075b503812
[ Upstream commit d412c31dae053bf30a1bc15582a9990df297a660 ]
The command interface can work in two modes: Events and Polling.
In the general case, each time we invoke a command, a work is
queued to handle it.
When working in events, the interrupt handler completes the
command execution. On the other hand, when working in polling
mode, the work itself completes it.
Due to a bug in the work handler, a command could have been
completed by the interrupt handler, while the work handler
hasn't finished yet, causing the it to complete once again
if the command interface mode was changed from Events to
polling after the interrupt handler was called.
mlx5_unload_one()
mlx5_stop_eqs()
// Destroy the EQ before cmd EQ
...cmd_work_handler()
write_doorbell()
--> EVENT_TYPE_CMD
mlx5_cmd_comp_handler() // First free
free_ent(cmd, ent->idx)
complete(&ent->done)
<-- mlx5_stop_eqs //cmd was complete
// move to polling before destroying the last cmd EQ
mlx5_cmd_use_polling()
cmd->mode = POLL;
--> cmd_work_handler (continues)
if (cmd->mode == POLL)
mlx5_cmd_comp_handler() // Double free
The solution is to store the cmd->mode before writing the doorbell.
Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.