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 X-Spam-Level: X-Spam-Status: No, score=-24.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 7423CC49EC9 for ; Mon, 28 Jun 2021 15:28:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C77761492 for ; Mon, 28 Jun 2021 15:28:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238771AbhF1PaU (ORCPT ); Mon, 28 Jun 2021 11:30:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:39834 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237234AbhF1PF1 (ORCPT ); Mon, 28 Jun 2021 11:05:27 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 67F6561D00; Mon, 28 Jun 2021 14:43:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624891408; bh=DiuStUnl/UWabAwInh+svJhBN1f29SHjfr4zy9UlSTI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NiQARpa2JHjqa7qOIU28Co+Kz8SMsV2gC81UcwZcNJmRCM2pshwceXuPeMlGb47ds OTqTdJEIqC5M6j6DaiH4cB7s2JShiMA5p+2bFjX0s6qQTvCmsFfE7+Hxg8wJVWR9KQ bZfgXWR1oqSQV2BvTsR4FX+buyyHFmqBCVyl//N/KuQU5mSRe5GT3H0aSluwarj1YT Q3Kb2+VRsPugsz/Ej/3/3f1Rk1C1Jv0nTAFaRTmatOPkwWXdU6RCOx3nnnzjyFxsZn h+P0vn/Ij2/oPMJ+IP4HcGMJNVzNImArfx2t6iF2IbvxYgQq1wB3PYlHynIRtxZaEA 8x+xA9wvGwKAw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vineet Gupta , kernel test robot , Vladimir Isaev , Greg Kroah-Hartman Subject: [PATCH 4.4 35/57] ARCv2: save ABI registers across signal handling Date: Mon, 28 Jun 2021 10:42:34 -0400 Message-Id: <20210628144256.34524-36-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628144256.34524-1-sashal@kernel.org> References: <20210628144256.34524-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.4.274-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.4.274-rc1 X-KernelTest-Deadline: 2021-06-30T14:42+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vineet Gupta commit 96f1b00138cb8f04c742c82d0a7c460b2202e887 upstream. ARCv2 has some configuration dependent registers (r30, r58, r59) which could be targetted by the compiler. To keep the ABI stable, these were unconditionally part of the glibc ABI (sysdeps/unix/sysv/linux/arc/sys/ucontext.h:mcontext_t) however we missed populating them (by saving/restoring them across signal handling). This patch fixes the issue by - adding arcv2 ABI regs to kernel struct sigcontext - populating them during signal handling Change to struct sigcontext might seem like a glibc ABI change (although it primarily uses ucontext_t:mcontext_t) but the fact is - it has only been extended (existing fields are not touched) - the old sigcontext was ABI incomplete to begin with anyways Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/53 Cc: Tested-by: kernel test robot Reported-by: Vladimir Isaev Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman --- arch/arc/include/uapi/asm/sigcontext.h | 1 + arch/arc/kernel/signal.c | 43 ++++++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/arch/arc/include/uapi/asm/sigcontext.h b/arch/arc/include/uapi/asm/sigcontext.h index 9678a11fc158..446259ec7431 100644 --- a/arch/arc/include/uapi/asm/sigcontext.h +++ b/arch/arc/include/uapi/asm/sigcontext.h @@ -17,6 +17,7 @@ */ struct sigcontext { struct user_regs_struct regs; + struct user_regs_arcv2 v2abi; }; #endif /* _ASM_ARC_SIGCONTEXT_H */ diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index 639f39f39917..b01c657a7a71 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -62,6 +62,41 @@ struct rt_sigframe { unsigned int sigret_magic; }; +static int save_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs) +{ + int err = 0; +#ifndef CONFIG_ISA_ARCOMPACT + struct user_regs_arcv2 v2abi; + + v2abi.r30 = regs->r30; +#ifdef CONFIG_ARC_HAS_ACCL_REGS + v2abi.r58 = regs->r58; + v2abi.r59 = regs->r59; +#else + v2abi.r58 = v2abi.r59 = 0; +#endif + err = __copy_to_user(&mctx->v2abi, &v2abi, sizeof(v2abi)); +#endif + return err; +} + +static int restore_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs) +{ + int err = 0; +#ifndef CONFIG_ISA_ARCOMPACT + struct user_regs_arcv2 v2abi; + + err = __copy_from_user(&v2abi, &mctx->v2abi, sizeof(v2abi)); + + regs->r30 = v2abi.r30; +#ifdef CONFIG_ARC_HAS_ACCL_REGS + regs->r58 = v2abi.r58; + regs->r59 = v2abi.r59; +#endif +#endif + return err; +} + static int stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs, sigset_t *set) @@ -95,6 +130,10 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs, err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), &uregs.scratch, sizeof(sf->uc.uc_mcontext.regs.scratch)); + + if (is_isa_arcv2()) + err |= save_arcv2_regs(&(sf->uc.uc_mcontext), regs); + err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t)); return err ? -EFAULT : 0; @@ -110,6 +149,10 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) err |= __copy_from_user(&uregs.scratch, &(sf->uc.uc_mcontext.regs.scratch), sizeof(sf->uc.uc_mcontext.regs.scratch)); + + if (is_isa_arcv2()) + err |= restore_arcv2_regs(&(sf->uc.uc_mcontext), regs); + if (err) return -EFAULT; -- 2.30.2