From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A28F63EAC84 for ; Mon, 15 Jun 2026 13:05:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781528712; cv=none; b=GkI+n8u6qNTdpcGPFy5lMG7qikbleDZNWDur3tXGMoGmNED64J+pvGl9PRE/fER7nWBmmkY3m26E6ZlRWC6R+PjZaiubRlY3BcPS2nxZmwBt1NW0LsbK1yqwLykBrYuIVFhhy29moXCkTtLDcRQC/+zbKrM63TUGiFWG3mYkgaE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781528712; c=relaxed/simple; bh=R8AvM6F0DLWd9jsFg2E3Sjy7aKxsj5DggySON7MHVxE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=m1DWOKqBEeqBXVZE01HVHAASIhQ5L1Fff+h8FEZguRBQ/GqYVby+jRX5v7qrMT6bYLW/dTGuRb8cAOXxhGlxMf09c0/tSbbHr0mGvGlv6kAYGjouzMODtNLZAueWMYdc9NCdb+3paT8AwYqPyzRiKMWReqzqelE8+oGNJWM9gVM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Somg/LqS; arc=none smtp.client-ip=209.85.208.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Somg/LqS" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-6915567d194so3412384a12.1 for ; Mon, 15 Jun 2026 06:05:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781528709; x=1782133509; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=8KgmRpZ89lCyw7TnUs9IavIMjs9smvt+SzytEeojGlY=; b=Somg/LqSnOYtxzaXbXreOjOVnTKSnnHx614j2rc7V9vApdx2HE/j0CjvCQGb+KtE2V dFrha39uVJY4HEuYwSDp0y9piX4Y62dRx2Q7Qupc1icyhvws/GnloHFp5NBoBa149LQv 7oCKLCakPD+/wC7YF7FYeVzBhVYXaGLn35XxQFoo4WUSjMN1HBrrnNXfMPd7ovyjp62X 1Vn9YGb/6aNXzsGxfbmDExpj3YSHHnqkehU1J7KAEjtLIRUldyMEOAGq8ik3Nh0KyjGx Ba5Apm2ATeUdczG7ZH999rrWh877+hESJXqOOOXkWo+AUfYnb42MjJEzMoeAvtOYSrej iyHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781528709; x=1782133509; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=8KgmRpZ89lCyw7TnUs9IavIMjs9smvt+SzytEeojGlY=; b=C5LW0hWxYj4xJit0dXrbbxxj50xTq8ietvs3kRkoPl+jXBNoUgA/ZheZ7wznUZJWKt JSDmuBoLYPzyxGThu4e3I1GIyVF2uMbbWuDHHaxV+ss9YRuMDWuko+nylDVD4dPzwYNr KQHUCTQzPrdF/90P1c62T7QEnMmKGLBHSPhpV9H5elX12cuCpkQQue/kImj5zvurogpp sxec/v4cQdN77rkCfadkEcJWbJf5O8Srb7d2dkEOE8zvLLCgvv2WXLFTjjmCvsWOSt7w BcO8ZyHzeFnWYlSLQWEsNHoXWPml9j6ZFOTy4fqJANHupZeD0qfnSlJ2sffSHkIHc9WZ Zvkg== X-Forwarded-Encrypted: i=1; AFNElJ9ijhJMOLq1GHRHz3LHPPezOfy91lWLO6AUMROIV3LsMmICAsM8eKMoC/HvcuYihRXQPut7Z7xf506yFeg=@vger.kernel.org X-Gm-Message-State: AOJu0YyTTg5IL3DRpIo3Nky1km/SQNHyNT/YCrPBGN/AkJOFpKE0ucPW wT7Al1uyQ3aguH7ccrFimYAgvlkAr7SMccnAlXxV2wJWqEY/J5Wmw+rmOeDe29l+6EKVabbfXub RMGZBPR4kT8utOVZnJQ== X-Received: from edi25.prod.google.com ([2002:a05:6402:3059:b0:676:2118:1564]) (user=tarunsahu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:40d5:b0:66e:56a2:b67b with SMTP id 4fb4d7f45d1cf-69378a457f8mr6300301a12.20.1781528708577; Mon, 15 Jun 2026 06:05:08 -0700 (PDT) Date: Mon, 15 Jun 2026 13:05:05 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.54.0.1136.gdb2ca164c4-goog Message-ID: <9fe93604bac096dd3edfa48a0d2e2ce6e2683f56.1781528022.git.tarunsahu@google.com> Subject: [PATCH 1/1] mm/memfd_luo: use KHOSER_PTR for serialized_data checks From: Tarun Sahu To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, Tarun Sahu Content-Type: text/plain; charset="UTF-8" In all callbacks (freeze, unpreserve, finish, retrieve), use the standard KHOSER_LOAD_PTR() and KHOSER_STORE_PTR() macros to safely load and store the serialized structure pointer. This resolves the issue where phys_to_virt() was previously called before checking if the physical address is valid, since KHOSER_LOAD_PTR() automatically handles translation and returns NULL if the physical address is 0. Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd") Signed-off-by: Tarun Sahu --- mm/memfd_luo.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c index 59de210bee5f..ec37693841a6 100644 --- a/mm/memfd_luo.c +++ b/mm/memfd_luo.c @@ -257,6 +257,7 @@ static void memfd_luo_unpreserve_folios(struct kho_vmalloc *kho_vmalloc, static int memfd_luo_preserve(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *); struct inode *inode = file_inode(args->file); struct memfd_luo_folio_ser *folios_ser; struct memfd_luo_ser *ser; @@ -309,7 +310,8 @@ static int memfd_luo_preserve(struct liveupdate_file_op_args *args) inode_unlock(inode); args->private_data = folios_ser; - args->serialized_data = virt_to_phys(ser); + KHOSER_STORE_PTR(sd, ser); + args->serialized_data = sd.phys; return 0; @@ -323,13 +325,15 @@ static int memfd_luo_preserve(struct liveupdate_file_op_args *args) static int memfd_luo_freeze(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *) = { + .phys = args->serialized_data + }; struct memfd_luo_ser *ser; - if (WARN_ON_ONCE(!args->serialized_data)) + ser = KHOSER_LOAD_PTR(sd); + if (WARN_ON_ONCE(!ser)) return -EINVAL; - ser = phys_to_virt(args->serialized_data); - /* * The pos might have changed since prepare. Everything else stays the * same. @@ -341,17 +345,19 @@ static int memfd_luo_freeze(struct liveupdate_file_op_args *args) static void memfd_luo_unpreserve(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *) = { + .phys = args->serialized_data + }; struct inode *inode = file_inode(args->file); struct memfd_luo_ser *ser; - if (WARN_ON_ONCE(!args->serialized_data)) + ser = KHOSER_LOAD_PTR(sd); + if (WARN_ON_ONCE(!ser)) return; inode_lock(inode); shmem_freeze(inode, false); - ser = phys_to_virt(args->serialized_data); - memfd_luo_unpreserve_folios(&ser->folios, args->private_data, ser->nr_folios); @@ -386,6 +392,9 @@ static void memfd_luo_discard_folios(const struct memfd_luo_folio_ser *folios_se static void memfd_luo_finish(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *) = { + .phys = args->serialized_data + }; struct memfd_luo_folio_ser *folios_ser; struct memfd_luo_ser *ser; @@ -397,7 +406,7 @@ static void memfd_luo_finish(struct liveupdate_file_op_args *args) if (args->retrieve_status) return; - ser = phys_to_virt(args->serialized_data); + ser = KHOSER_LOAD_PTR(sd); if (!ser) return; @@ -517,12 +526,15 @@ static int memfd_luo_retrieve_folios(struct file *file, static int memfd_luo_retrieve(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *) = { + .phys = args->serialized_data + }; struct memfd_luo_folio_ser *folios_ser; struct memfd_luo_ser *ser; struct file *file; int err; - ser = phys_to_virt(args->serialized_data); + ser = KHOSER_LOAD_PTR(sd); if (!ser) return -EINVAL; -- 2.54.0.1136.gdb2ca164c4-goog