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From: Marcos Del Sol Vives <marcos@orca.pet>
To: "H. Peter Anvin" <hpa@zytor.com>,
	kernel test robot <oliver.sang@intel.com>
Cc: oe-lkp@lists.linux.dev, lkp@intel.com,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
	Kees Cook <kees@kernel.org>, "Xin Li (Intel)" <xin@zytor.com>,
	Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Subject: Re: [PATCH v2] x86: add hintable NOPs emulation
Date: Mon, 1 Sep 2025 13:43:15 +0200	[thread overview]
Message-ID: <51c25fb7-46be-4364-9371-6a7cb6b07625@orca.pet> (raw)
In-Reply-To: <33A549B7-B442-402C-A82C-862C0F509274@zytor.com>

El 31/08/2025 a las 21:32, H. Peter Anvin escribió:
> I'm really, *really* starting to question this approach. 
> 
> The right thing would be to not compile in endbr instructions on 32 bits,
> since they aren't supported by the kernel (if you try to enable CET/IBT
> you will crash instantly, because there is no endbr32 at the vdso system
> can entry point right now.)
> 
> We are talking about a very small number of CPUs stuck between generation
> 5 and generation 6. Most likely we are talking about a much smaller number
> than the i486 support we have been debating lately...

I assume the kernel is currently simply ignoring the CET flag on ELF for
all 32-bit x86 binaries and libraries?

Anyhow, seeing this is indeed becoming more tricky and error-prone, I'm
contating the sudo developer which is, so far, the only software that
has this issue.

  reply	other threads:[~2025-09-01 14:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-20 11:04 [PATCH v2] x86: add hintable NOPs emulation Marcos Del Sol Vives
2025-08-20 15:31 ` H. Peter Anvin
2025-08-30  6:56 ` kernel test robot
2025-08-31 14:34   ` Marcos Del Sol Vives
2025-08-31 19:32     ` H. Peter Anvin
2025-09-01 11:43       ` Marcos Del Sol Vives [this message]
2025-09-01 21:28         ` H. Peter Anvin
2025-09-02  8:16           ` Marc Haber
2025-09-02 10:52             ` Marcos Del Sol Vives
2025-08-31 19:48     ` David Laight

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