Thread (8 messages) 8 messages, 4 authors, 2020-12-22

Re: [PATCH] powerpc:Don't print raw EIP/LR hex values in dump_stack() and show_regs()

From: Segher Boessenkool <hidden>
Date: 2020-12-21 16:40:11
Also in: lkml

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


Segher
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