diff options
| -rw-r--r-- | dyngen.c | 553 |
1 files changed, 546 insertions, 7 deletions
@@ -6,6 +6,8 @@ * The COFF object format support was extracted from Kazu's QEMU port * to Win32. * + * Mach-O Support by Matt Reda and Pierre d'Herbemont + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -34,6 +36,8 @@ compilation */ #if defined(CONFIG_WIN32) #define CONFIG_FORMAT_COFF +#elif defined(CONFIG_DARWIN) +#define CONFIG_FORMAT_MACH #else #define CONFIG_FORMAT_ELF #endif @@ -169,6 +173,35 @@ typedef struct coff_rel { #endif /* CONFIG_FORMAT_COFF */ +#ifdef CONFIG_FORMAT_MACH + +#include <mach-o/loader.h> +#include <mach-o/nlist.h> +#include <mach-o/reloc.h> +#include <mach-o/ppc/reloc.h> + +# define check_mach_header(x) (x.magic == MH_MAGIC) +typedef int32_t host_long; +typedef uint32_t host_ulong; + +struct nlist_extended +{ + union { + char *n_name; + long n_strx; + } n_un; + unsigned char n_type; + unsigned char n_sect; + short st_desc; + unsigned long st_value; + unsigned long st_size; +}; + +#define EXE_RELOC struct relocation_info +#define EXE_SYM struct nlist_extended + +#endif /* CONFIG_FORMAT_MACH */ + #include "bswap.h" enum { @@ -399,6 +432,11 @@ int find_reloc(int sh_index) return 0; } +static host_ulong get_rel_offset(EXE_RELOC *rel) +{ + return rel->r_offset; +} + static char *get_rel_sym_name(EXE_RELOC *rel) { return strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name; @@ -600,6 +638,11 @@ static char *get_rel_sym_name(EXE_RELOC *rel) return name; } +static host_ulong get_rel_offset(EXE_RELOC *rel) +{ + return rel->r_offset; +} + struct external_scnhdr *find_coff_section(struct external_scnhdr *shdr, int shnum, const char *name) { int i; @@ -758,6 +801,390 @@ int load_object(const char *filename) #endif /* CONFIG_FORMAT_COFF */ +#ifdef CONFIG_FORMAT_MACH + +/* File Header */ +struct mach_header mach_hdr; + +/* commands */ +struct segment_command *segment = 0; +struct dysymtab_command *dysymtabcmd = 0; +struct symtab_command *symtabcmd = 0; + +/* section */ +struct section *section_hdr; +struct section *text_sec_hdr; +uint8_t **sdata; + +/* relocs */ +struct relocation_info *relocs; + +/* symbols */ +EXE_SYM *symtab; +struct nlist *symtab_std; +char *strtab; + +/* indirect symbols */ +uint32_t *tocdylib; + +/* Utility functions */ + +static inline char *find_str_by_index(int index) +{ + return strtab+index; +} + +/* Used by dyngen common code */ +static char *get_sym_name(EXE_SYM *sym) +{ + char *name = find_str_by_index(sym->n_un.n_strx); + + if ( sym->n_type & N_STAB ) /* Debug symbols are ignored */ + return "debug"; + + if(!name) + return name; + if(name[0]=='_') + return name + 1; + else + return name; +} + +/* find a section index given its segname, sectname */ +static int find_mach_sec_index(struct section *section_hdr, int shnum, const char *segname, + const char *sectname) +{ + int i; + struct section *sec = section_hdr; + + for(i = 0; i < shnum; i++, sec++) { + if (!sec->segname || !sec->sectname) + continue; + if (!strcmp(sec->sectname, sectname) && !strcmp(sec->segname, segname)) + return i; + } + return -1; +} + +/* find a section header given its segname, sectname */ +struct section *find_mach_sec_hdr(struct section *section_hdr, int shnum, const char *segname, + const char *sectname) +{ + int index = find_mach_sec_index(section_hdr, shnum, segname, sectname); + if(index == -1) + return NULL; + return section_hdr+index; +} + + +static inline void fetch_next_pair_value(struct relocation_info * rel, unsigned int *value) +{ + struct scattered_relocation_info * scarel; + + if(R_SCATTERED & rel->r_address) { + scarel = (struct scattered_relocation_info*)rel; + if(scarel->r_type != PPC_RELOC_PAIR) + error("fetch_next_pair_value: looking for a pair which was not found (1)"); + *value = scarel->r_value; + } else { + if(rel->r_type != PPC_RELOC_PAIR) + error("fetch_next_pair_value: looking for a pair which was not found (2)"); + *value = rel->r_address; + } +} + +/* find a sym name given its value, in a section number */ +static const char * find_sym_with_value_and_sec_number( int value, int sectnum, int * offset ) +{ + int i, ret = -1; + + for( i = 0 ; i < nb_syms; i++ ) + { + if( !(symtab[i].n_type & N_STAB) && (symtab[i].n_type & N_SECT) && + (symtab[i].n_sect == sectnum) && (symtab[i].st_value <= value) ) + { + if( (ret<0) || (symtab[i].st_value >= symtab[ret].st_value) ) + ret = i; + } + } + if( ret < 0 ) { + *offset = 0; + return 0; + } else { + *offset = value - symtab[ret].st_value; + return get_sym_name(&symtab[ret]); + } +} + +/* + * Find symbol name given a (virtual) address, and a section which is of type + * S_NON_LAZY_SYMBOL_POINTERS or S_LAZY_SYMBOL_POINTERS or S_SYMBOL_STUBS + */ +static const char * find_reloc_name_in_sec_ptr(int address, struct section * sec_hdr) +{ + unsigned int tocindex, symindex, size; + const char *name = 0; + + /* Sanity check */ + if(!( address >= sec_hdr->addr && address < (sec_hdr->addr + sec_hdr->size) ) ) + return (char*)0; + + if( sec_hdr->flags & S_SYMBOL_STUBS ){ + size = sec_hdr->reserved2; + if(size == 0) + error("size = 0"); + + } + else if( sec_hdr->flags & S_LAZY_SYMBOL_POINTERS || + sec_hdr->flags & S_NON_LAZY_SYMBOL_POINTERS) + size = sizeof(unsigned long); + else + return 0; + + /* Compute our index in toc */ + tocindex = (address - sec_hdr->addr)/size; + symindex = tocdylib[sec_hdr->reserved1 + tocindex]; + + name = get_sym_name(&symtab[symindex]); + + return name; +} + +static const char * find_reloc_name_given_its_address(int address) +{ + unsigned int i; + for(i = 0; i < segment->nsects ; i++) + { + const char * name = find_reloc_name_in_sec_ptr(address, §ion_hdr[i]); + if((long)name != -1) + return name; + } + return 0; +} + +static const char * get_reloc_name(EXE_RELOC * rel, int * sslide) +{ + char * name = 0; + struct scattered_relocation_info * sca_rel = (struct scattered_relocation_info*)rel; + int sectnum = rel->r_symbolnum; + int sectoffset; + int other_half=0; + + /* init the slide value */ + *sslide = 0; + + if(R_SCATTERED & rel->r_address) + return (char *)find_reloc_name_given_its_address(sca_rel->r_value); + + if(rel->r_extern) + { + /* ignore debug sym */ + if ( symtab[rel->r_symbolnum].n_type & N_STAB ) + return 0; + return get_sym_name(&symtab[rel->r_symbolnum]); + } + + /* Intruction contains an offset to the symbols pointed to, in the rel->r_symbolnum section */ + sectoffset = *(uint32_t *)(text + rel->r_address) & 0xffff; + + if(sectnum==0xffffff) + return 0; + + /* Sanity Check */ + if(sectnum > segment->nsects) + error("sectnum > segment->nsects"); + + switch(rel->r_type) + { + case PPC_RELOC_LO16: fetch_next_pair_value(rel+1, &other_half); sectoffset = (sectoffset & 0xffff); + break; + case PPC_RELOC_HI16: fetch_next_pair_value(rel+1, &other_half); sectoffset = (other_half & 0xffff); + break; + case PPC_RELOC_HA16: fetch_next_pair_value(rel+1, &other_half); sectoffset = (other_half & 0xffff); + break; + case PPC_RELOC_BR24: + sectoffset = ( *(uint32_t *)(text + rel->r_address) & 0x03fffffc ); + if (sectoffset & 0x02000000) sectoffset |= 0xfc000000; + break; + default: + error("switch(rel->type) not found"); + } + + if(rel->r_pcrel) + sectoffset += rel->r_address; + + if (rel->r_type == PPC_RELOC_BR24) + name = (char *)find_reloc_name_in_sec_ptr((int)sectoffset, §ion_hdr[sectnum-1]); + + /* search it in the full symbol list, if not found */ + if(!name) + name = (char *)find_sym_with_value_and_sec_number(sectoffset, sectnum, sslide); + + return name; +} + +/* Used by dyngen common code */ +static const char * get_rel_sym_name(EXE_RELOC * rel) +{ + int sslide; + return get_reloc_name( rel, &sslide); +} + +/* Used by dyngen common code */ +static host_ulong get_rel_offset(EXE_RELOC *rel) +{ + struct scattered_relocation_info * sca_rel = (struct scattered_relocation_info*)rel; + if(R_SCATTERED & rel->r_address) + return sca_rel->r_address; + else + return rel->r_address; +} + +/* load a mach-o object file */ +int load_object(const char *filename) +{ + int fd; + unsigned int offset_to_segment = 0; + unsigned int offset_to_dysymtab = 0; + unsigned int offset_to_symtab = 0; + struct load_command lc; + unsigned int i, j; + EXE_SYM *sym; + struct nlist *syment; + + fd = open(filename, O_RDONLY); + if (fd < 0) + error("can't open file '%s'", filename); + + /* Read Mach header. */ + if (read(fd, &mach_hdr, sizeof (mach_hdr)) != sizeof (mach_hdr)) + error("unable to read file header"); + + /* Check Mach identification. */ + if (!check_mach_header(mach_hdr)) { + error("bad Mach header"); + } + + if (mach_hdr.cputype != CPU_TYPE_POWERPC) + error("Unsupported CPU"); + + if (mach_hdr.filetype != MH_OBJECT) + error("Unsupported Mach Object"); + + /* read segment headers */ + for(i=0, j=sizeof(mach_hdr); i<mach_hdr.ncmds ; i++) + { + if(read(fd, &lc, sizeof(struct load_command)) != sizeof(struct load_command)) + error("unable to read load_command"); + if(lc.cmd == LC_SEGMENT) + { + offset_to_segment = j; + lseek(fd, offset_to_segment, SEEK_SET); + segment = malloc(sizeof(struct segment_command)); + if(read(fd, segment, sizeof(struct segment_command)) != sizeof(struct segment_command)) + error("unable to read LC_SEGMENT"); + } + if(lc.cmd == LC_DYSYMTAB) + { + offset_to_dysymtab = j; + lseek(fd, offset_to_dysymtab, SEEK_SET); + dysymtabcmd = malloc(sizeof(struct dysymtab_command)); + if(read(fd, dysymtabcmd, sizeof(struct dysymtab_command)) != sizeof(struct dysymtab_command)) + error("unable to read LC_DYSYMTAB"); + } + if(lc.cmd == LC_SYMTAB) + { + offset_to_symtab = j; + lseek(fd, offset_to_symtab, SEEK_SET); + symtabcmd = malloc(sizeof(struct symtab_command)); + if(read(fd, symtabcmd, sizeof(struct symtab_command)) != sizeof(struct symtab_command)) + error("unable to read LC_SYMTAB"); + } + j+=lc.cmdsize; + + lseek(fd, j, SEEK_SET); + } + + if(!segment) + error("unable to find LC_SEGMENT"); + + /* read section headers */ + section_hdr = load_data(fd, offset_to_segment + sizeof(struct segment_command), segment->nsects * sizeof(struct section)); + + /* read all section data */ + sdata = (uint8_t **)malloc(sizeof(void *) * segment->nsects); + memset(sdata, 0, sizeof(void *) * segment->nsects); + + /* Load the data in section data */ + for(i = 0; i < segment->nsects; i++) { + sdata[i] = load_data(fd, section_hdr[i].offset, section_hdr[i].size); + } + + /* text section */ + text_sec_hdr = find_mach_sec_hdr(section_hdr, segment->nsects, SEG_TEXT, SECT_TEXT); + i = find_mach_sec_index(section_hdr, segment->nsects, SEG_TEXT, SECT_TEXT); + if (i == -1 || !text_sec_hdr) + error("could not find __TEXT,__text section"); + text = sdata[i]; + + /* Make sure dysym was loaded */ + if(!(int)dysymtabcmd) + error("could not find __DYSYMTAB segment"); + + /* read the table of content of the indirect sym */ + tocdylib = load_data( fd, dysymtabcmd->indirectsymoff, dysymtabcmd->nindirectsyms * sizeof(uint32_t) ); + + /* Make sure symtab was loaded */ + if(!(int)symtabcmd) + error("could not find __SYMTAB segment"); + nb_syms = symtabcmd->nsyms; + + symtab_std = load_data(fd, symtabcmd->symoff, symtabcmd->nsyms * sizeof(struct nlist)); + strtab = load_data(fd, symtabcmd->stroff, symtabcmd->strsize); + + symtab = malloc(sizeof(EXE_SYM) * nb_syms); + + /* Now transform the symtab, to an extended version, with the sym size, and the C name */ + for(i = 0, sym = symtab, syment = symtab_std; i < nb_syms; i++, sym++, syment++) { + const char *name; + struct nlist *sym_follow, *sym_next = 0; + unsigned int j; + name = find_str_by_index(sym->n_un.n_strx); + memset(sym, 0, sizeof(*sym)); + + if ( sym->n_type & N_STAB ) /* Debug symbols are skipped */ + continue; + + memcpy(sym, syment, sizeof(*syment)); + + /* Find the following symbol in order to get the current symbol size */ + for(j = 0, sym_follow = symtab_std; j < nb_syms; j++, sym_follow++) { + if ( sym_follow->n_sect != 1 || sym_follow->n_type & N_STAB || !(sym_follow->n_value > sym->st_value)) + continue; + if(!sym_next) { + sym_next = sym_follow; + continue; + } + if(!(sym_next->n_value > sym_follow->n_value)) + continue; + sym_next = sym_follow; + } + if(sym_next) + sym->st_size = sym_next->n_value - sym->st_value; + else + sym->st_size = text_sec_hdr->size - sym->st_value; + } + + /* Find Reloc */ + relocs = load_data(fd, text_sec_hdr->reloff, text_sec_hdr->nreloc * sizeof(struct relocation_info)); + nb_relocs = text_sec_hdr->nreloc; + + close(fd); + return 0; +} + +#endif /* CONFIG_FORMAT_MACH */ + #ifdef HOST_ARM int arm_emit_ldr_info(const char *name, unsigned long start_offset, @@ -1049,9 +1476,12 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, args_present[i] = 0; for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) { - if (rel->r_offset >= start_offset && - rel->r_offset < start_offset + (p_end - p_start)) { + host_ulong offset = get_rel_offset(rel); + if (offset >= start_offset && + offset < start_offset + (p_end - p_start)) { sym_name = get_rel_sym_name(rel); + if(!sym_name) + continue; if (strstart(sym_name, "__op_param", &p)) { n = strtoul(p, NULL, 10); if (n > MAX_ARGS) @@ -1087,9 +1517,12 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, fprintf(outfile, " extern void %s();\n", name); for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) { - if (rel->r_offset >= start_offset && - rel->r_offset < start_offset + (p_end - p_start)) { + host_ulong offset = get_rel_offset(rel); + if (offset >= start_offset && + offset < start_offset + (p_end - p_start)) { sym_name = get_rel_sym_name(rel); + if(!sym_name) + continue; if (*sym_name && !strstart(sym_name, "__op_param", NULL) && !strstart(sym_name, "__op_jmp", NULL)) { @@ -1101,12 +1534,18 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, continue; } #endif +#ifdef __APPLE__ +/* set __attribute((unused)) on darwin because we wan't to avoid warning when we don't use the symbol */ + fprintf(outfile, "extern char %s __attribute__((unused));\n", sym_name); +#else fprintf(outfile, "extern char %s;\n", sym_name); +#endif } } } - fprintf(outfile, " memcpy(gen_code_ptr, (void *)((char *)&%s+%d), %d);\n", name, start_offset - offset, copy_size); + fprintf(outfile, " memcpy(gen_code_ptr, (void *)((char *)&%s+%d), %d);\n", + name, (int)(start_offset - offset), copy_size); /* emit code offset information */ { @@ -1131,12 +1570,19 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, } else { ptr = NULL; } +#elif defined(CONFIG_FORMAT_MACH) + if(!sym->n_sect) + continue; + ptr = sdata[sym->n_sect-1]; #else ptr = sdata[sym->st_shndx]; #endif if (!ptr) error("__op_labelN in invalid section"); offset = sym->st_value; +#ifdef CONFIG_FORMAT_MACH + offset -= section_hdr[sym->n_sect-1].addr; +#endif val = *(unsigned long *)(ptr + offset); #ifdef ELF_USES_RELOCA { @@ -1284,6 +1730,7 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, } #elif defined(HOST_PPC) { +#ifdef CONFIG_FORMAT_ELF char name[256]; int type; int addend; @@ -1337,6 +1784,94 @@ void gen_code(const char *name, host_ulong offset, host_ulong size, } } } +#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 */ + } + + if (strstart(sym_name, "__op_param", &p)) { + snprintf(final_sym_name, sizeof(final_sym_name), "param%s", p); + } else { + snprintf(final_sym_name, sizeof(final_sym_name), "(long)(&%s)", sym_name); + } + + switch(type) { + case PPC_RELOC_BR24: + 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"); + 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) { @@ -1689,9 +2224,9 @@ int gen_file(FILE *outfile, int out_type) fprintf(outfile, "DEF(nop2, 2, 0)\n"); fprintf(outfile, "DEF(nop3, 3, 0)\n"); for(i = 0, sym = symtab; i < nb_syms; i++, sym++) { - const char *name, *p; + const char *name; name = get_sym_name(sym); - if (strstart(name, OP_PREFIX, &p)) { + if (strstart(name, OP_PREFIX, NULL)) { gen_code(name, sym->st_value, sym->st_size, outfile, 2); } } @@ -1702,8 +2237,10 @@ int gen_file(FILE *outfile, int out_type) const char *name; name = get_sym_name(sym); if (strstart(name, OP_PREFIX, NULL)) { +#if defined(CONFIG_FORMAT_ELF) || defined(CONFIG_FORMAT_COFF) if (sym->st_shndx != text_shndx) error("invalid section for opcode (0x%x)", sym->st_shndx); +#endif gen_code(name, sym->st_value, sym->st_size, outfile, 0); } } @@ -1747,8 +2284,10 @@ fprintf(outfile, printf("%4d: %s pos=0x%08x len=%d\n", i, name, sym->st_value, sym->st_size); #endif +#if defined(CONFIG_FORMAT_ELF) || defined(CONFIG_FORMAT_COFF) if (sym->st_shndx != text_shndx) error("invalid section for opcode (0x%x)", sym->st_shndx); +#endif gen_code(name, sym->st_value, sym->st_size, outfile, 1); } } |