From nobody Sun Feb 8 09:10:46 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B644EB64DA for ; Sat, 22 Jul 2023 07:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231338AbjGVHtR (ORCPT ); Sat, 22 Jul 2023 03:49:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231318AbjGVHtP (ORCPT ); Sat, 22 Jul 2023 03:49:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87BBA3C3D for ; Sat, 22 Jul 2023 00:48:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 941496010F for ; Sat, 22 Jul 2023 07:48:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A43DC433C8; Sat, 22 Jul 2023 07:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690012082; bh=6MQ29HDi9RobghOfq9ww6P1ehrV7jdzcjLwHNnWU8TY=; h=From:To:Cc:Subject:Date:From; b=Kj9zb2QV2XUlO6ArJk7Um1dVjnJix123wkWielmwHI1G12aNiMOftnyppaawHQ2Ev 9QihLXgFdtBBVHkdUPcfxtp1WVr9oya/sDbZZHbv5Kb0KTENPsRQoJpiK84Nf9JszY aSsTkzZicl1F5DjvqaDwI9SkAjwEaPqXUptOLRt+EbkNT4pzyFXhdl5Cyn8e/gkXum e76D0qNn7Zm3o1CUc/bhEHQtKDqPC4tV5gIUdbrXCZmma6fqI8R8SpEqaQeIK8ZVYJ HoNqbHSk/r12c+HB/7bmVVjDFGFtClCwxaOpVGUlPJlPNz0x5ot1ozRxr9xlTQOSuh fZztE9O4HIqIg== From: Arnd Bergmann To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Hou Tao Cc: Arnd Bergmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Kumar Kartikeya Dwivedi , bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] bpf: force inc_active()/dec_active() to be inline functions Date: Sat, 22 Jul 2023 09:47:44 +0200 Message-Id: <20230722074753.568696-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann Splitting these out into separate helper functions means that we actually pass an uninitialized variable into another function call if dec_active() happens to not be inlined, and CONFIG_PREEMPT_RT is disabled: kernel/bpf/memalloc.c: In function 'add_obj_to_free_list': kernel/bpf/memalloc.c:200:9: error: 'flags' is used uninitialized [-Werror= =3Duninitialized] 200 | dec_active(c, flags); Mark the two functions as __always_inline so gcc can see through this regardless of optimizations and other options that may prevent it otherwise. Fixes: 18e027b1c7c6d ("bpf: Factor out inc/dec of active flag into helpers.= ") Signed-off-by: Arnd Bergmann --- kernel/bpf/memalloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 51d6389e5152e..23906325298da 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -165,7 +165,7 @@ static struct mem_cgroup *get_memcg(const struct bpf_me= m_cache *c) #endif } =20 -static void inc_active(struct bpf_mem_cache *c, unsigned long *flags) +static __always_inline void inc_active(struct bpf_mem_cache *c, unsigned l= ong *flags) { if (IS_ENABLED(CONFIG_PREEMPT_RT)) /* In RT irq_work runs in per-cpu kthread, so disable @@ -183,7 +183,7 @@ static void inc_active(struct bpf_mem_cache *c, unsigne= d long *flags) WARN_ON_ONCE(local_inc_return(&c->active) !=3D 1); } =20 -static void dec_active(struct bpf_mem_cache *c, unsigned long flags) +static __always_inline void dec_active(struct bpf_mem_cache *c, unsigned l= ong flags) { local_dec(&c->active); if (IS_ENABLED(CONFIG_PREEMPT_RT)) --=20 2.39.2