linux-kernel - Objtool segfault inside an VM, based on commit 24172e0d7990

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Message-ID: <0b7d3e02-0609-410e-a221-8e68a0bd89b0@gmx.com>
Date: Mon, 17 Nov 2025 13:10:54 +1030
From: Qu Wenruo <quwenruo.btrfs@....com>
To: LKML <linux-kernel@...r.kernel.org>,
 linux-btrfs <linux-btrfs@...r.kernel.org>
Subject: Objtool segfault inside an VM, based on commit 24172e0d7990

Hi,

Recently I'm hitting pretty frequent objtool crashes, sometimes during 
module linking (btrfs in my case) sometimes during the vmlinux linking.

Unfortunately I don't have a coredump for it.

The only info so far is from dmesg (and obvious the compile failure):

[  625.066787] traps: objtool[46220] general protection fault 
ip:563ab54c6eb0 sp:7ffd9c2ba7c8 error:0 in objtool[19eb0,563ab54b2000+1f000]

The involved VM has the following spec:

- Kernel branch
   Btrfs' development branch.

   The base commit is 24172e0d79900908cf5ebf366600616d29c9b417, around
   v6.18-rc6.

- 10 vCPU, host CPU features pass-through, x86_64
   Host is using AMD HX370.

   Haven't yet hit the segfault on aarch64.

- 8G vRAM
   Thus it should be enough for most cases.

- Toolchain versions:
   gcc 15.2.1+r301+gf24307422d1d-1
   binutils 2.45.1-1

   All from the latest Archlinux.

   Older gcc (15.2.1+r22+gc4e96a094636-1) and binutils 
(2.45+r29+g2b2e51a31ec7-1) are causing the same segfault.

   Haven't yet tried LLVM.

- Kernel config
   Attached.

   Sometimes tweaking the config can workaround the bug a little,
   but not reliably.

Is this a known problem and can I work around the segfault?

Thanks,
Qu

View attachment "kernel_config" of type "text/plain" (154509 bytes)