From c751e5890724beeb0b41017f54ac5509f50697e8 Mon Sep 17 00:00:00 2001 From: Alaa Hleihel Date: Mon, 1 Jun 2020 15:40:31 -0400 Subject: [PATCH 278/312] [netdrv] net/mlx5: Add command entry handling completion Message-id: <20200601154102.25980-9-ahleihel@redhat.com> Patchwork-id: 315713 Patchwork-instance: patchwork O-Subject: [RHEL8.3 BZ 1842258 08/39] net/mlx5: Add command entry handling completion Bugzilla: 1842258 RH-Acked-by: Honggang Li RH-Acked-by: Kamal Heib RH-Acked-by: Marcelo Leitner RH-Acked-by: Jarod Wilson Bugzilla: http://bugzilla.redhat.com/1842258 Upstream: v5.7-rc7 commit 17d00e839d3b592da9659c1977d45f85b77f986a Author: Moshe Shemesh Date: Fri Dec 27 07:01:53 2019 +0200 net/mlx5: Add command entry handling completion When FW response to commands is very slow and all command entries in use are waiting for completion we can have a race where commands can get timeout before they get out of the queue and handled. Timeout completion on uninitialized command will cause releasing command's buffers before accessing it for initialization and then we will get NULL pointer exception while trying access it. It may also cause releasing buffers of another command since we may have timeout completion before even allocating entry index for this command. Add entry handling completion to avoid this race. Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Signed-off-by: Moshe Shemesh Signed-off-by: Eran Ben Elisha Signed-off-by: Saeed Mahameed Signed-off-by: Alaa Hleihel Signed-off-by: Frantisek Hrbata --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 14 ++++++++++++++ include/linux/mlx5/driver.h | 3 +++ 2 files changed, 17 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index 23acec5a31d4..50783828d2e8 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -861,6 +861,7 @@ static void cmd_work_handler(struct work_struct *work) int alloc_ret; int cmd_mode; + complete(&ent->handling); sem = ent->page_queue ? &cmd->pages_sem : &cmd->sem; down(sem); if (!ent->page_queue) { @@ -978,6 +979,11 @@ static int wait_func(struct mlx5_core_dev *dev, struct mlx5_cmd_work_ent *ent) struct mlx5_cmd *cmd = &dev->cmd; int err; + if (!wait_for_completion_timeout(&ent->handling, timeout) && + cancel_work_sync(&ent->work)) { + ent->ret = -ECANCELED; + goto out_err; + } if (cmd->mode == CMD_MODE_POLLING || ent->polling) { wait_for_completion(&ent->done); } else if (!wait_for_completion_timeout(&ent->done, timeout)) { @@ -985,12 +991,17 @@ static int wait_func(struct mlx5_core_dev *dev, struct mlx5_cmd_work_ent *ent) mlx5_cmd_comp_handler(dev, 1UL << ent->idx, true); } +out_err: err = ent->ret; if (err == -ETIMEDOUT) { mlx5_core_warn(dev, "%s(0x%x) timeout. Will cause a leak of a command resource\n", mlx5_command_str(msg_to_opcode(ent->in)), msg_to_opcode(ent->in)); + } else if (err == -ECANCELED) { + mlx5_core_warn(dev, "%s(0x%x) canceled on out of queue timeout.\n", + mlx5_command_str(msg_to_opcode(ent->in)), + msg_to_opcode(ent->in)); } mlx5_core_dbg(dev, "err %d, delivery status %s(%d)\n", err, deliv_status_to_str(ent->status), ent->status); @@ -1026,6 +1037,7 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in, ent->token = token; ent->polling = force_polling; + init_completion(&ent->handling); if (!callback) init_completion(&ent->done); @@ -1045,6 +1057,8 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in, err = wait_func(dev, ent); if (err == -ETIMEDOUT) goto out; + if (err == -ECANCELED) + goto out_free; ds = ent->ts2 - ent->ts1; op = MLX5_GET(mbox_in, in->first.data, opcode); diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 0d728007078c..df47476d6fca 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -761,6 +761,9 @@ struct mlx5_cmd_work_ent { struct delayed_work cb_timeout_work; void *context; int idx; +#ifndef __GENKSYMS__ + struct completion handling; +#endif struct completion done; struct mlx5_cmd *cmd; struct work_struct work; -- 2.13.6