From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226XY6xx5Q6wPSx7glf+tRB9n8iwnWX3LeiK9cIOS/2YYmdXoMkNis5FdA9tXuoYhWuD5+yB ARC-Seal: i=1; a=rsa-sha256; t=1516659723; cv=none; d=google.com; s=arc-20160816; b=Pnlwjf1oInzWAzFJTy+sM5sMJ19/BtQIzVKourv9+r7u6Zcxm+2OSpTJx0iyCcPYUc vp2ab+pZ6fj37W+FEF9Dmz/wEd2A1u9Dp9b9837iC3LdskgwhMwXTG+/8drrUjzaA03P kIcBtTLyvhWGtxSfq0913cszlaj5NPTPuEBuVTo6fXRV6m07A3emaWpx7Dv3/Z/Ds5t8 Rr6M6yAr98IvJkPGA06eNeXC8VnqwY0jVKXrpr9WB3vx9TJVnRQz4EticmxdHYQ9Ss6M jQ0LHtSpxGcZlw03dAYzryQdSYmJpTh60NWE5qIx0sMzNLCBHxbBFBRx3inwuyZnE1hY ZnmQ== 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=UOJcVMVKLX+Im4Rp85lEnWKC+v0y7cVNopnQaqhUIVU=; b=wDVxEUn8fxmmR4Hj3KWOW8cs6uiRD1tRG7N3ILBVpI03CPY+9xTJKwHaEgD8T8JWpq NrNRVgOivRy0HVfPZW65j/qWfM4ddJzrPlePC9abpCjz6Jvg9sAzgQR7fTmsvjakXDrf Tl9Sx8T63XIDgORE8INSwjhi57om9sDAnqE+cqauOO7m1bp8UDHE4QB2B6wDyw5C0JOa PqUm8++FW5QbII259IstVHK216ZkGIREwiNom0cPjSWuGgAq00UktLY+qgKgHwaCYpsD l966Hr4Tcn+0V06hNhlb0IvACxp2ngPRvjMWHqDt6ctmg/Uwhaul7V2Gbfqp1NOImdYC nSkQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=twosheds.20170209 header.b=su4Su2xs; spf=pass (google.com: best guess record for domain of batv+2d7d097349343b7b44ed+5265+infradead.org+dwmw2@twosheds.srs.infradead.org designates 2001:8b0:10b:1:21d:7dff:fe04:dbe2 as permitted sender) smtp.mailfrom=BATV+2d7d097349343b7b44ed+5265+infradead.org+dwmw2@twosheds.srs.infradead.org Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=twosheds.20170209 header.b=su4Su2xs; spf=pass (google.com: best guess record for domain of batv+2d7d097349343b7b44ed+5265+infradead.org+dwmw2@twosheds.srs.infradead.org designates 2001:8b0:10b:1:21d:7dff:fe04:dbe2 as permitted sender) smtp.mailfrom=BATV+2d7d097349343b7b44ed+5265+infradead.org+dwmw2@twosheds.srs.infradead.org Message-ID: <1516659707.9521.77.camel@infradead.org> Subject: Re: [PATCH] x86/retpoline: Remove the esp/rsp thunk From: David Woodhouse To: Waiman Long , Thomas Gleixner , Ingo Molnar , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Arjan van de Ven , Andi Kleen , Josh Poimboeuf , Jeff Law , Linus Torvalds , Jiri Kosina , Andy Lutomirski , Dave Hansen , Kees Cook , Tim Chen , Greg Kroah-Hartman , Paul Turner , Tom Lendacky In-Reply-To: <1516658974-27852-1-git-send-email-longman@redhat.com> References: <1516658974-27852-1-git-send-email-longman@redhat.com> Face: 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 Content-Type: multipart/signed; micalg="sha-256"; protocol="application/x-pkcs7-signature"; boundary="=-Dyw69AxBmgEScA9xFOvb" Date: Mon, 22 Jan 2018 22:21:47 +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?1590332241345318630?= X-GMAIL-MSGID: =?utf-8?q?1590332985904648970?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: --=-Dyw69AxBmgEScA9xFOvb Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2018-01-22 at 17:09 -0500, Waiman Long wrote: > It doesn't make sense to have an indirect call thunk with esp/rsp as > retpoline code won't work correctly with the stack pointer register. > Removing it will help compiler writers to catch error in case such > a thunk call is emitted incorrectly. >=20 > Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") > Suggested-by: Jeff Law > Signed-off-by: Waiman Long Acked-by: David Woodhouse I spotted that and *almost* removed it a couple of times in other refactoring, but after abandoning those I forgot to come back and do just this. Thanks. --=-Dyw69AxBmgEScA9xFOvb 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 3PZ0chY1PaVWjg59d4Uno+5LRDbgCnPkKJX4ysBGadibjBGQGJEZCjh94iiEebn2KsRLvtrJ72Ph 3W2HDEdngW3YP0wujFQVs81U7L8XN3kdPRsa9zNqGtYQP/+1KMMJQ57hnfi9AgMBAAGjggHpMIIB 5TAfBgNVHSMEGDAWgBSCr2yM+MX+lmF86B89K3FIXsSLwDAdBgNVHQ4EFgQUpL+/5lli9jmj2KHj ryyhnB2xRt0wDgYDVR0PAQH/BAQDAgWgMAwGA1UdEwEB/wQCMAAwIAYDVR0lBBkwFwYIKwYBBQUH AwQGCysGAQQBsjEBAwUCMBEGCWCGSAGG+EIBAQQEAwIFIDBGBgNVHSAEPzA9MDsGDCsGAQQBsjEB AgEBATArMCkGCCsGAQUFBwIBFh1odHRwczovL3NlY3VyZS5jb21vZG8ubmV0L0NQUzBaBgNVHR8E UzBRME+gTaBLhklodHRwOi8vY3JsLmNvbW9kb2NhLmNvbS9DT01PRE9SU0FDbGllbnRBdXRoZW50 aWNhdGlvbmFuZFNlY3VyZUVtYWlsQ0EuY3JsMIGLBggrBgEFBQcBAQR/MH0wVQYIKwYBBQUHMAKG SWh0dHA6Ly9jcnQuY29tb2RvY2EuY29tL0NPTU9ET1JTQUNsaWVudEF1dGhlbnRpY2F0aW9uYW5k U2VjdXJlRW1haWxDQS5jcnQwJAYIKwYBBQUHMAGGGGh0dHA6Ly9vY3NwLmNvbW9kb2NhLmNvbTAe BgNVHREEFzAVgRNkd213MkBpbmZyYWRlYWQub3JnMA0GCSqGSIb3DQEBCwUAA4IBAQCK28BdbVJ9 QKQqTDfXwogAYiRBEGptfE1Bjy4F5vC6eWJqOJ15vunxjLwdbZYb4L0qrJlh+ZHHHlbIK8uEZu7N XHUntmWMbGbZiu7JgrbSXJK1ct9gxrN/sdWYJ+JDjVHg7GfDTvTTPa26JMRqJsO1TjjyDX7A3K39 TjV8C0hqXvwF9BsNf+qBeWO6GVzJ5572awY221hc1umibmZaKV4fg+7fS7qscx5TSuIc6uvMBQhm 7NQiCq6euMMWBDUDlotQCDW0ilm0OuLW3IVLuZCm6Msc+6hT9+dCT4JUvxTHZnnO7uLCxV+Ujad+ PH3itRm38i96p2zvwgLr8vwWA0ckMIIFMTCCBBmgAwIBAgIQTUYRMpPx2e52jnkx1q87gDANBgkq hkiG9w0BAQsFADCBlzELMAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQ MA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMRQ09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENP TU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0EwHhcNMTcx MjIxMDAwMDAwWhcNMTgxMjIxMjM1OTU5WjAkMSIwIAYJKoZIhvcNAQkBFhNkd213MkBpbmZyYWRl YWQub3JnMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA4MyzVmtfAzaRlI/2Xh9EoM+d xEiG83T8NziXrjT+o2YcWaI28n8WzIRE7HMSPx4+lGeGu7B5uQZFY5bAdQH9mWvz11LfDJiwHDzB 5DDxrp75FImxL25Q76ajJEGZWmTPreT6hZlpG3oS2hL26TWO3ZhAAHioeJJU8yc66+QAM2gkN9nA Nnt/gxCL+TuZfVYjCI8vyTPsTEK319z2dHIWNT2lVo4OfXeFJ6PuS0Q24Apz5CiV+MrARmnYm4wR kBiRGQo4feIohHm59irES77aye9j4d1thwxHZ4Ft2D9MLoxUFbPNVOy/Fzd5HT0bGvczahrWED// tSjDCUOe4Z34vQIDAQABo4IB6TCCAeUwHwYDVR0jBBgwFoAUgq9sjPjF/pZhfOgfPStxSF7Ei8Aw HQYDVR0OBBYEFKS/v+ZZYvY5o9ih468soZwdsUbdMA4GA1UdDwEB/wQEAwIFoDAMBgNVHRMBAf8E AjAAMCAGA1UdJQQZMBcGCCsGAQUFBwMEBgsrBgEEAbIxAQMFAjARBglghkgBhvhCAQEEBAMCBSAw RgYDVR0gBD8wPTA7BgwrBgEEAbIxAQIBAQEwKzApBggrBgEFBQcCARYdaHR0cHM6Ly9zZWN1cmUu Y29tb2RvLm5ldC9DUFMwWgYDVR0fBFMwUTBPoE2gS4ZJaHR0cDovL2NybC5jb21vZG9jYS5jb20v Q09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1cmVFbWFpbENBLmNybDCBiwYIKwYB BQUHAQEEfzB9MFUGCCsGAQUFBzAChklodHRwOi8vY3J0LmNvbW9kb2NhLmNvbS9DT01PRE9SU0FD bGllbnRBdXRoZW50aWNhdGlvbmFuZFNlY3VyZUVtYWlsQ0EuY3J0MCQGCCsGAQUFBzABhhhodHRw Oi8vb2NzcC5jb21vZG9jYS5jb20wHgYDVR0RBBcwFYETZHdtdzJAaW5mcmFkZWFkLm9yZzANBgkq hkiG9w0BAQsFAAOCAQEAitvAXW1SfUCkKkw318KIAGIkQRBqbXxNQY8uBebwunliajideb7p8Yy8 HW2WG+C9KqyZYfmRxx5WyCvLhGbuzVx1J7ZljGxm2YruyYK20lyStXLfYMazf7HVmCfiQ41R4Oxn w0700z2tuiTEaibDtU448g1+wNyt/U41fAtIal78BfQbDX/qgXljuhlcyeee9msGNttYXNbpom5m WileH4Pu30u6rHMeU0riHOrrzAUIZuzUIgqunrjDFgQ1A5aLUAg1tIpZtDri1tyFS7mQpujLHPuo U/fnQk+CVL8Ux2Z5zu7iwsVflI2nfjx94rUZt/Iveqds78IC6/L8FgNHJDCCBeYwggPOoAMCAQIC EGqb4Tg7/ytrnwHV2binUlYwDQYJKoZIhvcNAQEMBQAwgYUxCzAJBgNVBAYTAkdCMRswGQYDVQQI ExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBD QSBMaW1pdGVkMSswKQYDVQQDEyJDT01PRE8gUlNBIENlcnRpZmljYXRpb24gQXV0aG9yaXR5MB4X DTEzMDExMDAwMDAwMFoXDTI4MDEwOTIzNTk1OVowgZcxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJH cmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBM aW1pdGVkMT0wOwYDVQQDEzRDT01PRE8gUlNBIENsaWVudCBBdXRoZW50aWNhdGlvbiBhbmQgU2Vj dXJlIEVtYWlsIENBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvrOeV6wodnVAFsc4 A5jTxhh2IVDzJXkLTLWg0X06WD6cpzEup/Y0dtmEatrQPTRI5Or1u6zf+bGBSyD9aH95dDSmeny1 nxdlYCeXIoymMv6pQHJGNcIDpFDIMypVpVSRsivlJTRENf+RKwrB6vcfWlP8dSsE3Rfywq09N0Zf xcBa39V0wsGtkGWC+eQKiz4pBZYKjrc5NOpG9qrxpZxyb4o4yNNwTqzaaPpGRqXB7IMjtf7tTmU2 jqPMLxFNe1VXj9XB1rHvbRikw8lBoNoSWY66nJN/VCJv5ym6Q0mdCbDKCMPybTjoNCQuelc0IAaO 4nLUXk0BOSxSxt8kCvsUtQIDAQABo4IBPDCCATgwHwYDVR0jBBgwFoAUu69+Aj36pvE8hI6t7jiY 7NkyMtQwHQYDVR0OBBYEFIKvbIz4xf6WYXzoHz0rcUhexIvAMA4GA1UdDwEB/wQEAwIBhjASBgNV HRMBAf8ECDAGAQH/AgEAMBEGA1UdIAQKMAgwBgYEVR0gADBMBgNVHR8ERTBDMEGgP6A9hjtodHRw Oi8vY3JsLmNvbW9kb2NhLmNvbS9DT01PRE9SU0FDZXJ0aWZpY2F0aW9uQXV0aG9yaXR5LmNybDBx BggrBgEFBQcBAQRlMGMwOwYIKwYBBQUHMAKGL2h0dHA6Ly9jcnQuY29tb2RvY2EuY29tL0NPTU9E T1JTQUFkZFRydXN0Q0EuY3J0MCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5jb21vZG9jYS5jb20w DQYJKoZIhvcNAQEMBQADggIBAHhcsoEoNE887l9Wzp+XVuyPomsX9vP2SQgG1NgvNc3fQP7TcePo 7EIMERoh42awGGsma65u/ITse2hKZHzT0CBxhuhb6txM1n/y78e/4ZOs0j8CGpfb+SJA3GaBQ+39 4k+z3ZByWPQedXLL1OdK8aRINTsjk/H5Ns77zwbjOKkDamxlpZ4TKSDMKVmU/PUWNMKSTvtlenlx Bhh7ETrN543j/Q6qqgCWgWuMAXijnRglp9fyadqGOncjZjaaSOGTTFB+E2pvOUtY+hPebuPtTbq7 vODqzCM6ryEhNhzf+enm0zlpXK7q332nXttNtjv7VFNYG+I31gnMrwfHM5tdhYF/8v5UY5g2xANP ECTQdu9vWPoqNSGDt87b3gXb1AiGGaI06vzgkejL580ul+9hz9D0S0U4jkhJiA7EuTecP/CFtR72 uYRBcunwwH3fciPjviDDAI9SnC/2aPY8ydehzuZutLbZdRJ5PDEJM/1tyZR2niOYihZ+FCbtf3D9 mB12D4ln9icgc7CwaxpNSCPt8i/GqK2HsOgkL3VYnwtx7cJUmpvVdZ4ognzgXtgtdk3ShrtOS1iA N2ZBXFiRmjVzmehoMof06r1xub+85hFQzVxZx5/bRaTKTlL8YXLI8nAbR9HWdFqzcOoB/hxfEyIQ px9/s81rgzdEZOofSlZHynoSMYIDxzCCA8MCAQEwgawwgZcxCzAJBgNVBAYTAkdCMRswGQYDVQQI ExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBD QSBMaW1pdGVkMT0wOwYDVQQDEzRDT01PRE8gUlNBIENsaWVudCBBdXRoZW50aWNhdGlvbiBhbmQg U2VjdXJlIEVtYWlsIENBAhBNRhEyk/HZ7naOeTHWrzuAMA0GCWCGSAFlAwQCAQUAoIIB6zAYBgkq hkiG9w0BCQMxCwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xODAxMjIyMjIxNDdaMC8GCSqG SIb3DQEJBDEiBCBx91ReOsTSRM4OObWV8MdkBag6uImJGJ2HdAWk5/h9FTCBvQYJKwYBBAGCNxAE MYGvMIGsMIGXMQswCQYDVQQGEwJHQjEbMBkGA1UECBMSR3JlYXRlciBNYW5jaGVzdGVyMRAwDgYD VQQHEwdTYWxmb3JkMRowGAYDVQQKExFDT01PRE8gQ0EgTGltaXRlZDE9MDsGA1UEAxM0Q09NT0RP IFJTQSBDbGllbnQgQXV0aGVudGljYXRpb24gYW5kIFNlY3VyZSBFbWFpbCBDQQIQTUYRMpPx2e52 jnkx1q87gDCBvwYLKoZIhvcNAQkQAgsxga+ggawwgZcxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJH cmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBM aW1pdGVkMT0wOwYDVQQDEzRDT01PRE8gUlNBIENsaWVudCBBdXRoZW50aWNhdGlvbiBhbmQgU2Vj dXJlIEVtYWlsIENBAhBNRhEyk/HZ7naOeTHWrzuAMA0GCSqGSIb3DQEBAQUABIIBAJ9GZeWZyou/ giQ+CCkN7sY6nWNXJm8OSO+fVoLXW6yI3qUEJ9fbjvUkiIX1p+mb1vaKvKWVRyCmTXqWUlBwhlC5 gWz6qI8grjLm1eo1Zy0RJq6QJRMmscIL1666j15BaF6AtFBm0c0zpMAVIr1Jh9i+JGXcBoGzor0j znOgeptLZABmruuQHqiErXK7ldpkshkzY0MsbYWRq4ywAXq6ej7HyBK0+h4GZMGllQUwTC2GyVpr QM7GDtUeWl+gaBPXGswaTW9x41Tmlp1gWqFeCnjjFoHKuO0hchByFqwVJAHinZDRuqOQIZpSY73E pgNki9EIlGrTg4fS/c4WLArSgGUAAAAAAAA= --=-Dyw69AxBmgEScA9xFOvb--