Re: [PATCH v6 00/41] Shadow stacks for userspace

[John Allen]

On Sat, Feb 18, 2023 at 01:13:52PM -0800, Rick Edgecombe wrote:
> I left tested-by tags in place per discussion with testers. Testers, please
> retest.

v6 is still working well on my AMD system (Dell PowerEdge
R6515 w/ EPYC 7713).

The selftests run cleanly:

[INFO]  new_ssp = 7f53069ffff8, *new_ssp = 7f5306a00001
[INFO]  changing ssp from 7f53071ffff0 to 7f53069ffff8
[INFO]  ssp is now 7f5306a00000
[OK]    Shadow stack pivot
[OK]    Shadow stack faults
[INFO]  Corrupting shadow stack
[INFO]  Generated shadow stack violation successfully
[OK]    Shadow stack violation test
[INFO]  Gup read -> shstk access success
[INFO]  Gup write -> shstk access success
[INFO]  Violation from normal write
[INFO]  Gup read -> write access success
[INFO]  Violation from normal write
[INFO]  Gup write -> write access success
[INFO]  Cow gup write -> write access success
[OK]    Shadow gup test
[INFO]  Violation from shstk access
[OK]    mprotect() test
[OK]    Userfaultfd test
[OK]    32 bit test

And I can see the control protection messages in dmesg when
running the shstk violation test from here:
https://gitlab.com/cet-software/cet-smoke-test

ld-linux-x86-64[51598] control protection ip:401139 sp:7ffd68b1b7c8 ssp:7fb433578fd8 error:1(near ret) in shstk1[401000+1000]

Tested-by: John Allen <john.allen@xxxxxxx>