From nobody Mon Apr 6 18:30:31 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 CE02936F40D for ; Tue, 24 Mar 2026 01:28:53 +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=1774315736; cv=none; b=jUW6xzOwN+/7w/Y+zkxt+nShcAya0bfd6Ru0/2oJtSkkS6xbf7Lzk03WOgxf+JH2i2cHsREa2A/MLzJz1l+VpmzfZUQh+uIAcQreT3wjbSz+vJfqYBT2C0iExhG2NNef8L0eR0xAiEXUGmaiyKj8esjwilBjIwLxVLlAdZG0RGQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774315736; c=relaxed/simple; bh=35YGp2+T6VXCB4RzIR/kfBxXhny6PETIzMsFZuQjqK0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WmPbIBbEJrjcnKyjUzeDTUOw1JcJWdXr90wPoRtycw4qZcuTCIOrJ1dzbSd8Qidb03g1+FRuUQ1EYFf3bzmkbFp8uR9ZRFkeI2MJLUGez/gEV6kEwoqdlY8kAu1o+xTJRj68ILnP3zj46Kx7/6h1lHSZBPFDa0vR7N62LUYnxZM= 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=YnWJ9ElD; 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="YnWJ9ElD" 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=W6JRFOUadqjciaiNHE1QDofRIxwv1kmNDZZ2Wj8Ios4=; b=YnWJ9ElDJrJ3NE6m8liGiTosd8 ybIFtdCxq4+uGxr0YUoML5Ie4NFc3ZRtUgXVtjfyMvDgiQ1HEimnkEtYs/fEMjzzVDl7dBm6fGdnh U/AkPcYscEjH4ztWCgUuD6DIwGjquju7iyDuC0y8fzslplZdJnAgz8Fgf5JPldCzjD+/tpOin4wDq G4sXk3gFYN0vpgWv8mHtxKGDWba9xJQ9n/y0PZDpCOP4dvaKu3tKsKjhRB09mXmobwkoX+H0Ti3zN y2UHdHmrSGtbZ4G59/TatYnuWdSenszH3SSKQFnfUqRqXGj4Qp356UKE0F6DKPjFIDhxRwruuCFJp eb6buPJQ==; 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 1w4qZc-0058EB-PU; Tue, 24 Mar 2026 02:28:49 +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 v4 1/2] mm/memblock: Print out errors on reserve_mem parser Date: Mon, 23 Mar 2026 22:22:17 -0300 Message-ID: <20260324012839.1991765-1-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 --- V4: no changes. V3 thread: https://lore.kernel.org/r/20260318190816.1811325-1-gpiccoli@igal= ia.com/ 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