On Tue, Jun 25, 2019 at 1:08 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Tue, Jun 25, 2019 at 05:15:27PM +0200, Florian Weimer wrote: > > Should we try mapping something at the magic address (without MAP_FIXED) > > and see if we get back a different address? Something in the auxiliary > > vector would work for us, too, but nothing seems to exists there > > unfortunately. > > It seems like mmap() won't even work because it's in the high memory > area. I can't map something a page under the vsyscall page either, so I > can't distinguish it with mmap, mprotect, madvise, or msync. :( > I keep contemplating making munmap() work on it. That would nicely answer the question: if munmap() fails, it's not there, and, if munmap() succeeds, it's not there :)
