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Diffstat (limited to 'unexec.c')
| -rw-r--r-- | unexec.c | 1238 |
1 files changed, 1238 insertions, 0 deletions
diff --git a/unexec.c b/unexec.c new file mode 100644 index 0000000..f7ff9ca --- /dev/null +++ b/unexec.c @@ -0,0 +1,1238 @@ +/* Copyright (C) 1985,86,87,88,92,93,94 Free Software Foundation, Inc. + +This file is part of GNU Emacs. + +GNU Emacs 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. + +GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + + +/* + * 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. + * On some machines, an existing a_name file is required. + * + * 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. + * The value you specify may be rounded down to a suitable boundary + * as required by the machine you are using. + * + * Specifying zero for data_start means the boundary between text and data + * should not be the same as when the program was loaded. + * If NO_REMAP is defined, the argument data_start is ignored and the + * segment boundaries are never changed. + * + * 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 + * + */ + +/* Modified to support SysVr3 shared libraries by James Van Artsdalen + * of Dell Computer Corporation. james@bigtex.cactus.org. + */ + +/* There are several compilation parameters affecting unexec: + +* COFF + +Define this if your system uses COFF for executables. + +* COFF_ENCAPSULATE + +Define this if you are using the GNU coff encapsulated a.out format. +This is closer to a.out than COFF. You should *not* define COFF if +you define COFF_ENCAPSULATE + +Otherwise we assume you use Berkeley format. + +* NO_REMAP + +Define this if you do not want to try to save Emacs's pure data areas +as part of the text segment. + +Saving them as text is good because it allows users to share more. + +However, on machines that locate the text area far from the data area, +the boundary cannot feasibly be moved. Such machines require +NO_REMAP. + +Also, remapping can cause trouble with the built-in startup routine +/lib/crt0.o, which defines `environ' as an initialized variable. +Dumping `environ' as pure does not work! So, to use remapping, +you must write a startup routine for your machine in Emacs's crt0.c. +If NO_REMAP is defined, Emacs uses the system's crt0.o. + +* SECTION_ALIGNMENT + +Some machines that use COFF executables require that each section +start on a certain boundary *in the COFF file*. Such machines should +define SECTION_ALIGNMENT to a mask of the low-order bits that must be +zero on such a boundary. This mask is used to control padding between +segments in the COFF file. + +If SECTION_ALIGNMENT is not defined, the segments are written +consecutively with no attempt at alignment. This is right for +unmodified system V. + +* SEGMENT_MASK + +Some machines require that the beginnings and ends of segments +*in core* be on certain boundaries. For most machines, a page +boundary is sufficient. That is the default. When a larger +boundary is needed, define SEGMENT_MASK to a mask of +the bits that must be zero on such a boundary. + +* A_TEXT_OFFSET(HDR) + +Some machines count the a.out header as part of the size of the text +segment (a_text); they may actually load the header into core as the +first data in the text segment. Some have additional padding between +the header and the real text of the program that is counted in a_text. + +For these machines, define A_TEXT_OFFSET(HDR) to examine the header +structure HDR and return the number of bytes to add to `a_text' +before writing it (above and beyond the number of bytes of actual +program text). HDR's standard fields are already correct, except that +this adjustment to the `a_text' field has not yet been made; +thus, the amount of offset can depend on the data in the file. + +* A_TEXT_SEEK(HDR) + +If defined, this macro specifies the number of bytes to seek into the +a.out file before starting to write the text segment. + +* EXEC_MAGIC + +For machines using COFF, this macro, if defined, is a value stored +into the magic number field of the output file. + +* ADJUST_EXEC_HEADER + +This macro can be used to generate statements to adjust or +initialize nonstandard fields in the file header + +* ADDR_CORRECT(ADDR) + +Macro to 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 macro has a default definition which is usually right. +This default definition is a no-op on most machines (where a +pointer looks like an int) but not on all machines. + +*/ + +#ifndef emacs +#define PERROR(arg) perror (arg); return -1 +#else +#define IN_UNEXEC +#include <config.h> +#define PERROR(file) report_error (file, new) +#endif + +#ifndef CANNOT_DUMP /* all rest of file! */ + +#ifdef COFF_ENCAPSULATE +int need_coff_header = 1; +#include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */ +#else +#ifdef MSDOS +#if __DJGPP__ > 1 +#include <fcntl.h> /* for O_RDONLY, O_RDWR */ +#include <crt0.h> /* for _crt0_startup_flags and its bits */ +static int save_djgpp_startup_flags; +#endif +#include <coff.h> +#define filehdr external_filehdr +#define scnhdr external_scnhdr +#define syment external_syment +#define auxent external_auxent +#define n_numaux e_numaux +#define n_type e_type +struct aouthdr +{ + unsigned short magic; /* type of file */ + unsigned short vstamp; /* version stamp */ + unsigned long tsize; /* text size in bytes, padded to FW bdry*/ + unsigned long dsize; /* initialized data " " */ + unsigned long bsize; /* uninitialized data " " */ + unsigned long entry; /* entry pt. */ + unsigned long text_start;/* base of text used for this file */ + unsigned long data_start;/* base of data used for this file */ +}; + + +#else /* not MSDOS */ +#include <a.out.h> +#endif /* not MSDOS */ +#endif + +/* Define getpagesize if the system does not. + Note that this may depend on symbols defined in a.out.h. */ +#include "getpagesize.h" + +#ifndef makedev /* Try to detect types.h already loaded */ +#include <sys/types.h> +#endif /* makedev */ +#include <stdio.h> +#include <sys/stat.h> +#include <errno.h> + +#include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/ + +#ifdef USG5 +#include <fcntl.h> +#endif + +#ifndef O_RDONLY +#define O_RDONLY 0 +#endif +#ifndef O_RDWR +#define O_RDWR 2 +#endif + + +extern char *start_of_text (); /* Start of text */ +extern char *start_of_data (); /* Start of initialized data */ + +#ifdef COFF +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 long text_scnptr; +static long data_scnptr; + +#else /* not COFF */ + +#ifdef HPUX +extern void *sbrk (); +#else +#if 0 +/* Some systems with __STDC__ compilers still declare this `char *' in some + header file, and our declaration conflicts. The return value is always + cast, so it should be harmless to leave it undefined. Hopefully + machines with different size pointers and ints declare sbrk in a header + file. */ +#ifdef __STDC__ +extern void *sbrk (); +#else +extern char *sbrk (); +#endif /* __STDC__ */ +#endif +#endif /* HPUX */ + +#define SYMS_START ((long) N_SYMOFF (ohdr)) + +/* Some machines override the structure name for an a.out header. */ +#ifndef EXEC_HDR_TYPE +#define EXEC_HDR_TYPE struct exec +#endif + +#ifdef HPUX +#ifdef HP9000S200_ID +#define MY_ID HP9000S200_ID +#else +#include <model.h> +#define MY_ID MYSYS +#endif /* no HP9000S200_ID */ +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 EXEC_HDR_TYPE hdr, ohdr; + +#else /* not HPUX */ + +#if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (LINUX) +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 /* IRIS or IBMAIX or not USG */ +static EXEC_HDR_TYPE hdr, ohdr; +#define NEWMAGIC ZMAGIC +#endif /* IRIS or IBMAIX not USG */ +#endif /* not HPUX */ + +static int unexec_text_start; +static int unexec_data_start; + +#ifdef COFF_ENCAPSULATE +/* coffheader is defined in the GNU a.out.encap.h file. */ +struct coffheader coffheader; +#endif + +#endif /* not COFF */ + +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 +report_error (file, fd) + 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 +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 +} + +static int make_hdr (); +static int copy_text_and_data (); +static int copy_sym (); +static void mark_x (); + +/* **************************************************************** + * 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, 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, a_out) < 0 + || copy_sym (new, a_out, a_name, new_name) < 0 +#ifdef COFF +#ifndef COFF_BSD_SYMBOLS + || adjust_lnnoptrs (new, a_out, new_name) < 0 +#endif +#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; +#endif /* COFF */ +#ifdef USG_SHARED_LIBRARIES + extern unsigned int bss_end; +#else + unsigned int bss_end; +#endif + + pagemask = getpagesize () - 1; + + /* 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 SEGMENT_MASK + data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */ +#else + data_start = data_start & ~pagemask; /* (Down) to page boundary. */ +#endif + + 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); + } + +#ifdef COFF + /* 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 */ + lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0); + for (scns = f_hdr.f_nscns; scns > 0; scns--) { + if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) + { + PERROR (a_name); + } + if (scntemp.s_scnptr > 0L) + { + if (block_copy_start < scntemp.s_scnptr + scntemp.s_size) + block_copy_start = scntemp.s_scnptr + 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"); + } + + /* Now we alter the contents of all the f_*hdr variables + to correspond to what we want to dump. */ + +#ifdef USG_SHARED_LIBRARIES + + /* The amount of data we're adding to the file is distance from the + * end of the original .data space to the current end of the .data + * space. + */ + + bias = bss_start - (f_ohdr.data_start + f_dhdr.s_size); + +#endif + + f_hdr.f_flags |= (F_RELFLG | F_EXEC); +#ifdef TPIX + f_hdr.f_nscns = 3; +#endif +#ifdef EXEC_MAGIC + f_ohdr.magic = EXEC_MAGIC; +#endif +#ifndef NO_REMAP + f_ohdr.text_start = (long) start_of_text (); + f_ohdr.tsize = data_start - f_ohdr.text_start; + f_ohdr.data_start = data_start; +#endif /* NO_REMAP */ + f_ohdr.dsize = bss_start - f_ohdr.data_start; + f_ohdr.bsize = bss_end - bss_start; +#ifndef KEEP_OLD_TEXT_SCNPTR + /* On some machines, the old values are right. + ??? Maybe on all machines with NO_REMAP. */ + 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)); +#endif /* KEEP_OLD_TEXT_SCNPTR */ +#ifdef ADJUST_TEXT_SCNHDR_SIZE + /* On some machines, `text size' includes all headers. */ + f_thdr.s_size -= f_thdr.s_scnptr; +#endif /* ADJUST_TEST_SCNHDR_SIZE */ + lnnoptr = f_thdr.s_lnnoptr; +#ifdef SECTION_ALIGNMENT + /* Some systems require special alignment + of the sections in the file itself. */ + f_thdr.s_scnptr + = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; +#endif /* SECTION_ALIGNMENT */ +#ifdef TPIX + f_thdr.s_scnptr = 0xd0; +#endif + text_scnptr = f_thdr.s_scnptr; +#ifdef ADJUST_TEXTBASE + text_scnptr = sizeof (f_hdr) + sizeof (f_ohdr) + (f_hdr.f_nscns) * (sizeof (f_thdr)); +#endif +#ifndef KEEP_OLD_PADDR + f_dhdr.s_paddr = f_ohdr.data_start; +#endif /* KEEP_OLD_PADDR */ + 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 SECTION_ALIGNMENT + /* Some systems require special alignment + of the sections in the file itself. */ + f_dhdr.s_scnptr + = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; +#endif /* SECTION_ALIGNMENT */ +#ifdef DATA_SECTION_ALIGNMENT + /* Some systems require special alignment + of the data section only. */ + f_dhdr.s_scnptr + = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT; +#endif /* DATA_SECTION_ALIGNMENT */ + data_scnptr = f_dhdr.s_scnptr; +#ifndef KEEP_OLD_PADDR + f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize; +#endif /* KEEP_OLD_PADDR */ + f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize; + f_bhdr.s_size = f_ohdr.bsize; + f_bhdr.s_scnptr = 0L; +#ifndef USG_SHARED_LIBRARIES + bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start; +#endif + + if (f_hdr.f_symptr > 0L) + { + f_hdr.f_symptr += bias; + } + + if (f_thdr.s_lnnoptr > 0L) + { + f_thdr.s_lnnoptr += bias; + } + +#ifdef ADJUST_EXEC_HEADER + ADJUST_EXEC_HEADER; +#endif /* ADJUST_EXEC_HEADER */ + + 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); + } + +#ifndef USG_SHARED_LIBRARIES + + 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); + } + +#else /* USG_SHARED_LIBRARIES */ + + /* The purpose of this code is to write out the new file's section + * header table. + * + * Scan through the original file's sections. If the encountered + * section is one we know (.text, .data or .bss), write out the + * correct header. If it is a section we do not know (such as + * .lib), adjust the address of where the section data is in the + * file, and write out the header. + * + * If any section precedes .text or .data in the file, this code + * will not adjust the file pointer for that section correctly. + */ + + /* This used to use sizeof (f_ohdr) instead of .f_opthdr. + .f_opthdr is said to be right when there is no optional header. */ + lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0); + + for (scns = f_hdr.f_nscns; scns > 0; scns--) + { + if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) + PERROR (a_name); + + if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */ + { + if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr)) + PERROR (new_name); + } + else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */ + { + if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr)) + PERROR (new_name); + } + else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */ + { + if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr)) + PERROR (new_name); + } + else + { + if (scntemp.s_scnptr) + scntemp.s_scnptr += bias; + if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) + PERROR (new_name); + } + } +#endif /* USG_SHARED_LIBRARIES */ + + return (0); + +#else /* if not COFF */ + + /* Get symbol table info from header of a.out file if given one. */ + if (a_out >= 0) + { +#ifdef COFF_ENCAPSULATE + if (read (a_out, &coffheader, sizeof coffheader) != sizeof coffheader) + { + PERROR(a_name); + } + if (coffheader.f_magic != COFF_MAGIC) + { + ERROR1("%s doesn't have legal coff magic number\n", a_name); + } +#endif + if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr) + { + PERROR (a_name); + } + + if (N_BADMAG (ohdr)) + { + ERROR1 ("invalid magic number in %s", a_name); + } + hdr = ohdr; + } + else + { +#ifdef COFF_ENCAPSULATE + /* We probably could without too much trouble. The code is in gld + * but I don't have that much time or incentive. + */ + ERROR0 ("can't build a COFF file from scratch yet"); +#else +#ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */ + bzero ((void *)&hdr, sizeof hdr); +#else + bzero (&hdr, sizeof hdr); +#endif +#endif + } + + unexec_text_start = (long) start_of_text (); + unexec_data_start = data_start; + + /* Machine-dependent fixup for header, or maybe for unexec_text_start */ +#ifdef ADJUST_EXEC_HEADER + ADJUST_EXEC_HEADER; +#endif /* ADJUST_EXEC_HEADER */ + + hdr.a_trsize = 0; + hdr.a_drsize = 0; + if (entry_address != 0) + hdr.a_entry = entry_address; + + hdr.a_bss = bss_end - bss_start; + hdr.a_data = bss_start - data_start; +#ifdef NO_REMAP + hdr.a_text = ohdr.a_text; +#else /* not NO_REMAP */ + hdr.a_text = data_start - unexec_text_start; + +#ifdef A_TEXT_OFFSET + hdr.a_text += A_TEXT_OFFSET (ohdr); +#endif + +#endif /* not NO_REMAP */ + +#ifdef COFF_ENCAPSULATE + /* We are encapsulating BSD format within COFF format. */ + { + struct coffscn *tp, *dp, *bp; + tp = &coffheader.scns[0]; + dp = &coffheader.scns[1]; + bp = &coffheader.scns[2]; + tp->s_size = hdr.a_text + sizeof(struct exec); + dp->s_paddr = data_start; + dp->s_vaddr = data_start; + dp->s_size = hdr.a_data; + bp->s_paddr = dp->s_vaddr + dp->s_size; + bp->s_vaddr = bp->s_paddr; + bp->s_size = hdr.a_bss; + coffheader.tsize = tp->s_size; + coffheader.dsize = dp->s_size; + coffheader.bsize = bp->s_size; + coffheader.text_start = tp->s_vaddr; + coffheader.data_start = dp->s_vaddr; + } + if (write (new, &coffheader, sizeof coffheader) != sizeof coffheader) + { + PERROR(new_name); + } +#endif /* COFF_ENCAPSULATE */ + + if (write (new, &hdr, sizeof hdr) != sizeof hdr) + { + PERROR (new_name); + } + +#if 0 /* This #ifndef caused a bug on Linux when using QMAGIC. */ + /* This adjustment was done above only #ifndef NO_REMAP, + so only undo it now #ifndef NO_REMAP. */ + /* #ifndef NO_REMAP */ +#endif +#ifdef A_TEXT_OFFSET + hdr.a_text -= A_TEXT_OFFSET (ohdr); +#endif + + return 0; + +#endif /* not COFF */ +} + +/* **************************************************************** + * copy_text_and_data + * + * Copy the text and data segments from memory to the new a.out + */ +static int +copy_text_and_data (new, a_out) + int new, a_out; +{ + register char *end; + register char *ptr; + +#ifdef COFF + +#ifdef USG_SHARED_LIBRARIES + + int scns; + struct scnhdr scntemp; /* Temporary section header */ + + /* The purpose of this code is to write out the new file's section + * contents. + * + * Step through the section table. If we know the section (.text, + * .data) do the appropriate thing. Otherwise, if the section has + * no allocated space in the file (.bss), do nothing. Otherwise, + * the section has space allocated in the file, and is not a section + * we know. So just copy it. + */ + + lseek (a_out, sizeof (struct filehdr) + sizeof (struct aouthdr), 0); + + for (scns = f_hdr.f_nscns; scns > 0; scns--) + { + if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) + PERROR ("temacs"); + + if (!strcmp (scntemp.s_name, ".text")) + { + lseek (new, (long) text_scnptr, 0); + ptr = (char *) f_ohdr.text_start; + end = ptr + f_ohdr.tsize; + write_segment (new, ptr, end); + } + else if (!strcmp (scntemp.s_name, ".data")) + { + lseek (new, (long) data_scnptr, 0); + ptr = (char *) f_ohdr.data_start; + end = ptr + f_ohdr.dsize; + write_segment (new, ptr, end); + } + else if (!scntemp.s_scnptr) + ; /* do nothing - no data for this section */ + else + { + char page[BUFSIZ]; + int size, n; + long old_a_out_ptr = lseek (a_out, 0, 1); + + lseek (a_out, scntemp.s_scnptr, 0); + for (size = scntemp.s_size; size > 0; size -= sizeof (page)) + { + n = size > sizeof (page) ? sizeof (page) : size; + if (read (a_out, page, n) != n || write (new, page, n) != n) + PERROR ("emacs"); + } + lseek (a_out, old_a_out_ptr, 0); + } + } + +#else /* COFF, but not USG_SHARED_LIBRARIES */ + +#ifdef MSDOS +#if __DJGPP__ >= 2 + /* Dump the original table of exception handlers, not the one + where our exception hooks are registered. */ + __djgpp_exception_toggle (); + + /* Switch off startup flags that might have been set at runtime + and which might change the way that dumped Emacs works. */ + save_djgpp_startup_flags = _crt0_startup_flags; + _crt0_startup_flags &= ~(_CRT0_FLAG_NO_LFN | _CRT0_FLAG_NEARPTR); +#endif +#endif + + lseek (new, (long) text_scnptr, 0); + ptr = (char *) f_ohdr.text_start; +#ifdef HEADER_INCL_IN_TEXT + /* For Gould UTX/32, text starts after headers */ + ptr = (char *) (ptr + text_scnptr); +#endif /* HEADER_INCL_IN_TEXT */ + end = ptr + f_ohdr.tsize; + write_segment (new, ptr, end); + + lseek (new, (long) data_scnptr, 0); + ptr = (char *) f_ohdr.data_start; + end = ptr + f_ohdr.dsize; + write_segment (new, ptr, end); + +#ifdef MSDOS +#if __DJGPP__ >= 2 + /* Restore our exception hooks. */ + __djgpp_exception_toggle (); + + /* Restore the startup flags. */ + _crt0_startup_flags = save_djgpp_startup_flags; +#endif +#endif + +#endif /* USG_SHARED_LIBRARIES */ + +#else /* if not COFF */ + +/* Some machines count the header as part of the text segment. + That is to say, the header appears in core + just before the address that start_of_text returns. + For them, N_TXTOFF is the place where the header goes. + We must adjust the seek to the place after the header. + Note that at this point hdr.a_text does *not* count + the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */ + +#ifdef A_TEXT_SEEK + lseek (new, (long) A_TEXT_SEEK (hdr), 0); +#else + lseek (new, (long) N_TXTOFF (hdr), 0); +#endif /* no A_TEXT_SEEK */ + +#ifdef RISCiX + + /* Acorn's RISC-iX has a wacky way of initialising the position of the heap. + * There is a little table in crt0.o that is filled at link time with + * the min and current brk positions, among other things. When start + * runs, it copies the table to where these parameters live during + * execution. This data is in text space, so it cannot be modified here + * before saving the executable, so the data is written manually. In + * addition, the table does not have a label, and the nearest accessible + * label (mcount) is not prefixed with a '_', thus making it inaccessible + * from within C programs. To overcome this, emacs's executable is passed + * through the command 'nm %s | fgrep mcount' into a pipe, and the + * resultant output is then used to find the address of 'mcount'. As far as + * is possible to determine, in RISC-iX releases prior to 1.2, the negative + * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is + * 0x30. bss_end has been rounded up to page boundary. This solution is + * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and + * avoids the need for a custom version of crt0.o for emacs which has its + * table in data space. + */ + + { + char command[1024]; + char errbuf[1024]; + char address_text[32]; + int proforma[4]; + FILE *pfile; + char *temp_ptr; + char c; + int mcount_address, mcount_offset, count; + extern char *_execname; + + + /* The use of _execname is incompatible with RISCiX 1.1 */ + sprintf (command, "nm %s | fgrep mcount", _execname); + + if ( (pfile = popen(command, "r")) == NULL) + { + sprintf (errbuf, "Could not open pipe"); + PERROR (errbuf); + } + + count=0; + while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31)) + address_text[count++]=c; + address_text[count]=0; + + if ((count == 0) || pclose(pfile) != NULL) + { + sprintf (errbuf, "Failed to execute the command '%s'\n", command); + PERROR (errbuf); + } + + sscanf(address_text, "%x", &mcount_address); + ptr = (char *) unexec_text_start; + mcount_offset = (char *)mcount_address - ptr; + +#ifdef RISCiX_1_1 +#define EDATA_OFFSET 0x2c +#else +#define EDATA_OFFSET 0x30 +#endif + + end = ptr + mcount_offset - EDATA_OFFSET; + + write_segment (new, ptr, end); + + proforma[0] = bss_end; /* becomes _edata */ + proforma[1] = bss_end; /* becomes _end */ + proforma[2] = bss_end; /* becomes _minbrk */ + proforma[3] = bss_end; /* becomes _curbrk */ + + write (new, proforma, 16); + + temp_ptr = ptr; + ptr = end + 16; + end = temp_ptr + hdr.a_text; + + write_segment (new, ptr, end); + } + +#else /* !RISCiX */ + ptr = (char *) unexec_text_start; + end = ptr + hdr.a_text; + write_segment (new, ptr, end); +#endif /* RISCiX */ + + ptr = (char *) unexec_data_start; + end = ptr + hdr.a_data; +/* This lseek is certainly incorrect when A_TEXT_OFFSET + and I believe it is a no-op otherwise. + Let's see if its absence ever fails. */ +/* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */ + write_segment (new, ptr, end); + +#endif /* not COFF */ + + return 0; +} + +write_segment (new, ptr, end) + int new; + register char *ptr, *end; +{ + register int i, nwrite, ret; + char buf[80]; + extern int errno; + /* This is the normal amount to write at once. + It is the size of block that NFS uses. */ + int writesize = 1 << 13; + int pagesize = getpagesize (); + char zeros[1 << 13]; + + bzero (zeros, sizeof (zeros)); + + for (i = 0; ptr < end;) + { + /* Distance to next multiple of writesize. */ + nwrite = (((int) ptr + writesize) & -writesize) - (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 +#ifdef EFAULT + && errno == EFAULT +#endif + ) + { + /* Write only a page of zeros at once, + so that we we don't overshoot the start + of the valid memory in the old data segment. */ + if (nwrite > pagesize) + nwrite = pagesize; + write (new, zeros, nwrite); + } +#if 0 /* Now that we have can ask `write' to write more than a page, + it is legit for write do less than the whole amount specified. */ + 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); + } +#endif + i += nwrite; + ptr += nwrite; + } +} + +/* **************************************************************** + * 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 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. */ + + 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 (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); +} + +#ifdef COFF +#ifndef COFF_BSD_SYMBOLS + +/* + * 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. + */ + +/* 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; +#if defined (amdahl_uts) || defined (pfa) + SYMENT symentry; + AUXENT auxentry; +#else + struct syment symentry; + union auxent auxentry; +#endif + + if (!lnnoptr || !f_hdr.f_symptr) + return 0; + +#ifdef MSDOS + if ((new = writedesc) < 0) +#else + if ((new = open (new_name, O_RDWR)) < 0) +#endif + { + 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) || symentry.n_type == 0x2400) + { + auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias; + lseek (new, -AUXESZ, 1); + write (new, &auxentry, AUXESZ); + } + } + } +#ifndef MSDOS + close (new); +#endif + return 0; +} + +#endif /* COFF_BSD_SYMBOLS */ + +#endif /* COFF */ + +#endif /* not CANNOT_DUMP */ |