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author | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:24 -0800 |
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committer | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:24 -0800 |
commit | 1edcb9b62a1a520eddae8403c19d841c9b18737f (patch) | |
tree | bc0a43d9b3905726a76ed6f0528b54275f23d082 /unexalpha.c | |
parent | 5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8 (diff) | |
download | scm-1edcb9b62a1a520eddae8403c19d841c9b18737f.tar.gz scm-1edcb9b62a1a520eddae8403c19d841c9b18737f.zip |
Import Upstream version 5b3upstream/5b3
Diffstat (limited to 'unexalpha.c')
-rw-r--r-- | unexalpha.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/unexalpha.c b/unexalpha.c new file mode 100644 index 0000000..2adfd1f --- /dev/null +++ b/unexalpha.c @@ -0,0 +1,495 @@ +/* Unexec for DEC alpha. schoepf@sc.ZIB-Berlin.DE (Rainer Schoepf). + + Copyright (C) 1994 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. */ + + +#include <config.h> +#include <sys/types.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <stdio.h> +#include <varargs.h> +#include <filehdr.h> +#include <aouthdr.h> +#include <scnhdr.h> +#include <syms.h> +#ifndef __linux__ +# include <reloc.h> +# include <elf_abi.h> +#endif + +static void fatal_unexec (); +static void mark_x (); + +#define READ(_fd, _buffer, _size, _error_message, _error_arg) \ + errno = EEOF; \ + if (read (_fd, _buffer, _size) != _size) \ + fatal_unexec (_error_message, _error_arg); + +#define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \ + if (write (_fd, _buffer, _size) != _size) \ + fatal_unexec (_error_message, _error_arg); + +#define SEEK(_fd, _position, _error_message, _error_arg) \ + errno = EEOF; \ + if (lseek (_fd, _position, L_SET) != _position) \ + fatal_unexec (_error_message, _error_arg); + +extern int errno; +extern char *strerror (); + +void *sbrk (); + +#define EEOF -1 + +static struct scnhdr *text_section; +static struct scnhdr *rel_dyn_section; +static struct scnhdr *dynstr_section; +static struct scnhdr *dynsym_section; +static struct scnhdr *init_section; +static struct scnhdr *finit_section; +static struct scnhdr *rdata_section; +static struct scnhdr *rconst_section; +static struct scnhdr *data_section; +static struct scnhdr *pdata_section; +static struct scnhdr *xdata_section; +static struct scnhdr *got_section; +static struct scnhdr *lit8_section; +static struct scnhdr *lit4_section; +static struct scnhdr *sdata_section; +static struct scnhdr *sbss_section; +static struct scnhdr *bss_section; + +static struct scnhdr old_data_scnhdr; + +static unsigned long Brk; + +struct headers { + struct filehdr fhdr; + struct aouthdr aout; + struct scnhdr section[_MIPS_NSCNS_MAX]; +}; + + + +/* Define name of label for entry point for the dumped executable. */ + +#ifndef DEFAULT_ENTRY_ADDRESS +#define DEFAULT_ENTRY_ADDRESS __start +#endif + +unexec (new_name, a_name, data_start, bss_start, entry_address) + char *new_name, *a_name; + unsigned long data_start, bss_start, entry_address; +{ + int new, old; + char * oldptr; + struct headers ohdr, nhdr; + struct stat stat; + long pagesize, brk; + long newsyms, symrel; + int nread; + int i; + long vaddr, scnptr; +#define BUFSIZE 8192 + char buffer[BUFSIZE]; + + if ((old = open (a_name, O_RDONLY)) < 0) + fatal_unexec ("opening %s", a_name); + + new = creat (new_name, 0666); + if (new < 0) fatal_unexec ("creating %s", new_name); + + if ((fstat (old, &stat) == -1)) + fatal_unexec ("fstat %s", a_name); + + oldptr = (char *)mmap (0, stat.st_size, PROT_READ, MAP_FILE|MAP_SHARED, old, 0); + + if (oldptr == (char *)-1) + fatal_unexec ("mmap %s", a_name); + + close (old); + + /* This is a copy of the a.out header of the original executable */ + + ohdr = (*(struct headers *)oldptr); + + /* This is where we build the new header from the in-memory copy */ + + nhdr = *((struct headers *)TEXT_START); + + /* First do some consistency checks */ + + if (nhdr.fhdr.f_magic != ALPHAMAGIC + && nhdr.fhdr.f_magic != ALPHAUMAGIC) + { + fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n", + nhdr.fhdr.f_magic, ALPHAMAGIC, ALPHAUMAGIC); + exit (1); + } + + if (nhdr.fhdr.f_opthdr != sizeof (nhdr.aout)) + { + fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n", + nhdr.fhdr.f_opthdr, sizeof (nhdr.aout)); + exit (1); + } + if (nhdr.aout.magic != ZMAGIC) + { + fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n", + nhdr.aout.magic, ZMAGIC); + exit (1); + } + + + /* Now check the existence of certain header section and grab + their addresses. */ + +#define CHECK_SCNHDR(ptr, name, flags) \ + ptr = NULL; \ + for (i = 0; i < nhdr.fhdr.f_nscns && !ptr; i++) \ + if (strncmp (nhdr.section[i].s_name, name, 8) == 0) \ + { \ + if (nhdr.section[i].s_flags != flags) \ + fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \ + nhdr.section[i].s_flags, flags, name); \ + ptr = nhdr.section + i; \ + } \ + + CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT); + CHECK_SCNHDR (init_section, _INIT, STYP_INIT); +#ifdef _REL_DYN + CHECK_SCNHDR (rel_dyn_section, _REL_DYN, STYP_REL_DYN); +#endif /* _REL_DYN */ +#ifdef _DYNSYM + CHECK_SCNHDR (dynsym_section, _DYNSYM, STYP_DYNSYM); +#endif /* _REL_DYN */ +#ifdef _DYNSTR + CHECK_SCNHDR (dynstr_section, _DYNSTR, STYP_DYNSTR); +#endif /* _REL_DYN */ +#ifdef _FINI + CHECK_SCNHDR (finit_section, _FINI, STYP_FINI); +#endif /* _FINI */ + CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA); +#ifdef _RCONST + CHECK_SCNHDR (rconst_section, _RCONST, STYP_RCONST); +#endif +#ifdef _PDATA + CHECK_SCNHDR (pdata_section, _PDATA, STYP_PDATA); +#endif _PDATA +#ifdef _GOT + CHECK_SCNHDR (got_section, _GOT, STYP_GOT); +#endif _GOT + CHECK_SCNHDR (data_section, _DATA, STYP_DATA); +#ifdef _XDATA + CHECK_SCNHDR (xdata_section, _XDATA, STYP_XDATA); +#endif /* _XDATA */ +#ifdef _LIT8 + CHECK_SCNHDR (lit8_section, _LIT8, STYP_LIT8); + CHECK_SCNHDR (lit4_section, _LIT4, STYP_LIT4); +#endif /* _LIT8 */ + CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA); + CHECK_SCNHDR (sbss_section, _SBSS, STYP_SBSS); + CHECK_SCNHDR (bss_section, _BSS, STYP_BSS); + + + pagesize = getpagesize (); + brk = (((long) (sbrk (0))) + pagesize - 1) & (-pagesize); + + /* Remember the current break */ + + Brk = brk; + + bcopy (data_section, &old_data_scnhdr, sizeof (old_data_scnhdr)); + + nhdr.aout.dsize = brk - DATA_START; + nhdr.aout.bsize = 0; + if (entry_address == 0) + { + extern DEFAULT_ENTRY_ADDRESS (); + nhdr.aout.entry = (unsigned long)DEFAULT_ENTRY_ADDRESS; + } + else + nhdr.aout.entry = entry_address; + + nhdr.aout.bss_start = nhdr.aout.data_start + nhdr.aout.dsize; + + if (rdata_section != NULL) + { + rdata_section->s_size = data_start - DATA_START; + + /* Adjust start and virtual addresses of rdata_section, too. */ + rdata_section->s_vaddr = DATA_START; + rdata_section->s_paddr = DATA_START; + rdata_section->s_scnptr = text_section->s_scnptr + nhdr.aout.tsize; + } + + data_section->s_vaddr = data_start; + data_section->s_paddr = data_start; + data_section->s_size = brk - data_start; + + if (rdata_section != NULL) + { + data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size; + } + + vaddr = data_section->s_vaddr + data_section->s_size; + scnptr = data_section->s_scnptr + data_section->s_size; + if (lit8_section != NULL) + { + lit8_section->s_vaddr = vaddr; + lit8_section->s_paddr = vaddr; + lit8_section->s_size = 0; + lit8_section->s_scnptr = scnptr; + } + if (lit4_section != NULL) + { + lit4_section->s_vaddr = vaddr; + lit4_section->s_paddr = vaddr; + lit4_section->s_size = 0; + lit4_section->s_scnptr = scnptr; + } + if (sdata_section != NULL) + { + sdata_section->s_vaddr = vaddr; + sdata_section->s_paddr = vaddr; + sdata_section->s_size = 0; + sdata_section->s_scnptr = scnptr; + } +#ifdef _XDATA + if (xdata_section != NULL) + { + xdata_section->s_vaddr = vaddr; + xdata_section->s_paddr = vaddr; + xdata_section->s_size = 0; + xdata_section->s_scnptr = scnptr; + } +#endif +#ifdef _GOT + if (got_section != NULL) + { + bcopy (got_section, buffer, sizeof (struct scnhdr)); + + got_section->s_vaddr = vaddr; + got_section->s_paddr = vaddr; + got_section->s_size = 0; + got_section->s_scnptr = scnptr; + } +#endif /*_GOT */ + if (sbss_section != NULL) + { + sbss_section->s_vaddr = vaddr; + sbss_section->s_paddr = vaddr; + sbss_section->s_size = 0; + sbss_section->s_scnptr = scnptr; + } + if (bss_section != NULL) + { + bss_section->s_vaddr = vaddr; + bss_section->s_paddr = vaddr; + bss_section->s_size = 0; + bss_section->s_scnptr = scnptr; + } + + WRITE (new, (char *)TEXT_START, nhdr.aout.tsize, + "writing text section to %s", new_name); + WRITE (new, (char *)DATA_START, nhdr.aout.dsize, + "writing data section to %s", new_name); + +#ifdef _GOT +#define old_got_section ((struct scnhdr *)buffer) + + if (got_section != NULL) + { + SEEK (new, old_got_section->s_scnptr, + "seeking to start of got_section in %s", new_name); + WRITE (new, oldptr + old_got_section->s_scnptr, old_got_section->s_size, + "writing new got_section of %s", new_name); + SEEK (new, nhdr.aout.tsize + nhdr.aout.dsize, + "seeking to end of data section of %s", new_name); + } + +#undef old_got_section +#endif + + /* + * Construct new symbol table header + */ + + bcopy (oldptr + nhdr.fhdr.f_symptr, buffer, cbHDRR); + +#define symhdr ((pHDRR)buffer) + newsyms = nhdr.aout.tsize + nhdr.aout.dsize; + symrel = newsyms - nhdr.fhdr.f_symptr; + nhdr.fhdr.f_symptr = newsyms; + symhdr->cbLineOffset += symrel; + symhdr->cbDnOffset += symrel; + symhdr->cbPdOffset += symrel; + symhdr->cbSymOffset += symrel; + symhdr->cbOptOffset += symrel; + symhdr->cbAuxOffset += symrel; + symhdr->cbSsOffset += symrel; + symhdr->cbSsExtOffset += symrel; + symhdr->cbFdOffset += symrel; + symhdr->cbRfdOffset += symrel; + symhdr->cbExtOffset += symrel; + + WRITE (new, buffer, cbHDRR, "writing symbol table header of %s", new_name); + + /* + * Copy the symbol table and line numbers + */ + WRITE (new, oldptr + ohdr.fhdr.f_symptr + cbHDRR, + stat.st_size - ohdr.fhdr.f_symptr - cbHDRR, + "writing symbol table of %s", new_name); + +#ifndef __linux__ + update_dynamic_symbols (oldptr, new_name, new, nhdr.aout); +#endif + +#undef symhdr + + SEEK (new, 0, "seeking to start of header in %s", new_name); + WRITE (new, &nhdr, sizeof (nhdr), + "writing header of %s", new_name); + + close (old); + close (new); + mark_x (new_name); +} + + + + +#ifndef __linux__ + +update_dynamic_symbols (old, new_name, new, aout) + char *old; /* Pointer to old executable */ + char *new_name; /* Name of new executable */ + int new; /* File descriptor for new executable */ + struct aouthdr aout; /* a.out info from the file header */ +{ + typedef struct dynrel_info { + char * addr; + unsigned type:8; + unsigned index:24; + unsigned info:8; + unsigned pad:8; + } dr_info; + + int nsyms = rel_dyn_section->s_size / sizeof (struct dynrel_info); + int i; + dr_info * rd_base = (dr_info *) (old + rel_dyn_section->s_scnptr); + Elf32_Sym * ds_base = (Elf32_Sym *) (old + dynsym_section->s_scnptr); + + for (i = 0; i < nsyms; i++) { + register Elf32_Sym x; + + if (rd_base[i].index == 0) + continue; + + x = ds_base[rd_base[i].index]; + +#if 0 + fprintf (stderr, "Object inspected: %s, addr = %lx, shndx = %x", + old + dynstr_section->s_scnptr + x.st_name, rd_base[i].addr, x.st_shndx); +#endif + + + if ((ELF32_ST_BIND (x.st_info) == STB_GLOBAL) + && (x.st_shndx == 0) + /* && (x.st_value == NULL) */ + ) { + /* OK, this is probably a reference to an object in a shared + library, so copy the old value. This is done in several steps: + 1. reladdr is the address of the location in question relative to + the start of the data section, + 2. oldref is the addr is the mapped in temacs executable, + 3. newref is the address of the location in question in the + undumped executable, + 4. len is the size of the object reference in bytes -- + currently only 4 (long) and 8 (quad) are supported. + */ + register unsigned long reladdr = rd_base[i].addr - old_data_scnhdr.s_vaddr; + char * oldref = old + old_data_scnhdr.s_scnptr + reladdr; + unsigned long newref = aout.tsize + reladdr; + int len; + +#if 0 + fprintf (stderr, "...relocated\n"); +#endif + + if (rd_base[i].type == R_REFLONG) + len = 4; + else if (rd_base[i].type == R_REFQUAD) + len = 8; + else + fatal_unexec ("unrecognized relocation type in .dyn.rel section (symbol #%d)", i); + + SEEK (new, newref, "seeking to dynamic symbol in %s", new_name); + WRITE (new, oldref, len, "writing old dynrel info in %s", new_name); + } + +#if 0 + else + fprintf (stderr, "...not relocated\n"); +#endif + + } + +} + +#endif /* !__linux__ */ + + +/* + * mark_x + * + * After successfully building the new a.out, mark it executable + */ + +static void +mark_x (name) + char *name; +{ + struct stat sbuf; + int um = umask (777); + umask (um); + if (stat (name, &sbuf) < 0) + fatal_unexec ("getting protection on %s", name); + sbuf.st_mode |= 0111 & ~um; + if (chmod (name, sbuf.st_mode) < 0) + fatal_unexec ("setting protection on %s", name); +} + +static void +fatal_unexec (s, arg) + char *s; + char *arg; +{ + if (errno == EEOF) + fputs ("unexec: unexpected end of file, ", stderr); + else + fprintf (stderr, "unexec: %s, ", strerror (errno)); + fprintf (stderr, s, arg); + fputs (".\n", stderr); + exit (1); +} |