From nobody Fri Dec 19 20:05:33 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6C71E2505CA for ; Wed, 12 Mar 2025 16:47:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741798079; cv=none; b=lyKQfGDmIM30aN1X744Mq3YYws2G/ltLzkMRQK4yOc2aUPqkNCnMRSgZd92DUUVqw1zmKHzlbM8etj7aUsJieRFxwteC++hHaJ8JmxNDYxy29AvNsnjRd0pnhSPqtuqAy847NwWKwseG4kxPV0qhEBDtMjDFgZ3er0GRyrXH3x0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741798079; c=relaxed/simple; bh=oQN+mH789PvTmGLvlHTcsIxu+Znjze2S0+wMa1s72FE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=J3uU6USs7LhlxE2bRlWIoYkQakAeiXhnioX4DA6IgnPhXKXYv1dRwhaiDv9v+/4K/FKslP49/GL/uaDTEGf3ON/jQf1Z28HBWXLqcKpx31EZxnwTtbk6DPYEA7FKH58ck+zqGUU3vr+wLKG/ogyMWjVTAk2Hj6e5ehxx1jD4b3M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j0R2BVOR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="j0R2BVOR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5A71C4CEF0; Wed, 12 Mar 2025 16:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741798078; bh=oQN+mH789PvTmGLvlHTcsIxu+Znjze2S0+wMa1s72FE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j0R2BVORIe3z3UqUZHwFFZiyYbMSgywv0UHdCOInvRehpN+8M8jbPX0167V/218YG 2qliFJ0mz4oVhqtkYaYWxKe2lkFz02tzY6LYW5mtMnMSptWnh8H3l7geT0gB5ZLYIy GVHYLAUraEAbLRgf+zuN+hUBplGQ45BwMF/QUW8U+Kr4AzUqNkDZ6l84Nf6X9mogRg scc7lFkhIPwaxHi8n6+e02hoWJWOEjkGji4YNe88ubCHrlq87dnOx7cgjqWIJjhXO1 0P3wJu6fSNnOmmCBXgWmWiycwscR3SABGzd9IFDFN6hf8ssnoDlMvK0CSyDomfjHJH ED5w+PmylaquQ== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "Liam R. Howlett" , David Hildenbrand , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , kernel-team@meta.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 3/4] mm/madvise: deduplicate madvise_do_behavior() skip case handlings Date: Wed, 12 Mar 2025 09:47:49 -0700 Message-Id: <20250312164750.59215-4-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250312164750.59215-1-sj@kernel.org> References: <20250312164750.59215-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The logic for checking if a given madvise() request for a single memory range can skip real work, namely madvise_do_behavior(), is duplicated in do_madvise() and vector_madvise(). Split out the logic to a function and reuse it. Signed-off-by: SeongJae Park Reviewed-by: Lorenzo Stoakes Reviewed-by: Shakeel Butt --- mm/madvise.c | 57 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 34 insertions(+), 23 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 611db868ae38..ba006d05c7ea 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1640,6 +1640,31 @@ static bool is_valid_madvise(unsigned long start, si= ze_t len_in, int behavior) return true; } =20 +/* + * madvise_should_skip() - Return if the request is invalid or nothing. + * @start: Start address of madvise-requested address range. + * @len_in: Length of madvise-requested address range. + * @behavior: Requested madvise behavor. + * @err: Pointer to store an error code from the check. + * + * If the specified behaviour is invalid or nothing would occur, we skip t= he + * operation. This function returns true in the cases, otherwise false. = In + * the former case we store an error on @err. + */ +static bool madvise_should_skip(unsigned long start, size_t len_in, + int behavior, int *err) +{ + if (!is_valid_madvise(start, len_in, behavior)) { + *err =3D -EINVAL; + return true; + } + if (start + PAGE_ALIGN(len_in) =3D=3D start) { + *err =3D 0; + return true; + } + return false; +} + static bool is_madvise_populate(int behavior) { switch (behavior) { @@ -1747,23 +1772,15 @@ static int madvise_do_behavior(struct mm_struct *mm, */ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, i= nt behavior) { - unsigned long end; int error; - size_t len; - - if (!is_valid_madvise(start, len_in, behavior)) - return -EINVAL; - - len =3D PAGE_ALIGN(len_in); - end =3D start + len; - - if (end =3D=3D start) - return 0; =20 + if (madvise_should_skip(start, len_in, behavior, &error)) + return error; error =3D madvise_lock(mm, behavior); if (error) return error; - error =3D madvise_do_behavior(mm, start, len_in, len, behavior); + error =3D madvise_do_behavior(mm, start, len_in, PAGE_ALIGN(len_in), + behavior); madvise_unlock(mm, behavior); =20 return error; @@ -1790,19 +1807,13 @@ static ssize_t vector_madvise(struct mm_struct *mm,= struct iov_iter *iter, while (iov_iter_count(iter)) { unsigned long start =3D (unsigned long)iter_iov_addr(iter); size_t len_in =3D iter_iov_len(iter); - size_t len; - - if (!is_valid_madvise(start, len_in, behavior)) { - ret =3D -EINVAL; - break; - } + int error; =20 - len =3D PAGE_ALIGN(len_in); - if (start + len =3D=3D start) - ret =3D 0; + if (madvise_should_skip(start, len_in, behavior, &error)) + ret =3D error; else - ret =3D madvise_do_behavior(mm, start, len_in, len, - behavior); + ret =3D madvise_do_behavior(mm, start, len_in, + PAGE_ALIGN(len_in), behavior); /* * An madvise operation is attempting to restart the syscall, * but we cannot proceed as it would not be correct to repeat --=20 2.39.5