Christophe LEROY <christophe.le...@c-s.fr> writes: > Le 19/09/2018 à 13:58, Peter Zijlstra a écrit : >> On Wed, Sep 19, 2018 at 11:14:43AM +0000, Christophe Leroy wrote: >>> In order to allow the use of non global stack protector canary, >>> the stack canary needs to be located at a know offset defined >>> in Makefile via -mstack-protector-guard-offset. >>> >>> On powerpc/32, register r2 points to current task_struct at >>> all time, the stack_canary located inside task_struct can be >>> used directly if it is located in a known place. >>> >>> In order to allow that, this patch moves the stack_canary field >>> out of the randomized area of task_struct. >> >> And you cannot use something like asm-offsets to extract this? > > I have not been able to find a way to define the compilation flags AFTER > building asm-offsets.h, see https://patchwork.ozlabs.org/patch/971521/ > > If you have a suggestion, it is welcomed.
Hmm, that's something of a hard problem. But the stack canary is one of the things we really *do* want to be randomised, so we should probably try to come up with a solution. cheers
