Re: [PATCH v2] expand: fix SIGBUS due to unaligned access

[email protected] Wed, 18 Feb 2026 20:10:56 -0800
Newsgroups org.kernel.vger.dash
Message-ID <CAO_NRt67P+61s4T0AY0GwgbdPKQSKH7HHKC80mnVTpBB0N=PSw@mail.gmail.com>
On Fri, 16 Jan, 2026 at 09:55:39PM +0100, Natanael Copa wrote:
> Replace direct uint64_t dereference with memcpy() to avoid
> SIGBUS on armv7 when p is not 8-byte aligned.
>
> Fixes crashes in dash during IFS splitting on strict-alignment
> architectures.

Hi, just wanted to mention that the issue also affects x86-64 when
compiled with '-march=x86-64-v2 -O3' (requires both), causing dash
to crash constantly. It would probably affect distros that provide
binaries for microarchitecture revisions, like CachyOS [1] if they
had upgraded dash.

In any case, your patch fixes the issue for me, even when compiling
with '-march=native -mtune=native -O3' on AMD Zen 4. Thanks!

[1]: https://packages.cachyos.org/package/cachyos-core-v4/x86_64/dash