+/* Copyright (C) 1985 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY. No author or distributor
+accepts responsibility to anyone for the consequences of using it
+or for whether it serves any particular purpose or works at all,
+unless he says so in writing. Refer to the GNU Emacs General Public
+License for full details.
+
+Everyone is granted permission to copy, modify and redistribute
+GNU Emacs, but only under the conditions described in the
+GNU Emacs General Public License. A copy of this license is
+supposed to have been given to you along with GNU Emacs so you
+can know your rights and responsibilities. It should be in a
+file named COPYING. Among other things, the copyright notice
+and this notice must be preserved on all copies. */
+
+
+/*
+ * unexec.c - Convert a running program into an a.out file.
+ *
+ * Author: Spencer W. Thomas
+ * Computer Science Dept.
+ * University of Utah
+ * Date: Tue Mar 2 1982
+ * Modified heavily since then.
+ *
+ * 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.
+ *
+ * The boundaries within the a.out file may be adjusted with the data_start
+ * and bss_start arguments. Either or both may be given as 0 for defaults.
+ *
+ * Data_start gives the boundary between the text segment and the data
+ * segment of the program. The text segment can contain shared, read-only
+ * program code and literal data, while the data segment is always unshared
+ * and unprotected. Data_start gives the lowest unprotected address. Since
+ * the granularity of write-protection is on 1k page boundaries on the VAX, a
+ * given data_start value which is not on a page boundary is rounded down to
+ * the beginning of the page it is on. The default when 0 is given leaves the
+ * number of protected pages the same as it was before.
+ *
+ * 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
+ * break (2).
+ *
+ * The new file is set up to start at entry_address.
+ *
+ * If you make improvements I'd like to get them too.
+ * harpo!utah-cs!thomas, thomas@Utah-20
+ *
+ */
+
+#ifndef emacs
+#define PERROR(arg) perror (arg); return -1
+#else
+#include "config.h"
+#define PERROR(file) report_error (file, new)
+#endif
+
+#ifndef CANNOT_DUMP /* all rest of file! */
+
+#include <sys/param.h>
+#ifndef makedev /* Try to detect types.h already loaded */
+#include <sys/types.h>
+#endif
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+extern char *start_of_text (); /* Start of text */
+extern char *start_of_data (); /* Start of initialized data */
+
+#ifdef COFF
+#include <filehdr.h>
+#include <aouthdr.h>
+#include <scnhdr.h>
+#include <syms.h>
+static long block_copy_start; /* Old executable start point */
+static struct filehdr f_hdr; /* File header */
+static struct aouthdr f_ohdr; /* Optional file header (a.out) */
+long bias; /* Bias to add for growth */
+long lnnoptr; /* Pointer to line-number info within file */
+#define SYMS_START block_copy_start
+
+static int text_scnptr;
+
+#else /* not COFF */
+
+extern char *sbrk ();
+
+#include <a.out.h>
+#define SYMS_START ((long) N_SYMOFF (ohdr))
+
+#ifdef HPUX
+#ifdef hp9000s200
+#define MY_ID HP9000S200_ID
+#else
+#include <model.h>
+#define MY_ID MYSYS
+#endif /* not hp9000s200 */
+static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
+static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
+#define N_TXTOFF(x) TEXT_OFFSET(x)
+#define N_SYMOFF(x) LESYM_OFFSET(x)
+static struct exec hdr, ohdr;
+
+#else /* not HPUX */
+
+#ifdef USG
+static struct bhdr hdr, ohdr;
+#define a_magic fmagic
+#define a_text tsize
+#define a_data dsize
+#define a_bss bsize
+#define a_syms ssize
+#define a_trsize rtsize
+#define a_drsize rdsize
+#define a_entry entry
+#define N_BADMAG(x) \
+ (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
+ ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
+#define NEWMAGIC FMAGIC
+#else /* not USG */
+static struct exec hdr, ohdr;
+#define NEWMAGIC ZMAGIC
+#endif /* not USG */
+#endif /* not HPUX */
+
+#endif /* not COFF */
+
+static int pagemask;
+
+#if defined (BSD4_1) || defined (USG)
+#ifdef EXEC_PAGESIZE
+#define getpagesize() EXEC_PAGESIZE
+#else
+#ifdef NBPG
+#define getpagesize() NBPG * CLSIZE
+#ifndef CLSIZE
+#define CLSIZE 1
+#endif /* no CLSIZE */
+#else /* no NBPG */
+#define getpagesize() NBPC
+#endif /* no NBPG */
+#endif /* no EXEC_PAGESIZE */
+#endif /* BSD4_1 or USG */
+
+/* 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
+
+static
+report_error (file, fd)
+ char *file;
+ int fd;
+{
+ if (fd)
+ close (fd);
+ error ("Failure operating on %s", file);
+}
+#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
+report_error_1 (fd, msg, a1, a2)
+ int fd;
+ char *msg;
+ int a1, a2;
+{
+ close (fd);
+#ifdef emacs
+ error (msg, a1, a2);
+#else
+ fprintf (stderr, msg, a1, a2);
+ fprintf (stderr, "\n");
+#endif
+}
+\f
+/* ****************************************************************
+ * unexec
+ *
+ * driving logic.
+ */
+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, a_out = -1;
+
+ if (a_name && (a_out = open (a_name, 0)) < 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
+#ifdef COFF
+ || adjust_lnnoptrs (new, a_out, new_name) < 0
+#endif
+ )
+ {
+ close (new);
+ /* unlink (new_name); /* Failed, unlink new a.out */
+ 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 (new, a_out, data_start, bss_start, entry_address, a_name, new_name)
+ int new, a_out;
+ unsigned data_start, bss_start, entry_address;
+ char *a_name;
+ char *new_name;
+{
+ int tem;
+#ifdef COFF
+ auto struct scnhdr f_thdr; /* Text section header */
+ auto struct scnhdr f_dhdr; /* Data section header */
+ auto struct scnhdr f_bhdr; /* Bss section header */
+ auto struct scnhdr scntemp; /* Temporary section header */
+ register int scns;
+
+ /* Salvage as much info from the existing file as possible */
+ if (a_out >= 0)
+ {
+ if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+ {
+ PERROR (a_name);
+ }
+ block_copy_start += sizeof (f_hdr);
+ if (f_hdr.f_opthdr > 0)
+ {
+ if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+ {
+ PERROR (a_name);
+ }
+ block_copy_start += sizeof (f_ohdr);
+ }
+ /* Loop through section headers, copying them in */
+ for (scns = f_hdr.f_nscns; scns > 0; scns--) {
+ if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
+ {
+ PERROR (a_name);
+ }
+ block_copy_start += sizeof (scntemp);
+ if (scntemp.s_scnptr > 0L)
+ {
+ block_copy_start += scntemp.s_size;
+ }
+ if (strcmp (scntemp.s_name, ".text") == 0)
+ {
+ f_thdr = scntemp;
+ }
+ else if (strcmp (scntemp.s_name, ".data") == 0)
+ {
+ f_dhdr = scntemp;
+ }
+ else if (strcmp (scntemp.s_name, ".bss") == 0)
+ {
+ f_bhdr = scntemp;
+ }
+ }
+ }
+ else
+ {
+ ERROR0 ("can't build a COFF file from scratch yet");
+ }
+
+ pagemask = getpagesize () - 1;
+
+#ifdef NO_REMAP
+ data_start = (int) start_of_data ();
+#else /* not NO_REMAP */
+ if (!data_start)
+ data_start = (int) start_of_data ();
+#endif /* not NO_REMAP */
+ data_start = ADDR_CORRECT (data_start);
+ data_start = data_start & ~pagemask; /* down to a page boundary */
+
+ f_hdr.f_flags |= (F_RELFLG | F_EXEC);
+#ifdef EXEC_MAGIC
+ f_ohdr.magic = EXEC_MAGIC;
+#endif
+ f_ohdr.text_start = (long) start_of_text ();
+ f_ohdr.tsize = data_start - f_ohdr.text_start;
+ f_ohdr.data_start = data_start;
+ f_ohdr.dsize = (long) sbrk (0) - f_ohdr.data_start;
+ f_ohdr.bsize = 0;
+ f_thdr.s_size = f_ohdr.tsize;
+ f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr);
+ f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr));
+ lnnoptr = f_thdr.s_lnnoptr;
+#ifdef UMAX
+ /* Umax is bsd using coff; it has restrictions on alignment
+ of the sections in the file itself. */
+ f_thdr.s_scnptr = (f_thdr.s_scnptr + pagemask) & ~pagemask; /* round up */
+#endif /* UMAX */
+ text_scnptr = f_thdr.s_scnptr;
+ f_dhdr.s_paddr = f_ohdr.data_start;
+ f_dhdr.s_vaddr = f_ohdr.data_start;
+ f_dhdr.s_size = f_ohdr.dsize;
+ f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size;
+#ifdef UMAX
+ f_dhdr.s_scnptr &= ~pagemask; /* round down to page boundary */
+#endif /* UMAX */
+ f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
+ f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
+ f_bhdr.s_size = f_ohdr.bsize;
+ f_bhdr.s_scnptr = 0L;
+ bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
+
+ if (f_hdr.f_symptr > 0L)
+ {
+ f_hdr.f_symptr += bias;
+ }
+
+ if (f_thdr.s_lnnoptr > 0L)
+ {
+ f_thdr.s_lnnoptr += bias;
+ }
+
+ if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
+ {
+ PERROR (new_name);
+ }
+ return (0);
+
+#else /* if not COFF */
+
+ /* Get symbol table info from header of a.out file if given one. */
+ if (a_out >= 0)
+ {
+ if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr)
+ {
+ PERROR (a_name);
+ }
+
+ if N_BADMAG (ohdr)
+ {
+ ERROR1 ("invalid magic number in %s", a_name);
+ }
+#ifdef celerity
+ hdr.a_scovrfl = ohdr.a_scovrfl;
+#endif
+#ifdef HPUX
+ hdr.a_lesyms = ohdr.a_lesyms;
+ hdr.a_sltsize = ohdr.a_sltsize;
+ hdr.a_dnttsize = ohdr.a_dnttsize;
+ hdr.a_vtsize = ohdr.a_vtsize;
+#else /* not HPUX */
+ hdr.a_syms = ohdr.a_syms;
+#endif /* not HPUX */
+ }
+ else
+ {
+#ifdef celerity
+ hdr.a_scovrfl = 0;
+#endif
+#ifdef HPUX
+ hdr.a_lesyms = 0;
+ hdr.a_sltsize = 0;
+ hdr.a_dnttsize = 0;
+ hdr.a_vtsize = 0;
+#else /* not HPUX */
+ hdr.a_syms = 0; /* No a.out, so no symbol info. */
+#endif /* not HPUX */
+ }
+
+ /* Construct header from user structure. */
+#ifdef HPUX
+ /* (((MAGIC) ohdr.a_magic) == ((MAGIC) OLDMAGIC)) This does not work */
+ hdr.a_magic = ((ohdr.a_magic.file_type == OLDMAGIC.file_type) ?
+ NEWMAGIC : ohdr.a_magic);
+#else /* not HPUX */
+/* hdr.a_magic = NEWMAGIC; */
+ hdr.a_magic = ohdr.a_magic;
+#endif /* not HPUX */
+
+#ifdef sun3
+ hdr.a_machtype = ohdr.a_machtype;
+#endif /* sun3 */
+ hdr.a_trsize = 0;
+ hdr.a_drsize = 0;
+ hdr.a_entry = entry_address;
+
+ pagemask = getpagesize () - 1;
+
+ /* Adjust data/bss boundary. */
+ if (bss_start != 0)
+ {
+ bss_start = (ADDR_CORRECT (bss_start) + pagemask) & ~pagemask; /* (Up) to page bdry. */
+ if (bss_start > ADDR_CORRECT (sbrk (0)))
+ {
+ ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
+ bss_start);
+ }
+ }
+ else
+ {
+ bss_start = ADDR_CORRECT (sbrk (0));
+ bss_start = (bss_start + pagemask) & ~pagemask;
+ }
+
+ /* Adjust text/data boundary. */
+#ifdef NO_REMAP
+ data_start = (int) start_of_data ();
+#else /* not NO_REMAP */
+ if (!data_start)
+ data_start = (int) start_of_data ();
+#endif /* not NO_REMAP */
+ data_start = ADDR_CORRECT (data_start);
+
+#ifdef sun
+ data_start = data_start & ~(SEGSIZ - 1); /* (Down) to segment boundary. */
+#else
+ data_start = data_start & ~pagemask; /* (Down) to page boundary. */
+#endif
+
+ 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);
+ }
+
+ tem = ADDR_CORRECT (sbrk (0));
+ hdr.a_bss = tem - bss_start;
+ if (tem < bss_start) /* Note a_bss is unsigned on some systems */
+ hdr.a_bss = 0;
+ hdr.a_data = bss_start - data_start;
+#if defined(sequent)
+ hdr.a_text = data_start - (long) start_of_text () + sizeof(hdr) + N_ADDRADJ(ohdr);
+#else
+ hdr.a_text = data_start - (long) start_of_text ();
+#endif /* not sequent */
+
+ if (write (new, &hdr, sizeof hdr) != sizeof hdr)
+ {
+ PERROR (new_name);
+ }
+ return 0;
+
+#endif /* not COFF */
+}
+\f
+/* ****************************************************************
+ * copy_text_and_data
+ *
+ * Copy the text and data segments from memory to the new a.out
+ */
+static int
+copy_text_and_data (new)
+ int new;
+{
+ register int nwrite, ret;
+ register char *end;
+ int i;
+ register char *ptr;
+ char buf[80];
+ extern int errno;
+
+#ifdef COFF
+ lseek (new, (long) text_scnptr, 0);
+ ptr = (char *) f_ohdr.text_start;
+ end = ptr + f_ohdr.tsize + f_ohdr.dsize;
+ while (ptr < end)
+ {
+ nwrite = 128;
+ if (nwrite > end - ptr) nwrite = end - ptr;
+ ret = write (new, ptr, nwrite);
+ if (nwrite != ret)
+ {
+ sprintf (buf,
+ "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
+ ptr, new, nwrite, ret, errno);
+ PERROR (buf);
+ }
+ ptr += nwrite;
+ }
+ return (0);
+
+#else /* if not COFF */
+
+#if defined(sun3) || defined(sequent)
+ lseek (new, (long) (N_TXTOFF (hdr) + sizeof (hdr)), 0);
+#else
+ lseek (new, (long) N_TXTOFF (hdr), 0);
+#endif
+
+ ptr = start_of_text ();
+ end = ptr + hdr.a_text + hdr.a_data;
+#if defined(sequent)
+ end -= (sizeof(hdr) + N_ADDRADJ(hdr));
+#endif
+ for (i = 0; ptr < end;)
+ {
+ nwrite = 128;
+ if (nwrite > end - ptr) nwrite = end - ptr;
+ ret = write (new, ptr, nwrite);
+ if (ret == -1 && errno == EFAULT)
+ {
+ /* BZS - again, see above about N_TXTOFF on a SUN */
+#if defined(sun3) || defined(sequent)
+ lseek (new, (long) (N_TXTOFF (hdr) + i + nwrite + sizeof (hdr)), 0);
+#else
+ lseek (new, (long) (N_TXTOFF (hdr) + i + nwrite), 0);
+#endif
+ }
+ else if (nwrite != ret)
+ {
+ sprintf (buf,
+ "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
+ ptr, new, nwrite, ret, errno);
+ PERROR (buf);
+ }
+ i += nwrite;
+ ptr += nwrite;
+ }
+
+ return 0;
+#endif /* not COFF */
+}
+\f
+/* ****************************************************************
+ * copy_sym
+ *
+ * Copy the relocation information and symbol table from the a.out to the new
+ */
+static int
+copy_sym (new, a_out, a_name, new_name)
+ int new, a_out;
+ char *a_name, *new_name;
+{
+ char page[1024];
+ int n;
+
+ if (a_out < 0)
+ return 0;
+
+#ifdef COFF
+ if (SYMS_START == 0L)
+ return 0;
+#endif /* COFF */
+
+#ifdef sun3
+ /* BZS - I might be covering a sin with this */
+ lseek (new, N_SYMOFF (hdr), 0);
+#else
+#ifdef COFF
+ if (lnnoptr) /* if there is line number info */
+ lseek (a_out, lnnoptr, 0); /* start copying from there */
+ else
+#endif /* COFF */
+ lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */
+#endif
+ 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;
+}
+\f
+/* ****************************************************************
+ * mark_x
+ *
+ * After succesfully building the new a.out, mark it executable
+ */
+static
+mark_x (name)
+ 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);
+}
+\f
+/*
+ * If the COFF file contains a symbol table and a line number section,
+ * then any auxiliary entries that have values for x_lnnoptr must
+ * be adjusted by the amount that the line number section has moved
+ * in the file (bias computed in make_hdr). The #@$%&* designers of
+ * the auxiliary entry structures used the absolute file offsets for
+ * the line number entry rather than an offset from the start of the
+ * line number section!
+ *
+ * When I figure out how to scan through the symbol table and pick out
+ * the auxiliary entries that need adjustment, this routine will
+ * be fixed. As it is now, all such entries are wrong and sdb
+ * will complain. Fred Fish, UniSoft Systems Inc.
+ */
+
+#ifdef COFF
+
+/* This function is probably very slow. Instead of reopening the new
+ file for input and output it should copy from the old to the new
+ using the two descriptors already open (WRITEDESC and READDESC).
+ Instead of reading one small structure at a time it should use
+ a reasonable size buffer. But I don't have time to work on such
+ things, so I am installing it as submitted to me. -- RMS. */
+
+adjust_lnnoptrs (writedesc, readdesc, new_name)
+ int writedesc;
+ int readdesc;
+ char *new_name;
+{
+ register int nsyms;
+ register int new;
+ struct syment symentry;
+ struct auxent auxentry;
+
+ if (!lnnoptr || !f_hdr.f_symptr)
+ return 0;
+
+ if ((new = open (new_name, 2)) < 0)
+ {
+ PERROR (new_name);
+ return -1;
+ }
+
+ lseek (new, f_hdr.f_symptr, 0);
+ for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
+ {
+ read (new, &symentry, SYMESZ);
+ if (symentry.n_numaux)
+ {
+ read (new, &auxentry, AUXESZ);
+ nsyms++;
+ if (ISFCN (symentry.n_type)) {
+ auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
+ lseek (new, -AUXESZ, 1);
+ write (new, &auxentry, AUXESZ);
+ }
+ }
+ }
+ close (new);
+}
+
+#endif /* COFF */
+
+#endif /* not CANNOT_DUMP */
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