From patchwork Mon Mar 29 07:56:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 411478 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 D49C0C433E9 for ; Mon, 29 Mar 2021 08:19:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAF9361554 for ; Mon, 29 Mar 2021 08:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233281AbhC2ITg (ORCPT ); Mon, 29 Mar 2021 04:19:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:35846 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232939AbhC2ITD (ORCPT ); Mon, 29 Mar 2021 04:19:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7492261580; Mon, 29 Mar 2021 08:19:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005942; bh=0m4JfSlrMTrCVvzYnSKX7M8SxB0GrqoW95y4dwsWLus=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NCAyQgTKQtxB5C9cMwL1HSNeFvzmyEwP2Qh+8VcYQDQ6KG4m/5Pq++ALhQEYjbJD2 RKF8IDHBQ7Dbx2c9FSviJOV4RgzaCRfIMZvOBejkeA12aD0V5rz8FBCmMcWqHYfP3V v+UNDre3gnt/+eYTAFZs5d4EP4j0TA4dInpfzg+U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steven Rostedt , "Peter Zijlstra (Intel)" , Ingo Molnar , Sasha Levin Subject: [PATCH 5.10 059/221] static_call: Fix the module key fixup Date: Mon, 29 Mar 2021 09:56:30 +0200 Message-Id: <20210329075631.160677004@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075629.172032742@linuxfoundation.org> References: <20210329075629.172032742@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peter Zijlstra [ Upstream commit 50bf8080a94d171e843fc013abec19d8ab9f50ae ] Provided the target address of a R_X86_64_PC32 relocation is aligned, the low two bits should be invariant between the relative and absolute value. Turns out the address is not aligned and things go sideways, ensure we transfer the bits in the absolute form when fixing up the key address. Fixes: 73f44fe19d35 ("static_call: Allow module use without exposing static_call_key") Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Steven Rostedt (VMware) Link: https://lkml.kernel.org/r/20210225220351.GE4746@worktop.programming.kicks-ass.net Signed-off-by: Sasha Levin --- kernel/static_call.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/static_call.c b/kernel/static_call.c index db64c2331a32..5d53c354fbe7 100644 --- a/kernel/static_call.c +++ b/kernel/static_call.c @@ -358,7 +358,8 @@ static int static_call_add_module(struct module *mod) struct static_call_site *site; for (site = start; site != stop; site++) { - unsigned long addr = (unsigned long)static_call_key(site); + unsigned long s_key = (long)site->key + (long)&site->key; + unsigned long addr = s_key & ~STATIC_CALL_SITE_FLAGS; unsigned long key; /* @@ -382,8 +383,8 @@ static int static_call_add_module(struct module *mod) return -EINVAL; } - site->key = (key - (long)&site->key) | - (site->key & STATIC_CALL_SITE_FLAGS); + key |= s_key & STATIC_CALL_SITE_FLAGS; + site->key = key - (long)&site->key; } return __static_call_init(mod, start, stop);