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 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 19974C27C7B for ; Wed, 12 Jun 2024 14:11:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=d89DrUEs1kIDLyhtwQqJqL6IksFgShhaBWcU6xLTz3Q=; b=CBNnT8j8dWLmb8BAPGw5HkiJSo f6Ca3KYdLGeXUczS+SZYRhuwlRfhne98oEoLPvTNrKBKmmmForSR7DyzNHB6JiIDp+k2V2wncnUXi asesYEeM/sm8pRHFmo50DXAsxsYXaV+PLHN8/HKdpX2ZYLvpkPcRsrFvxGXgQ8XXAVgLKUGZfku0i dkOUv0qnxcgIpCmjx1EB8SBPyEbPzSN5p2NAohWkNYDBsRf0TameWE2vpXN69JYXKvvZZleVwMbEj zAi/WtdV9MPKUyt30hGWH/P4qnYFyyoScoQrnX/ANlD/dFZJj6e9lOPO3z01QJQR1/PCvjPlm2SPQ rnlhSNpQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHOgn-0000000CtbD-2Z66; Wed, 12 Jun 2024 14:11:01 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHOgk-0000000CtYN-1s7i for linux-um@lists.infradead.org; Wed, 12 Jun 2024 14:10:59 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=d89DrUEs1kIDLyhtwQqJqL6IksFgShhaBWcU6xLTz3Q=; t=1718201458; x=1719411058; b=eVhFVDgYK95gdICLOJ5MyRxnWVOts5jcIA7ZBXH7hwetEBe CSATsD6z6IqqLKdY0jFRB/V5gdNxHWSG1Pe0TtawWnQWZvyu8JY4hC5VjBpZ2miFtBmqvD2grygK4 p/RcRkrxz/ppGbV7Mp7TYAK/sTFl3GMQBHbTSqy0HJpAnmZPJXzUUhPNCx/fl0eO8CJntrmrEAd+z Tmh0YvJpuNT1wHYifkOSyJlsKCFw1zB7EOOnH9WjR3d3KE398CVQ/GrSl4GXT9APkARrNG80L55ZJ 4LUPRpEhpff0VV0UoUKiEaNrAHfsHLxPjSPAQ3B9f/a+/e3zhpVrI+f58bDuf3vg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1sHOgi-0000000AN5N-05Xj; Wed, 12 Jun 2024 16:10:56 +0200 From: benjamin@sipsolutions.net To: linux-um@lists.infradead.org Cc: Benjamin Berg Subject: [PATCH v3 1/5] um: Fix stub_start address calculation Date: Wed, 12 Jun 2024 16:10:43 +0200 Message-ID: <20240612141047.1633303-2-benjamin@sipsolutions.net> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240612141047.1633303-1-benjamin@sipsolutions.net> References: <20240612141047.1633303-1-benjamin@sipsolutions.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240612_071058_492537_E231763E X-CRM114-Status: UNSURE ( 9.62 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@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-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org From: Benjamin Berg The calculation was wrong as it only subtracted one and then rounded down for alignment. However, this is incorrect if host_task_size is not already aligned. This probably worked fine because on 64 bit the host_task_size is bigger than returned by os_get_top_address. Signed-off-by: Benjamin Berg --- arch/um/kernel/um_arch.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index e95f805e5004..0d8b1a73cd5b 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -331,7 +331,8 @@ int __init linux_main(int argc, char **argv) /* reserve a few pages for the stubs (taking care of data alignment) */ /* align the data portion */ BUILD_BUG_ON(!is_power_of_2(STUB_DATA_PAGES)); - stub_start = (host_task_size - 1) & ~(STUB_DATA_PAGES * PAGE_SIZE - 1); + stub_start = (host_task_size - STUB_DATA_PAGES * PAGE_SIZE) & + ~(STUB_DATA_PAGES * PAGE_SIZE - 1); /* another page for the code portion */ stub_start -= PAGE_SIZE; host_task_size = stub_start; -- 2.45.1