On Fri, Nov 06, 2015 at 12:30:09PM +0000, Will Deacon wrote: > On Wed, Nov 04, 2015 at 09:37:51AM -0800, Yang Shi wrote: > > FRAME_POINTER is defined in lib/Kconfig.debug, it is unnecessary to redefine > > it in arch/arm64/Kconfig.debug. > > It might be worth noting that this adds a dependency on DEBUG_KERNEL > for building with frame pointers. I'm ok with that (it appears to be > enabled in defconfig and follows the vast majority of other archs) but > it is a change in behaviour. > > With that: > > Acked-by: Will Deacon <[email protected]>
The code in arch/arm64/kernel/stacktrace.c assumes we have frame pointers regardless of FRAME_POINTER. Depending on what the compiler decides to use x29 for, we could get some weird fake unwinding and/or dodgy memory accesses. I think we should first audit the uses of frame pointers to ensure that they are guarded for !FRAME_POINTER. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
