From: Segher Boessenkool

Sent: 21 December 2020 16:32

On Mon, Dec 21, 2020 at 04:17:21PM +0100, Christophe Leroy wrote:

quoted

Le 21/12/2020 à 04:27, Xiaoming Ni a écrit :

quoted

Since the commit 2b0e86cc5de6 ("powerpc/fsl_booke/32: implement KASLR
infrastructure"), the powerpc system is ready to support KASLR.
To reduces the risk of invalidating address randomization, don't print the
EIP/LR hex values in dump_stack() and show_regs().

quoted

I think your change is not enough to hide EIP address, see below a dump
with you patch, you get "Faulting instruction address: 0xc03a0c14"

As far as I can see the patch does nothing to the GPR printout.  Often
GPRs contain code addresses.  As one example, the LR is moved via a GPR
(often GPR0, but not always) for storing on the stack.

So this needs more work.

If the dump_stack() is from an oops you need the real EIP value
on order to stand any chance of making headway.

Otherwise you might just as well just print 'borked - tough luck'.

	David

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