diff options
Diffstat (limited to 'src/unexmacosx.c')
| -rw-r--r-- | src/unexmacosx.c | 86 |
1 files changed, 81 insertions, 5 deletions
diff --git a/src/unexmacosx.c b/src/unexmacosx.c index c84e5c95d03..b41c586d2e0 100644 --- a/src/unexmacosx.c +++ b/src/unexmacosx.c @@ -95,6 +95,10 @@ Boston, MA 02111-1307, USA. */ #include <unistd.h> #include <mach/mach.h> #include <mach-o/loader.h> +#include <mach-o/reloc.h> +#if defined (__ppc__) +#include <mach-o/ppc/reloc.h> +#endif #include <objc/malloc.h> #define VERBOSE 1 @@ -158,6 +162,11 @@ int in_dumped_exec = 0; malloc_zone_t *emacs_zone; +/* file offset of input file's data segment */ +off_t data_segment_old_fileoff; + +struct segment_command *data_segment_scp; + /* Read n bytes from infd into memory starting at address dest. Return true if successful, false otherwise. */ static int @@ -183,6 +192,7 @@ static int unexec_copy (off_t dest, off_t src, ssize_t count) { ssize_t bytes_read; + ssize_t bytes_to_read; char buf[UNEXEC_COPY_BUFSZ]; @@ -194,7 +204,8 @@ unexec_copy (off_t dest, off_t src, ssize_t count) while (count > 0) { - bytes_read = read (infd, buf, UNEXEC_COPY_BUFSZ); + bytes_to_read = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count; + bytes_read = read (infd, buf, bytes_to_read); if (bytes_read <= 0) return 0; if (write (outfd, buf, bytes_read) != bytes_read) @@ -763,6 +774,65 @@ copy_symtab (struct load_command *lc) curr_header_offset += lc->cmdsize; } +/* Fix up relocation entries. */ +static void +unrelocate (const char *name, off_t reloff, int nrel) +{ + int i, unreloc_count; + struct relocation_info reloc_info; + struct scattered_relocation_info *sc_reloc_info + = (struct scattered_relocation_info *) &reloc_info; + + for (unreloc_count = 0, i = 0; i < nrel; i++) + { + if (lseek (infd, reloff, L_SET) != reloff) + unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name, i); + if (!unexec_read (&reloc_info, sizeof (reloc_info))) + unexec_error ("unrelocate: %s:%d cannot read reloc_info", name, i); + reloff += sizeof (reloc_info); + + if (sc_reloc_info->r_scattered == 0) + switch (reloc_info.r_type) + { + case GENERIC_RELOC_VANILLA: + if (reloc_info.r_address >= data_segment_scp->vmaddr + && reloc_info.r_address < (data_segment_scp->vmaddr + + data_segment_scp->vmsize)) + { + off_t src_off = data_segment_old_fileoff + + reloc_info.r_address - data_segment_scp->vmaddr; + off_t dst_off = data_segment_scp->fileoff + + reloc_info.r_address - data_segment_scp->vmaddr; + + if (!unexec_copy (dst_off, src_off, 1 << reloc_info.r_length)) + unexec_error ("unrelocate: %s:%d cannot copy original value", + name, i); + unreloc_count++; + } + break; + default: + unexec_error ("unrelocate: %s:%d cannot handle type = %d", + name, i, reloc_info.r_type); + } + else + switch (sc_reloc_info->r_type) + { +#if defined (__ppc__) + case PPC_RELOC_PB_LA_PTR: + /* nothing to do for prebound lazy pointer */ + break; +#endif + default: + unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d", + name, i, sc_reloc_info->r_type); + } + } + + if (nrel > 0) + printf ("Fixed up %d/%d %s relocation entries in data segment.\n", + unreloc_count, nrel, name); +} + /* Copy a LC_DYSYMTAB load command from the input file to the output file, adjusting the file offset fields. */ static void @@ -770,10 +840,8 @@ copy_dysymtab (struct load_command *lc) { struct dysymtab_command *dstp = (struct dysymtab_command *) lc; - /* If Mach-O executable is not prebound, relocation entries need - fixing up. This is not supported currently. */ - if (!(mh.flags & MH_PREBOUND) && (dstp->nextrel != 0 || dstp->nlocrel != 0)) - unexec_error ("cannot handle LC_DYSYMTAB with relocation entries"); + unrelocate ("local", dstp->locreloff, dstp->nlocrel); + unrelocate ("external", dstp->extreloff, dstp->nextrel); if (dstp->nextrel > 0) { dstp->extreloff += delta; @@ -845,6 +913,11 @@ dump_it () struct segment_command *scp = (struct segment_command *) lca[i]; if (strncmp (scp->segname, SEG_DATA, 16) == 0) { + /* save data segment file offset and segment_command for + unrelocate */ + data_segment_old_fileoff = scp->fileoff; + data_segment_scp = scp; + copy_data_segment (lca[i]); } else @@ -976,3 +1049,6 @@ unexec_free (void *ptr) else malloc_zone_free (emacs_zone, ptr); } + +/* arch-tag: 1a784f7b-a184-4c4f-9544-da8619593d72 + (do not change this comment) */ |