The body of mlx5e_napi_poll is wrapped into rcu_read_lock to be able to read the XDP program pointer using rcu_dereference. However, the trap RQ NAPI doesn't use rcu_read_lock, because the trap RQ works only in the non-linear mode, and mlx5e_skb_from_cqe_nonlinear, until recently, didn't support XDP and didn't call rcu_dereference. Starting from the cited commit, mlx5e_skb_from_cqe_nonlinear supports XDP and calls rcu_dereference, but mlx5e_trap_napi_poll doesn't wrap it into rcu_read_lock. It leads to RCU-lockdep warnings like this: WARNING: suspicious RCU usage This commit fixes the issue by adding an rcu_read_lock to mlx5e_trap_napi_poll, similarly to mlx5e_napi_poll. Fixes: ea5d49bdae8b ("net/mlx5e: Add XDP multi buffer support to the non-linear legacy RQ") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. 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.
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