From 1edcb9b62a1a520eddae8403c19d841c9b18737f Mon Sep 17 00:00:00 2001 From: Bryan Newbold Date: Mon, 20 Feb 2017 00:05:24 -0800 Subject: Import Upstream version 5b3 --- unexhp9k800.c | 319 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 unexhp9k800.c (limited to 'unexhp9k800.c') diff --git a/unexhp9k800.c b/unexhp9k800.c new file mode 100644 index 0000000..f33340c --- /dev/null +++ b/unexhp9k800.c @@ -0,0 +1,319 @@ +/* Unexec for HP 9000 Series 800 machines. + Bob Desinger + + Note that the GNU project considers support for HP operation 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 users send them in, but aside from that we don't + plan to think about it, or about whether other Emacs maintenance + might break it. + + + 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); +*/ + +#include +#include +#include + +#include + +#ifdef emacs +#include +#endif + +#ifdef HPUX_USE_SHLIBS +#include +#endif + +/* brk value to restore, stored as a global. + This is really used only if we used shared libraries. */ +static long brk_on_dump = 0; + +/* Called from main, if we use shared libraries. */ +int +run_time_remap (ignored) + char *ignored; +{ + brk ((char *) brk_on_dump); +} + +#undef roundup +#define roundup(x,n) (((x) + ((n) - 1)) & ~((n) - 1)) /* n is power of 2 */ +#define min(x,y) (((x) < (y)) ? (x) : (y)) + + +/* Create a new a.out file, same as old but with current data space */ + +unexec (new_name, old_name, new_end_of_text, dummy1, dummy2) + char new_name[]; /* name of the new a.out file to be created */ + char old_name[]; /* name of the old a.out file */ + char *new_end_of_text; /* ptr to new edata/etext; NOT USED YET */ + 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); + + brk_on_dump = (long) sbrk (0); + + /* 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) + int file; + struct header *hdr; + struct som_exec_auxhdr *auxhdr; + int size; +{ + /* Write the entire data space out to the file */ + if (write (file, 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) + int file; + struct header *hdr; + struct som_exec_auxhdr *auxhdr; + 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->compiler_location); + update (hdr->symbol_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) + int file; + 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. */ + +write_header (file, hdr, 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. */ + +calculate_checksum (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. */ + +copy_file (old, new, 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); } + if (write (new, buffer, len) != len) + { perror ("Write failure in a.out file"); exit (1); } + } +} + +/* Copy the rest of the file, up to EOF. */ + +copy_rest (old, 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) + 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"); + printf ("data file loc %d size %d\n", + auxhdr->exec_dfile, auxhdr->exec_dsize); + printf ("som_length %d\n", hdr->som_length); + printf ("unloadable sploc %d size %d\n", + hdr->unloadable_sp_location, hdr->unloadable_sp_size); +} +#endif /* DEBUG */ -- cgit v1.2.3