From patchwork Tue Jan 31 20:04:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 13123364 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 23C37C38142 for ; Tue, 31 Jan 2023 20:04:42 +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=lyajDN0HYSW5WmLS6AvcD8sXDm0uJk8Jfo6nlkCurhw=; b=cLpLzEWzTt4ZTn em4gMoBGNLdNEDqqmLr/WX9ay/GWYOq1AZ2PJZIlpXScNNrjq4m20CTJlW+IrN+x99CmMzr+RYb8N DeJauAuggzRhXPAhsLVM7GA8RKFHUi8L4y9N/ir+1fDm4RfqR6b4ScIdjpF+naWMm29uZAjROxq7S pj+7CAyDZpE5ADbAoNRPEn3rXH52VwgI/Rt2rQiq0MTFgUVycPBLtyiVP0n5Mn3vcyd3YS+DJeWrs eWyYeKOpvRSFaa9c7ewpVgkdaEzCoSehlJ7mWDHb3WyuvDtEQqYVDTPZ7kpZj73ZZ9T035cdv9Nqo N4iPBW8O0euYGiZGamog==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMwrq-009Cyg-Bg; Tue, 31 Jan 2023 20:04:34 +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 1pMwrn-009CxR-W6 for linux-riscv@lists.infradead.org; Tue, 31 Jan 2023 20:04:33 +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=Bl5iUXqmXEOZR8ifG6HKyF4x1jQ0mIa3D3l9XR4PaTE=; b=T1pWKmZWPHuHO8Jyn7S5P/zto+ UZfPKBZyRLG27ebQFQOn/fWzfDlIAMxY5HnpFAsDM33oCZ+/Oqy97hkFrd/ty/TtBVplGI9UlZkpc fbW++/mewnSYFO9jvmdzRomSgggz4wlhTLgqvJVMyFQJo7JNjGdbYjrvvOCf8fp0gxg7cOp7xtr3r ESdWCs27/xj5QzXKLgnJBxqhbIe9xDzRoYllJ//kxI1dcU2VM9HH60bLK1f0Ri53IBKDWu4a9kqmF F2PtXGW3wiF+E43i3v0Rvv/Ti4b5qXLpcgoQxKTylUS/49rUu8IB+gb4J12gNq/O4ec6MWulnmUSJ YSws+EYw==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1pMwrk-005Ilr-0p; Tue, 31 Jan 2023 20:04:28 +0000 Date: Tue, 31 Jan 2023 20:04:28 +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 03/10] ia64: 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_120432_045249_2E0AB79C 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 ia64 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/ia64/mm/fault.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index ef78c2d66cdd..85c4d9ac8686 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -136,8 +136,11 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re */ 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)