diff options
Diffstat (limited to 'com32/tools')
-rw-r--r-- | com32/tools/Makefile | 2 | ||||
-rw-r--r-- | com32/tools/include/tools/le_byteshift.h | 70 | ||||
-rw-r--r-- | com32/tools/relocs.c | 305 |
3 files changed, 283 insertions, 94 deletions
diff --git a/com32/tools/Makefile b/com32/tools/Makefile index 7badabd2..0161baf1 100644 --- a/com32/tools/Makefile +++ b/com32/tools/Makefile @@ -15,6 +15,8 @@ include $(MAKEDIR)/build.mk BINS = relocs +INCLUDES += -I./include + all : $(BINS) relocs : relocs.o diff --git a/com32/tools/include/tools/le_byteshift.h b/com32/tools/include/tools/le_byteshift.h new file mode 100644 index 00000000..c99d45a6 --- /dev/null +++ b/com32/tools/include/tools/le_byteshift.h @@ -0,0 +1,70 @@ +#ifndef _TOOLS_LE_BYTESHIFT_H +#define _TOOLS_LE_BYTESHIFT_H + +#include <linux/types.h> + +static inline __u16 __get_unaligned_le16(const __u8 *p) +{ + return p[0] | p[1] << 8; +} + +static inline __u32 __get_unaligned_le32(const __u8 *p) +{ + return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24; +} + +static inline __u64 __get_unaligned_le64(const __u8 *p) +{ + return (__u64)__get_unaligned_le32(p + 4) << 32 | + __get_unaligned_le32(p); +} + +static inline void __put_unaligned_le16(__u16 val, __u8 *p) +{ + *p++ = val; + *p++ = val >> 8; +} + +static inline void __put_unaligned_le32(__u32 val, __u8 *p) +{ + __put_unaligned_le16(val >> 16, p + 2); + __put_unaligned_le16(val, p); +} + +static inline void __put_unaligned_le64(__u64 val, __u8 *p) +{ + __put_unaligned_le32(val >> 32, p + 4); + __put_unaligned_le32(val, p); +} + +static inline __u16 get_unaligned_le16(const void *p) +{ + return __get_unaligned_le16((const __u8 *)p); +} + +static inline __u32 get_unaligned_le32(const void *p) +{ + return __get_unaligned_le32((const __u8 *)p); +} + +static inline __u64 get_unaligned_le64(const void *p) +{ + return __get_unaligned_le64((const __u8 *)p); +} + +static inline void put_unaligned_le16(__u16 val, void *p) +{ + __put_unaligned_le16(val, p); +} + +static inline void put_unaligned_le32(__u32 val, void *p) +{ + __put_unaligned_le32(val, p); +} + +static inline void put_unaligned_le64(__u64 val, void *p) +{ + __put_unaligned_le64(val, p); +} + +#endif /* _TOOLS_LE_BYTESHIFT_H */ diff --git a/com32/tools/relocs.c b/com32/tools/relocs.c index 24742060..86fc7c50 100644 --- a/com32/tools/relocs.c +++ b/com32/tools/relocs.c @@ -13,12 +13,16 @@ #define USE_BSD #include <endian.h> #include <regex.h> -#include <sys/types.h> +#include <tools/le_byteshift.h> + +static void die(char *fmt, ...); #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) static Elf32_Ehdr ehdr; static unsigned long reloc_count, reloc_idx; static unsigned long *relocs; +static unsigned long reloc16_count, reloc16_idx; +static unsigned long *relocs16; struct section { Elf32_Shdr shdr; @@ -29,60 +33,87 @@ struct section { }; static struct section *secs; -static void die(char *fmt, ...) -{ - va_list ap; - va_start(ap, fmt); - vfprintf(stderr, fmt, ap); - va_end(ap); - exit(1); -} +enum symtype { + S_ABS, + S_REL, + S_SEG, + S_LIN, + S_NSYMTYPES +}; +static const char * const sym_regex_kernel[S_NSYMTYPES] = { /* * Following symbols have been audited. Don't warn user about * absolute relocations present w.r.t these symbols. */ + [S_ABS] = + "^(__.*_len|__.*_dwords)$", -/* True absolute relocations */ +/* + * These symbols are known to be relative, even if the linker marks them + * as absolute (typically defined outside any section in the linker script.) + */ + [S_REL] = + "^(__.*_start|__.*_end|_end|_[se](text|data))$", +}; -static const char safe_abs_regex[] = -"^(__.*_len|__.*_dwords)$"; -static regex_t safe_abs_regex_c; -static int is_safe_abs_reloc(const char *sym_name) -{ - return !regexec(&safe_abs_regex_c, sym_name, 0, NULL, 0); -} +static const char * const sym_regex_realmode[S_NSYMTYPES] = { +/* + * These are 16-bit segment symbols when compiling 16-bit code. + */ + [S_SEG] = + "^real_mode_seg$", -/* These are relative even though the linker marks them absolute */ +/* + * These are offsets belonging to segments, as opposed to linear addresses, + * when compiling 16-bit code. + */ + [S_LIN] = + "^pa_", +}; -static const char safe_rel_regex[] = -"^(__.*_start|__.*_end|_end|_[se](text|data))$"; -static regex_t safe_rel_regex_c; +static const char * const *sym_regex; -static int is_safe_rel_reloc(const char *sym_name) +static regex_t sym_regex_c[S_NSYMTYPES]; +static int is_reloc(enum symtype type, const char *sym_name) { - return !regexec(&safe_rel_regex_c, sym_name, 0, NULL, 0); + return sym_regex[type] && + !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0); } -static void regex_init(void) +static void regex_init(int use_real_mode) { - char errbuf[128]; - int err; + char errbuf[128]; + int err; + int i; - err = regcomp(&safe_abs_regex_c, safe_abs_regex, - REG_EXTENDED|REG_NOSUB); - if (err) { - regerror(err, &safe_abs_regex_c, errbuf, sizeof errbuf); - die("%s", errbuf); - } + if (use_real_mode) + sym_regex = sym_regex_realmode; + else + sym_regex = sym_regex_kernel; - err = regcomp(&safe_rel_regex_c, safe_rel_regex, - REG_EXTENDED|REG_NOSUB); - if (err) { - regerror(err, &safe_rel_regex_c, errbuf, sizeof errbuf); - die("%s", errbuf); - } + for (i = 0; i < S_NSYMTYPES; i++) { + if (!sym_regex[i]) + continue; + + err = regcomp(&sym_regex_c[i], sym_regex[i], + REG_EXTENDED|REG_NOSUB); + + if (err) { + regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf); + die("%s", errbuf); + } + } +} + +static void die(char *fmt, ...) +{ + va_list ap; + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + exit(1); } static const char *sym_type(unsigned type) @@ -153,13 +184,16 @@ static const char *rel_type(unsigned type) REL_TYPE(R_386_RELATIVE), REL_TYPE(R_386_GOTOFF), REL_TYPE(R_386_GOTPC), + REL_TYPE(R_386_8), + REL_TYPE(R_386_PC8), + REL_TYPE(R_386_16), + REL_TYPE(R_386_PC16), #undef REL_TYPE }; - const char *name = NULL; - if (type < ARRAY_SIZE(type_name)) + const char *name = "unknown type rel type name"; + if (type < ARRAY_SIZE(type_name) && type_name[type]) { name = type_name[type]; - if (!name) - name = "unknown"; + } return name; } @@ -189,7 +223,7 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym) name = sym_strtab + sym->st_name; } else { - name = sec_name(secs[sym->st_shndx].shdr.sh_name); + name = sec_name(sym->st_shndx); } return name; } @@ -428,7 +462,7 @@ static void print_absolute_symbols(void) printf("\n"); } -static int print_absolute_relocs(FILE *f) +static void print_absolute_relocs(void) { int i, printed = 0; @@ -472,17 +506,18 @@ static int print_absolute_relocs(FILE *f) * Before warning check if this absolute symbol * relocation is harmless. */ - if (is_safe_abs_reloc(name) || - is_safe_rel_reloc(name)) + if (is_reloc(S_ABS, name) || is_reloc(S_REL, name)) continue; if (!printed) { - fprintf(f, "Unknown absolute relocations present\n"); - fprintf(f, "Offset Info Type Sym.Value Sym.Name\n"); + printf("WARNING: Absolute relocations" + " present\n"); + printf("Offset Info Type Sym.Value " + "Sym.Name\n"); printed = 1; } - fprintf(f, "%08x %08x %10s %08x %s\n", + printf("%08x %08x %10s %08x %s\n", rel->r_offset, rel->r_info, rel_type(ELF32_R_TYPE(rel->r_info)), @@ -492,12 +527,11 @@ static int print_absolute_relocs(FILE *f) } if (printed) - fputc('\n', f); - - return printed; + printf("\n"); } -static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) +static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym), + int use_real_mode) { int i; /* Walk through the relocations */ @@ -522,31 +556,71 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) Elf32_Rel *rel; Elf32_Sym *sym; unsigned r_type; + const char *symname; + int shn_abs; + rel = &sec->reltab[j]; sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; r_type = ELF32_R_TYPE(rel->r_info); - /* Don't visit relocations to absolute symbols */ - if (sym->st_shndx == SHN_ABS && - !is_safe_rel_reloc(sym_name(sym_strtab, sym))) - continue; + + shn_abs = sym->st_shndx == SHN_ABS; switch (r_type) { case R_386_NONE: case R_386_PC32: + case R_386_PC16: + case R_386_PC8: case R_386_GOTPC: case R_386_GOTOFF: case R_386_GOT32: case R_386_PLT32: - /* Relative relocations don't need to - be adjusted */ + /* + * NONE can be ignored and and PC relative + * relocations don't need to be adjusted. + */ break; + + case R_386_16: + symname = sym_name(sym_strtab, sym); + if (!use_real_mode) + goto bad; + if (shn_abs) { + if (is_reloc(S_ABS, symname)) + break; + else if (!is_reloc(S_SEG, symname)) + goto bad; + } else { + if (is_reloc(S_LIN, symname)) + goto bad; + else + break; + } + visit(rel, sym); + break; + case R_386_32: - /* Visit relocations that need adjustment */ + symname = sym_name(sym_strtab, sym); + if (shn_abs) { + if (is_reloc(S_ABS, symname)) + break; + else if (!is_reloc(S_REL, symname)) + goto bad; + } else { + if (use_real_mode && + !is_reloc(S_LIN, symname)) + break; + } visit(rel, sym); break; default: die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type); + break; + bad: + symname = sym_name(sym_strtab, sym); + die("Invalid %s %s relocation: %s\n", + shn_abs ? "absolute" : "relative", + rel_type(r_type), symname); } } } @@ -554,8 +628,12 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym) { - (void)rel; (void)sym; - reloc_count += 1; + (void)sym; + + if (ELF32_R_TYPE(rel->r_info) == R_386_16) + reloc16_count++; + else + reloc_count++; } static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym) @@ -563,7 +641,10 @@ static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym) (void)sym; /* Remember the address that needs to be adjusted. */ - relocs[reloc_idx++] = rel->r_offset; + if (ELF32_R_TYPE(rel->r_info) == R_386_16) + relocs16[reloc16_idx++] = rel->r_offset; + else + relocs[reloc_idx++] = rel->r_offset; } static int cmp_relocs(const void *va, const void *vb) @@ -573,23 +654,41 @@ static int cmp_relocs(const void *va, const void *vb) return (*a == *b)? 0 : (*a > *b)? 1 : -1; } -static void emit_relocs(int as_text) +static int write32(unsigned int v, FILE *f) +{ + unsigned char buf[4]; + + put_unaligned_le32(v, buf); + return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; +} + +static void emit_relocs(int as_text, int use_real_mode) { int i; /* Count how many relocations I have and allocate space for them. */ reloc_count = 0; - walk_relocs(count_reloc); + walk_relocs(count_reloc, use_real_mode); relocs = malloc(reloc_count * sizeof(relocs[0])); if (!relocs) { die("malloc of %d entries for relocs failed\n", reloc_count); } + + relocs16 = malloc(reloc16_count * sizeof(relocs[0])); + if (!relocs16) { + die("malloc of %d entries for relocs16 failed\n", + reloc16_count); + } /* Collect up the relocations */ reloc_idx = 0; - walk_relocs(collect_reloc); + walk_relocs(collect_reloc, use_real_mode); + + if (reloc16_count && !use_real_mode) + die("Segment relocations found but --realmode not specified\n"); /* Order the relocations for more efficient processing */ qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs); + qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs); /* Print the relocations */ if (as_text) { @@ -598,61 +697,83 @@ static void emit_relocs(int as_text) */ printf(".section \".data.reloc\",\"a\"\n"); printf(".balign 4\n"); - for (i = 0; i < reloc_count; i++) { - printf("\t .long 0x%08lx\n", relocs[i]); + if (use_real_mode) { + printf("\t.long %lu\n", reloc16_count); + for (i = 0; i < reloc16_count; i++) + printf("\t.long 0x%08lx\n", relocs16[i]); + printf("\t.long %lu\n", reloc_count); + for (i = 0; i < reloc_count; i++) { + printf("\t.long 0x%08lx\n", relocs[i]); + } + } else { + for (i = 0; i < reloc_count; i++) { + printf("\t.long 0x%08lx\n", relocs[i]); + } + /* Print a stop */ + printf("\t.long 0x%08lx\n", (unsigned long)0); } + printf("\n"); } else { - unsigned char buf[4]; - /* Now print each relocation */ - for (i = 0; i < reloc_count; i++) { - buf[0] = (relocs[i] >> 0) & 0xff; - buf[1] = (relocs[i] >> 8) & 0xff; - buf[2] = (relocs[i] >> 16) & 0xff; - buf[3] = (relocs[i] >> 24) & 0xff; - fwrite(buf, 4, 1, stdout); + if (use_real_mode) { + write32(reloc16_count, stdout); + for (i = 0; i < reloc16_count; i++) + write32(relocs16[i], stdout); + write32(reloc_count, stdout); + + /* Now print each relocation */ + for (i = 0; i < reloc_count; i++) + write32(relocs[i], stdout); + } else { + /* Now print each relocation */ + for (i = 0; i < reloc_count; i++) { + write32(relocs[i], stdout); + } + + /* Print a stop */ + write32(0, stdout); } - /* Print a stop */ - memset(buf, 0, sizeof buf); - fwrite(buf, 4, 1, stdout); } } static void usage(void) { - die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n"); + die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n"); } int main(int argc, char **argv) { int show_absolute_syms, show_absolute_relocs; - int as_text; + int as_text, use_real_mode; const char *fname; FILE *fp; int i; - int err = 0; show_absolute_syms = 0; show_absolute_relocs = 0; as_text = 0; + use_real_mode = 0; fname = NULL; for (i = 1; i < argc; i++) { char *arg = argv[i]; if (*arg == '-') { - if (strcmp(argv[1], "--abs-syms") == 0) { + if (strcmp(arg, "--abs-syms") == 0) { show_absolute_syms = 1; continue; } - - if (strcmp(argv[1], "--abs-relocs") == 0) { + if (strcmp(arg, "--abs-relocs") == 0) { show_absolute_relocs = 1; continue; } - else if (strcmp(argv[1], "--text") == 0) { + if (strcmp(arg, "--text") == 0) { as_text = 1; continue; } + if (strcmp(arg, "--realmode") == 0) { + use_real_mode = 1; + continue; + } } else if (!fname) { fname = arg; @@ -663,10 +784,7 @@ int main(int argc, char **argv) if (!fname) { usage(); } - - - regex_init(); - + regex_init(use_real_mode); fp = fopen(fname, "r"); if (!fp) { die("Cannot open %s: %s\n", @@ -682,10 +800,9 @@ int main(int argc, char **argv) return 0; } if (show_absolute_relocs) { - print_absolute_relocs(stdout); + print_absolute_relocs(); return 0; } - err = print_absolute_relocs(stderr); - emit_relocs(as_text); - return err; + emit_relocs(as_text, use_real_mode); + return 0; } |