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Code Issues Releases Activity

Fix subspace record bug on HP-UX 10.20.

Browse Source 
* unexhp9k800.c (unexec_error): New function, to simplify the code.
(check_lseek): New function, to report lseek errors.
(save_data_space, update_file_ptrs, read_header, write_header)
(copy_file, copy_rest, unexec): Use these news functions.
(update_file_ptrs): Don't assume wraparound behavior when
converting a large size_t value to off_t.

Fixes: debbugs:16717
This commit is contained in:
Paul Eggert 2014-02-13 09:23:08 -08:00
parent ccd5d23b0a
commit d51c175a53
2 changed files with 58 additions and 34 deletions
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10
src/ChangeLog
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@ -1,3 +1,13 @@
2014-02-13 Paul Eggert <eggert@cs.ucla.edu>
Fix subspace record bug on HP-UX 10.20 (Bug#16717).
* unexhp9k800.c (unexec_error): New function, to simplify the code.
(check_lseek): New function, to report lseek errors.
(save_data_space, update_file_ptrs, read_header, write_header)
(copy_file, copy_rest, unexec): Use these news functions.
(update_file_ptrs): Don't assume wraparound behavior when
converting a large size_t value to off_t.
2014-02-13 Dmitry Antipov <dmantipov@yandex.ru>
* composite.c (fill_gstring_header): Pass positions as C integers

82
src/unexhp9k800.c
View File

@ -74,6 +74,22 @@ run_time_remap (char *ignored)
#define roundup(x,n) (((x) + ((n) - 1)) & ~((n) - 1)) /* n is power of 2 */
#define min(x,y) (((x) < (y)) ? (x) : (y))
/* Report a fatal error and exit. */
static _Noreturn void
unexec_error (char const *msg)
{
perror (msg);
exit (1);
}
/* 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. */
static void
@ -82,7 +98,7 @@ save_data_space (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr,
{
/* 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;
@ -115,20 +131,21 @@ update_file_ptrs (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr,
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");
}
}
@ -144,9 +161,9 @@ 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)
@ -155,12 +172,9 @@ read_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
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. */
@ -172,12 +186,12 @@ write_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr)
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. */
@ -207,9 +221,9 @@ copy_file (int old, int new, int size)
{
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");
}
}
@ -226,7 +240,7 @@ copy_rest (int old, int new)
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
@ -268,44 +282,44 @@ unexec (const char *new_name, /* name of the new a.out file to be created *
it is still executing. If problems occur, everything is still
intact. NOT implemented. */
/* Open the input and output a.out files */
/* Open the input and output a.out files. */
old = emacs_open (old_name, O_RDONLY, 0);
if (old < 0)
{ perror (old_name); exit (1); }
unexec_error (old_name);
new = emacs_open (new_name, O_CREAT | O_RDWR | O_TRUNC, 0777);
if (new < 0)
{ perror (new_name); exit (1); }
unexec_error (new_name);
/* Read the old headers */
/* 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 */
/* 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 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 */
lseek (old, old_size, 1);
/* 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 the rest of the file. */
copy_rest (old, new);
/* Update file pointers since we probably changed size of data area */
/* 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 */
/* Save the modified header. */
write_header (new, &hdr, &auxhdr);
/* Close the binary file */
/* Close the binary file. */
emacs_close (old);
emacs_close (new);
}