From: Peter Zijlstra <peterz@infradead.org>
To: 李则良 <lizeliang.linux@gmail.com>
Cc: "Jürgen Groß" <jgross@suse.com>,
"Thomas Gleixner" <tglx@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Kees Cook" <kees@kernel.org>,
"Nathan Chancellor" <nathan@kernel.org>,
"Josh Poimboeuf" <jpoimboe@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/alternatives: gracefully skip unrecognized indirect call instructions
Date: Thu, 13 Aug 2026 11:51:39 +0200 [thread overview]
Message-ID: <20260813095139.GB1246887@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CANd6bgKhZG3z2d7j16vqoW9iEbqvgE9nR=x8S-C5Y2xjHTT24Q@mail.gmail.com>
On Thu, Aug 13, 2026 at 01:14:41AM +0800, 李则良 wrote:
> >
> > I don't think we want to cater for this. But what actual instruction
> > sequences is it emitting?
>
> This is the scene that triggers the bug, which can be perfectly
> reproduced when KCFLAGS=-O1.
>
That's not what I asked, now was it. I asked what opcodes it does
generate. Disassemble an affected function and show the difference
between the normal -O2 and your -O1 build that causes the failure.
next prev parent reply other threads:[~2026-08-13 9:51 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CANd6bgL=v+uReoQznRGKunZQApwV5ESHAQn2_MOt-J-=cPkm9g@mail.gmail.com>
2026-08-11 11:50 ` Jürgen Groß
2026-08-12 9:22 ` 李则良
2026-08-12 11:00 ` Peter Zijlstra
2026-08-12 11:24 ` H. Peter Anvin
2026-08-12 15:30 ` Borislav Petkov
2026-08-12 17:14 ` 李则良
2026-08-12 19:01 ` H. Peter Anvin
2026-08-12 19:02 ` H. Peter Anvin
2026-08-13 9:51 ` Peter Zijlstra [this message]
2026-08-13 19:35 ` 李则良
2026-08-13 19:57 ` 李则良
2026-08-14 10:15 ` Jürgen Groß
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