From nobody Fri Apr 10 02:38:14 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 40750375F8A for ; Wed, 4 Mar 2026 20:34:05 +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=1772656449; cv=none; b=eY5RUqMSxxjsiz05zYS/YKCj/k6n/GyyUDgwMUkiu02CEOqD7pg9ty6ENPxpwvtVbMO71BtfxZTh9H1EFYz4uLNpQpCi+H7yTQ1rxd8NWlLDW4XtuhwU5w6Jqj03pELxRXRTrUCJEVcCQJtS9xJwJIHA9lCfuvBRgv1rW6bW1m0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772656449; c=relaxed/simple; bh=JH6jbM5PWTRtIfx6P7u/5FDTx2Fl36YSXwxTs18glk8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ivtvfNs7MhssTDMbuRlWNb0E0FtZMspCE/X1ECnetEUrb97HaOpir2rjiDRMeAW6B941eOkuTPOsGyCVMzP8XMeTDht5ftZW24xrDLpq4uOhtIXq8VOUzZrH5wJu3VRCOORDbq2SAAaUh9uj/0sW9NO9MSFaEBdPriIDMClE1lg= 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=HA6Gqfub; 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="HA6Gqfub" 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=EqT9WNYz3ZuMaGbrnnkO9KS8167OdxqpYCX1Aav7XuQ=; b=HA6GqfubG6VXpDBQk5CCcRzIMI 1fwLyYT43MrRyS85hVWtBrTc5jOMD4lxpRQSz0j7ofCuKNQxZ04ZrS6l2RJYFZTneKU+r03ZvkkOc i/G5PuZDYrw04tOexmGdl+++rC7Msa6JLArWWSpqGwI9n2iYnAiSbQ6QT4lq5+ll4460beOfthRVn NaDteLOEvz4vV7r7em0d4k0Ylyeimv+UVDMdh18guimyPtxVyy70R18oO53iLl0cNhPQ6icfPdwqV 8EOk8NHqjdgym/ofZR3OI09ktL/gEXBjFlFHofBWI8rM+RZl93RzsMoDpYhtcGykydGyyoiatWwaX 7DCxyIlQ==; Received: from [187.90.181.146] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1vxsut-0095KJ-SD; Wed, 04 Mar 2026 21:34:00 +0100 From: "Guilherme G. Piccoli" To: linux-mm@kvack.org, rppt@kernel.org Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, gpiccoli@igalia.com, Andrew Morton , Steven Rostedt Subject: [PATCH V2 1/2] mm/memblock: Print out errors on reserve_mem parser Date: Wed, 4 Mar 2026 17:14:10 -0300 Message-ID: <20260304203300.1414286-3-gpiccoli@igalia.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260304203300.1414286-2-gpiccoli@igalia.com> References: <20260304203300.1414286-2-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 Signed-off-by: Guilherme G. Piccoli Reviewed-by: SeongJae Park --- V2: no changes. mm/memblock.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index b3ddfdec7a80..2d2646f7a120 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 +2696,18 @@ 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