KFunc `bpf_io_uring_get_region`

Get a pointer to a memory region (kernel-userspace shared chunk of memory).

Definition

Parameters

loop_ctx: a pointer to the struct iou_ctx to act on. region_id: the ID of the region, which can be one of: * IOU_REGION_SQ returns the submission queue. * IOU_REGION_CQ stores the Completion Queue, Submission Queue/Completion Queue headers and the sqarray. In other words, it gives same memory that would normally be mmap'ed with IORING_FEAT_SINGLE_MMAP enabled IORING_OFF_SQ_RING. * IOU_REGION_MEM represents the memory / parameter region. It can be used to store request indirect parameters and for kernel - user communication. rdwr_buf_size: the size as an argument, which should be a load time constant.

Returns

A pointer to the specified region, where io_uring regions are kernel-userspace shared chunks of memory.

Signature

__u8 *bpf_io_uring_get_region(struct io_ring_ctx *ctx, __u32 region_id, const size_t rdwr_buf_size)

Note

The pointer returned by the kfunc may be NULL. Hence, it forces the user to do a NULL check on the pointer returned from the kfunc before making use of it (dereferencing or passing to another helper).

Usage

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Program types

The following program types can make use of this kfunc:

BPF_PROG_TYPE_STRUCT_OPS

Example