diff options
Diffstat (limited to 'include-linux-module.h-mark-init-cleanup_module-aliases-as-__cold.patch')
| -rw-r--r-- | include-linux-module.h-mark-init-cleanup_module-aliases-as-__cold.patch | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/include-linux-module.h-mark-init-cleanup_module-aliases-as-__cold.patch b/include-linux-module.h-mark-init-cleanup_module-aliases-as-__cold.patch new file mode 100644 index 000000000..f350e6f32 --- /dev/null +++ b/include-linux-module.h-mark-init-cleanup_module-aliases-as-__cold.patch @@ -0,0 +1,149 @@ +From patchwork Wed Jan 23 17:37:07 2019 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +X-Patchwork-Submitter: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> +X-Patchwork-Id: 1034989 +Return-Path: <SRS0=drEb=P7=vger.kernel.org=linux-kernel-owner@kernel.org> +Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) + by smtp.lore.kernel.org (Postfix) with ESMTP id A7D50C282C0 + for <linux-kernel@archiver.kernel.org>; Wed, 23 Jan 2019 17:38:31 +0000 (UTC) +Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) + by mail.kernel.org (Postfix) with ESMTP id 7CE1F20870 + for <linux-kernel@archiver.kernel.org>; Wed, 23 Jan 2019 17:38:31 +0000 (UTC) +Authentication-Results: mail.kernel.org; + dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com + header.b="qdRA7oPl" +Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand + id S1726152AbfAWRi3 (ORCPT + <rfc822;linux-kernel@archiver.kernel.org>); + Wed, 23 Jan 2019 12:38:29 -0500 +Received: from mail-wm1-f67.google.com ([209.85.128.67]:52719 "EHLO + mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org + with ESMTP id S1725896AbfAWRi3 (ORCPT + <rfc822;linux-kernel@vger.kernel.org>); + Wed, 23 Jan 2019 12:38:29 -0500 +Received: by mail-wm1-f67.google.com with SMTP id m1so242485wml.2 + for <linux-kernel@vger.kernel.org>; + Wed, 23 Jan 2019 09:38:27 -0800 (PST) +DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; + d=gmail.com; s=20161025; + h=date:from:to:cc:subject:message-id:mime-version:content-disposition + :user-agent; + bh=1joVTuHcQFv5PhIFvZBlpu1jeKwRQi2Ty1HKsqzNx+0=; + b=qdRA7oPloipduZyiYE/EECaW/vCZup5EXmE5a1XgE9mc55H+TTPNNRTt44QJbQgbnn + wTNksIkBx8Gs0k3pJI9QIDO2J5AipLN8OOoxkPiDIJtAC8buHzQrdTxFG/4Uxw7tRf8X + A6PNyuUGr+02itkYIlALzEuDHvZna8yZx0zCeCDXF2IrGt0NBHZVTzz1XfX8LeQlCh9L + hleyVdDQnDvwxA7dXqrA4UugXUlEqT8HnIAUdg8+/xubsXOSz9T/22+zc9pZ9uSHm2uq + DpO/hgx1e5DONDN8T+sjjKCO0LnJ8Z9ZS0Huf+8W2XH1uxo48jSgXUOsygPQ36+8R/7t + ng6Q== +X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; + d=1e100.net; s=20161025; + h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version + :content-disposition:user-agent; + bh=1joVTuHcQFv5PhIFvZBlpu1jeKwRQi2Ty1HKsqzNx+0=; + b=ZQrXdTIYsCSUGNJS1C0dn+gibvoSHb2o+kcUMGTbH6G2tag3Zy4vnfIcBT0xhmvPLq + 5pU8jskcufXp0qQ0sivNsBpJYJCbsqqiChoivTs9WC4rxoM5G62Wi0pAZL59fGGDnmyV + xjSTkSoxe8CiB+26BDzg52zkynkWC2v0OHgaM7/1lTeTqNxdYIvQ+hC4LXdy40bAP64/ + JIC1nET+KwewpPHJQc2u87ah4xp6nEjzO/4wTP3CUi4zbZPTU17oH007IAXhObL7JO0r + XkRBJAgpcTKexfAJB7HnAUc4KLSv5L5Uz+Z14TusskTuK6njE11PE9GSJ7Z7lqufqJNZ + Z4GQ== +X-Gm-Message-State: AJcUukdaW+EjUkHLIrpaLWRYCoF9XYWdpSiPfNnJgu3VB9CW8t9xYlZJ + NDU6hJ2AXvnDR+awfdjm6IU= +X-Google-Smtp-Source: + ALg8bN59XklA0HTVEDaLFI+8dguNdipIQWTlgIi23N78PjaLBzniLMXowf2nCpIra7boIidjtFvfYg== +X-Received: by 2002:a1c:7c05:: with SMTP id x5mr3525198wmc.54.1548265106544; + Wed, 23 Jan 2019 09:38:26 -0800 (PST) +Received: from gmail.com (79.108.96.12.dyn.user.ono.com. [79.108.96.12]) + by smtp.gmail.com with ESMTPSA id + r77sm74200791wmd.22.2019.01.23.09.38.25 + (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); + Wed, 23 Jan 2019 09:38:25 -0800 (PST) +Date: Wed, 23 Jan 2019 18:37:07 +0100 +From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> +To: Jessica Yu <jeyu@kernel.org> +Cc: Laura Abbott <labbott@redhat.com>, + Martin Sebor <msebor@gcc.gnu.org>, linux-kernel@vger.kernel.org +Subject: [PATCH] include/linux/module.h: mark init/cleanup_module aliases as + __cold +Message-ID: <20190123173707.GA16603@gmail.com> +MIME-Version: 1.0 +Content-Type: text/plain; charset=us-ascii +Content-Disposition: inline +User-Agent: elm/2 +Sender: linux-kernel-owner@vger.kernel.org +Precedence: bulk +List-ID: <linux-kernel.vger.kernel.org> +X-Mailing-List: linux-kernel@vger.kernel.org + +The upcoming GCC 9 release adds the -Wmissing-attributes warnings +(enabled by -Wall), which trigger for all the init/cleanup_module +aliases in the kernel (defined by the module_init/exit macros), +ending up being very noisy. + +These aliases point to the __init/__exit functions of a module, +which are defined as __cold (among other attributes). However, +the aliases themselves do not have the __cold attribute. + +Since the compiler behaves differently when compiling a __cold +function as well as when compiling paths leading to calls +to __cold functions, the warning is trying to point out +the possibly-forgotten attribute in the alias. + +In order to keep the warning enabled, we choose to silence +the warning by marking the aliases as __cold. This is possible +marking either the extern declaration, the definition, or both. +In order to avoid changing the behavior of callers, we do it +only in the definition of the aliases (since those are not +seen by any other TU). + +Suggested-by: Martin Sebor <msebor@gcc.gnu.org> +Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> +--- +Note that an alternative is using the new copy attribute +introduced by GCC 9 (Martin told me about it, as well as the +new warning). + +What I am concerned about using __copy is that I am not sure +we should be copying all the attributes (even if some are +blacklisted by the copy itself), since: + - We have unknown-to-GCC attributes (e.g. from plugins). + - We wouldn't enjoy the fix for older compilers + (e.g. if the fix had an actual impact). + +So here I took the conservative approach for the moment, +and we can discuss/apply whether another solution is best. + +Jessica: please review what I explain in the commit message. +Do we actually want the __cold attribute in the declaration +as well? If yes, AFAIK, GCC would assume paths that end up +calling the __init/__exit functions are not meant to be taken +(but when we are asked to load modules, that is the expected +path, no?). + +I will put this in the compiler-attributes tree and get +some time in linux-next, unless you want to pick it up! + + include/linux/module.h | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/include/linux/module.h b/include/linux/module.h +index 8fa38d3e7538..c4e805e87628 100644 +--- a/include/linux/module.h ++++ b/include/linux/module.h +@@ -129,13 +129,13 @@ extern void cleanup_module(void); + #define module_init(initfn) \ + static inline initcall_t __maybe_unused __inittest(void) \ + { return initfn; } \ +- int init_module(void) __attribute__((alias(#initfn))); ++ int init_module(void) __cold __attribute__((alias(#initfn))); + + /* This is only required if you want to be unloadable. */ + #define module_exit(exitfn) \ + static inline exitcall_t __maybe_unused __exittest(void) \ + { return exitfn; } \ +- void cleanup_module(void) __attribute__((alias(#exitfn))); ++ void cleanup_module(void) __cold __attribute__((alias(#exitfn))); + + #endif + |