xemacs-beta: src/unexhp9k800.c comparison

comparison src/unexhp9k800.c @ 272:c5d627a313b1 r21-0b34

Import from CVS: tag r21-0b34

author	cvs
date	Mon, 13 Aug 2007 10:28:48 +0200
parents	376386a54a3c
children	7df0dd720c89

comparison

equal deleted inserted replaced

-:c7b7086b0a39
+:c5d627a313b1
 Unexec creates a copy of the old a.out file, and replaces the old data
 area with the current data area.  When the new file is executed, the
 process will see the same data structures and data values that the
 original process had when unexec was called.
 Unlike other versions of unexec, this one copies symbol table and
 debug information to the new a.out file.  Thus, the new a.out file
 may be debugged with symbolic debuggers.
 If you fix any bugs in this, I'd like to incorporate your fixes.
 Send them to uunet!hpda!hpsemc!jmorris or jmorris%hpsemc@hplabs.HP.COM.
 CAVEATS:
 This routine saves the current value of all static and external
 variables.  This means that any data structure that needs to be
 initialized must be explicitly reset.  Variables will not have their
 expected default values.
 Unfortunately, the HP-UX signal handler has internal initialization
 flags which are not explicitly reset.  Thus, for signals to work in
 conjunction with this routine, the following code must executed when
 the new process starts up.
 void _sigreturn();
 ...
 sigsetreturn(_sigreturn);
 */
 *
 * 2. Assumes that the data and bss area are adjacent, which is true of the
 *    current VM implementation.
 *
 * 3. Any setup that defines HPUX_USE_SHLIBS *must* also define
 *    RUN_TIME_REMAP.
 */
 #ifdef HPUX_USE_SHLIBS
 #include <dl.h>			/* User-space dynamic loader entry points */
 void Save_Shared_Data();
 #endif
 #define roundup(x,n) ( ( (x)+(n-1) ) & ~(n-1) )  /* n is power of 2 */
 #define min(x,y)  ( ((x)<(y))?(x):(y) )
+void write_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr);
+void read_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr);
+void save_data_space (int file, struct header *hdr,
+		      struct som_exec_auxhdr *auxhdr, int size);
+void copy_rest (int old, int new);
+void copy_file (int old, int new, int size);
+void update_file_ptrs(int file, struct header *hdr,
+		      struct som_exec_auxhdr *auxhdr,
+		      unsigned int location, int offset);
 /* Create a new a.out file, same as old but with current data space */
+int
-unexec(new_name, old_name, new_end_of_text, dummy1, dummy2)
+unexec(char new_name[],		/* name of the new a.out file to be created */
-char new_name[];		/* name of the new a.out file to be created */
+char old_name[],		/* name of the old a.out file */
-char old_name[];		/* name of the old a.out file */
+char *new_end_of_text,	/* ptr to new edata/etext; NOT USED YET */
-char *new_end_of_text;	/* ptr to new edata/etext; NOT USED YET */
+int dummy1, int dummy2)	/* not used by emacs */
-int dummy1, dummy2;	/* not used by emacs */
 {
 int old, new;
 int old_size, new_size;
 struct header hdr;
 struct som_exec_auxhdr auxhdr;
 long i;
 /* For the greatest flexibility, should create a temporary file in
 the same directory as the new file.  When everything is complete,
 rename the temp file to the new name.
 This way, a program could update its own a.out file even while
 it is still executing.  If problems occur, everything is still
 intact.  NOT implemented.  */
 /* Open the input and output a.out files */
 old = open (old_name, O_RDONLY);
 if (old < 0)
 { perror(old_name); exit(1); }
 new = open (new_name, O_CREAT|O_RDWR|O_TRUNC, 0777);
 if (new < 0)
 { perror(new_name); exit(1); }
 /* Read the old headers */
 read_header(old, &hdr, &auxhdr);
 #ifdef HPUX_USE_SHLIBS
 Save_Shared_Data(); /* Save break value (added: dg@hplb.hpl.hp.com) */
 #endif
 /* Decide how large the new and old data areas are */
 old_size = auxhdr.exec_dsize;
 /* I suspect these two statements are separate
 to avoid a compiler bug in hpux version 8.  */
 i = (long) sbrk (0);
 new_size = i - auxhdr.exec_dmem;
 /* Copy the old file to the new, up to the data space */
 lseek(old, 0, 0);
 copy_file(old, new, auxhdr.exec_dfile);
 /* Skip the old data segment and write a new one */
 lseek(old, old_size, 1);
 save_data_space(new, &hdr, &auxhdr, new_size);
 /* Copy the rest of the file */
 copy_rest(old, new);
 /* Update file pointers since we probably changed size of data area */
 update_file_ptrs(new, &hdr, &auxhdr, auxhdr.exec_dfile, new_size-old_size);
 /* Save the modified header */
 write_header(new, &hdr, &auxhdr);
 /* Close the binary file */
 close (old);
 close (new);
 return 0;
 }
 /* Save current data space in the file, update header.  */
-save_data_space(file, hdr, auxhdr, size)
+void
-int file;
+save_data_space (int file, struct header *hdr,
-struct header *hdr;
+		 struct som_exec_auxhdr *auxhdr, int size)
-struct som_exec_auxhdr *auxhdr;
-int size;
 {
 /* Write the entire data space out to the file */
 if (write(file, (void *)auxhdr->exec_dmem, size) != size)
 { perror("Can't save new data space"); exit(1); }
 /* Update the header to reflect the new data size */
 auxhdr->exec_dsize = size;
 auxhdr->exec_bsize = 0;
 }
 /* Update the values of file pointers when something is inserted.  */
-update_file_ptrs(file, hdr, auxhdr, location, offset)
+void
-int file;
+update_file_ptrs(int file, struct header *hdr,
-struct header *hdr;
+		 struct som_exec_auxhdr *auxhdr,
-struct som_exec_auxhdr *auxhdr;
+		 unsigned int location, int offset)
-unsigned int location;
-int offset;
 {
 struct subspace_dictionary_record subspace;
 int i;
 /* Increase the overall size of the module */
 hdr->som_length += offset;
 /* Update the various file pointers in the header */
 #define update(ptr) if (ptr > location) ptr = ptr + offset
 update(hdr->aux_header_location);
 update(hdr->space_strings_location);
 update(hdr->init_array_location);
 update(hdr->fixup_request_location);
 update(hdr->symbol_strings_location);
 update(hdr->unloadable_sp_location);
 update(auxhdr->exec_tfile);
 update(auxhdr->exec_dfile);
 /* Do for each subspace dictionary entry */
 lseek(file, hdr->subspace_location, 0);
 for (i = 0; i < hdr->subspace_total; i++)
 {
 if (read(file, &subspace, sizeof(subspace)) != sizeof(subspace))
 	{ perror("Can't read subspace record"); exit(1); }
 /* If subspace has a file location, update it */
 if (subspace.initialization_length > 0
 	  && subspace.file_loc_init_value > location)
 	{
 	  subspace.file_loc_init_value += offset;
 	  lseek(file, -sizeof(subspace), 1);
 	  if (write(file, &subspace, sizeof(subspace)) != sizeof(subspace))
 	    { perror("Can't update subspace record"); exit(1); }
 	}
 }
 /* Do for each initialization pointer record */
 /* (I don't think it applies to executable files, only relocatables) */
 #undef update
 }
 /* Read in the header records from an a.out file.  */
-read_header(file, hdr, auxhdr)
+void
-int file;
+read_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
-struct header *hdr;
+{
-struct som_exec_auxhdr *auxhdr;
-{
 /* Read the header in */
 lseek(file, 0, 0);
 if (read(file, hdr, sizeof(*hdr)) != sizeof(*hdr))
 { perror("Couldn't read header from a.out file"); exit(1); }
 if (hdr->a_magic != EXEC_MAGIC && hdr->a_magic != SHARE_MAGIC
 &&  hdr->a_magic != DEMAND_MAGIC)
 {
 fprintf(stderr, "a.out file doesn't have legal magic number\n");
 exit(1);
 }
 lseek(file, hdr->aux_header_location, 0);
 if (read(file, auxhdr, sizeof(*auxhdr)) != sizeof(*auxhdr))
 {
 perror("Couldn't read auxiliary header from a.out file");
 exit(1);
 }
 }
 /* Write out the header records into an a.out file.  */
+void
-write_header(file, hdr, auxhdr)
+write_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
-int file;
-struct header *hdr;
-struct som_exec_auxhdr *auxhdr;
 {
 /* Update the checksum */
 hdr->checksum = calculate_checksum(hdr);
 /* Write the header back into the a.out file */
 lseek(file, 0, 0);
 if (write(file, hdr, sizeof(*hdr)) != sizeof(*hdr))
 { perror("Couldn't write header to a.out file"); exit(1); }
 lseek(file, hdr->aux_header_location, 0);
 if (write(file, auxhdr, sizeof(*auxhdr)) != sizeof(*auxhdr))
 { perror("Couldn't write auxiliary header to a.out file"); exit(1); }
 }
 /* Calculate the checksum of a SOM header record. */
+int
-calculate_checksum(hdr)
+calculate_checksum(struct header *hdr)
-struct header *hdr;
 {
 int checksum, i, *ptr;
 checksum = 0;  ptr = (int *) hdr;
 for (i=0; i<sizeof(*hdr)/sizeof(int)-1; i++)
 checksum ^= ptr[i];
 return(checksum);
 }
 /* Copy size bytes from the old file to the new one.  */
+void
-copy_file(old, new, size)
+copy_file (int old, int new, int size)
-int new, old;
-int size;
 {
 int len;
 int buffer[8192];  /* word aligned will be faster */
 for (; size > 0; size -= len)
 {
 len = min(size, sizeof(buffer));
 if (read(old, buffer, len) != len)
 	{ perror("Read failure on a.out file"); exit(1); }
 	{ perror("Write failure in a.out file"); exit(1); }
 }
 }
 /* Copy the rest of the file, up to EOF.  */
+void
-copy_rest(old, new)
+copy_rest (int old, int new)
-int new, old;
 {
 int buffer[4096];
 int len;
 /* Copy bytes until end of file or error */
 while ( (len = read(old, buffer, sizeof(buffer))) > 0)
 if (write(new, buffer, len) != len) break;
 if (len != 0)
 { perror("Unable to copy the rest of the file"); exit(1); }
 }
 #ifdef	DEBUG
-display_header(hdr, auxhdr)
+display_header(struct header *hdr, struct som_exec_auxhdr *auxhdr)
-struct header *hdr;
-struct som_exec_auxhdr *auxhdr;
 {
 /* Display the header information (debug) */
 printf("\n\nFILE HEADER\n");
 printf("magic number %d \n", hdr->a_magic);
 printf("text loc %.8x   size %d \n", auxhdr->exec_tmem, auxhdr->exec_tsize);
 printf("data loc %.8x   size %d \n", auxhdr->exec_dmem, auxhdr->exec_dsize);
 printf("entry     %x \n",   auxhdr->exec_entry);
 printf("Bss  segment size %u\n", auxhdr->exec_bsize);
 printf("\n");
 void *Brk_On_Dump = 0;		/* Brk value to restore... stored as a global */
 void Save_Shared_Data () {
 Brk_On_Dump = sbrk( 0 );
 }
 void Restore_Shared_Data () {
 brk ( Brk_On_Dump );
 }
 int run_time_remap (int d) {
 Restore_Shared_Data();
 }
 /* run_time_remap is the magic called by startup code in the dumped executable
 * if RUN_TIME_REMAP is set.
 */
 #endif /* HPUX_USE_SHLIBS */

Mercurial > hg > xemacs-beta

comparison src/unexhp9k800.c @ 272:c5d627a313b1 r21-0b34