From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5C70A3E9593 for ; Tue, 10 Mar 2026 07:30:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773127858; cv=none; b=XHBdOTM8lfxaB61bATIcSVHoO1eH4x7qHyJDHtC8GEa90qFBmK5jr4JcURaXq7OfHg9Zu5Ct9nqI+rOQgISH+4br3XtyftStXsENNik6jPzNAucxn4m2F7g5XL2iy+VCuKGvq1IEPx5Kv5DtTT+truWWyBtssofDOJ8BBb/BFfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773127858; c=relaxed/simple; bh=MRlcBvZLEUKmw8dJBFH04z8FpXAXusVfgkni9JIk3Kc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=J2FEZEdHpsxSZ6Eyw3nvUEsRqqTk4/dcbPI9J6kcQeSAeU6JfNrZXyUc78qPGy6d1Sw2JgLwaeXa7uBWTcj7y1a++++/IhMxuVQiwSbug6XvawUelh51HRHYF8mpD6jLDz8TJckrnzNopjsj9mAYDc7afq/abNqD2lUj/ANi4i8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 721DF152B; Tue, 10 Mar 2026 00:30:49 -0700 (PDT) Received: from a080796.blr.arm.com (a080796.arm.com [10.164.21.51]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BE6DA3F73B; Tue, 10 Mar 2026 00:30:46 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, david@kernel.org, hughd@google.com, chrisl@kernel.org, kasong@tencent.com Cc: weixugc@google.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, riel@surriel.com, harry.yoo@oracle.com, jannh@google.com, pfalcato@suse.de, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, baohua@kernel.org, youngjun.park@lge.com, ziy@nvidia.com, kas@kernel.org, willy@infradead.org, yuzhao@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, Dev Jain Subject: [PATCH 1/9] mm/rmap: make nr_pages signed in try_to_unmap_one Date: Tue, 10 Mar 2026 13:00:05 +0530 Message-Id: <20260310073013.4069309-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260310073013.4069309-1-dev.jain@arm.com> References: <20260310073013.4069309-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently, nr_pages is defined as unsigned long. We use nr_pages to manipulate mm rss counters for lazyfree folios as follows: add_mm_counter(mm, MM_ANONPAGES, -nr_pages); Suppose nr_pages = 3. -nr_pages underflows and becomes ULONG_MAX - 2. Then, since add_mm_counter() uses this -nr_pages as a long, ULONG_MAX - 2 does not fit into the positive range of long, and is converted to -3. Eventually all of this works out, but for keeping things simple, declare nr_pages as a signed variable. Signed-off-by: Dev Jain --- mm/rmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/rmap.c b/mm/rmap.c index 6398d7eef393f..087c9f5b884fe 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1979,9 +1979,10 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, struct page *subpage; struct mmu_notifier_range range; enum ttu_flags flags = (enum ttu_flags)(long)arg; - unsigned long nr_pages = 1, end_addr; + unsigned long end_addr; unsigned long pfn; unsigned long hsz = 0; + long nr_pages = 1; int ptes = 0; /* -- 2.34.1