Messages in this thread |  | | | Subject | Re: [PATCH] x86: Don't randomize stack unless current->personality permits it | | From | Arjan van de Ven <> | | Date | Sat, 15 Jul 2006 18:15:21 +0200 |
| |
On Sat, 2006-07-15 at 17:09 +0300, Al Boldi wrote: > Arjan van de Ven wrote: > > On Sat, 2006-07-15 at 14:29 +0300, Al Boldi wrote: > > > Arjan van de Ven wrote: > > > > > BTW, why does randomize_stack_top() mod against (8192*1024) instead > > > > > of (8192) like arch_align_stack()? > > > > > > > > because it wants to randomize for 8Mb, unlike arch_align_stack which > > > > wants to randomize the last 8Kb within this 8Mb ;) > > > > > > Randomizing twice? > > > > a VMA can only be randomized in 4Kb (well page size) granularity, so the > > 8Mb randomization can only work in that 4Kb unit, the "second" > > randomization can work in 16 byte granularity. > > > > > There is even a case where a mere rename or running through an extra > > > shell causes a slowdown. And that's with randomization turned off. > > > > randomization off will slow stuff down yes... you get cache alias > > contention that way.
a question.. do you have prelink installed/active on your system? that may very well mess with timings...
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |