binfmt_flat: update libraries' data segment pointer with userspace accessors

This is needed on systems with a MMU.  This also gets rid of the
strangest C code I've seen lateli i.e. an integer indexed with a
pointer value within square brackets. That really looked backwards.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
This commit is contained in:
Nicolas Pitre 2016-07-24 11:30:24 -04:00 committed by Greg Ungerer
parent 467aa1465a
commit af521f92dc
1 changed files with 13 additions and 6 deletions

View File

@ -894,12 +894,19 @@ static int load_flat_binary(struct linux_binprm *bprm)
return res;
/* Update data segment pointers for all libraries */
for (i = 0; i < MAX_SHARED_LIBS; i++)
if (libinfo.lib_list[i].loaded)
for (j = 0; j < MAX_SHARED_LIBS; j++)
(-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
(libinfo.lib_list[j].loaded) ?
libinfo.lib_list[j].start_data : UNLOADED_LIB;
for (i = 0; i < MAX_SHARED_LIBS; i++) {
if (!libinfo.lib_list[i].loaded)
continue;
for (j = 0; j < MAX_SHARED_LIBS; j++) {
unsigned long val = libinfo.lib_list[j].loaded ?
libinfo.lib_list[j].start_data : UNLOADED_LIB;
unsigned long __user *p = (unsigned long __user *)
libinfo.lib_list[i].start_data;
p -= j + 1;
if (put_user(val, p))
return -EFAULT;
}
}
install_exec_creds(bprm);