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 DECDEC433F5 for ; Mon, 2 May 2022 13:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385152AbiEBNNO (ORCPT ); Mon, 2 May 2022 09:13:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234947AbiEBNNM (ORCPT ); Mon, 2 May 2022 09:13:12 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4C5319290 for ; Mon, 2 May 2022 06:09:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=lEEpp6Yh5c17KamMJCZy6/ew0Vycd9WIVP93R8z7Vuc=; b=mVJscScUJ9u/IezeDDPgHYhNoC LH4VIJwDlSwRibe5Wlt6baYceOoWgSVtXPObRhZVZbvber38kBcjC478fiS6lGmPVrgF1cx6hD1cN DBmRb8AhFFJip93WgfDZeOTD+aawpzpSUEiCc8vm86wTwi9p3WHXtJBZmILZKF/A4OxALgHMbyrFM fX7vDu4llt0eQ++gNOhS0W2/agaRyKYZnZtmjkkwQHoes/HOE0DBjXt3DHc8U2mMhDYHb6NKOou8x WYvnXEeuJb6S1olbM0kHCs1z+CkZzlsFQCs1N2+6U5CVP5VLDe6fFcGMFpGTUZrmE5TpYVq3oH/2K ozgGhRRA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nlVnj-00ATF3-14; Mon, 02 May 2022 13:09:19 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 15EB030017D; Mon, 2 May 2022 15:09:17 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DEC0A20288CED; Mon, 2 May 2022 15:09:16 +0200 (CEST) Date: Mon, 2 May 2022 15:09:16 +0200 From: Peter Zijlstra To: x86@kernel.org, jpoimboe@redhat.com Cc: linux-kernel@vger.kernel.org, elver@google.com, jbaron@akamai.com, rostedt@goodmis.org, ardb@kernel.org, kernel test robot Subject: [PATCH v2 3/3] jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds Message-ID: References: <20220502110741.951055904@infradead.org> <20220502111216.350926848@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220502111216.350926848@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Subject: jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds From: Peter Zijlstra Date: Mon May 2 12:30:20 CEST 2022 When building x86_64 with JUMP_LABEL=n it's possible for instrumentation to sneak into noinstr: vmlinux.o: warning: objtool: exit_to_user_mode+0x14: call to static_key_count.constprop.0() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_exit_to_user_mode+0x2d: call to static_key_count.constprop.0() leaves .noinstr.text section vmlinux.o: warning: objtool: irqentry_exit_to_user_mode+0x1b: call to static_key_count.constprop.0() leaves .noinstr.text section Reported-by: kernel test robot Signed-off-by: Peter Zijlstra (Intel) --- include/linux/jump_label.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -256,9 +256,9 @@ extern void static_key_disable_cpuslocke #include #include -static inline int static_key_count(struct static_key *key) +static __always_inline int static_key_count(struct static_key *key) { - return atomic_read(&key->enabled); + return arch_atomic_read(&key->enabled.count); } static __always_inline void jump_label_init(void)