Messages in this thread | | | Subject | Re: [RFC 17/17] arm64: compile the kernel with ptrauth -msign-return-address | From | Ramana Radhakrishnan <> | Date | Fri, 5 Oct 2018 10:01:04 +0100 |
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On 05/10/2018 09:47, Kristina Martsenko wrote: > Compile all functions with two ptrauth instructions: paciasp in the > prologue to sign the return address, and autiasp in the epilogue to > authenticate the return address. This should help protect the kernel > against attacks using return-oriented programming. > > CONFIG_ARM64_PTR_AUTH enables pointer auth for both userspace and the > kernel. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> > --- > arch/arm64/Makefile | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile > index 106039d25e2f..dbcd43ea99d8 100644 > --- a/arch/arm64/Makefile > +++ b/arch/arm64/Makefile > @@ -56,6 +56,10 @@ KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) > KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) > KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) > > +ifeq ($(CONFIG_ARM64_PTR_AUTH),y) > +KBUILD_CFLAGS += -msign-return-address=all
Glad to see this being done and being proposed for mainline.
I can see why you would prefer this though have you guys experimented at all with -msign-return-address=non-leaf as well ?
Orthogonally and just fair warning - the command lines for this are also being revised to provide ROP and JOP protection using BTI from v8.5-a during the GCC-9 timeframe but I suspect that's a different option.
regards Ramana
Reviewed-by: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
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