From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 36335951 for ; Wed, 27 Jul 2016 13:33:49 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 3E1A4DF for ; Wed, 27 Jul 2016 13:33:48 +0000 (UTC) Message-ID: <1469626423.120686.408.camel@infradead.org> From: David Woodhouse To: James Bottomley , Julia Lawall Date: Wed, 27 Jul 2016 14:33:43 +0100 In-Reply-To: <1469625916.27356.18.camel@HansenPartnership.com> References: <87inw1skws.fsf@x220.int.ebiederm.org> <25598.1469113525@warthog.procyon.org.uk> <18158a39-1297-7368-3c0e-3e9b3ce2c3ab@suse.com> <1469533716.120686.281.camel@infradead.org> <1469625916.27356.18.camel@HansenPartnership.com> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/x-pkcs7-signature"; boundary="=-sTsoo2s/HxLX/ddvwQWu" Mime-Version: 1.0 Cc: ksummit-discuss@lists.linuxfoundation.org Subject: Re: [Ksummit-discuss] [CORE TOPIC] More useful types in the linux kernel List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-sTsoo2s/HxLX/ddvwQWu Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2016-07-27 at 09:25 -0400, James Bottomley wrote: > On Wed, 2016-07-27 at 14:40 +0200, Julia Lawall wrote: > >=20 > > On Tue, 26 Jul 2016, David Woodhouse wrote: > >=20 > > > On Fri, 2016-07-22 at 15:57 +0200, Hannes Reinecke wrote: > > > >=20 > > > > > I guess that almost all functions return only a few possible > > > > > error codes? > > > >=20 > > > > Precisely. If we had a way of specifying "the return value is an= =20 > > > > errno with the possible values '0', '-EIO', and '-EINVAL'" that=20 > > > > would be _so_ cool. > > >=20 > > > And perpetually out of date. Because functions call through to=20 > > > *other* functions which might return an errno outside the 'known' > > > set. > >=20 > > If you have a script to calculate it, it doesn't have to be=20 > > perpetually out of date.=C2=A0 The problem is just the time to collect = the=20 > > information for the whole kernel.=C2=A0 It could be a good intern proje= ct. >=20 > It's a lot of pain, for what gain?=C2=A0 What, practically would we get a= s a > benefit if we did this?=C2=A0 Every time I see proposals about scripting > checks in the kernel, I'm reminded of our section mismatch debacle.=20 > =C2=A0Life is so much easier without every kernel release generating 100s= of > patches trying to correct section mismatches which didn't matter in the > first place ... To find functions where the -errno returns might be ambiguous with real valid return values, might be beneficial. If it doesn't have too many false positives. To tell *which* specific errnos might be returned by a given function... I can't see any benefit in that ever. --=20 dwmw2 --=-sTsoo2s/HxLX/ddvwQWu Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCEeAw ggXiMIIDyqADAgECAhBrp4p9CteI1lEK+Vnk57ThMA0GCSqGSIb3DQEBCwUAMH0xCzAJBgNVBAYT AklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSswKQYDVQQLEyJTZWN1cmUgRGlnaXRhbCBDZXJ0 aWZpY2F0ZSBTaWduaW5nMSkwJwYDVQQDEyBTdGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0 eTAeFw0xNTEyMTYwMTAwMDVaFw0zMDEyMTYwMTAwMDVaMHUxCzAJBgNVBAYTAklMMRYwFAYDVQQK Ew1TdGFydENvbSBMdGQuMSkwJwYDVQQLEyBTdGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0 eTEjMCEGA1UEAxMaU3RhcnRDb20gQ2xhc3MgMSBDbGllbnQgQ0EwggEiMA0GCSqGSIb3DQEBAQUA A4IBDwAwggEKAoIBAQC9fdr3w6J9g/Zbgv3bW1+uHht1wLUZr5gkrLtXedg17AkefMyUGwrQdvwO bhajcVmnKVxhrUwkZPXRAwZZosRHfEIi5FH7x6SV/8Sp5lZEuiMnvMFG2MzLA84J6Ws5T4NfXZ0q n4TPgnr3X2vPVS51M7Ua9nIJgn8jvTra4eyyQzxvuA/GZwKg7VQfDCmCS+kICslYYWgXOMt2xlsS 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