From: Andrew Morton <akpm@linux-foundation.org>
To: Aleksandr Nogikh <nogikh@google.com>
Cc: bp@alien8.de, tglx@kernel.org, mingo@redhat.com, x86@kernel.org,
linux-kernel@vger.kernel.org, dvyukov@google.com,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
stable@vger.kernel.org
Subject: Re: [PATCH v2] x86/kexec: Disable KCOV instrumentation after load_segments()
Date: Sat, 21 Mar 2026 17:08:41 -0700 [thread overview]
Message-ID: <20260321170841.179ceada68dc55bb22064fda@linux-foundation.org> (raw)
In-Reply-To: <20260317220319.788561-1-nogikh@google.com>
On Tue, 17 Mar 2026 23:03:19 +0100 Aleksandr Nogikh <nogikh@google.com> wrote:
> The load_segments() function changes segment registers, invalidating
> GS base (which KCOV relies on for per-cpu data). When CONFIG_KCOV is
> enabled, any subsequent instrumented C code call (e.g.
> native_gdt_invalidate()) begins crashing the kernel in an endless
> loop.
>
> ...
>
> Disabling instrumentation for the individual functions would be too
> fragile, so let's fix the bug by disabling KCOV instrumentation for
> the entire machine_kexec_64.c and physaddr.c. If coverage-guided
> fuzzing ever needs these components in the future, we should consider
> other approaches.
>
AI review has questions:
https://sashiko.dev/#/patchset/20260317220319.788561-1-nogikh@google.com
next prev parent reply other threads:[~2026-03-22 0:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-17 22:03 [PATCH v2] x86/kexec: Disable KCOV instrumentation after load_segments() Aleksandr Nogikh
2026-03-20 15:56 ` Borislav Petkov
2026-03-22 0:08 ` Andrew Morton [this message]
2026-03-23 10:46 ` Aleksandr Nogikh
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