Messages in this thread | | | From | Al Boldi <> | Subject | Re: [PATCH] x86: Don't randomize stack unless current->personality permits it | Date | Thu, 13 Jul 2006 23:51:04 +0300 |
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Frank van Maarseveen wrote: > On Wed, Jul 12, 2006 at 06:03:18PM +0200, Andi Kleen wrote: > > Al Boldi <a1426z@gawab.com> writes: > > > Frank van Maarseveen wrote: > > > > Do not randomize stack location unless current->personality permits > > > > it. > > [...] > > > > It still blips on my system. > > > > > > echo 0 > /proc/sys/kernel/randomize_va_space makes the blips go away. > > > > > > ??? > > > > fs/binfmt_elf.c:randomize_stack_top would need the same check > > Actually, randomize_stack_top() checks > > if (current->flags & PF_RANDOMIZE) { > > and it's only called from load_elf_binary() right after this: > > if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) > current->flags |= PF_RANDOMIZE; > > Further on create_elf_tables() is called and that one calls > arch_align_stack() so maybe it is more appropriate to test (current->flags > & PF_RANDOMIZE) in arch_align_stack() instead of recomputing it.
exec.c uses arch_align_stack() also for non-elf.
BTW, why does randomize_stack_top() mod against (8192*1024) instead of (8192) like arch_align_stack()?
Thanks!
-- Al
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