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(unexec_write_zero): New function.

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(copy_data_segment): Clear uninitialized local variables in
statically linked libraries.
This commit is contained in:
YAMAMOTO Mitsuharu 2005-11-09 08:08:34 +00:00
parent 10ae126cfc
commit 433456d7a7
1 changed files with 59 additions and 9 deletions
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68
src/unexmacosx.c
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@ -174,7 +174,7 @@ off_t data_segment_old_fileoff;
struct segment_command *data_segment_scp;
/* Read n bytes from infd into memory starting at address dest.
/* Read N bytes from infd into memory starting at address DEST.
Return true if successful, false otherwise. */
static int
unexec_read (void *dest, size_t n)
@ -182,8 +182,9 @@ unexec_read (void *dest, size_t n)
return n == read (infd, dest, n);
}
/* Write n bytes from memory starting at address src to outfd starting
at offset dest. Return true if successful, false otherwise. */
/* Write COUNT bytes from memory starting at address SRC to outfd
starting at offset DEST. Return true if successful, false
otherwise. */
static int
unexec_write (off_t dest, const void *src, size_t count)
{
@ -193,8 +194,32 @@ unexec_write (off_t dest, const void *src, size_t count)
return write (outfd, src, count) == count;
}
/* Copy n bytes from starting offset src in infd to starting offset
dest in outfd. Return true if successful, false otherwise. */
/* Write COUNT bytes of zeros to outfd starting at offset DEST.
Return true if successful, false otherwise. */
static int
unexec_write_zero (off_t dest, size_t count)
{
char buf[UNEXEC_COPY_BUFSZ];
ssize_t bytes;
bzero (buf, UNEXEC_COPY_BUFSZ);
if (lseek (outfd, dest, SEEK_SET) != dest)
return 0;
while (count > 0)
{
bytes = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count;
if (write (outfd, buf, bytes) != bytes)
return 0;
count -= bytes;
}
return 1;
}
/* Copy COUNT bytes from starting offset SRC in infd to starting
offset DEST in outfd. Return true if successful, false
otherwise. */
static int
unexec_copy (off_t dest, off_t src, ssize_t count)
{
@ -684,14 +709,39 @@ copy_data_segment (struct load_command *lc)
if (!unexec_write (header_offset, sectp, sizeof (struct section)))
unexec_error ("cannot write section %s's header", SECT_DATA);
}
else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0
|| strncmp (sectp->sectname, SECT_COMMON, 16) == 0)
else if (strncmp (sectp->sectname, SECT_COMMON, 16) == 0)
{
sectp->flags = S_REGULAR;
if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size))
unexec_error ("cannot write section %s", SECT_DATA);
unexec_error ("cannot write section %s", sectp->sectname);
if (!unexec_write (header_offset, sectp, sizeof (struct section)))
unexec_error ("cannot write section %s's header", SECT_DATA);
unexec_error ("cannot write section %s's header", sectp->sectname);
}
else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0)
{
extern char *my_endbss_static;
unsigned long my_size;
sectp->flags = S_REGULAR;
/* Clear uninitialized local variables in statically linked
libraries. In particular, function pointers stored by
libSystemStub.a, which is introduced in Mac OS X 10.4 for
binary compatibility with respect to long double, are
cleared so that they will be reinitialized when the
dumped binary is executed on other versions of OS. */
my_size = (unsigned long)my_endbss_static - sectp->addr;
if (!(sectp->addr <= (unsigned long)my_endbss_static
&& my_size <= sectp->size))
unexec_error ("my_endbss_static is not in section %s",
sectp->sectname);
if (!unexec_write (sectp->offset, (void *) sectp->addr, my_size))
unexec_error ("cannot write section %s", sectp->sectname);
if (!unexec_write_zero (sectp->offset + my_size,
sectp->size - my_size))
unexec_error ("cannot write section %s", sectp->sectname);
if (!unexec_write (header_offset, sectp, sizeof (struct section)))
unexec_error ("cannot write section %s's header", sectp->sectname);
}
else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0
|| strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0