From nobody Mon Apr 6 18:22:50 2026 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (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 44A283EF65D for ; Wed, 18 Mar 2026 19:09:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773860993; cv=none; b=OBASAQRbKgxN0vY4Poo+rvqfPPM6rvPFLP6gdPJAkUoQHeUUCVHLoJEbeTWfrX/LJfxrxvNjuLbVokQIYo3jnGagK9mVoU5jm1R57QEDhvC5q2bPeI6JpeYODIjdoDUx/ku+MFTlt0Q5lF5DU386cYyW4b4S/lZNed5sVnXqXQM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773860993; c=relaxed/simple; bh=a5FRB9kQRdFCAY6J56PenoUIuCgyNROgXYr2/HQMLU0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LqRT0y38vW80QnuSECrXUnGgKw4y8+L5rqRdTuqX5/H8C/2dplwLZ/jOY7QRP/sfQ+mms70iy4uUi2GE9/PrxsMU+hE/AdZLar27bF0x8/pbLmEgtMnEe7Zv4Hlfs9zYLvU6mFxXG2K4grFWlWmcGgtV3T/QXosl1e5bFS4jcWI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=YNRPCRI5; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="YNRPCRI5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=c5teEie7C3ePZgybh/X+lnNmt1q5goT5Jx00idPTCrA=; b=YNRPCRI57rf3zAqRC0P7QRYu92 p7mPCnkVq2GJl1vWixeCAsenGmp9lGyZantrZEIOtPonMlp9y2rbDcbvT7w3hP0MkUvi3TyHlNcxi fsBIY7KIxgeCu31eC7xpDBAdnBetqAD/A8qVAp2yDuF0euH5Pfw8wgB3qg3PaqcTTjSQ3xTjs4eZF Mk1oo5K6Wl9qqFXsXybx5w1hG1UWJrlH6sdhVCppR/IK+Z/T1f3miUeuZMQUKNo89wcK8tRgu5U81 s0sfBV4ZKKD1EEt+qDul1FlJUOpkOzPXuLTi0k5N87mfCBLMQ/kXRwGdYpuya1WnewsG2jw/6yzr6 soGTiMGA==; Received: from [179.93.15.111] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1w2wH5-002x5r-Ku; Wed, 18 Mar 2026 20:09:48 +0100 From: "Guilherme G. Piccoli" To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, "Guilherme G. Piccoli" , Andrew Morton , Mike Rapoport , Steven Rostedt , SeongJae Park Subject: [PATCH v3 1/2] mm/memblock: Print out errors on reserve_mem parser Date: Wed, 18 Mar 2026 15:56:32 -0300 Message-ID: <20260318190816.1811325-2-gpiccoli@igalia.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260318190816.1811325-1-gpiccoli@igalia.com> References: <20260318190816.1811325-1-gpiccoli@igalia.com> 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 parsing of kernel parameter "reserve_mem=3D" is subject to multiple failures, like duplicate naming, malformed expression or even lack of available memory. Right now, all of these fail silently. Let's add some messages so the kernel log can provide useful information in case of failures. Cc: Andrew Morton Cc: Mike Rapoport Cc: Steven Rostedt Reviewed-by: SeongJae Park Signed-off-by: Guilherme G. Piccoli --- V3: - Removed unnecessary blank line (thanks SJ!). mm/memblock.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index b3ddfdec7a80..ac08d7f8c15e 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -2642,23 +2642,25 @@ static int __init reserve_mem(char *p) int len; =20 if (!p) - return -EINVAL; + goto err_param; =20 /* Check if there's room for more reserved memory */ - if (reserved_mem_count >=3D RESERVE_MEM_MAX_ENTRIES) + if (reserved_mem_count >=3D RESERVE_MEM_MAX_ENTRIES) { + pr_err("reserve_mem: no more room for reserved memory\n"); return -EBUSY; + } =20 oldp =3D p; size =3D memparse(p, &p); if (!size || p =3D=3D oldp) - return -EINVAL; + goto err_param; =20 if (*p !=3D ':') - return -EINVAL; + goto err_param; =20 align =3D memparse(p+1, &p); if (*p !=3D ':') - return -EINVAL; + goto err_param; =20 /* * memblock_phys_alloc() doesn't like a zero size align, @@ -2672,7 +2674,7 @@ static int __init reserve_mem(char *p) =20 /* name needs to have length but not too big */ if (!len || len >=3D RESERVE_MEM_NAME_SIZE) - return -EINVAL; + goto err_param; =20 /* Make sure that name has text */ for (p =3D name; *p; p++) { @@ -2680,11 +2682,13 @@ static int __init reserve_mem(char *p) break; } if (!*p) - return -EINVAL; + goto err_param; =20 /* Make sure the name is not already used */ - if (reserve_mem_find_by_name(name, &start, &tmp)) + if (reserve_mem_find_by_name(name, &start, &tmp)) { + pr_err("reserve_mem: name \"%s\" was already used\n", name); return -EBUSY; + } =20 /* Pick previous allocations up from KHO if available */ if (reserve_mem_kho_revive(name, size, align)) @@ -2692,12 +2696,17 @@ static int __init reserve_mem(char *p) =20 /* TODO: Allocation must be outside of scratch region */ start =3D memblock_phys_alloc(size, align); - if (!start) + if (!start) { + pr_err("reserve_mem: memblock allocation failed\n"); return -ENOMEM; + } =20 reserved_mem_add(start, size, name); =20 return 1; +err_param: + pr_err("reserve_mem: empty or malformed parameter\n"); + return -EINVAL; } __setup("reserve_mem=3D", reserve_mem); =20 --=20 2.50.1