From nobody Sun Oct 5 03:35:57 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 B9B882D8DAA; Mon, 11 Aug 2025 08:25:29 +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=1754900729; cv=none; b=BXvFvInAT0Ir+OifWwe/PkD2LxAqAWoTqW4acs9k7rQfyQ9pLIQC6KFCAH6aAPIBirbt3JaMcjOk/Ik2KhJWKaeEmKEcCOWO6c5zuG7WZp2OHDvaVgtdAKd/pTgxhtDSwrqGsrxLXtgCrSU3kdHMHZH2JXncGjoKxD1NKRmT9TU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754900729; c=relaxed/simple; bh=GD0CZJPipj/scvOiwO86D4QvWu2bhvyPoPfEPeM7R1g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EShq22+XHaH2ScD01Hau97M4hqDGBdo70RMFXTvDgDjXS5HzN3xfCh7Plt5HBZZBSSD0jmerqTsZJ1SOEyp7dtmzk76GgHeZT7gtdoGFJEQGcYUMuU1j5nf/de4PBiU6Vv5foOI3i4rzCTP06A9ePbNCEK4LybPRgRPFUN2tk4o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mVk5V2vX; 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="mVk5V2vX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC748C4CEF7; Mon, 11 Aug 2025 08:25:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754900729; bh=GD0CZJPipj/scvOiwO86D4QvWu2bhvyPoPfEPeM7R1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mVk5V2vX3KTa6TTrst2P85RRH05lSqF0XHkEtbdHC7XoprqtDZ1clLzEoeeQ8KLuR U6PvynDjMIG3Eo9QnHWbTT+EKN9IVGPnwNaBEfjSi/uckjWPQn7KJFqgA4CacMTKw6 9wUZQVsVqwXh5eewwvehW8hxHCT52OMZG72LMZ8T9+490eIS1WoY9Rp1p+4OcK6hqn Mzc/g6UG3olKoudsttAg9N2gc/ZMiXq445iE0fnbZLPRIy/im7Pd+LUShSAu+DHdfu ep2YrMSWxgbIEqnKPB/RMVav5E7YKyX8IPyz7mVX+c1mKshftSmB3rxoI1wNbJ3ddY PWpdlLQJ294vw== From: Mike Rapoport To: Andrew Morton Cc: Alexander Graf , Baoquan He , Changyuan Lyu , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Shuah Khan , =?UTF-8?q?Thomas=20Wei=DFschuh?= , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/3] kho: allow scratch areas with zero size Date: Mon, 11 Aug 2025 11:25:08 +0300 Message-ID: <20250811082510.4154080-2-rppt@kernel.org> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250811082510.4154080-1-rppt@kernel.org> References: <20250811082510.4154080-1-rppt@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" From: "Mike Rapoport (Microsoft)" Parsing of kho_scratch parameter treats zero size as an invalid value, although it should be fine for user to request zero sized scratch area for some types if scratch memory, when for example there is no need to create scratch area in the low memory. Treat zero as a valid value for a scratch area size but reject kho_scratch parameter that defines no scratch memory at all. Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Pratyush Yadav --- kernel/kexec_handover.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c index e49743ae52c5..c6ac5a5e51cb 100644 --- a/kernel/kexec_handover.c +++ b/kernel/kexec_handover.c @@ -385,6 +385,7 @@ static int __init kho_parse_scratch_size(char *p) { size_t len; unsigned long sizes[3]; + size_t total_size =3D 0; int i; =20 if (!p) @@ -421,11 +422,15 @@ static int __init kho_parse_scratch_size(char *p) } =20 sizes[i] =3D memparse(p, &endp); - if (!sizes[i] || endp =3D=3D p) + if (endp =3D=3D p) return -EINVAL; p =3D endp; + total_size +=3D sizes[i]; } =20 + if (!total_size) + return -EINVAL; + scratch_size_lowmem =3D sizes[0]; scratch_size_global =3D sizes[1]; scratch_size_pernode =3D sizes[2]; --=20 2.47.2