From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C699C433E0 for ; Thu, 28 May 2020 11:57:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2318221532 for ; Thu, 28 May 2020 11:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590667034; bh=spiQCSehLksZ1U1DFOVj36xXX1RJUiJgJUZFd14D1qw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vS7iipxzEsDVhCgj3BZKUE31ePKB7bm0ks58YSD9wBravLKfmZEg16W2Nmq98wG+2 XZ78ldFsbZ/e+KjETJ+6DU9ZjS47/ORiLKu06UBTph4yAfzUX8KhMBnTjklmQGgRhN 793x653zPFPqz+xzvBdEpBrMmVp+m0N9tHB4yXrw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388950AbgE1L5L (ORCPT ); Thu, 28 May 2020 07:57:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:48926 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388802AbgE1L4o (ORCPT ); Thu, 28 May 2020 07:56:44 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CC34421548; Thu, 28 May 2020 11:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590667003; bh=spiQCSehLksZ1U1DFOVj36xXX1RJUiJgJUZFd14D1qw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U03P5kSNppCpXfBP8IABSKxsWzxOtiEHlOhHmS3XbjJL34rizyvQe9P28IyYgYQOt 75+LTdOMB/2o3B0EWdDUp7jX+qPRnPoWf17qTMDFsXtoxRTjy1gIEltd8qj31uQ1U1 +kjbu72i65INrZcG295MS+UCX5lXsVHf3bgBf+qU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eran Ben Elisha , Moshe Shemesh , Saeed Mahameed , Sasha Levin , netdev@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 38/47] net/mlx5: Fix a race when moving command interface to events mode Date: Thu, 28 May 2020 07:55:51 -0400 Message-Id: <20200528115600.1405808-38-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200528115600.1405808-1-sashal@kernel.org> References: <20200528115600.1405808-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eran Ben Elisha [ Upstream commit d43b7007dbd1195a5b6b83213e49b1516aaf6f5e ] After driver creates (via FW command) an EQ for commands, the driver will be informed on new commands completion by EQE. However, due to a race in driver's internal command mode metadata update, some new commands will still be miss-handled by driver as if we are in polling mode. Such commands can get two non forced completion, leading to already freed command entry access. CREATE_EQ command, that maps EQ to the command queue must be posted to the command queue while it is empty and no other command should be posted. Add SW mechanism that once the CREATE_EQ command is about to be executed, all other commands will return error without being sent to the FW. Allow sending other commands only after successfully changing the driver's internal command mode metadata. We can safely return error to all other commands while creating the command EQ, as all other commands might be sent from the user/application during driver load. Application can rerun them later after driver's load was finished. Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Signed-off-by: Eran Ben Elisha Signed-off-by: Moshe Shemesh Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 35 ++++++++++++++++--- drivers/net/ethernet/mellanox/mlx5/core/eq.c | 3 ++ include/linux/mlx5/driver.h | 6 ++++ 3 files changed, 40 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index d695b75bc0af..2f3cafdc3b1f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -848,6 +848,14 @@ static void free_msg(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *msg); static void mlx5_free_cmd_msg(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *msg); +static bool opcode_allowed(struct mlx5_cmd *cmd, u16 opcode) +{ + if (cmd->allowed_opcode == CMD_ALLOWED_OPCODE_ALL) + return true; + + return cmd->allowed_opcode == opcode; +} + static void cmd_work_handler(struct work_struct *work) { struct mlx5_cmd_work_ent *ent = container_of(work, struct mlx5_cmd_work_ent, work); @@ -914,7 +922,8 @@ static void cmd_work_handler(struct work_struct *work) /* Skip sending command to fw if internal error */ if (pci_channel_offline(dev->pdev) || - dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) { + dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR || + !opcode_allowed(&dev->cmd, ent->op)) { u8 status = 0; u32 drv_synd; @@ -1405,6 +1414,22 @@ static void create_debugfs_files(struct mlx5_core_dev *dev) mlx5_cmdif_debugfs_init(dev); } +void mlx5_cmd_allowed_opcode(struct mlx5_core_dev *dev, u16 opcode) +{ + struct mlx5_cmd *cmd = &dev->cmd; + int i; + + for (i = 0; i < cmd->max_reg_cmds; i++) + down(&cmd->sem); + down(&cmd->pages_sem); + + cmd->allowed_opcode = opcode; + + up(&cmd->pages_sem); + for (i = 0; i < cmd->max_reg_cmds; i++) + up(&cmd->sem); +} + static void mlx5_cmd_change_mod(struct mlx5_core_dev *dev, int mode) { struct mlx5_cmd *cmd = &dev->cmd; @@ -1681,12 +1706,13 @@ static int cmd_exec(struct mlx5_core_dev *dev, void *in, int in_size, void *out, int err; u8 status = 0; u32 drv_synd; + u16 opcode; u8 token; + opcode = MLX5_GET(mbox_in, in, opcode); if (pci_channel_offline(dev->pdev) || - dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) { - u16 opcode = MLX5_GET(mbox_in, in, opcode); - + dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR || + !opcode_allowed(&dev->cmd, opcode)) { err = mlx5_internal_err_ret_value(dev, opcode, &drv_synd, &status); MLX5_SET(mbox_out, out, status, status); MLX5_SET(mbox_out, out, syndrome, drv_synd); @@ -1988,6 +2014,7 @@ int mlx5_cmd_init(struct mlx5_core_dev *dev) mlx5_core_dbg(dev, "descriptor at dma 0x%llx\n", (unsigned long long)(cmd->dma)); cmd->mode = CMD_MODE_POLLING; + cmd->allowed_opcode = CMD_ALLOWED_OPCODE_ALL; create_msg_cache(dev); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c index cccea3a8eddd..ce6c621af043 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c @@ -611,11 +611,13 @@ static int create_async_eqs(struct mlx5_core_dev *dev) .nent = MLX5_NUM_CMD_EQE, .mask[0] = 1ull << MLX5_EVENT_TYPE_CMD, }; + mlx5_cmd_allowed_opcode(dev, MLX5_CMD_OP_CREATE_EQ); err = setup_async_eq(dev, &table->cmd_eq, ¶m, "cmd"); if (err) goto err1; mlx5_cmd_use_events(dev); + mlx5_cmd_allowed_opcode(dev, CMD_ALLOWED_OPCODE_ALL); param = (struct mlx5_eq_param) { .irq_index = 0, @@ -645,6 +647,7 @@ err2: mlx5_cmd_use_polling(dev); cleanup_async_eq(dev, &table->cmd_eq, "cmd"); err1: + mlx5_cmd_allowed_opcode(dev, CMD_ALLOWED_OPCODE_ALL); mlx5_eq_notifier_unregister(dev, &table->cq_err_nb); return err; } diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index b596353a3a12..6050264ebde1 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -301,6 +301,7 @@ struct mlx5_cmd { struct semaphore sem; struct semaphore pages_sem; int mode; + u16 allowed_opcode; struct mlx5_cmd_work_ent *ent_arr[MLX5_MAX_COMMANDS]; struct dma_pool *pool; struct mlx5_cmd_debug dbg; @@ -893,10 +894,15 @@ mlx5_frag_buf_get_idx_last_contig_stride(struct mlx5_frag_buf_ctrl *fbc, u32 ix) return min_t(u32, last_frag_stride_idx - fbc->strides_offset, fbc->sz_m1); } +enum { + CMD_ALLOWED_OPCODE_ALL, +}; + int mlx5_cmd_init(struct mlx5_core_dev *dev); void mlx5_cmd_cleanup(struct mlx5_core_dev *dev); void mlx5_cmd_use_events(struct mlx5_core_dev *dev); void mlx5_cmd_use_polling(struct mlx5_core_dev *dev); +void mlx5_cmd_allowed_opcode(struct mlx5_core_dev *dev, u16 opcode); struct mlx5_async_ctx { struct mlx5_core_dev *dev; -- 2.25.1