xemacs-beta: src/unexaix.c comparison

comparison src/unexaix.c @ 428:3ecd8885ac67 r21-2-22

Import from CVS: tag r21-2-22

author	cvs
date	Mon, 13 Aug 2007 11:28:15 +0200
parents
children	84b14dcb0985

comparison

equal deleted inserted replaced

-:0a0253eac470
+:3ecd8885ac67
+/* Dump an executable image.
+Copyright (C) 1985, 1986, 1987, 1988 Free Software Foundation, Inc.
+This file is part of XEmacs.
+XEmacs 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, or (at your option) any
+later version.
+XEmacs 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 XEmacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+/* Synched up with: FSF 20.2. */
+/* Originally based on the COFF unexec.c by Spencer W. Thomas.
+*
+* Subsequently hacked on by
+* Bill Mann <Bill_Man@praxisint.com>
+* Andrew Vignaux <Andrew.Vignaux@comp.vuw.ac.nz>
+* Mike Sperber <sperber@informatik.uni-tuebingen.de>
+*
+* Synopsis:
+*	unexec (new_name, a_name, data_start, bss_start, entry_address)
+*	char *new_name, *a_name;
+*	unsigned data_start, bss_start, entry_address;
+*
+* Takes a snapshot of the program and makes an a.out format file in the
+* file named by the string argument new_name.
+* If a_name is non-NULL, the symbol table will be taken from the given file.
+* On some machines, an existing a_name file is required.
+*
+* data_start and entry_address are ignored.
+*
+* bss_start indicates how much of the data segment is to be saved in the
+* a.out file and restored when the program is executed.  It gives the lowest
+* unsaved address, and is rounded up to a page boundary.  The default when 0
+* is given assumes that the entire data segment is to be stored, including
+* the previous data and bss as well as any additional storage allocated with
+* sbrk(2).
+*
+*/
+#ifndef emacs
+#define PERROR(arg) perror (arg); return -1
+#else
+#include <config.h>
+#define PERROR(file) report_error (file, new)
+#endif
+#include <a.out.h>
+/* Define getpagesize () if the system does not.
+Note that this may depend on symbols defined in a.out.h
+*/
+#include "getpagesize.h"
+#include <sys/types.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+extern char *start_of_text (void);		/* Start of text */
+extern char *start_of_data (void);		/* Start of initialized data */
+extern int _data;
+extern int _text;
+#include <filehdr.h>
+#include <aouthdr.h>
+#include <scnhdr.h>
+#include <syms.h>
+static struct filehdr f_hdr;		/* File header */
+static struct aouthdr f_ohdr;		/* Optional file header (a.out) */
+static long bias;			/* Bias to add for growth */
+static long lnnoptr;			/* Pointer to line-number info within file */
+static long text_scnptr;
+static long data_scnptr;
+#define ALIGN(val, pwr) (((val) + ((1L<<(pwr))-1)) & ~((1L<<(pwr))-1))
+static long load_scnptr;
+static long orig_load_scnptr;
+static long orig_data_scnptr;
+static int unrelocate_symbols (int, int, char *, char *);
+#ifndef MAX_SECTIONS
+#define MAX_SECTIONS	10
+#endif
+static int adjust_lnnoptrs (int, int, char *);
+static int pagemask;
+/* Correct an int which is the bit pattern of a pointer to a byte
+into an int which is the number of a byte.
+This is a no-op on ordinary machines, but not on all.  */
+#ifndef ADDR_CORRECT   /* Let m-*.h files override this definition */
+#define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
+#endif
+#ifdef emacs
+#include "lisp.h"
+static void
+report_error (char *file, int fd)
+{
+if (fd)
+close (fd);
+report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil));
+}
+#endif /* emacs */
+#define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
+#define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
+#define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
+static void
+report_error_1 (int fd, char *msg, int a1, int a2)
+{
+close (fd);
+#ifdef emacs
+error (msg, a1, a2);
+#else
+fprintf (stderr, msg, a1, a2);
+fprintf (stderr, "\n");
+#endif
+}
+static int make_hdr (int, int, unsigned, unsigned, unsigned, char *, char *);
+static void mark_x (char *);
+static int copy_text_and_data (int);
+static int copy_sym (int, int, char *, char *);
+static void write_segment (int, char *, char *);
+/* ****************************************************************
+* unexec
+*
+* driving logic.
+*/
+int unexec (char *new_name, char *a_name,
+	    uintptr_t data_start,
+	    uintptr_t bss_start,
+	    uintptr_t entry_address)
+{
+int new = -1, a_out = -1;
+if (a_name && (a_out = open (a_name, O_RDONLY)) < 0)
+{
+PERROR (a_name);
+}
+if ((new = creat (new_name, 0666)) < 0)
+{
+PERROR (new_name);
+}
+if (make_hdr (new, a_out,
+		data_start, bss_start,
+		entry_address,
+		a_name, new_name) < 0
+|| copy_text_and_data (new) < 0
+|| copy_sym (new, a_out, a_name, new_name) < 0
+|| adjust_lnnoptrs (new, a_out, new_name) < 0
+|| unrelocate_symbols (new, a_out, a_name, new_name) < 0)
+{
+close (new);
+return -1;
+}
+close (new);
+if (a_out >= 0)
+close (a_out);
+mark_x (new_name);
+return 0;
+}
+/* ****************************************************************
+* make_hdr
+*
+* Make the header in the new a.out from the header in core.
+* Modify the text and data sizes.
+*/
+static int
+make_hdr (int new, int a_out,
+	  unsigned data_start, unsigned bss_start,
+	  unsigned entry_address,
+	  char *a_name, char *new_name)
+{
+int scns;
+unsigned int bss_end;
+struct scnhdr section[MAX_SECTIONS];
+struct scnhdr * f_thdr;		/* Text section header */
+struct scnhdr * f_dhdr;		/* Data section header */
+struct scnhdr * f_bhdr;		/* Bss section header */
+struct scnhdr * f_lhdr;		/* Loader section header */
+struct scnhdr * f_tchdr;		/* Typechk section header */
+struct scnhdr * f_dbhdr;		/* Debug section header */
+struct scnhdr * f_xhdr;		/* Except section header */
+load_scnptr = orig_load_scnptr = lnnoptr = 0;
+pagemask = getpagesize () - 1;
+/* Adjust text/data boundary. */
+data_start = (long) start_of_data ();
+data_start = ADDR_CORRECT (data_start);
+data_start = data_start & ~pagemask; /* (Down) to page boundary. */
+bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
+bss_end &= ~ pagemask;
+/* Adjust data/bss boundary. */
+if (bss_start != 0)
+{
+bss_start = (ADDR_CORRECT (bss_start) + pagemask);
+/* (Up) to page bdry. */
+bss_start &= ~ pagemask;
+if (bss_start > bss_end)
+	{
+	  ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
+		  bss_start);
+	}
+}
+else
+bss_start = bss_end;
+if (data_start > bss_start)	/* Can't have negative data size. */
+{
+ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
+	      data_start, bss_start);
+}
+/* Salvage as much info from the existing file as possible */
+f_thdr = NULL; f_dhdr = NULL; f_bhdr = NULL;
+f_lhdr = NULL; f_tchdr = NULL; f_dbhdr = NULL; f_xhdr = NULL;
+if (a_out >= 0)
+{
+if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+	{
+	  PERROR (a_name);
+	}
+if (f_hdr.f_opthdr > 0)
+	{
+	  if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+	    {
+	      PERROR (a_name);
+	    }
+	}
+if (f_hdr.f_nscns > MAX_SECTIONS)
+	{
+	  ERROR0 ("unexec: too many section headers -- increase MAX_SECTIONS");
+	}
+/* Loop through section headers */
+for (scns = 0; scns < f_hdr.f_nscns; scns++) {
+	struct scnhdr *s = &section[scns];
+	if (read (a_out, s, sizeof (*s)) != sizeof (*s))
+	  {
+	    PERROR (a_name);
+	  }
+#define CHECK_SCNHDR(ptr, name, flags) \
+if (strcmp(s->s_name, name) == 0) { \
+if (s->s_flags != flags) { \
+fprintf(stderr, "unexec: %lx flags where %x expected in %s section.\n", \
+	      (unsigned long)s->s_flags, flags, name); \
+} \
+if (ptr) { \
+fprintf(stderr, "unexec: duplicate section header for section %s.\n", \
+	      name); \
+} \
+ptr = s; \
+}
+	CHECK_SCNHDR(f_thdr, _TEXT, STYP_TEXT);
+	CHECK_SCNHDR(f_dhdr, _DATA, STYP_DATA);
+	CHECK_SCNHDR(f_bhdr, _BSS, STYP_BSS);
+	CHECK_SCNHDR(f_lhdr, _LOADER, STYP_LOADER);
+	CHECK_SCNHDR(f_dbhdr, _DEBUG,  STYP_DEBUG);
+	CHECK_SCNHDR(f_tchdr, _TYPCHK,  STYP_TYPCHK);
+	CHECK_SCNHDR(f_xhdr, _EXCEPT,  STYP_EXCEPT);
+}
+if (f_thdr == 0)
+	{
+	  ERROR1 ("unexec: couldn't find \"%s\" section", (int) _TEXT);
+	}
+if (f_dhdr == 0)
+	{
+	  ERROR1 ("unexec: couldn't find \"%s\" section", (int) _DATA);
+	}
+if (f_bhdr == 0)
+	{
+	  ERROR1 ("unexec: couldn't find \"%s\" section", (int) _BSS);
+	}
+}
+else
+{
+ERROR0 ("can't build a COFF file from scratch yet");
+}
+orig_data_scnptr = f_dhdr->s_scnptr;
+orig_load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0;
+/* Now we alter the contents of all the f_*hdr variables
+to correspond to what we want to dump.  */
+/* Indicate that the reloc information is no longer valid for ld (bind);
+we only update it enough to fake out the exec-time loader.  */
+f_hdr.f_flags |= (F_RELFLG | F_EXEC);
+f_ohdr.dsize = bss_start - f_ohdr.data_start;
+f_ohdr.bsize = bss_end - bss_start;
+f_dhdr->s_size = f_ohdr.dsize;
+f_bhdr->s_size = f_ohdr.bsize;
+f_bhdr->s_paddr = f_ohdr.data_start + f_ohdr.dsize;
+f_bhdr->s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
+/* fix scnptr's */
+{
+ulong ptr = section[0].s_scnptr;
+bias = -1;
+for (scns = 0; scns < f_hdr.f_nscns; scns++)
+{
+	struct scnhdr *s = &section[scns];
+	if (s->s_flags & STYP_PAD)        /* .pad sections omitted in AIX 4.1 */
+	  {
+	    /*
+	     * the text_start should probably be o_algntext but that doesn't
+	     * seem to change
+	     */
+	    if (f_ohdr.text_start != 0) /* && scns != 0 */
+	      {
+		s->s_size = 512 - (ptr % 512);
+		if (s->s_size == 512)
+		  s->s_size = 0;
+	      }
+	    s->s_scnptr = ptr;
+	  }
+	else if (s->s_flags & STYP_DATA)
+	  s->s_scnptr = ptr;
+	else if (!(s->s_flags & (STYP_TEXT | STYP_BSS)))
+	  {
+	    if (bias == -1)                /* if first section after bss */
+	      bias = ptr - s->s_scnptr;
+	    s->s_scnptr += bias;
+	    ptr = s->s_scnptr;
+	  }
+	ptr = ptr + s->s_size;
+}
+}
+/* fix other pointers */
+for (scns = 0; scns < f_hdr.f_nscns; scns++)
+{
+struct scnhdr *s = &section[scns];
+if (s->s_relptr != 0)
+	{
+	  s->s_relptr += bias;
+	}
+if (s->s_lnnoptr != 0)
+	{
+	  if (lnnoptr == 0) lnnoptr = s->s_lnnoptr;
+	  s->s_lnnoptr += bias;
+	}
+}
+if (f_hdr.f_symptr > 0L)
+{
+f_hdr.f_symptr += bias;
+}
+text_scnptr = f_thdr->s_scnptr;
+data_scnptr = f_dhdr->s_scnptr;
+load_scnptr = f_lhdr ? f_lhdr->s_scnptr : 0;
+if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+{
+PERROR (new_name);
+}
+if (f_hdr.f_opthdr > 0)
+{
+if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+	{
+	  PERROR (new_name);
+	}
+}
+for (scns = 0; scns < f_hdr.f_nscns; scns++) {
+struct scnhdr *s = &section[scns];
+if (write (new, s, sizeof (*s)) != sizeof (*s))
+{
+	PERROR (new_name);
+}
+}
+return (0);
+}
+/* ****************************************************************
+*
+* Copy the text and data segments from memory to the new a.out
+*/
+static int
+copy_text_and_data (int new)
+{
+char *end;
+char *ptr;
+lseek (new, (long) text_scnptr, SEEK_SET);
+ptr = start_of_text () + text_scnptr;
+end = ptr + f_ohdr.tsize;
+write_segment (new, ptr, end);
+lseek (new, (long) data_scnptr, SEEK_SET);
+ptr = (char *) f_ohdr.data_start;
+end = ptr + f_ohdr.dsize;
+write_segment (new, ptr, end);
+return 0;
+}
+#define UnexBlockSz (1<<12)			/* read/write block size */
+static void
+write_segment (int new, char *ptr, char *end)
+{
+int i, nwrite, ret;
+char buf[80];
+extern int errno;
+char zeros[UnexBlockSz];
+for (i = 0; ptr < end;)
+{
+/* distance to next block.  */
+nwrite = (((int) ptr + UnexBlockSz) & -UnexBlockSz) - (int) ptr;
+/* But not beyond specified end.  */
+if (nwrite > end - ptr) nwrite = end - ptr;
+ret = write (new, ptr, nwrite);
+/* If write gets a page fault, it means we reached
+	 a gap between the old text segment and the old data segment.
+	 This gap has probably been remapped into part of the text segment.
+	 So write zeros for it.  */
+if (ret == -1 && errno == EFAULT)
+	{
+	  memset (zeros, 0, nwrite);
+	  write (new, zeros, nwrite);
+	}
+else if (nwrite != ret)
+	{
+	  sprintf (buf,
+		   "unexec write failure: addr 0x%lx, fileno %d, size 0x%x, wrote 0x%x, errno %d",
+		   (unsigned long)ptr, new, nwrite, ret, errno);
+	  PERROR (buf);
+	}
+i += nwrite;
+ptr += nwrite;
+}
+}
+/* ****************************************************************
+* copy_sym
+*
+* Copy the relocation information and symbol table from the a.out to the new
+*/
+static int
+copy_sym (int new, int a_out, char *a_name, char *new_name)
+{
+char page[UnexBlockSz];
+int n;
+if (a_out < 0)
+return 0;
+if (orig_load_scnptr == 0L)
+return 0;
+if (lnnoptr && lnnoptr < orig_load_scnptr) /* if there is line number info  */
+lseek (a_out, lnnoptr, SEEK_SET);  /* start copying from there */
+else
+lseek (a_out, orig_load_scnptr, SEEK_SET); /* Position a.out to symtab. */
+while ((n = read (a_out, page, sizeof page)) > 0)
+{
+if (write (new, page, n) != n)
+	{
+	  PERROR (new_name);
+	}
+}
+if (n < 0)
+{
+PERROR (a_name);
+}
+return 0;
+}
+/* ****************************************************************
+* mark_x
+*
+* After successfully building the new a.out, mark it executable
+*/
+static void
+mark_x (char *name)
+{
+struct stat sbuf;
+int um;
+int new = 0;  /* for PERROR */
+um = umask (777);
+umask (um);
+if (stat (name, &sbuf) == -1)
+{
+PERROR (name);
+}
+sbuf.st_mode |= 0111 & ~um;
+if (chmod (name, sbuf.st_mode) == -1)
+PERROR (name);
+}
+static int
+adjust_lnnoptrs (int writedesc, int readdesc, char *new_name)
+{
+int nsyms;
+int naux;
+int new;
+struct syment symentry;
+union auxent auxentry;
+if (!lnnoptr || !f_hdr.f_symptr)
+return 0;
+if ((new = open (new_name, O_RDWR)) < 0)
+{
+PERROR (new_name);
+return -1;
+}
+lseek (new, f_hdr.f_symptr, SEEK_SET);
+for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
+{
+read (new, &symentry, SYMESZ);
+if (symentry.n_sclass == C_BINCL || symentry.n_sclass == C_EINCL)
+	{
+	  symentry.n_value += bias;
+	  lseek (new, -SYMESZ, SEEK_CUR);
+	  write (new, &symentry, SYMESZ);
+	}
+for (naux = symentry.n_numaux; naux-- != 0; )
+	{
+	  read (new, &auxentry, AUXESZ);
+	  nsyms++;
+	  if (naux != 0              /* skip csect auxentry (last entry) */
+&& (symentry.n_sclass == C_EXT || symentry.n_sclass == C_HIDEXT))
+{
+auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
+lseek (new, -AUXESZ, SEEK_CUR);
+write (new, &auxentry, AUXESZ);
+}
+	}
+}
+close (new);
+return 0;
+}
+static int
+unrelocate_symbols (int new, int a_out, char *a_name, char *new_name)
+{
+int i;
+LDHDR ldhdr;
+LDREL ldrel;
+ulong t_reloc = (ulong) &_text - f_ohdr.text_start;
+#ifndef ALIGN_DATA_RELOC
+ulong d_reloc = (ulong) &_data - f_ohdr.data_start;
+#else
+/* This worked (and was needed) before AIX 4.2.
+I have no idea why. -- Mike */
+ulong d_reloc = (ulong) &_data - ALIGN(f_ohdr.data_start, 2);
+#endif
+int * p;
+if (load_scnptr == 0)
+return 0;
+lseek (a_out, orig_load_scnptr, SEEK_SET);
+if (read (a_out, &ldhdr, sizeof (ldhdr)) != sizeof (ldhdr))
+{
+PERROR (new_name);
+}
+#define SYMNDX_TEXT	0
+#define SYMNDX_DATA	1
+#define SYMNDX_BSS	2
+for (i = 0; i < ldhdr.l_nreloc; i++)
+{
+lseek (a_out,
+	     orig_load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i,
+	     SEEK_SET);
+if (read (a_out, &ldrel, LDRELSZ) != LDRELSZ)
+	{
+	  PERROR (a_name);
+	}
+/* move the BSS loader symbols to the DATA segment */
+if (ldrel.l_symndx == SYMNDX_BSS)
+	{
+	  ldrel.l_symndx = SYMNDX_DATA;
+	  lseek (new,
+		 load_scnptr + LDHDRSZ + LDSYMSZ*ldhdr.l_nsyms + LDRELSZ*i,
+		 SEEK_SET);
+	  if (write (new, &ldrel, LDRELSZ) != LDRELSZ)
+	    {
+	      PERROR (new_name);
+	    }
+	}
+if (ldrel.l_rsecnm == f_ohdr.o_sndata)
+	{
+	  int orig_int;
+	  lseek (a_out,
+orig_data_scnptr + (ldrel.l_vaddr - f_ohdr.data_start),
+		 SEEK_SET);
+	  if (read (a_out, (void *) &orig_int, sizeof (orig_int))
+	      != sizeof (orig_int))
+	    {
+	      PERROR (a_name);
+	    }
+p = (int *) (ldrel.l_vaddr + d_reloc);
+	  switch (ldrel.l_symndx) {
+	  case SYMNDX_TEXT:
+	    orig_int = * p - t_reloc;
+	    break;
+	  case SYMNDX_DATA:
+	  case SYMNDX_BSS:
+	    orig_int = * p - d_reloc;
+	    break;
+	  }
+if (orig_int != * p)
+{
+lseek (new,
+data_scnptr + (ldrel.l_vaddr - f_ohdr.data_start),
+		     SEEK_SET);
+if (write (new, (void *) &orig_int, sizeof (orig_int))
+!= sizeof (orig_int))
+{
+PERROR (new_name);
+}
+}
+	}
+}
+return 0;
+}

Mercurial > hg > xemacs-beta

comparison src/unexaix.c @ 428:3ecd8885ac67 r21-2-22