From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 07/14] proc/kcore: hide a harmless warning Date: Tue, 18 Jul 2017 21:53:40 +0200 Message-ID: References: <20170714092540.1217397-1-arnd@arndb.de> <20170714092540.1217397-8-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Ard Biesheuvel Cc: Pratyush Anand , Kees Cook , Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" , dri-devel , IDE-ML , Jiri Olsa , Tejun Heo , Andrew Morton , Linus Torvalds , Ingo Molnar , Guenter Roeck , Linux Media Mailing List List-Id: linux-ide@vger.kernel.org T24gRnJpLCBKdWwgMTQsIDIwMTcgYXQgMjoyOCBQTSwgQXJkIEJpZXNoZXV2ZWwKPGFyZC5iaWVz aGV1dmVsQGxpbmFyby5vcmc+IHdyb3RlOgo+IE9uIDE0IEp1bHkgMjAxNyBhdCAxMDoyNSwgQXJu ZCBCZXJnbWFubiA8YXJuZEBhcm5kYi5kZT4gd3JvdGU6Cj4+IGdjYyB3YXJucyB3aGVuIE1PRFVM RVNfVkFERFIvRU5EIGlzIGRlZmluZWQgdG8gdGhlIHNhbWUgdmFsdWUgYXMKPj4gVk1BTExPQ19T VEFSVC9WTUFMTE9DX0VORCwgZS5nLiBvbiB4ODYtMzI6Cj4+Cj4+IGZzL3Byb2Mva2NvcmUuYzog SW4gZnVuY3Rpb24g4oCYYWRkX21vZHVsZXNfcmFuZ2XigJk6Cj4+IGZzL3Byb2Mva2NvcmUuYzo2 MjI6MTYxOiBlcnJvcjogc2VsZi1jb21wYXJpc29uIGFsd2F5cyBldmFsdWF0ZXMgdG8gZmFsc2Ug Wy1XZXJyb3I9dGF1dG9sb2dpY2FsLWNvbXBhcmVdCj4+ICAgaWYgKC8qTU9EVUxFU19WQUREUiAh PSBWTUFMTE9DX1NUQVJUICYmICovTU9EVUxFU19FTkQgIT0gVk1BTExPQ19FTkQpIHsKPj4KPgo+ IERvZXMgaXQgb2NjdXIgZm9yIHN1YnRyYWN0aW9uIGFzIHdlbGw/IE9yIG9ubHkgZm9yIGNvbXBh cmlzb24/CgpUaGlzIHJlcGxhY2VtZW50IHBhdGNoIHdvdWxkIGFsc28gYWRkcmVzcyB0aGUgd2Fy bmluZzoKCmRpZmYgLS1naXQgYS9mcy9wcm9jL2tjb3JlLmMgYi9mcy9wcm9jL2tjb3JlLmMKaW5k ZXggNDU2MjlmNGI1NDAyLi4zNTgyNGU5ODZjMmMgMTAwNjQ0Ci0tLSBhL2ZzL3Byb2Mva2NvcmUu YworKysgYi9mcy9wcm9jL2tjb3JlLmMKQEAgLTYyMyw3ICs2MjMsNyBAQCBzdGF0aWMgdm9pZCBf X2luaXQgcHJvY19rY29yZV90ZXh0X2luaXQodm9pZCkKIHN0cnVjdCBrY29yZV9saXN0IGtjb3Jl X21vZHVsZXM7CiBzdGF0aWMgdm9pZCBfX2luaXQgYWRkX21vZHVsZXNfcmFuZ2Uodm9pZCkKIHsK LSAgICAgICBpZiAoTU9EVUxFU19WQUREUiAhPSBWTUFMTE9DX1NUQVJUICYmIE1PRFVMRVNfRU5E ICE9IFZNQUxMT0NfRU5EKSB7CisgICAgICAgaWYgKE1PRFVMRVNfVkFERFIgLSBWTUFMTE9DX1NU QVJUICYmIE1PRFVMRVNfRU5EIC0gVk1BTExPQ19FTkQpIHsKICAgICAgICAgICAgICAgIGtjbGlz dF9hZGQoJmtjb3JlX21vZHVsZXMsICh2b2lkICopTU9EVUxFU19WQUREUiwKICAgICAgICAgICAg ICAgICAgICAgICAgTU9EVUxFU19FTkQgLSBNT0RVTEVTX1ZBRERSLCBLQ09SRV9WTUFMTE9DKTsK ICAgICAgICB9CgpJIGhhdmUgYWxzbyB2ZXJpZmllZCB0aGF0IGZvdXIgb2YgdGhlIDE0IHBhdGNo ZXMgYXJlIG5vdCBuZWVkZWQgd2hlbiBidWlsZGluZwp3aXRob3V0IGNjYWNoZSwgdGhpcyBpcyBv bmUgb2YgdGhlbToKCiBhY3BpOiB0aGVybWFsOiBmaXggZ2NjLTYvY2NhY2hlIHdhcm5pbmcKIHBy b2Mva2NvcmU6IGhpZGUgYSBoYXJtbGVzcyB3YXJuaW5nCiBTRkk6IGZpeCB0YXV0b2xvZ2ljYWwt Y29tcGFyZSB3YXJuaW5nCiBbbWVkaWFdIGZpeCB3YXJuaW5nIG9uIHY0bDJfc3ViZGV2X2NhbGwo KSByZXN1bHQgaW50ZXJwcmV0ZWQgYXMgYm9vbAoKTm90IHN1cmUgd2hhdCB0byBkbyB3aXRoIHRo b3NlLCB3ZSBjb3VsZCBlaXRoZXIgaWdub3JlIHRoZW0gYWxsIGFuZApub3QgY2FyZSBhYm91dCBj Y2FjaGUsIG9yIHdlIHRyeSB0byBhZGRyZXNzIHRoZW0gYWxsIGluIHNvbWUgd2F5LgoKICAgICAg ICBBcm5kCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRy aS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRw czovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752255AbdGRTxp (ORCPT ); Tue, 18 Jul 2017 15:53:45 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:35469 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500AbdGRTxm (ORCPT ); Tue, 18 Jul 2017 15:53:42 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170714092540.1217397-1-arnd@arndb.de> <20170714092540.1217397-8-arnd@arndb.de> From: Arnd Bergmann Date: Tue, 18 Jul 2017 21:53:40 +0200 X-Google-Sender-Auth: wumBE5T1hi98gpVrj3xH0Jk5uu0 Message-ID: Subject: Re: [PATCH 07/14] proc/kcore: hide a harmless warning To: Ard Biesheuvel Cc: "linux-kernel@vger.kernel.org" , Jiri Olsa , Greg Kroah-Hartman , Linus Torvalds , Tejun Heo , Guenter Roeck , IDE-ML , Linux Media Mailing List , Andrew Morton , dri-devel , Kees Cook , Ingo Molnar , Laura Abbott , Pratyush Anand Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6IJrnUd029776 On Fri, Jul 14, 2017 at 2:28 PM, Ard Biesheuvel wrote: > On 14 July 2017 at 10:25, Arnd Bergmann wrote: >> gcc warns when MODULES_VADDR/END is defined to the same value as >> VMALLOC_START/VMALLOC_END, e.g. on x86-32: >> >> fs/proc/kcore.c: In function ‘add_modules_range’: >> fs/proc/kcore.c:622:161: error: self-comparison always evaluates to false [-Werror=tautological-compare] >> if (/*MODULES_VADDR != VMALLOC_START && */MODULES_END != VMALLOC_END) { >> > > Does it occur for subtraction as well? Or only for comparison? This replacement patch would also address the warning: diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 45629f4b5402..35824e986c2c 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -623,7 +623,7 @@ static void __init proc_kcore_text_init(void) struct kcore_list kcore_modules; static void __init add_modules_range(void) { - if (MODULES_VADDR != VMALLOC_START && MODULES_END != VMALLOC_END) { + if (MODULES_VADDR - VMALLOC_START && MODULES_END - VMALLOC_END) { kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_END - MODULES_VADDR, KCORE_VMALLOC); } I have also verified that four of the 14 patches are not needed when building without ccache, this is one of them: acpi: thermal: fix gcc-6/ccache warning proc/kcore: hide a harmless warning SFI: fix tautological-compare warning [media] fix warning on v4l2_subdev_call() result interpreted as bool Not sure what to do with those, we could either ignore them all and not care about ccache, or we try to address them all in some way. Arnd