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Diffstat (limited to 'src/unexconvex.c')
| -rw-r--r-- | src/unexconvex.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/src/unexconvex.c b/src/unexconvex.c new file mode 100644 index 00000000000..09a7dfff400 --- /dev/null +++ b/src/unexconvex.c @@ -0,0 +1,601 @@ +/* Modified version of unexec for convex machines. + Note that the GNU project considers support for the peculiarities + of the Convex operating system 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 Convex system + maintainers send them in, but aside from that we don't plan to + think about it, or about whether other Emacs maintenance might + break it. + + Copyright (C) 1985, 1986, 1988 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ + + +/* modified for C-1 arch by jthomp@convex 871103 */ +/* Corrected to support convex SOFF object file formats and thread specific + * regions. streepy@convex 890302 +*/ + +/* + * 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 + * + */ + +/* There are several compilation parameters affecting unexec: + +* COFF + +Define this if your system uses COFF for executables. +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.a + +* 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. + +*/ + +#include "config.h" +#define PERROR(file) report_error (file, new) + +#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> + +extern char *start_of_text (); /* Start of text */ +extern char *start_of_data (); /* Start of initialized data */ + +#include <machine/filehdr.h> +#include <machine/opthdr.h> +#include <machine/scnhdr.h> +#include <machine/pte.h> + +static long block_copy_start; /* Old executable start point */ +static struct filehdr f_hdr; /* File header */ +static struct opthdr f_ohdr; /* Optional file header (a.out) */ +long bias; /* Bias to add for growth */ +#define SYMS_START block_copy_start + +static long text_scnptr; +static long data_scnptr; + +static int pagemask; +static int pagesz; + +static +report_error (file, fd) + char *file; + int fd; +{ + if (fd) + close (fd); + error ("Failure operating on %s", file); +} + +#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); + error (msg, a1, a2); +} + +/* **************************************************************** + * 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 ) { + 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. + */ + + struct scnhdr *stbl; /* Table of all scnhdr's */ + struct scnhdr *f_thdr; /* Text section header */ + struct scnhdr *f_dhdr; /* Data section header */ + struct scnhdr *f_tdhdr; /* Thread Data section header */ + struct scnhdr *f_bhdr; /* Bss section header */ + struct scnhdr *f_tbhdr; /* Thread Bss section header */ + +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; +{ + register int scns; + unsigned int bss_end; + unsigned int eo_data; /* End of initialized data in new exec file */ + int scntype; /* Section type */ + int i; /* Var for sorting by vaddr */ + struct scnhdr scntemp; /* For swapping entries in sort */ + extern char *start_of_data(); + + pagemask = (pagesz = getpagesize()) - 1; + + /* Adjust text/data boundary. */ + if (!data_start) + data_start = (unsigned) start_of_data (); + + data_start = data_start & ~pagemask; /* (Down) to page boundary. */ + + bss_end = (sbrk(0) + pagemask) & ~pagemask; + + /* Adjust data/bss boundary. */ + if (bss_start != 0) { + bss_start = (bss_start + pagemask) & ~pagemask;/* (Up) to page bdry. */ + if (bss_start > bss_end) { + ERROR1 ("unexec: Specified bss_start (%x) 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 (%x) can't be greater than bss_start (%x)", + data_start, bss_start); + } + + /* Salvage as much info from the existing file as possible */ + if (a_out < 0) { + ERROR0 ("can't build a COFF file from scratch yet"); + /*NOTREACHED*/ + } + + if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) { + PERROR (a_name); + } + block_copy_start += sizeof (f_hdr); + if (f_hdr.h_opthdr > 0) { + if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) { + PERROR (a_name); + } + block_copy_start += sizeof (f_ohdr); + } + + /* Allocate room for scn headers */ + stbl = (struct scnhdr *)malloc( sizeof(struct scnhdr) * f_hdr.h_nscns ); + if( stbl == NULL ) { + ERROR0( "unexec: malloc of stbl failed" ); + } + + f_tdhdr = f_tbhdr = NULL; + + /* Loop through section headers, copying them in */ + for (scns = 0; scns < f_hdr.h_nscns; scns++) { + + if( read( a_out, &stbl[scns], sizeof(*stbl)) != sizeof(*stbl)) { + PERROR (a_name); + } + + scntype = stbl[scns].s_flags & S_TYPMASK; /* What type of section */ + + if( stbl[scns].s_scnptr > 0L) { + if( block_copy_start < stbl[scns].s_scnptr + stbl[scns].s_size ) + block_copy_start = stbl[scns].s_scnptr + stbl[scns].s_size; + } + + if( scntype == S_TEXT) { + f_thdr = &stbl[scns]; + } else if( scntype == S_DATA) { + f_dhdr = &stbl[scns]; +#ifdef S_TDATA + } else if( scntype == S_TDATA ) { + f_tdhdr = &stbl[scns]; + } else if( scntype == S_TBSS ) { + f_tbhdr = &stbl[scns]; +#endif /* S_TDATA (thread stuff) */ + + } else if( scntype == S_BSS) { + f_bhdr = &stbl[scns]; + } + + } + + /* We will now convert TEXT and DATA into TEXT, BSS into DATA, and leave + * all thread stuff alone. + */ + + /* Now we alter the contents of all the f_*hdr variables + to correspond to what we want to dump. */ + + f_thdr->s_vaddr = (long) start_of_text (); + f_thdr->s_size = data_start - f_thdr->s_vaddr; + f_thdr->s_scnptr = pagesz; + f_thdr->s_relptr = 0; + f_thdr->s_nrel = 0; + + eo_data = f_thdr->s_scnptr + f_thdr->s_size; + + if( f_tdhdr ) { /* Process thread data */ + + f_tdhdr->s_vaddr = data_start; + f_tdhdr->s_size += f_dhdr->s_size - (data_start - f_dhdr->s_vaddr); + f_tdhdr->s_scnptr = eo_data; + f_tdhdr->s_relptr = 0; + f_tdhdr->s_nrel = 0; + + eo_data += f_tdhdr->s_size; + + /* And now for DATA */ + + f_dhdr->s_vaddr = f_bhdr->s_vaddr; /* Take BSS start address */ + f_dhdr->s_size = bss_end - f_bhdr->s_vaddr; + f_dhdr->s_scnptr = eo_data; + f_dhdr->s_relptr = 0; + f_dhdr->s_nrel = 0; + + eo_data += f_dhdr->s_size; + + } else { + + f_dhdr->s_vaddr = data_start; + f_dhdr->s_size = bss_start - data_start; + f_dhdr->s_scnptr = eo_data; + f_dhdr->s_relptr = 0; + f_dhdr->s_nrel = 0; + + eo_data += f_dhdr->s_size; + + } + + f_bhdr->s_vaddr = bss_start; + f_bhdr->s_size = bss_end - bss_start + pagesz /* fudge */; + f_bhdr->s_scnptr = 0; + f_bhdr->s_relptr = 0; + f_bhdr->s_nrel = 0; + + text_scnptr = f_thdr->s_scnptr; + data_scnptr = f_dhdr->s_scnptr; + bias = eo_data - block_copy_start; + + if (f_ohdr.o_symptr > 0L) { + f_ohdr.o_symptr += bias; + } + + if (f_hdr.h_strptr > 0) { + f_hdr.h_strptr += 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); + } + + for( scns = 0; scns < f_hdr.h_nscns; scns++ ) { + + /* This is a cheesey little loop to write out the section headers + * in order of increasing virtual address. Dull but effective. + */ + + for( i = scns+1; i < f_hdr.h_nscns; i++ ) { + if( stbl[i].s_vaddr < stbl[scns].s_vaddr ) { /* Swap */ + scntemp = stbl[i]; + stbl[i] = stbl[scns]; + stbl[scns] = scntemp; + } + } + + } + + for( scns = 0; scns < f_hdr.h_nscns; scns++ ) { + + if( write( new, &stbl[scns], sizeof(*stbl)) != sizeof(*stbl)) { + PERROR (new_name); + } + + } + + return (0); + +} + +/* **************************************************************** + * 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 scns; + + for( scns = 0; scns < f_hdr.h_nscns; scns++ ) + write_segment( new, &stbl[scns] ); + + return 0; +} + +write_segment( new, sptr ) +int new; +struct scnhdr *sptr; +{ + register char *ptr, *end; + register int nwrite, ret; + char buf[80]; + extern int errno; + char zeros[128]; + + if( sptr->s_scnptr == 0 ) + return; /* Nothing to do */ + + if( lseek( new, (long) sptr->s_scnptr, 0 ) == -1 ) + PERROR( "unexecing" ); + + bzero (zeros, sizeof zeros); + + ptr = (char *) sptr->s_vaddr; + end = ptr + sptr->s_size; + + while( ptr < end ) { + + /* distance to next multiple of 128. */ + nwrite = (((int) ptr + 128) & -128) - (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) + write (new, zeros, nwrite); + 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); + } + 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; + + if (SYMS_START == 0L) + return 0; + + lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */ + lseek( new, (long)f_ohdr.o_symptr, 0 ); + + 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 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); +} + +/* Find the first pty letter. This is usually 'p', as in ptyp0, but + is sometimes configured down to 'm', 'n', or 'o' for some reason. */ + +first_pty_letter () +{ + struct stat buf; + char pty_name[16]; + char c; + + for (c = 'o'; c >= 'a'; c--) + { + sprintf (pty_name, "/dev/pty%c0", c); + if (stat (pty_name, &buf) < 0) + return c + 1; + } + return 'a'; +} + |