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imf16.hostedemail.com; dkim=none; spf=pass (imf16.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773127856; a=rsa-sha256; cv=none; b=xJLGfsASXjdrP4prTaSLKjjWltxUCwSro2Ija/O7CeZyZ0+pB/aWREB0Dy4d3g6cKEvN/k lf6BFPOpI+qtx6Pxjgq4GwzUvKB2EadIuYP4JIs1zbd1KcGJOqPnDdaU86xmCCT7f8hHPW rS1AGN4AdHRVbLOM841Ni7YoyS1HTS0= 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: C395F180006 X-Stat-Signature: xwfkodsc11opbab68hwhpuka6pk66rm1 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1773127856-400274 X-HE-Meta: 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 JyEPsypd bCBxC4tNMRbhTPwWXgzvLufkiB+3m3yqDh2QcBhe1iFrQWSS95JzHKNAAnmAZR9Rbd/Bl2SiGG7uWU5WE6yO3xkTNsV/I7lVairJKTXAbwFn0e7IGKDcRKIP1g9q21DHjkHVLAelNQyWmx6F/1nq5HUr3irzegLwjhLgsiUhKlRWjKk1Q2kTFV8nKps/BSJAHshoxybXg4kYIr3U= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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