From patchwork Tue Jan 31 20:06:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 13123368 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CCAEC636CC for ; Tue, 31 Jan 2023 20:06:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=p6cRZpvCyqir0T860hshVhXNrBKe2FIcdCH6S4ZBwbw=; b=jE1d1QvTEaFWU1 K4KDh0TkIEssbdJhtuPzTDJVuh9pxgi7aMTIchnnzKuVdkjfEuqEY36R3nZ9V8PrZDE0GyH0owHUT nqA/DMz5eGvdQH/jKXsLdnIglPAhItXl3hymzlZ06zv1soQv9Vb+iMckbs7VzeIwKTTNRQ1HH2k95 93mR0pgTZvIF8eU3cMufRFppHeHRrZtiiA4Mf40uvyXuCbNNrF2i4Z9X3mP6m4XDpYjAbosoAZQu1 +IRTWP4kBNIPpUFW99svNT6haPLFCuWcnB9OUcbo148j1hJcEcJFVFVIdiiAwiik8L2y5VoqKwa5Z WCaBffoDLszPTSA7ig6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMwtP-009DYB-S1; Tue, 31 Jan 2023 20:06:11 +0000 Received: from zeniv.linux.org.uk ([2a03:a000:7:0:5054:ff:fe1c:15ff]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMwtM-009DWZ-SS for linux-riscv@lists.infradead.org; Tue, 31 Jan 2023 20:06:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VASyJZSBEquFV0KDKoogdy4OX3OzJhAh5o0jO+QEP/8=; b=HB3AztPi+msrmE3oE5yxiRYHVr ykikKMa5v2Yo/giiWWzK4KJyD5/Ga89pUwCA5QwIcEFZBjT6oE1RFuEVpeMiy76e/ZXx+0nL5crYs 8IK4nTQuAawNWyAZkdVLhCPSzC1A/uzuiGDGdxxpBOFsX7lUljEbBv6ahdNY643XjTRayt1YFEoJx 2sQZ3b5XcI1+dhT9RX453RW2gqZWp14s31ix2dzgEhP3KVyyOxoPEN9O1p0Xp124Si6XBthNYbFUh lczTWd+6ntJSifvArW39txP0ZNkdkGGYFRV1xXxHbQIvUoxSo7pon5BnAUMC8WjMHKxggfzsDaq8a E+6hb8kg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1pMwtJ-005Inr-0r; Tue, 31 Jan 2023 20:06:05 +0000 Date: Tue, 31 Jan 2023 20:06:05 +0000 From: Al Viro To: linux-arch@vger.kernel.org Cc: linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Michal Simek , Dinh Nguyen , openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, sparclinux@vger.kernel.org, Linus Torvalds Subject: [PATCH 07/10] openrisc: fix livelock in uaccess Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230131_120608_945800_1D853AB3 X-CRM114-Status: GOOD ( 13.39 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org openrisc equivalent of 26178ec11ef3 "x86: mm: consolidate VM_FAULT_RETRY handling" If e.g. get_user() triggers a page fault and a fatal signal is caught, we might end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything to page tables. In such case we must *not* return to the faulting insn - that would repeat the entire thing without making any progress; what we need instead is to treat that as failed (user) memory access. Signed-off-by: Al Viro --- arch/openrisc/mm/fault.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c index b4762d66e9ef..6734fee3134f 100644 --- a/arch/openrisc/mm/fault.c +++ b/arch/openrisc/mm/fault.c @@ -162,8 +162,11 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, fault = handle_mm_fault(vma, address, flags, regs); - if (fault_signal_pending(fault, regs)) + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) + goto no_context; return; + } /* The fault is fully completed (including releasing mmap lock) */ if (fault & VM_FAULT_COMPLETED)