*/
\f
#include <config.h>
+#include "unexec.h"
+#include "lisp.h"
+
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
/* Called from main, if we use shared libraries. */
int
-run_time_remap (ignored)
- char *ignored;
+run_time_remap (char *ignored)
{
brk ((char *) brk_on_dump);
}
#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 */
-int
-unexec (const char *new_name, /* name of the new a.out file to be created */
- const char *old_name) /* name of the old a.out file */
+/* Report a fatal error and exit. */
+static _Noreturn void
+unexec_error (char const *msg)
{
- 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);
+ perror (msg);
+ exit (1);
+}
- /* Close the binary file */
- close (old);
- close (new);
- return 0;
+/* Do an lseek and check the result. */
+static void
+check_lseek (int fd, off_t offset, int whence)
+{
+ if (lseek (fd, offset, whence) < 0)
+ unexec_error ("Cannot lseek");
}
/* 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;
+static void
+save_data_space (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); }
+ unexec_error ("Can't save new data space");
/* Update the header to reflect the new data size */
auxhdr->exec_dsize = size;
/* 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;
+static void
+update_file_ptrs (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr,
+ unsigned int location, int offset)
{
struct subspace_dictionary_record subspace;
int i;
update (auxhdr->exec_dfile);
/* Do for each subspace dictionary entry */
- lseek (file, hdr->subspace_location, 0);
+ check_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); }
+ ptrdiff_t subspace_size = sizeof subspace;
+ if (read (file, &subspace, subspace_size) != subspace_size)
+ unexec_error ("Can't read subspace record");
/* 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); }
+ check_lseek (file, -subspace_size, 1);
+ if (write (file, &subspace, subspace_size) != subspace_size)
+ unexec_error ("Can't update subspace record");
}
}
/* 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;
+static void
+read_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
{
/* Read the header in */
- lseek (file, 0, 0);
+ check_lseek (file, 0, 0);
if (read (file, hdr, sizeof (*hdr)) != sizeof (*hdr))
- { perror ("Couldn't read header from a.out file"); exit (1); }
+ unexec_error ("Couldn't read header from a.out file");
if (hdr->a_magic != EXEC_MAGIC && hdr->a_magic != SHARE_MAGIC
&& hdr->a_magic != DEMAND_MAGIC)
exit (1);
}
- lseek (file, hdr->aux_header_location, 0);
+ check_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);
- }
+ unexec_error ("Couldn't read auxiliary header from a.out file");
}
/* 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;
+static void
+write_header (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);
+ check_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);
+ unexec_error ("Couldn't write header to a.out file");
+ check_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); }
+ unexec_error ("Couldn't write auxiliary header to a.out file");
}
/* Calculate the checksum of a SOM header record. */
-calculate_checksum (hdr)
- struct header *hdr;
+static int
+calculate_checksum (struct header *hdr)
{
int checksum, i, *ptr;
/* Copy size bytes from the old file to the new one. */
-copy_file (old, new, size)
- int new, old;
- int size;
+static void
+copy_file (int old, int new, int size)
{
int len;
int buffer[8192]; /* word aligned will be faster */
{
len = min (size, sizeof (buffer));
if (read (old, buffer, len) != len)
- { perror ("Read failure on a.out file"); exit (1); }
+ unexec_error ("Read failure on a.out file");
if (write (new, buffer, len) != len)
- { perror ("Write failure in a.out file"); exit (1); }
+ unexec_error ("Write failure in a.out file");
}
}
/* Copy the rest of the file, up to EOF. */
-copy_rest (old, new)
- int new, old;
+static void
+copy_rest (int old, int new)
{
int buffer[4096];
int len;
if (write (new, buffer, len) != len) break;
if (len != 0)
- { perror ("Unable to copy the rest of the file"); exit (1); }
+ unexec_error ("Unable to copy the rest of the file");
}
#ifdef DEBUG
-display_header (hdr, auxhdr)
- struct header *hdr;
- struct som_exec_auxhdr *auxhdr;
+static void
+display_header (struct header *hdr, struct som_exec_auxhdr *auxhdr)
{
/* Display the header information (debug) */
printf ("\n\nFILE HEADER\n");
}
#endif /* DEBUG */
-/* arch-tag: d55a09ac-9427-4ec4-8496-cb9d7710774f
- (do not change this comment) */
+
+/* Create a new a.out file, same as old but with current data space */
+void
+unexec (const char *new_name, /* name of the new a.out file to be created */
+ const char *old_name) /* name of the old a.out file */
+{
+ 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 = emacs_open (old_name, O_RDONLY, 0);
+ if (old < 0)
+ unexec_error (old_name);
+ new = emacs_open (new_name, O_CREAT | O_RDWR | O_TRUNC, 0777);
+ if (new < 0)
+ unexec_error (new_name);
+
+ /* 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. */
+ check_lseek (old, 0, 0);
+ copy_file (old, new, auxhdr.exec_dfile);
+
+ /* Skip the old data segment and write a new one. */
+ check_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. */
+ emacs_close (old);
+ emacs_close (new);
+}
HCoop / bpt / emacs.git / blobdiff