From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226mdE+BKzZZWTJiTwgy/sotVQTbd1lyQFuaRx4S5wRXk6oFiuNvojYn/TFHdrs9AnY7byNz ARC-Seal: i=1; a=rsa-sha256; t=1516874536; cv=none; d=google.com; s=arc-20160816; b=c5vOcVcA0neR5Re7/y3TQelOhAvmeCFjPpCzOwupENk423mocjhhpJkMGzc6YICwCk +CgAf+9WWHrWXFjlmxlm5MQFso3SYlHcVOpOBC9WZm6yMach4Geh0DYpQ2fQJswYQRto gNpRzhrG3iZfZ8Tvvh5p60t9NoJ7XeMGobKMvG7FHd+ziZ0J1cZL7Ohh6nvUHC9sreE7 G9Mdv/x846NMfBbHVR3FnO0OakRygnBBwhaAUKbvvkspmJHkDpPjsdKuoglHKeZIq5I+ JeoQuzSxXCPJ+QZYEORUFIdfqy0/HLNj39faIKmpsO6V6nJ3ndqQ5t6FeGrMIOHsEgLl MoXg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:date:face:references:in-reply-to:cc:to:from:subject :message-id:dkim-signature:arc-authentication-results; bh=VHm8cvH13BQNG3+BX18DRF1hUwgmcw5GwspYxNH8ims=; b=GwC9RxJJ9F50pnzZ5pagr+DJsDLL7JDSnkfWel9rx7rkhnG2im8B7LuZoy/XNsYV9B fbiW5t0xsJmJdEscUKmURDvW3/bj63OFfXV7E8fhsQJA8li06nqoV3N7dyRHLdWlpu3G g6gT6ZPN/acdGLmujcNAG4R2ridsWHs8DEaR0SXg3e/A3M66fqvqc1qMYuUciS+bkdBM o0UXNgGktvqGrd9f1mHSu8k8mFcsN65SFzbHwdWWcKoCnSk+MYhzhLcrXhqcjNv7CJ8W OTbBk/Bvp2DBi23j/+4bVueVxpS/XI55Lu0nayVQXPcUv2nvbLWpq7/qfYSgi2h/+2yZ d3bA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=twosheds.20170209 header.b=vZhdo5BW; spf=pass (google.com: best guess record for domain of batv+c81c304d53d4f47de05e+5268+infradead.org+dwmw2@twosheds.srs.infradead.org designates 90.155.92.209 as permitted sender) smtp.mailfrom=BATV+c81c304d53d4f47de05e+5268+infradead.org+dwmw2@twosheds.srs.infradead.org Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=twosheds.20170209 header.b=vZhdo5BW; spf=pass (google.com: best guess record for domain of batv+c81c304d53d4f47de05e+5268+infradead.org+dwmw2@twosheds.srs.infradead.org designates 90.155.92.209 as permitted sender) smtp.mailfrom=BATV+c81c304d53d4f47de05e+5268+infradead.org+dwmw2@twosheds.srs.infradead.org Message-ID: <1516874525.30244.41.camel@infradead.org> Subject: Re: [PATCH 03/24] x86/paravirt: Annotate indirect calls From: David Woodhouse To: Peter Zijlstra , Thomas Gleixner , Josh Poimboeuf Cc: linux-kernel@vger.kernel.org, Dave Hansen , Ashok Raj , Tim Chen , Andy Lutomirski , Linus Torvalds , Greg KH , Andrea Arcangeli , Andi Kleen , Arjan Van De Ven , Dan Williams , Paolo Bonzini , Jun Nakajima , Asit Mallick , Jason Baron In-Reply-To: <20180123152638.162540737@infradead.org> References: <20180123152539.374360046@infradead.org> <20180123152638.162540737@infradead.org> Face: 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 Content-Type: multipart/signed; micalg="sha-256"; protocol="application/x-pkcs7-signature"; boundary="=-BqWKJA5I8pZ9g8iVT6LK" Date: Thu, 25 Jan 2018 10:02:05 +0000 Mime-Version: 1.0 X-Mailer: Evolution 3.18.5.2-0ubuntu3.2 X-SRS-Rewrite: SMTP reverse-path rewritten from by twosheds.infradead.org. See http://www.infradead.org/rpr.html X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590397845189698377?= X-GMAIL-MSGID: =?utf-8?q?1590558234055931699?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: --=-BqWKJA5I8pZ9g8iVT6LK Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2018-01-23 at 16:25 +0100, Peter Zijlstra wrote: > Paravirt emits indirect calls which get flagged by objtool retpoline > checks, annotate it away because all these indirect calls will be > patched out before we start userspace. I've seen this asserted repeatedly but I've never truly convinced myself of it. Is this absolutely unconditionally true in every case, even when we're running as a guest and there are *actual* calls to be made? We turn them into direct calls, never leave them indirect? --=-BqWKJA5I8pZ9g8iVT6LK Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCEFQw ggUxMIIEGaADAgECAhBNRhEyk/HZ7naOeTHWrzuAMA0GCSqGSIb3DQEBCwUAMIGXMQswCQYDVQQG EwJHQjEbMBkGA1UECBMSR3JlYXRlciBNYW5jaGVzdGVyMRAwDgYDVQQHEwdTYWxmb3JkMRowGAYD VQQKExFDT01PRE8gQ0EgTGltaXRlZDE9MDsGA1UEAxM0Q09NT0RPIFJTQSBDbGllbnQgQXV0aGVu dGljYXRpb24gYW5kIFNlY3VyZSBFbWFpbCBDQTAeFw0xNzEyMjEwMDAwMDBaFw0xODEyMjEyMzU5 NTlaMCQxIjAgBgkqhkiG9w0BCQEWE2R3bXcyQGluZnJhZGVhZC5vcmcwggEiMA0GCSqGSIb3DQEB AQUAA4IBDwAwggEKAoIBAQDgzLNWa18DNpGUj/ZeH0Sgz53ESIbzdPw3OJeuNP6jZhxZojbyfxbM hETscxI/Hj6UZ4a7sHm5BkVjlsB1Af2Za/PXUt8MmLAcPMHkMPGunvkUibEvblDvpqMkQZlaZM+t 5PqFmWkbehLaEvbpNY7dmEAAeKh4klTzJzrr5AAzaCQ32cA2e3+DEIv5O5l9ViMIjy/JM+xMQrfX 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