Re: [PATCH v2 0/2] Clean up x86_32 stackprotector

[Sedat Dilek]

On Sat, Feb 13, 2021 at 8:19 PM Andy Lutomirski <luto@xxxxxxxxxx> wrote:
>
> x86_32 stackprotector is a maintenance nightmare.  Clean it up.  This
> disables stackprotector on x86_32 on GCC 8.1 and on all clang
> versions.  Some clang people are cc'd.
>
> Changes from v1:
>  - Changelog fixes.
>  - Comment fixes (mostly from Sean).
>  - Fix the !SMP case.
>
> Andy Lutomirski (2):
>   x86/stackprotector/32: Make the canary into a regular percpu variable
>   x86/entry/32: Remove leftover macros after stackprotector cleanups
>

Happy Valentine's Day,

I have no rose or pralines for you, Andy :-).

First, I tried to apply your patchset on top of <tip.git#autolatest>
which has shown some conflicts.
AFAICS it conflicts with <tip.git#x86/entry> (or more precisely with
the recent "Merge branch 'x86/paravirt' into x86/entry").
Just wanna let you know.

I have tested this on Debian/testing AMD64 (x86 64bit) with LLVM/Clang
v12.0.0-rc1 and my custom patchset.
Means compile-tested and booted into bare metal and checked build-log
and dmesg-log for warnings.
So far nothing scary.

Feel free to give credits like a Tested-by if you like.
( Roses and pralines are welcome, too, hahaha :-). )

Icecold and sunshiny Greetings from North-West Germany,
- Sedat -

>  arch/x86/Kconfig                          |  7 +-
>  arch/x86/Makefile                         |  8 ++
>  arch/x86/entry/entry_32.S                 | 95 +----------------------
>  arch/x86/include/asm/processor.h          | 15 +---
>  arch/x86/include/asm/ptrace.h             |  5 +-
>  arch/x86/include/asm/segment.h            | 30 ++-----
>  arch/x86/include/asm/stackprotector.h     | 79 ++++---------------
>  arch/x86/include/asm/suspend_32.h         |  6 +-
>  arch/x86/kernel/asm-offsets_32.c          |  5 --
>  arch/x86/kernel/cpu/common.c              |  5 +-
>  arch/x86/kernel/doublefault_32.c          |  4 +-
>  arch/x86/kernel/head_32.S                 | 18 +----
>  arch/x86/kernel/setup_percpu.c            |  1 -
>  arch/x86/kernel/tls.c                     |  8 +-
>  arch/x86/kvm/svm/svm.c                    | 10 +--
>  arch/x86/lib/insn-eval.c                  |  4 -
>  arch/x86/platform/pvh/head.S              | 14 ----
>  arch/x86/power/cpu.c                      |  6 +-
>  arch/x86/xen/enlighten_pv.c               |  1 -
>  scripts/gcc-x86_32-has-stack-protector.sh |  6 +-
>  20 files changed, 62 insertions(+), 265 deletions(-)
>
> --
> 2.29.2
>