From: Peter Zijlstra <peterz@infradead.org>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, kees@kernel.org, alyssa.milburn@intel.com,
scott.d.constable@intel.com, joao@overdrivepizza.com,
samitolvanen@google.com, nathan@kernel.org,
alexei.starovoitov@gmail.com, mhiramat@kernel.org,
ojeda@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] x86,ibt: Use UDB instead of 0xEA
Date: Fri, 15 Aug 2025 12:59:08 +0200 [thread overview]
Message-ID: <20250815105908.GB3245006@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <fc0715e0-42f2-4b5d-be31-ac44657afc56@citrix.com>
On Fri, Aug 15, 2025 at 11:43:11AM +0100, Andrew Cooper wrote:
> >> I've had to use cs prefixed jcc.d32, because our older toolchains don't
> >> like the ,pn notation.
> > And then I forgot to move that cs prefix around in the bhi1 case...
> > fixed that.
>
> Dare I ask what ,pn notation is? It's not only the older toolchains
> that don't know it :)
Some fancy notation for the CS/DS branch hints.
CS Jcc, decodes to Jcc,pn for non-taken
DS Jcc, decodes to Jcc,pt for taken
next prev parent reply other threads:[~2025-08-15 10:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-14 11:17 [RFC][PATCH] x86,ibt: Use UDB instead of 0xEA Peter Zijlstra
2025-08-14 11:23 ` Peter Zijlstra
2025-08-14 19:40 ` Nathan Chancellor
2025-08-15 1:27 ` H. Peter Anvin
2025-08-15 7:49 ` Peter Zijlstra
2025-08-15 10:28 ` Peter Zijlstra
2025-08-15 10:30 ` Peter Zijlstra
2025-08-15 10:43 ` Andrew Cooper
2025-08-15 10:59 ` Peter Zijlstra [this message]
2025-08-15 11:19 ` Andrew Cooper
2025-08-15 17:14 ` H. Peter Anvin
2025-08-15 17:21 ` Andrew Cooper
2025-08-15 17:28 ` H. Peter Anvin
2025-08-15 5:42 ` Alexei Starovoitov
2025-08-15 7:57 ` Peter Zijlstra
2025-08-15 8:28 ` Leon Hwang
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