--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/unexaix.c	Mon Aug 13 11:28:15 2007 +0200
@@ -0,0 +1,675 @@
+/* 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;
+}