diff options
Diffstat (limited to 'editors/mule-common/files/unexfreebsd.c')
| -rw-r--r-- | editors/mule-common/files/unexfreebsd.c | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/editors/mule-common/files/unexfreebsd.c b/editors/mule-common/files/unexfreebsd.c new file mode 100644 index 000000000000..142feafd3c5e --- /dev/null +++ b/editors/mule-common/files/unexfreebsd.c @@ -0,0 +1,692 @@ +/* Code to do an unexec for FreeBSD for a temacs linked -Bdynamic. + Derived from unexnetbsd.c, which was derived from unexsunos4.c + Copyright (C) 1992, 1993 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: Not in FSF? */ + +/* +Created 29-Oct-92 by Harlan Sexton +Tweaked 06-Aug-93 by Dean Michaels to work with sun3. +Converted 01-Dec-93 by Paul Mackerras to work with NetBSD shared libraries. +Tweaked 26-Feb-94 by Shawn Carey for use with FreeBSD-1.1 shared libraries. +*/ + +/********************** Included .h Files **************************/ + +#include <config.h> + +#include <stdarg.h> +#include <sys/param.h> +#include <sys/mman.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <string.h> +#include <stdio.h> +#include <a.out.h> +#include <unistd.h> +#include <ctype.h> +#include <stab.h> +#include <dirent.h> +#include <link.h> + +/********************** Macros *************************************/ + +#define SYS_ERR strerror(errno) + +#define MASK_UP(x,p_of_two) \ + ((((unsigned long) (x)) + ((p_of_two) - 1)) & (~((p_of_two) - 1))) + +#define MASK_DOWN(x,p_of_two) (((unsigned long) (x)) & (~((p_of_two) - 1))) + +/********************** Typedefs and Structs ***********************/ + +struct translation_struct +{ + long txtaddr; + long txtoff; + long dataddr; + long datoff; + long bssaddr; + long endaddr; +}; + +/********************** Function Prototypes/Declarations ***********/ + +static void unexec_error (const char *m, int use_errno, ...); +static int unexec_open (char *filename, int flag, int mode); +static caddr_t unexec_mmap (int fd, size_t len, int prot, int flags); +static long unexec_seek (int fd, long position); +static void unexec_read (int fd, long position, char *buf, int bytes); +static void unexec_write (int fd, long position, char *buf, int bytes); +static void unexec_pad (int fd, int bytes); +static void unexec_fstat (int fd, struct stat *statptr); +static void unexec_fchmod (int fd, int mode); +static long unexec_addr_to_offset (long addr, struct translation_struct *ts); +static void copy_relocation_site (struct relocation_info *ri, + caddr_t from_base_addr, + caddr_t to_base_addr, + struct translation_struct *ts); +static void reset_symtab (struct nlist *start, struct nlist *end, + char *strtab, long edata_value, long end_value, + int shlib_image); +static void reset_ldso_symtab (struct nzlist *start, struct nzlist *end, + char *strtab, long edata_value, long end_value, + int shlib_image); +int run_time_remap (char *dummy); + +/********************** Variables **********************************/ + +/* for reporting error messages from system calls */ +extern int errno; +extern int _DYNAMIC; +extern char **environ; + +static unsigned long sbrk_of_0_at_unexec; + +/*******************************************************************/ + +static void +unexec_error (const char *fmt, int use_errno, ...) +{ + const char *err_msg = SYS_ERR; + va_list args; + + fprintf (stderr, "unexec - "); + va_start (args, use_errno); + vfprintf (stderr, fmt, args); + va_end (args); + + if (use_errno) + fprintf (stderr, ": %s", err_msg); + fprintf (stderr, "\n"); + exit (1); + return; +} + +static int +unexec_open (char *filename, int flag, int mode) +{ + int fd; + + errno = 0; + + fd = open (filename, flag, mode); + + if (fd < 0) + unexec_error ("Failure opening file %s", 1, filename); + return fd; +} + +static caddr_t +unexec_mmap (int fd, size_t len, int prot, int flags) +{ + caddr_t return_val; + + unexec_seek (fd, 0); + errno = 0; + return_val = mmap (0, len, prot, flags, fd, 0); + + if (return_val == (caddr_t) -1) + unexec_error ("Failure mmap'ing file", 1); + return return_val; +} + + +static long +unexec_seek (int fd, long position) +{ + long seek_value; + + if (fd <= 0) + unexec_error ("No file open in which to seek", 0); + + errno = 0; + + if (position < 0) + seek_value = (long) lseek (fd, 0, L_INCR); + else + seek_value = (long) lseek (fd, position, L_SET); + + if (seek_value < 0) + unexec_error ("Failed to do a seek to 0x%x in %s", 1, + position, "unexec() output file"); + + return seek_value; +} + +static void +unexec_read (int fd, long position, char *buf, int bytes) +{ + int n_read; + int remains = bytes; + position = unexec_seek (fd, position); + + if (bytes < 0) + unexec_error ("Attempted read of %d bytes", 0, bytes); + + errno = 0; + + while (remains > 0) + { + n_read = read (fd, buf, remains); + if (n_read <= 0) + unexec_error ("Read failed for 0x%x bytes at offset 0x%x in %s", + 1, bytes, position, "unexec() output file"); + buf += n_read; + remains -= n_read; + } + + return; +} + +static void +unexec_write (int fd, long position, char *buf, int bytes) +{ + int n_written; + int remains = bytes; + position = unexec_seek (fd, position); + + if (bytes < 0) + unexec_error ("Attempted write of %d bytes in %s", + 0, bytes, "unexec() output file"); + + errno = 0; + + while (remains > 0) + { + n_written = write (fd, buf, remains); + if (n_written <= 0) + unexec_error ("Write failed for 0x%x bytes at offset 0x%x in %s", + 1, bytes, position, "unexec() output file"); + buf += n_written; + remains -= n_written; + } + + return; +} + +static void +unexec_pad (int fd, int bytes) +{ + if (bytes > 0) + { + char buf[1024]; + int remaining = bytes; + + memset (buf, 0, sizeof (buf)); + + while (remaining > 0) + { + int this_write = (remaining > sizeof(buf))?sizeof(buf):remaining; + unexec_write (fd, -1, buf, this_write); + remaining -= this_write; + } + } +} + +static void +unexec_fstat (int fd, struct stat *statptr) +{ + errno = 0; + if (-1 == fstat (fd, statptr)) + unexec_error ("fstat() failed for descriptor %d", 1, fd); + return; +} + +static void +unexec_fchmod (int fd, int mode) +{ + errno = 0; + if (-1 == fchmod (fd, mode)) + unexec_error ("fchmod() failed for descriptor %d", 1, fd); + return; +} + +static long +unexec_addr_to_offset (long addr, struct translation_struct *ts) + +{ + if ((addr < ts->txtaddr) || (addr >= ts->bssaddr)) + return -1; + else if (addr >= ts->dataddr) + return ((long) ((addr - ts->dataddr) + ts->datoff)); + else + return ((long) ((addr - ts->txtaddr) + ts->txtoff)); +} + + +/* + * "LD.SO" DATA AND SYMBOL TABLE OPERATIONS + */ + +static void +copy_relocation_site (struct relocation_info *ri, + caddr_t from_base_addr, + caddr_t to_base_addr, + struct translation_struct *ts) +{ + long offset; + caddr_t from, to; + + /* We can get relocation sites in the bss region, for objects whose + contents are copied from a shared library. We don't need or want + to restore these at present. */ +#ifndef sparc + if (ri->r_copy) + return; +#else + /* Struct relocation_info_sparc doesn't have member r_copy. + Instead, we use the address to check if this is run-time-copied. */ + if (ri->r_address >= ts->bssaddr && ri->r_address < ts->endaddr) + return; +#endif + + offset = unexec_addr_to_offset (ri->r_address, ts); + if (offset == -1) + unexec_error ("bad relocation address 0x%x (0x%x)", 0, ri->r_address, + ((long *)ri)[1]); + + from = from_base_addr + offset; + to = to_base_addr + offset; + /* This stuff should be in a md_ file somewhere... */ +#ifndef sparc + switch (ri->r_length) + { + case 0: + *((char *) to) = *((char *) from); + break; + case 1: + *((short *) to) = *((short *) from); + break; + case 2: + *((long *) to) = *((long *) from); + break; + default: + unexec_error ("unknown reloc length %d seen during unexec()", + 0, ri->r_length); + break; + } +#else /* sparc */ + switch (ri->r_type) + { + case RELOC_8: + case RELOC_DISP8: + *((char *) to) = *((char *) from); + break; + case RELOC_16: + case RELOC_DISP16: + *((short *) to) = *((short *) from); + break; + case RELOC_LO10: + case RELOC_13: + case RELOC_22: + case RELOC_HI22: + case RELOC_WDISP22: + case RELOC_WDISP30: + case RELOC_32: + case RELOC_DISP32: + case RELOC_GLOB_DAT: + *((long *) to) = *((long *) from); + break; + case RELOC_JMP_SLOT: + { + long *target = (long *) to; + long *source = (long *) from; + *target = *source; + target++; + source++; + *target = *source; + target++; + source++; + *target = *source; + } + break; + default: + unexec_error ("unknown reloc type %d seen during unexec()", + 0, ri->r_type); + break; + } +#endif /* sparc */ +} + +static void +reset_symtab (struct nlist *start, struct nlist *end, char *strtab, + long edata_value, long end_value, int shlib_image) +{ + struct nlist *tmp = start; + int found_edata = 0; + int found_end = 0; + + while (tmp < end) + { + int type = tmp->n_type; + + if ((type == (N_UNDF | N_EXT)) && + (tmp->n_value != 0)) + unexec_error ("unexec'ing image has COMMON symbols in it -- we quit!", + 0); + + if (!(type & N_STAB)) + { + if (!found_edata && + (type == (N_EXT | N_DATA)) && + tmp->n_un.n_strx && + !strcmp ("_edata", strtab + tmp->n_un.n_strx)) + { + tmp->n_value = edata_value; + found_edata = 1; + } + + + if ((type & N_TYPE) == N_BSS) + { + if (!found_end && + (type == (N_EXT | N_BSS)) && + tmp->n_un.n_strx && + !strcmp ("_end", strtab + tmp->n_un.n_strx)) + { + tmp->n_value = end_value; + found_end = 1; + } + else if (type & N_EXT) + tmp->n_type = N_DATA | N_EXT; + else + tmp->n_type = N_DATA; + } + + /* the way things are being handled here, having sbrk() in the + image is fatal for an image linked with shared lib's (although + the code could be modified to support it), but this should + never happen anyway */ + if (shlib_image && + (type == (N_EXT | N_TEXT)) && + tmp->n_un.n_strx && + !strcmp ("_sbrk", strtab + tmp->n_un.n_strx)) + unexec_error ("unexec'd shlib image has sbrk() in it -- we quit!", + 0); + } + + tmp++; + } +} + +static void +reset_ldso_symtab (struct nzlist *start, struct nzlist *end, char *strtab, + long edata_value, long end_value, int shlib_image) +{ + struct nzlist *tmp = start; + int found_edata = 0; + int found_end = 0; + + while (tmp < end) { + int type = tmp->nz_type; +/* + * the following code breaks under FreeBSD-1.1-BETA, but everything + * seems to work perfectly if it's commented out. This did not break + * anything until the changes to ld.so were made. + */ +/* + if ((type == (N_UNDF | N_EXT)) && (tmp->nz_value != 0)) + unexec_error("unexec'ing image has COMMON symbols in rel -- we quit!",0); +*/ + if (!(type & N_STAB)) { + if (!found_edata && + (type == (N_EXT | N_DATA)) && + !strcmp ("_edata", strtab + tmp->nz_strx)) { + tmp->nz_value = edata_value; + found_edata = 1; + } + + if ((type & N_TYPE) == N_BSS) { + if (!found_end && + (type == (N_EXT | N_BSS)) && + !strcmp ("_end", strtab + tmp->nz_strx)) { + tmp->nz_value = end_value; + found_end = 1; + } else if (type & N_EXT) + tmp->nz_type = N_DATA | N_EXT; + else + tmp->nz_type = N_DATA; + } + + /* the way things are being handled here, having sbrk() in the + image is fatal for an image linked with shared lib's (although + the code could be modified to support it), but this should + never happen anyway */ + if (shlib_image && + (type == (N_EXT | N_TEXT)) && + !strcmp ("_sbrk", strtab + tmp->nz_strx)) + unexec_error("unexec'd shlib image has sbrk() ref -- we quit!", 0); + } + tmp++; + } +} + +extern int getpagesize (void); + +/* + * EXPORTED FUNCTIONS + */ + +/* this has to be a global variable to prevent the optimizers from + * assuming that it can not be 0. +*/ +static void *dynamic_addr = (void *) &_DYNAMIC; + +int +unexec (char *new_name, char *old_name, + unsigned int emacs_edata, unsigned int dummy1, unsigned int dummy2) +{ + /* ld.so data */ + struct _dynamic *ld = 0; + struct section_dispatch_table *ld2 = 0; + /* old and new state */ + int old_fd; + int new_fd; + caddr_t old_base_addr; + caddr_t new_base_addr; + struct exec old_hdr; + struct exec new_hdr; + struct stat old_buf; + struct stat new_buf; + /* some process specific "constants" */ + unsigned long n_pagsiz, new_edata; + long page_size = getpagesize (); + caddr_t plt_end; + caddr_t current_break = (caddr_t) sbrk (0); + + if (!page_size) + unexec_error ("unexec() failed because we can't get the size of a page!", + 0); + + /* see if this is a -Bdynamic image -- if so, find ld.so structures */ + if (dynamic_addr) + { + ld = (struct _dynamic *) dynamic_addr; + ld2 = ld->d_un.d_sdt; + if (ld->d_version < LD_VERSION_BSD) + unexec_error ("%s linked with obsolete version of ld -- we quit!", + 0, old_name); + } + + /* open the old and new files, figuring out how big the old one is + so that we can map it in */ + old_fd = unexec_open (old_name, O_RDONLY, 0); + new_fd = unexec_open (new_name, O_RDWR | O_CREAT | O_TRUNC, 0666); + + /* setup the header and the statbuf for old_fd */ + unexec_read (old_fd, 0, (char *) &old_hdr, sizeof (old_hdr)); + unexec_fstat (old_fd, &old_buf); + + + /* set up some important constants */ + n_pagsiz = __LDPGSZ; + if (dynamic_addr) + plt_end = (caddr_t) MASK_UP (ld2->sdt_plt + ld2->sdt_plt_sz, sizeof (double)); + else + plt_end = (caddr_t) N_DATADDR (old_hdr); + +#if 0 + /* never write protect the variable "environ", defined in /lib/crt0.o, and + set in process.c and callproc.c */ + mprotect_bottom_addr = ((unsigned long) &environ) + sizeof (char **); + /* never protect ABOVE the end of data emacs_edata specified */ + mprotect_top_addr = MIN (emacs_edata, N_DATADDR (old_hdr) + old_hdr.a_data); +#endif + + /* Set up the image of the old file */ + old_base_addr = unexec_mmap (old_fd, old_buf.st_size, PROT_READ, + MAP_FILE | MAP_PRIVATE); + close (old_fd); + + /* set up the new exec */ + new_hdr = old_hdr; + new_edata = (unsigned long) MASK_UP (current_break, n_pagsiz); + new_hdr.a_data = new_edata - ((unsigned long) N_DATADDR (old_hdr)); + new_hdr.a_bss = 0; + + /* set up this variable, in case we want to reset "the break" + when restarting */ + sbrk_of_0_at_unexec = ((unsigned long) MASK_UP (current_break, n_pagsiz)); + + /* Write out the first approximation to the new file. The sizes of + each section will be correct, but there will be a number of + corrections that will need to be made. */ + { + long old_datoff = N_DATOFF (old_hdr); + long old_dataddr = N_DATADDR (old_hdr); + long new_treloff = N_RELOFF (new_hdr); + long old_treloff = N_RELOFF (old_hdr); + long ld_so_size = ((unsigned long) plt_end) - old_dataddr; + long real_data_size = current_break - plt_end; + long pad_size = + MASK_UP (current_break, n_pagsiz) - ((unsigned long) current_break); + + + /* First, write the text segment with new header -- copy everything until + the start of the data segment from the old file, and then go back and + write the new header. */ + unexec_write (new_fd, 0, old_base_addr, old_datoff + ld_so_size); + unexec_write (new_fd, 0, (char *) &new_hdr, sizeof (new_hdr)); + + /* Copy the rest of the data segment from the running image. */ + unexec_write (new_fd, old_datoff + ld_so_size, + plt_end, real_data_size); + + /* pad out the data segment */ + unexec_pad (new_fd, pad_size); + + /* Finally, copy the symbol table information from the old file. */ + unexec_write (new_fd, new_treloff, + old_base_addr + old_treloff, + old_buf.st_size - old_treloff); + } + + + /* Next, map in the output file so that we can jump around fixing it + up. We retain the old file so that we can refer to it. */ + unexec_fstat (new_fd, &new_buf); + new_base_addr = unexec_mmap (new_fd, + MASK_UP (new_buf.st_size, page_size), + PROT_READ | PROT_WRITE, + MAP_FILE | MAP_SHARED); + + + + /* We need to do 2 things. First, make sure that _edata and _end (and + hence, curbrk) are set to the correct values. At the same time, for + neatness and to help with debugging, mark all the types of all ld.so + and nm BSS symbols in the new file to be DATA, and make sure that + there are no COMMON symbols in the output file, as any references to + these can lose really big. Second, reset all of the ld.so "relocation + sites" in the new file to have the values that appear in the old file + -- the failure to do this was the biggest loser in the old version of + this code. */ + + /* STEP 1 */ + /* Reset the regular symbol table first. */ + reset_symtab ((struct nlist *) (new_base_addr + N_SYMOFF(new_hdr)), + (struct nlist *) (new_base_addr + N_SYMOFF(new_hdr) + + new_hdr.a_syms), + (char *) (new_base_addr + N_STROFF(new_hdr)), + new_edata, new_edata, + !!dynamic_addr); + + /* Now reset the ld.so symbol table. */ + if (dynamic_addr) + { + struct translation_struct ts; + struct relocation_info *tmp, *end; + caddr_t syms, strings; + + /* set up the structure that we use to translate addresses in the + old file into file offsets */ + ts.txtaddr = N_TXTADDR (old_hdr); + ts.txtoff = N_TXTOFF (old_hdr); + ts.dataddr = N_DATADDR (old_hdr); + ts.datoff = N_DATOFF (old_hdr); + ts.bssaddr = N_DATADDR (old_hdr) + old_hdr.a_data; + ts.endaddr = ts.bssaddr + old_hdr.a_bss; + + syms = new_base_addr + unexec_addr_to_offset(ld2->sdt_nzlist, &ts); + strings = new_base_addr + unexec_addr_to_offset(ld2->sdt_strings, &ts); + reset_ldso_symtab ((struct nzlist *) syms, (struct nzlist *) strings, + (char *) strings, + new_edata, new_edata, + !!dynamic_addr); + + /* STEP 2 */ + tmp = (struct relocation_info *) + (old_base_addr + unexec_addr_to_offset(ld2->sdt_rel, &ts)); + end = (struct relocation_info *) + (old_base_addr + unexec_addr_to_offset(ld2->sdt_hash, &ts)); + while (tmp < end) + { + copy_relocation_site (tmp, old_base_addr, new_base_addr, &ts); + tmp++; + } + } + + /* get rid of the mmap-ed file space and make the output file + executable -- then quit */ + munmap (new_base_addr, MASK_UP (new_buf.st_size, page_size)); + munmap (old_base_addr, MASK_UP (old_buf.st_size, page_size)); + unexec_fchmod (new_fd, 0755); + close (new_fd); + return 0; +} + + +int +run_time_remap (char *dummy) +{ + unsigned long current_sbrk = (unsigned long) sbrk (0); + + if (sbrk_of_0_at_unexec > current_sbrk) + { + errno = 0; + if (brk ((caddr_t) sbrk_of_0_at_unexec)) + fprintf (stderr, "failed to change brk addr to 0x%lx: %s\n", + sbrk_of_0_at_unexec, SYS_ERR); + } + + return 0; +} |