6.9-stable review patch. If anyone has any objections, please let me know.
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From: Akiva Goldberger agoldberger@nvidia.com
[ Upstream commit 485d65e1357123a697c591a5aeb773994b247ad7 ]
Prevent forced completion handling on an entry that has not yet been assigned an index, causing an out of bounds access on idx = -22. Instead of waiting indefinitely for the sem, blocking flow now waits for index to be allocated or a sem acquisition timeout before beginning the timer for FW completion.
Kernel log example: mlx5_core 0000:06:00.0: wait_func_handle_exec_timeout:1128:(pid 185911): cmd[-22]: CREATE_UCTX(0xa04) No done completion
Fixes: 8e715cd613a1 ("net/mlx5: Set command entry semaphore up once got index free") Signed-off-by: Akiva Goldberger agoldberger@nvidia.com Reviewed-by: Moshe Shemesh moshe@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Link: https://lore.kernel.org/r/20240509112951.590184-5-tariqt@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 41 +++++++++++++++---- include/linux/mlx5/driver.h | 1 + 2 files changed, 33 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index 4957412ff1f65..511e7fee39ac5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -969,19 +969,32 @@ static void cmd_work_handler(struct work_struct *work) bool poll_cmd = ent->polling; struct mlx5_cmd_layout *lay; struct mlx5_core_dev *dev; - unsigned long cb_timeout; - struct semaphore *sem; + unsigned long timeout; unsigned long flags; int alloc_ret; int cmd_mode;
+ complete(&ent->handling); + dev = container_of(cmd, struct mlx5_core_dev, cmd); - cb_timeout = msecs_to_jiffies(mlx5_tout_ms(dev, CMD)); + timeout = msecs_to_jiffies(mlx5_tout_ms(dev, CMD));
- complete(&ent->handling); - sem = ent->page_queue ? &cmd->vars.pages_sem : &cmd->vars.sem; - down(sem); if (!ent->page_queue) { + if (down_timeout(&cmd->vars.sem, timeout)) { + mlx5_core_warn(dev, "%s(0x%x) timed out while waiting for a slot.\n", + mlx5_command_str(ent->op), ent->op); + if (ent->callback) { + ent->callback(-EBUSY, ent->context); + mlx5_free_cmd_msg(dev, ent->out); + free_msg(dev, ent->in); + cmd_ent_put(ent); + } else { + ent->ret = -EBUSY; + complete(&ent->done); + } + complete(&ent->slotted); + return; + } alloc_ret = cmd_alloc_index(cmd, ent); if (alloc_ret < 0) { mlx5_core_err_rl(dev, "failed to allocate command entry\n"); @@ -994,10 +1007,11 @@ static void cmd_work_handler(struct work_struct *work) ent->ret = -EAGAIN; complete(&ent->done); } - up(sem); + up(&cmd->vars.sem); return; } } else { + down(&cmd->vars.pages_sem); ent->idx = cmd->vars.max_reg_cmds; spin_lock_irqsave(&cmd->alloc_lock, flags); clear_bit(ent->idx, &cmd->vars.bitmask); @@ -1005,6 +1019,8 @@ static void cmd_work_handler(struct work_struct *work) spin_unlock_irqrestore(&cmd->alloc_lock, flags); }
+ complete(&ent->slotted); + lay = get_inst(cmd, ent->idx); ent->lay = lay; memset(lay, 0, sizeof(*lay)); @@ -1023,7 +1039,7 @@ static void cmd_work_handler(struct work_struct *work) ent->ts1 = ktime_get_ns(); cmd_mode = cmd->mode;
- if (ent->callback && schedule_delayed_work(&ent->cb_timeout_work, cb_timeout)) + if (ent->callback && schedule_delayed_work(&ent->cb_timeout_work, timeout)) cmd_ent_get(ent); set_bit(MLX5_CMD_ENT_STATE_PENDING_COMP, &ent->state);
@@ -1143,6 +1159,9 @@ static int wait_func(struct mlx5_core_dev *dev, struct mlx5_cmd_work_ent *ent) ent->ret = -ECANCELED; goto out_err; } + + wait_for_completion(&ent->slotted); + if (cmd->mode == CMD_MODE_POLLING || ent->polling) wait_for_completion(&ent->done); else if (!wait_for_completion_timeout(&ent->done, timeout)) @@ -1157,6 +1176,9 @@ static int wait_func(struct mlx5_core_dev *dev, struct mlx5_cmd_work_ent *ent) } else if (err == -ECANCELED) { mlx5_core_warn(dev, "%s(0x%x) canceled on out of queue timeout.\n", mlx5_command_str(ent->op), ent->op); + } else if (err == -EBUSY) { + mlx5_core_warn(dev, "%s(0x%x) timeout while waiting for command semaphore.\n", + mlx5_command_str(ent->op), ent->op); } mlx5_core_dbg(dev, "err %d, delivery status %s(%d)\n", err, deliv_status_to_str(ent->status), ent->status); @@ -1208,6 +1230,7 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in, ent->polling = force_polling;
init_completion(&ent->handling); + init_completion(&ent->slotted); if (!callback) init_completion(&ent->done);
@@ -1225,7 +1248,7 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in, return 0; /* mlx5_cmd_comp_handler() will put(ent) */
err = wait_func(dev, ent); - if (err == -ETIMEDOUT || err == -ECANCELED) + if (err == -ETIMEDOUT || err == -ECANCELED || err == -EBUSY) goto out_free;
ds = ent->ts2 - ent->ts1; diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index bf9324a31ae97..80452bd982531 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -862,6 +862,7 @@ struct mlx5_cmd_work_ent { void *context; int idx; struct completion handling; + struct completion slotted; struct completion done; struct mlx5_cmd *cmd; struct work_struct work;