if the path was given in a user buffer, return the new path in
a user buffer.
if the path was given in a kernel buffer, allocate a new kernel buffer
to return the new path; the caller is responsible for freeing the buffer
if we fail always set the new path to NULL.
This usage broke when I adde the /../ shortcut. Noted by cgd.
struct member cn_nameptr 'const', since they should never be used to
modify the path name. (Only the pathname buffer, cn_pnbuf, should be
modified.) Propagate the const poisoning to code that uses the namei
and componentname structs.
- Created compat_util.c and compat_util.h to be used by the compatibility
modules, so they don't duplicate the same code.
- Added prototypes to the stackgap allocation routines.