Re: [PATCH 0/3] nolibc fixes marked for -stable

From: Paul E. McKenney
Date: Sun Oct 24 2021 - 18:56:34 EST


On Sun, Oct 24, 2021 at 07:28:13PM +0200, Willy Tarreau wrote:
> Hi Paul,
>
> here are a few fixes for nolibc. Ammar Faizi figured that the stack was
> not properly aligned on x86_64, it was aligned for after the call instead
> of before due to my misunderstanding of the spec. This made me check i386
> and I got it wrong there as well. Others are OK as they do not push but
> switch pointers on a call. The problem is essentially detected when using
> SIMD instructions (either voluntarily or when the compiler does it on its
> own).
>
> A second (less important) issue is that I thought that it was up to the
> userland code to truncate the code passed to exit() to 8 bits while it's
> the kernel that does it. The difference is subtle but is visible in strace,
> and this was reported by Ammar as well. This time it affected all supported
> archs.
>
> This series is based on 5.15-rc6. I marked them for backport to stable,
> just in case anyone uses nolibc for bisecting bugs.
>
> Thanks!
> Willy

Queued for v5.17, thank you both!

Thanx, Paul

> Ammar Faizi (1):
> tools/nolibc: x86-64: Fix startup code bug
>
> Willy Tarreau (2):
> tools/nolibc: i386: fix initial stack alignment
> tools/nolibc: fix incorrect truncation of exit code
>
> tools/include/nolibc/nolibc.h | 33 ++++++++++++++++++++++-----------
> 1 file changed, 22 insertions(+), 11 deletions(-)
>
> --
> 2.17.5
>