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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C19DC00140 for ; Thu, 18 Aug 2022 04:24:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243252AbiHREYm (ORCPT ); Thu, 18 Aug 2022 00:24:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243264AbiHREYl (ORCPT ); Thu, 18 Aug 2022 00:24:41 -0400 Received: from smtp-fw-80006.amazon.com (smtp-fw-80006.amazon.com [99.78.197.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0298E31DE8; Wed, 17 Aug 2022 21:24:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1660796679; x=1692332679; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=xOACXq2DwWqPC931oHvOXlr7smPuDeluiES7aNAPrxc=; b=W/BO54iydJzhaduPd283TwfRx0a1oKwdkvUYIToGBzP2l+BIFFvkncdz 3+76c9Wv5To+1FZVjuXPA50Dmj50T9TMSZLePm9SSzKGJjoGaZ/CPn3s+ JIJ6uoe/fMF3oxnbG7g09eHNjhOQCzP7dyIemdDobt1tMwjWu/40+/3Y6 U=; X-IronPort-AV: E=Sophos;i="5.93,245,1654560000"; d="scan'208";a="120461401" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-pdx-2c-388992e0.us-west-2.amazon.com) ([10.25.36.210]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2022 04:24:39 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-pdx-2c-388992e0.us-west-2.amazon.com (Postfix) with ESMTPS id 3B13B818EF; Thu, 18 Aug 2022 04:24:38 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Thu, 18 Aug 2022 04:24:34 +0000 Received: from 88665a182662.ant.amazon.com.com (10.43.162.158) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Thu, 18 Aug 2022 04:24:32 +0000 From: Kuniyuki Iwashima To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v1 bpf 3/4] bpf: Fix data-races around bpf_jit_kallsyms. Date: Wed, 17 Aug 2022 21:23:38 -0700 Message-ID: <20220818042339.82992-4-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220818042339.82992-1-kuniyu@amazon.com> References: <20220818042339.82992-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.162.158] X-ClientProxiedBy: EX13D43UWC002.ant.amazon.com (10.43.162.172) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org While reading bpf_jit_kallsyms, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Signed-off-by: Kuniyuki Iwashima --- include/linux/filter.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 09566ad211bd..35881fccce05 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1110,14 +1110,16 @@ static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) static inline bool bpf_jit_kallsyms_enabled(void) { + int jit_kallsyms = READ_ONCE(bpf_jit_kallsyms); + /* There are a couple of corner cases where kallsyms should * not be enabled f.e. on hardening. */ if (READ_ONCE(bpf_jit_harden)) return false; - if (!bpf_jit_kallsyms) + if (!jit_kallsyms) return false; - if (bpf_jit_kallsyms == 1) + if (jit_kallsyms == 1) return true; return false; -- 2.30.2