On Fri, Nov 06, 2015 at 04:21:09PM +0000, Catalin Marinas wrote: > On Fri, Nov 06, 2015 at 12:50:02PM +0000, Mark Rutland wrote: > > 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 <will.dea...@arm.com> > > > > 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. > > Or we just select FRAME_POINTER in the ARM64 Kconfig entry.
Yang, did you see any benefit disabling frame pointers, or was this patch purely based on you spotting a duplicate Kconfig entry? Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
