On Tue, 2019-09-10 at 13:34 +0800, Jason Yan wrote:

Hi Scott,

On 2019/8/28 12:05, Scott Wood wrote:

quoted

On Fri, 2019-08-09 at 18:07 +0800, Jason Yan wrote:

quoted

This series implements KASLR for powerpc/fsl_booke/32, as a security
feature that deters exploit attempts relying on knowledge of the
location
of kernel internals.

Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate.

Have you tested this with a kernel that was loaded at a non-zero
address?  I
tried loading a kernel at 0x04000000 (by changing the address in the
uImage,
and setting bootm_low to 04000000 in U-Boot), and it works without
CONFIG_RANDOMIZE and fails with.

How did you change the load address of the uImage, by changing the
kernel config CONFIG_PHYSICAL_START or the "-a/-e" parameter of mkimage?
I tried both, but it did not work with or without CONFIG_RANDOMIZE.

With mkimage.  Did you set bootm_low in U-Boot as described above?  Was
CONFIG_RELOCATABLE set in the non-CONFIG_RANDOMIZE kernel?

-Scott