From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 510CF1FC0EF for ; Sun, 21 Dec 2025 20:23:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766348612; cv=none; b=goGEKJCgp/F4ciQqcnfXOfJtX8KVmBs3E3lTU+Y7pxXbXVWTQNlaR2pWM6umdkqsmxg9oXDbkrxYag8njQeQ49AJCY7KH5imwpzvdD9fG7S1ZEsKiHxZJahVsyjodnYg7JAGLCRH643Hv7RuyKxrG1K4R4gDAFf/V+JibfQC2n4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766348612; c=relaxed/simple; bh=Jar0q80a0PsFmUWYb4ox2BJrEcSjMWCIdxHrtPWEDr4=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=m759QFtP3v/fByf3ubOODfGj7KAwi4HUXl6seqDitzObWxYyGEetvC2M/dgYOe7gVrZ1CUT1YfTBS6d+vFULd34pxXoFlZoFAfywPjwuk8yB5t0QQY6MrlxGdnepJvnVDPPMtx62izehRvLmUltqWndupfvFeC/Kg5wlNAk2EqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Wn/3iHGK; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=g8yVAtJh; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Wn/3iHGK"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="g8yVAtJh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1766348609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4osTBFq4Gt0hw66CGVoVJKRG+p6FOpxRLfdhZSqIwF8=; b=Wn/3iHGKHn/eQWSMxHoLplPzG96aYmTyEDoDBTeZxm+lb4kMga2CJD5dWhySG8Zaeoccg1 OD7mhYBWnyMSom2gCW2DlCOg5luDz0zdBHPgXSQjJ0uWvoQo7vzG4Ew7MOwik8RUGd67qe GlmibbdpnhiSw6ARAZVQ3cpGjIdD/q8= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-528-3cuMVirAPka_EeGTaZ0X2A-1; Sun, 21 Dec 2025 15:23:27 -0500 X-MC-Unique: 3cuMVirAPka_EeGTaZ0X2A-1 X-Mimecast-MFC-AGG-ID: 3cuMVirAPka_EeGTaZ0X2A_1766348607 Received: by mail-qv1-f69.google.com with SMTP id 6a1803df08f44-8888447ffebso84389396d6.1 for ; Sun, 21 Dec 2025 12:23:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1766348607; x=1766953407; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:from:to :cc:subject:date:message-id:reply-to; bh=4osTBFq4Gt0hw66CGVoVJKRG+p6FOpxRLfdhZSqIwF8=; b=g8yVAtJhMKDs96SWpQ+oJ2EBPJu065hNbx2zO38NkhKSbE3JRSDm/xhYCru2nq46EB WjXbOlaOPiaJdHeX2sF1envsxSy2vUFlckUn1li/HHAiwca/Cyu3S2JBbLRbpSlqh2NU VWkSsNWVvVQfO9Gay+CLqRLnwE4QQjvZJQqvWFKs8pt86yeT1c+HxbS//gVIsaTADACI 8RkYZ0aPRN1nhj9qeh964J+cnEfJeShLqkmi8eI/y4Q3Him7Cw7SIPCe8uCOcSbxltV3 fvAqBz2YARDWkqVbG6NCs1rbsCrFE1D4evXXD0VVgBJ7FO4VxQtp40pMpL5Pj+JHoxOg ybBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766348607; x=1766953407; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=4osTBFq4Gt0hw66CGVoVJKRG+p6FOpxRLfdhZSqIwF8=; b=awR/TnkeaiZSEzVCeq/3UZVfe083LgeedPvvuL+Y9aTgIgUgF7gvpeSR9+LfwamxuT BEOVSafi9ATqC83lLTwKh2xjWuYq1Y+WEtvn1aA5p0DDKPXh8WkGUmIu2dwOzcP1lbkf d3F/FvaciCmWT2BllOSQ/lkFItijEJJkplTfpKeBeVGlvr1ngtj9zQlw/OJ9QMbeZqtX hzwjAlaUkh5VR0aojC6P9mb9Ts+gBQa7dRsd8yr8ijT3XQF44Gba5iR+72NxpfM1XPBc 8JKhqgDd8d+KU6SRXL5VASkeQCVUwdreEvYeuOSTuaS7ctODs+IqdtPN9fZvfnmf2twr N9qg== X-Forwarded-Encrypted: i=1; AJvYcCXxTA79yShaA819/p6rBa+d9149MTyTkBoBtZCcNT2aGDtlO+qWu0EdZm8yo9pknVhQHLyJQp8FWdm2bWonZAk=@vger.kernel.org X-Gm-Message-State: AOJu0Yw29J0sUwu566+QwkhVId2Z9yPKqTsjBu2TL7Zg2QY9/5iaoPeh 6swYlGlbzhUhDuMLgNNYaSahXvShKO+Djx4CYqs6+FZ1CJ3QWuzlFYu1Vwm4OrHmexlfc4BStLh i980aOUObGLkO5GEKPm5frFews8l6e/v1+r2hv2F2ETenqJiSnynzVFFak6lZyHXJWDNttw== X-Gm-Gg: AY/fxX4aYpYTX8PBwGN+G8GKBtd96wCmUgZRJGy3QlXqTCQKgZsPYU4LCfPZ6W5edwu Om1qkcJ2Lu8ja3rif3PiK42U3cgQPpZCVu5yycVBDcji+veKKN4kOMnhpa4iVywIxKSTswVjjc3 ys9I6VwjpFT66tBH+y3/T6njmVS6dZFiaSaThDQwpSRcQ3xosUVkXKGd/9c/W3qLhefdmVK1ys5 z7vZnsF/HJl9NlDSkmxOhqws2JQsjCFe3dJ93482iUuGp1q/E4dSQYaOg33ZLDdbOh5/EpPr3fU 76NZUxRqv86e08JjZM1uHSA/10m/JBzKf/xOBTSj0CJ6QyL0VgyNCrVK1Y09dul9Rtl6eD4oetb tTTrqALdm/Gir5dS3czGz6wvil43b8tqFEfz36iiS3ddoL2yy9h9TmKK9 X-Received: by 2002:a05:620a:2945:b0:8a6:ee41:1b48 with SMTP id af79cd13be357-8c08fc0ebb3mr1494135785a.26.1766348607252; Sun, 21 Dec 2025 12:23:27 -0800 (PST) X-Google-Smtp-Source: AGHT+IHH1hKRiYLU7cK0Wkvqmr52oHSn2x4SgTCG2kximSipAI6VB4lbhPeQOdZR7L7ni/aX63l7iQ== X-Received: by 2002:a05:620a:2945:b0:8a6:ee41:1b48 with SMTP id af79cd13be357-8c08fc0ebb3mr1494133585a.26.1766348606764; Sun, 21 Dec 2025 12:23:26 -0800 (PST) Received: from ?IPV6:2601:600:947f:f020:85dc:d2b2:c5ee:e3c4? ([2601:600:947f:f020:85dc:d2b2:c5ee:e3c4]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-88d96bec1d3sm66333926d6.17.2025.12.21.12.23.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 21 Dec 2025 12:23:25 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <39c9af10-d66f-4bcc-93a6-9e2d33827938@redhat.com> Date: Sun, 21 Dec 2025 15:23:22 -0500 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/3] selftests/mm/write_to_hugetlbfs: parse -s as size_t To: Li Wang , akpm@linux-foundation.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: David Hildenbrand , Mark Brown , Shuah Khan References: <20251221122639.3168038-1-liwang@redhat.com> <20251221122639.3168038-2-liwang@redhat.com> Content-Language: en-US In-Reply-To: <20251221122639.3168038-2-liwang@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/21/25 7:26 AM, Li Wang wrote: > write_to_hugetlbfs currently parses the -s size argument with atoi() > into an int. This silently accepts malformed input, cannot report overflow, > and can truncate large sizes. > > --- Error log --- > # uname -r > 6.12.0-xxx.el10.aarch64+64k > > # ls /sys/kernel/mm/hugepages/hugepages-* > hugepages-16777216kB/ hugepages-2048kB/ hugepages-524288kB/ > > #./charge_reserved_hugetlb.sh -cgroup-v2 > # ----------------------------------------- > ... > # nr hugepages = 10 > # writing cgroup limit: 5368709120 > # writing reseravation limit: 5368709120 > ... > # Writing to this path: /mnt/huge/test > # Writing this size: -1610612736 <-------- > > Switch the size variable to size_t and parse -s with sscanf("%zu", ...). > Also print the size using %zu. > > This avoids incorrect behavior with large -s values and makes the utility > more robust. > > Signed-off-by: Li Wang > Cc: David Hildenbrand > Cc: Mark Brown > Cc: Shuah Khan > Cc: Waiman Long > Acked-by: David Hildenbrand (Red Hat) > --- > tools/testing/selftests/mm/write_to_hugetlbfs.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/mm/write_to_hugetlbfs.c b/tools/testing/selftests/mm/write_to_hugetlbfs.c > index 34c91f7e6128..ecb5f7619960 100644 > --- a/tools/testing/selftests/mm/write_to_hugetlbfs.c > +++ b/tools/testing/selftests/mm/write_to_hugetlbfs.c > @@ -68,7 +68,7 @@ int main(int argc, char **argv) > int key = 0; > int *ptr = NULL; > int c = 0; > - int size = 0; > + size_t size = 0; > char path[256] = ""; > enum method method = MAX_METHOD; > int want_sleep = 0, private = 0; > @@ -86,7 +86,10 @@ int main(int argc, char **argv) > while ((c = getopt(argc, argv, "s:p:m:owlrn")) != -1) { > switch (c) { > case 's': > - size = atoi(optarg); > + if (sscanf(optarg, "%zu", &size) != 1) { > + perror("Invalid -s."); > + exit_usage(); > + } > break; > case 'p': > strncpy(path, optarg, sizeof(path) - 1); > @@ -131,7 +134,7 @@ int main(int argc, char **argv) > } > > if (size != 0) { > - printf("Writing this size: %d\n", size); > + printf("Writing this size: %zu\n", size); > } else { > errno = EINVAL; > perror("size not found"); LGTM Acked-by: Waiman Long