From patchwork Sat Feb 27 01:12:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christopher M. Riedl" X-Patchwork-Id: 1445118 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DnT7J3MzTz9sRR for ; Sat, 27 Feb 2021 12:13:48 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DnT7J2K2Nz3d8G for ; Sat, 27 Feb 2021 12:13:48 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=codefail.de (client-ip=131.153.2.45; helo=h4.fbrelay.privateemail.com; envelope-from=cmr@codefail.de; receiver=) Received: from h4.fbrelay.privateemail.com (h4.fbrelay.privateemail.com [131.153.2.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DnT6g4tFmz3cYK for ; Sat, 27 Feb 2021 12:13:15 +1100 (AEDT) Received: from MTA-14-4.privateemail.com (mta-14.privateemail.com [198.54.118.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by h3.fbrelay.privateemail.com (Postfix) with ESMTPS id E047380D7C for ; Fri, 26 Feb 2021 20:13:11 -0500 (EST) Received: from mta-14.privateemail.com (localhost [127.0.0.1]) by mta-14.privateemail.com (Postfix) with ESMTP id 5B5B480087; Fri, 26 Feb 2021 20:13:09 -0500 (EST) Received: from oc8246131445.ibm.com (unknown [10.20.151.203]) by mta-14.privateemail.com (Postfix) with ESMTPA id 1B77080086; Sat, 27 Feb 2021 01:13:09 +0000 (UTC) From: "Christopher M. Riedl" To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v7 09/10] powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switches Date: Fri, 26 Feb 2021 19:12:58 -0600 Message-Id: <20210227011259.11992-10-cmr@codefail.de> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20210227011259.11992-1-cmr@codefail.de> References: <20210227011259.11992-1-cmr@codefail.de> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Axtens Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Daniel Axtens Add uaccess blocks and use the 'unsafe' versions of functions doing user access where possible to reduce the number of times uaccess has to be opened/closed. Signed-off-by: Daniel Axtens Co-developed-by: Christopher M. Riedl Signed-off-by: Christopher M. Riedl --- arch/powerpc/kernel/signal_64.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 788854734b9a..00c907022707 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -822,11 +822,11 @@ SYSCALL_DEFINE0(rt_sigreturn) */ current->thread.regs->msr &= ~MSR_TS_MASK; if (!user_read_access_begin(&uc->uc_mcontext, sizeof(uc->uc_mcontext))) - return -EFAULT; - if (__unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) { - user_read_access_end(); goto badframe; - } + + unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext, + badframe_block); + user_read_access_end(); } @@ -836,6 +836,8 @@ SYSCALL_DEFINE0(rt_sigreturn) set_thread_flag(TIF_RESTOREALL); return 0; +badframe_block: + user_read_access_end(); badframe: signal_fault(current, regs, "rt_sigreturn", uc);