,
				      "    ia64_imm21b(gen_code_ptr + %ld,"
				      " (long) (%s + %ld -\n\t\t"
				      "((long) gen_code_ptr + %ld)) >> 4);\n",
				      code_offset, name, addend,
				      code_offset & ~0xfUL);
			  } else {
			      fprintf(outfile,
				      "    IA64