From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 839C0C07E99 for ; Mon, 5 Jul 2021 11:55:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66AD461370 for ; Mon, 5 Jul 2021 11:55:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231303AbhGEL6G (ORCPT ); Mon, 5 Jul 2021 07:58:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231159AbhGEL6F (ORCPT ); Mon, 5 Jul 2021 07:58:05 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33F8DC061574; Mon, 5 Jul 2021 04:55:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Pq7bP+MTawU/za6/1KcKOrsotUVcyEKhovbCd0LbYxs=; b=a+qDzygSNKqUonGPkaGwhrnB5T Nm56mhN/nkb4qEMQf8wo67ZcRNY40zF/g8Gq5vbUJaVK6mdWQghoQ3ItzYisV3ahD7M1pZPf0+pBq sMzo8GAzPGX7lfnm0nAj6EskGk523UnvjSQpgad6kBB0C5v77Q6AGNxYZr02WitwcdudQVcBcMInY 6oJbrQKYUcJSntqCQhanhsjE6+0gv0E97fMm8JyML0mfWCAHZ27WkdgxeMsVwmZy3KG1q+3WYKGWK shmZK3c9fzIarX5AleY8Gzgbx+FgK67mHhpgrYKQN1XMfP4QzQkghUyF0KQ16pFGsHG6PfrECEfNe xihRRcrA==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0NBl-00ADQL-7P; Mon, 05 Jul 2021 11:55:09 +0000 Date: Mon, 5 Jul 2021 12:55:01 +0100 From: Christoph Hellwig To: Marco Elver Cc: akpm@linux-foundation.org, glider@google.com, dvyukov@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com, Andrii Nakryiko , Daniel Borkmann , Vlastimil Babka , Yang Shi , bpf@vger.kernel.org, Mel Gorman , Alexei Starovoitov Subject: Re: [PATCH] Revert "mm/page_alloc: make should_fail_alloc_page() static" Message-ID: References: <20210705103806.2339467-1-elver@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210705103806.2339467-1-elver@google.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Jul 05, 2021 at 12:38:06PM +0200, Marco Elver wrote: > This reverts commit f7173090033c70886d925995e9dfdfb76dbb2441. > > Commit 76cd61739fd1 ("mm/error_inject: Fix allow_error_inject function > signatures") explicitly made should_fail_alloc_page() non-static, due to > worries of remaining compiler optimizations in the absence of function > side-effects while being noinline. > > Furthermore, kernel/bpf/verifier.c pushes should_fail_alloc_page onto > the btf_non_sleepable_error_inject BTF IDs set, which when enabling > CONFIG_DEBUG_INFO_BTF results in an error at the BTFIDS stage: > > FAILED unresolved symbol should_fail_alloc_page > > To avoid the W=1 warning, add a function declaration right above the > function itself, with a comment it is required in a BTF IDs set. NAK. We're not going to make symbols pointlessly global for broken instrumentation coe. Someone needs to fixthis eBPF mess as we had the same kind of issue before already.