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Message-ID: <c61402de-c61e-4d7f-a2b1-3eaa13e4ef33@citrix.com>
Date:   Fri, 1 Dec 2023 19:39:05 +0000
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User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v4 1/6] x86/bugs: Add asm helpers for executing VERW
Content-Language: en-GB
To:     Josh Poimboeuf <jpoimboe@kernel.org>,
        Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc:     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,
        "H. Peter Anvin" <hpa@zytor.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>, tony.luck@intel.com,
        ak@linux.intel.com, tim.c.chen@linux.intel.com,
        Nikolay Borisov <nik.borisov@suse.com>,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        kvm@vger.kernel.org,
        Alyssa Milburn <alyssa.milburn@linux.intel.com>,
        Daniel Sneddon <daniel.sneddon@linux.intel.com>,
        antonio.gomez.iglesias@linux.intel.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alyssa Milburn <alyssa.milburn@intel.com>
References: <20231027-delay-verw-v4-0-9a3622d4bcf7@linux.intel.com>
 <20231027-delay-verw-v4-1-9a3622d4bcf7@linux.intel.com>
 <20231201193657.mvzslo4nlcbuv2q4@treble>
From:   Andrew Cooper <andrew.cooper3@citrix.com>
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In-Reply-To: <20231201193657.mvzslo4nlcbuv2q4@treble>
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On 01/12/2023 7:36 pm, Josh Poimboeuf wrote:
> On Fri, Oct 27, 2023 at 07:38:40AM -0700, Pawan Gupta wrote:
>> +.pushsection .entry.text, "ax"
>> +
>> +.align L1_CACHE_BYTES, 0xcc
>> +SYM_CODE_START_NOALIGN(mds_verw_sel)
>> +	UNWIND_HINT_UNDEFINED
>> +	ANNOTATE_NOENDBR
>> +	.word __KERNEL_DS
>> +.align L1_CACHE_BYTES, 0xcc
>> +SYM_CODE_END(mds_verw_sel);
>> +/* For KVM */
>> +EXPORT_SYMBOL_GPL(mds_verw_sel);
>> +
>> +.popsection
> This is data, so why is it "CODE" in .entry.text?

Because KPTI.

~Andrew