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 A9177C433EF for ; Tue, 12 Jul 2022 19:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235544AbiGLTHx (ORCPT ); Tue, 12 Jul 2022 15:07:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235539AbiGLTHI (ORCPT ); Tue, 12 Jul 2022 15:07:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76985FB8F0; Tue, 12 Jul 2022 11:51:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A2AD86149A; Tue, 12 Jul 2022 18:51:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEEA0C3411C; Tue, 12 Jul 2022 18:51:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657651871; bh=sO/NRT++o1GVJ2ZubOWRLCd5AukTe/ungHx3/aluXy8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UMSBg/upjTUYNgowMTS3eRPly58zf3TxI//bKZNRxxOCMJCP55UIhVoUPBiv/lrK5 ihTPlGho9ZE55wPwMKBjy4w6F5ZG3R3+Q9UP+h6s+PpiHIF4kXubCFpfKdZvxLeg4m 60WqgiudDwrieQXvo3TJSRW+iDM7vLNbaX2BTAjo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Borislav Petkov Subject: [PATCH 5.15 78/78] x86/static_call: Serialize __static_call_fixup() properly Date: Tue, 12 Jul 2022 20:39:48 +0200 Message-Id: <20220712183242.085202699@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220712183238.844813653@linuxfoundation.org> References: <20220712183238.844813653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner commit c27c753ea6fd1237f4f96abf8b623d7bab505513 upstream. __static_call_fixup() invokes __static_call_transform() without holding text_mutex, which causes lockdep to complain in text_poke_bp(). Adding the proper locking cures that, but as this is either used during early boot or during module finalizing, it's not required to use text_poke_bp(). Add an argument to __static_call_transform() which tells it to use text_poke_early() for it. Fixes: ee88d363d156 ("x86,static_call: Use alternative RET encoding") Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/static_call.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/arch/x86/kernel/static_call.c +++ b/arch/x86/kernel/static_call.c @@ -25,7 +25,8 @@ static const u8 xor5rax[] = { 0x2e, 0x2e static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc }; -static void __ref __static_call_transform(void *insn, enum insn_type type, void *func) +static void __ref __static_call_transform(void *insn, enum insn_type type, + void *func, bool modinit) { const void *emulate = NULL; int size = CALL_INSN_SIZE; @@ -60,7 +61,7 @@ static void __ref __static_call_transfor if (memcmp(insn, code, size) == 0) return; - if (unlikely(system_state == SYSTEM_BOOTING)) + if (system_state == SYSTEM_BOOTING || modinit) return text_poke_early(insn, code, size); text_poke_bp(insn, code, size, emulate); @@ -108,12 +109,12 @@ void arch_static_call_transform(void *si if (tramp) { __static_call_validate(tramp, true); - __static_call_transform(tramp, __sc_insn(!func, true), func); + __static_call_transform(tramp, __sc_insn(!func, true), func, false); } if (IS_ENABLED(CONFIG_HAVE_STATIC_CALL_INLINE) && site) { __static_call_validate(site, tail); - __static_call_transform(site, __sc_insn(!func, tail), func); + __static_call_transform(site, __sc_insn(!func, tail), func, false); } mutex_unlock(&text_mutex); @@ -139,8 +140,10 @@ bool __static_call_fixup(void *tramp, u8 return false; } + mutex_lock(&text_mutex); if (op == RET_INSN_OPCODE || dest == &__x86_return_thunk) - __static_call_transform(tramp, RET, NULL); + __static_call_transform(tramp, RET, NULL, true); + mutex_unlock(&text_mutex); return true; }