From mboxrd@z Thu Jan 1 00:00:00 1970 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 BBEBD1E50A; Tue, 30 Apr 2024 11:08:17 +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=1714475297; cv=none; b=oJEqhoRva/w9ZBIgS6OKupHFbYkoCt8gEyJNKWZbVyvGWrUoYpOk+MyFgmZY11TohMw0QuWOx88N9amr40CC7lIFrlSEcsTovTBxWO2lOe88GGGhXxKcq2RoSbhpQE6Vs+xqmkF4I/PsnxhrH6fuH9TasWNhV63vehrhMZ1G8BY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714475297; c=relaxed/simple; bh=FsZVI+MU9SdGJesUXDX0nQPEswRAR8IaV+/jVDYv64k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NKF5eFEie73zFZKtWkJkKg5IZqPu/Ezii/esV4WjjvBYtexojxi/ZViwKvAzLCsyVTuBHYyh5RInmGGYia+3dfPkb/79FRBl++Z4urFwWI0ziCMMaJ/p1w9claWtzwsdVTjyY2ViRR5B6GRVrKnhsheeT2GyWQT04o8NV5NROII= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gmiirRMy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gmiirRMy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B451C2BBFC; Tue, 30 Apr 2024 11:08:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714475297; bh=FsZVI+MU9SdGJesUXDX0nQPEswRAR8IaV+/jVDYv64k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gmiirRMyLsM7yTJIsM982IPuqd4UfxFC/42F4ciEDAilemG5b01/X9bIS+WnV1SlS nR1TkurvtUvaIYnsSz22DsgrM8INrGY7kI4UIG5kX3u2t62lCXHzEJlEzRWf3Ms/YY i6YXilOwb1OqF4gvk/YobKBnYJYNIKGHJoYheXrE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kwangjin Ko , Alison Schofield , Dan Williams , Ira Weiny , Dave Jiang , Sasha Levin Subject: [PATCH 6.6 054/186] cxl/core: Fix potential payload size confusion in cxl_mem_get_poison() Date: Tue, 30 Apr 2024 12:38:26 +0200 Message-ID: <20240430103059.600144903@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103058.010791820@linuxfoundation.org> References: <20240430103058.010791820@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams [ Upstream commit 4b759dd5765503bd466defac7d93aca14c23a15d ] A recent change to cxl_mem_get_records_log() [1] highlighted a subtle nuance of looping calls to cxl_internal_send_cmd(), i.e. that cxl_internal_send_cmd() modifies the 'size_out' member of the @mbox_cmd argument. That mechanism is useful for communicating underflow, but it is unwanted when reusing @mbox_cmd for a subsequent submission. It turns out that cxl_xfer_log() avoids this scenario by always redefining @mbox_cmd each iteration. Update cxl_mem_get_records_log() and cxl_mem_get_poison() to follow the same style as cxl_xfer_log(), i.e. re-define @mbox_cmd each iteration. The cxl_mem_get_records_log() change is just a style fixup, but the cxl_mem_get_poison() change is a potential fix, per Alison [2]: Poison list retrieval can hit this case if the MORE flag is set and a follow on read of the list delivers more records than the previous read. ie. device gives one record, sets the _MORE flag, then gives 5. Not an urgent fix since this behavior has not been seen in the wild, but worth tracking as a fix. Cc: Kwangjin Ko Cc: Alison Schofield Fixes: ed83f7ca398b ("cxl/mbox: Add GET_POISON_LIST mailbox command") Link: http://lore.kernel.org/r/20240402081404.1106-2-kwangjin.ko@sk.com [1] Link: http://lore.kernel.org/r/ZhAhAL/GOaWFrauw@aschofie-mobl2 [2] Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Alison Schofield Link: https://lore.kernel.org/r/171235441633.2716581.12330082428680958635.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang Signed-off-by: Sasha Levin --- drivers/cxl/core/mbox.c | 38 +++++++++++++++++--------------------- 1 file changed, 17 insertions(+), 21 deletions(-) diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 4b4c15e943380..fecaa18f4dd20 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -959,25 +959,22 @@ static void cxl_mem_get_records_log(struct cxl_memdev_state *mds, struct cxl_memdev *cxlmd = mds->cxlds.cxlmd; struct device *dev = mds->cxlds.dev; struct cxl_get_event_payload *payload; - struct cxl_mbox_cmd mbox_cmd; u8 log_type = type; u16 nr_rec; mutex_lock(&mds->event.log_lock); payload = mds->event.buf; - mbox_cmd = (struct cxl_mbox_cmd) { - .opcode = CXL_MBOX_OP_GET_EVENT_RECORD, - .payload_in = &log_type, - .size_in = sizeof(log_type), - .payload_out = payload, - .min_out = struct_size(payload, records, 0), - }; - do { int rc, i; - - mbox_cmd.size_out = mds->payload_size; + struct cxl_mbox_cmd mbox_cmd = (struct cxl_mbox_cmd) { + .opcode = CXL_MBOX_OP_GET_EVENT_RECORD, + .payload_in = &log_type, + .size_in = sizeof(log_type), + .payload_out = payload, + .size_out = mds->payload_size, + .min_out = struct_size(payload, records, 0), + }; rc = cxl_internal_send_cmd(mds, &mbox_cmd); if (rc) { @@ -1311,7 +1308,6 @@ int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len, struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); struct cxl_mbox_poison_out *po; struct cxl_mbox_poison_in pi; - struct cxl_mbox_cmd mbox_cmd; int nr_records = 0; int rc; @@ -1323,16 +1319,16 @@ int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len, pi.offset = cpu_to_le64(offset); pi.length = cpu_to_le64(len / CXL_POISON_LEN_MULT); - mbox_cmd = (struct cxl_mbox_cmd) { - .opcode = CXL_MBOX_OP_GET_POISON, - .size_in = sizeof(pi), - .payload_in = &pi, - .size_out = mds->payload_size, - .payload_out = po, - .min_out = struct_size(po, record, 0), - }; - do { + struct cxl_mbox_cmd mbox_cmd = (struct cxl_mbox_cmd){ + .opcode = CXL_MBOX_OP_GET_POISON, + .size_in = sizeof(pi), + .payload_in = &pi, + .size_out = mds->payload_size, + .payload_out = po, + .min_out = struct_size(po, record, 0), + }; + rc = cxl_internal_send_cmd(mds, &mbox_cmd); if (rc) break; -- 2.43.0