diff options
Diffstat (limited to 'src/unexmips.c')
| -rw-r--r-- | src/unexmips.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/src/unexmips.c b/src/unexmips.c new file mode 100644 index 00000000000..9d1638d653a --- /dev/null +++ b/src/unexmips.c @@ -0,0 +1,317 @@ +/* Unexec for MIPS (including IRIS4D). + Copyright (C) 1988 Free Software Foundation, Inc. + + Note that the GNU project considers support for MIPS operation + a peripheral activity which should not be allowed to divert effort + from development of the GNU system. Changes in this code will be + installed when users send them in, but aside from that + we don't plan to think about it, or about whether other Emacs + maintenance might break it. + + 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 1, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +In other words, you are welcome to use, share and improve this program. +You are forbidden to forbid anyone else to use, share and improve +what you give them. Help stamp out software-hoarding! */ + +#include "config.h" +#include <sys/types.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <stdio.h> +#include <varargs.h> +#include <filehdr.h> +#include <aouthdr.h> +#include <scnhdr.h> +#include <sym.h> + +#if defined (IRIS_4D) || defined (sony) +#include "getpagesize.h" +#include <fcntl.h> +#endif + +static void fatal_unexec (); +static int mark_x (); + +#define READ(_fd, _buffer, _size, _error_message, _error_arg) \ + errno = EEOF; \ + if (read (_fd, _buffer, _size) != _size) \ + fatal_unexec (_error_message, _error_arg); + +#define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \ + if (write (_fd, _buffer, _size) != _size) \ + fatal_unexec (_error_message, _error_arg); + +#define SEEK(_fd, _position, _error_message, _error_arg) \ + errno = EEOF; \ + if (lseek (_fd, _position, L_SET) != _position) \ + fatal_unexec (_error_message, _error_arg); + +extern int errno; +extern int sys_nerr; +extern char *sys_errlist[]; +#define EEOF -1 + +static struct scnhdr *text_section; +static struct scnhdr *init_section; +static struct scnhdr *finit_section; +static struct scnhdr *rdata_section; +static struct scnhdr *data_section; +static struct scnhdr *lit8_section; +static struct scnhdr *lit4_section; +static struct scnhdr *sdata_section; +static struct scnhdr *sbss_section; +static struct scnhdr *bss_section; + +struct headers { + struct filehdr fhdr; + struct aouthdr aout; + struct scnhdr section[10]; +}; + +/* Define name of label for entry point for the dumped executable. */ + +#ifndef DEFAULT_ENTRY_ADDRESS +#define DEFAULT_ENTRY_ADDRESS __start +#endif + +unexec (new_name, a_name, data_start, bss_start, entry_address) + char *new_name, *a_name; + unsigned data_start, bss_start, entry_address; +{ + int new, old; + int pagesize, brk; + int newsyms, symrel; + int nread; + struct headers hdr; + int i; + int vaddr, scnptr; +#define BUFSIZE 8192 + char buffer[BUFSIZE]; + + old = open (a_name, O_RDONLY, 0); + if (old < 0) fatal_unexec ("opening %s", a_name); + + new = creat (new_name, 0666); + if (new < 0) fatal_unexec ("creating %s", new_name); + + hdr = *((struct headers *)TEXT_START); +#ifdef MIPS2 + if (hdr.fhdr.f_magic != MIPSELMAGIC + && hdr.fhdr.f_magic != MIPSEBMAGIC + && hdr.fhdr.f_magic != (MIPSELMAGIC | 1) + && hdr.fhdr.f_magic != (MIPSEBMAGIC | 1)) + { + fprintf (stderr, + "unexec: input file magic number is %x, not %x, %x, %x or %x.\n", + hdr.fhdr.f_magic, + MIPSELMAGIC, MIPSEBMAGIC, + MIPSELMAGIC | 1, MIPSEBMAGIC | 1); + exit (1); + } +#else /* not MIPS2 */ + if (hdr.fhdr.f_magic != MIPSELMAGIC + && hdr.fhdr.f_magic != MIPSEBMAGIC) + { + fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n", + hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC); + exit (1); + } +#endif /* not MIPS2 */ + if (hdr.fhdr.f_opthdr != sizeof (hdr.aout)) + { + fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n", + hdr.fhdr.f_opthdr, sizeof (hdr.aout)); + exit (1); + } + if (hdr.aout.magic != ZMAGIC) + { + fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n", + hdr.aout.magic, ZMAGIC); + exit (1); + } + +#define CHECK_SCNHDR(ptr, name, flags) \ + ptr = NULL; \ + for (i = 0; i < hdr.fhdr.f_nscns && !ptr; i++) \ + if (strcmp (hdr.section[i].s_name, name) == 0) { \ + if (hdr.section[i].s_flags != flags) { \ + fprintf (stderr, "unexec: %x flags where %x expected in %s section.\n", \ + hdr.section[i].s_flags, flags, name); \ + } \ + ptr = hdr.section + i; \ + } + + CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT); + CHECK_SCNHDR (init_section, _INIT, STYP_INIT); + CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA); + CHECK_SCNHDR (data_section, _DATA, STYP_DATA); +#ifdef _LIT8 + CHECK_SCNHDR (lit8_section, _LIT8, STYP_LIT8); + CHECK_SCNHDR (lit4_section, _LIT4, STYP_LIT4); +#endif /* _LIT8 */ + CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA); + CHECK_SCNHDR (sbss_section, _SBSS, STYP_SBSS); + CHECK_SCNHDR (bss_section, _BSS, STYP_BSS); +#if 0 /* Apparently this error check goes off on irix 3.3, + but it doesn't indicate a real problem. */ + if (i != hdr.fhdr.f_nscns) + fprintf (stderr, "unexec: %d sections found instead of %d.\n", + i, hdr.fhdr.f_nscns); +#endif + + text_section->s_scnptr = 0; + + pagesize = getpagesize (); + brk = (sbrk (0) + pagesize - 1) & (-pagesize); + hdr.aout.dsize = brk - DATA_START; + hdr.aout.bsize = 0; + if (entry_address == 0) + { + extern DEFAULT_ENTRY_ADDRESS (); + hdr.aout.entry = (unsigned)DEFAULT_ENTRY_ADDRESS; + } + else + hdr.aout.entry = entry_address; + + hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize; + rdata_section->s_size = data_start - DATA_START; + + /* Adjust start and virtual addresses of rdata_section, too. */ + rdata_section->s_vaddr = DATA_START; + rdata_section->s_paddr = DATA_START; + rdata_section->s_scnptr = text_section->s_scnptr + hdr.aout.tsize; + + data_section->s_vaddr = data_start; + data_section->s_paddr = data_start; + data_section->s_size = brk - data_start; + data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size; + vaddr = data_section->s_vaddr + data_section->s_size; + scnptr = data_section->s_scnptr + data_section->s_size; + if (lit8_section != NULL) + { + lit8_section->s_vaddr = vaddr; + lit8_section->s_paddr = vaddr; + lit8_section->s_size = 0; + lit8_section->s_scnptr = scnptr; + } + if (lit4_section != NULL) + { + lit4_section->s_vaddr = vaddr; + lit4_section->s_paddr = vaddr; + lit4_section->s_size = 0; + lit4_section->s_scnptr = scnptr; + } + if (sdata_section != NULL) + { + sdata_section->s_vaddr = vaddr; + sdata_section->s_paddr = vaddr; + sdata_section->s_size = 0; + sdata_section->s_scnptr = scnptr; + } + if (sbss_section != NULL) + { + sbss_section->s_vaddr = vaddr; + sbss_section->s_paddr = vaddr; + sbss_section->s_size = 0; + sbss_section->s_scnptr = scnptr; + } + if (bss_section != NULL) + { + bss_section->s_vaddr = vaddr; + bss_section->s_paddr = vaddr; + bss_section->s_size = 0; + bss_section->s_scnptr = scnptr; + } + + WRITE (new, TEXT_START, hdr.aout.tsize, + "writing text section to %s", new_name); + WRITE (new, DATA_START, hdr.aout.dsize, + "writing text section to %s", new_name); + + SEEK (old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name); + errno = EEOF; + nread = read (old, buffer, BUFSIZE); + if (nread < sizeof (HDRR)) fatal_unexec ("reading symbols from %s", a_name); +#define symhdr ((pHDRR)buffer) + newsyms = hdr.aout.tsize + hdr.aout.dsize; + symrel = newsyms - hdr.fhdr.f_symptr; + hdr.fhdr.f_symptr = newsyms; + symhdr->cbLineOffset += symrel; + symhdr->cbDnOffset += symrel; + symhdr->cbPdOffset += symrel; + symhdr->cbSymOffset += symrel; + symhdr->cbOptOffset += symrel; + symhdr->cbAuxOffset += symrel; + symhdr->cbSsOffset += symrel; + symhdr->cbSsExtOffset += symrel; + symhdr->cbFdOffset += symrel; + symhdr->cbRfdOffset += symrel; + symhdr->cbExtOffset += symrel; +#undef symhdr + do + { + if (write (new, buffer, nread) != nread) + fatal_unexec ("writing symbols to %s", new_name); + nread = read (old, buffer, BUFSIZE); + if (nread < 0) fatal_unexec ("reading symbols from %s", a_name); +#undef BUFSIZE + } while (nread != 0); + + SEEK (new, 0, "seeking to start of header in %s", new_name); + WRITE (new, &hdr, sizeof (hdr), + "writing header of %s", new_name); + + close (old); + close (new); + mark_x (new_name); +} + +/* + * mark_x + * + * After succesfully building the new a.out, mark it executable + */ + +static int +mark_x (name) + char *name; +{ + struct stat sbuf; + int um = umask (777); + umask (um); + if (stat (name, &sbuf) < 0) + fatal_unexec ("getting protection on %s", name); + sbuf.st_mode |= 0111 & ~um; + if (chmod (name, sbuf.st_mode) < 0) + fatal_unexec ("setting protection on %s", name); +} + +static void +fatal_unexec (s, va_alist) + va_dcl +{ + va_list ap; + if (errno == EEOF) + fputs ("unexec: unexpected end of file, ", stderr); + else if (errno < sys_nerr) + fprintf (stderr, "unexec: %s, ", sys_errlist[errno]); + else + fprintf (stderr, "unexec: error code %d, ", errno); + va_start (ap); + _doprnt (s, ap, stderr); + fputs (".\n", stderr); + exit (1); +} |