dumping large buffers to file

Hi. I'm currently debugging a ISP DMA issue in a kernel module. For debugging, I would like to dump buffers to a file on run time. The buffers are quite big, 1MB at least. As saving a file directly from kernel is discouraged, is there any available framework for doing such a thing ? I can think of numerous ways of transferring the buffer to user space and saving it by a dedicated user process (Netlink, sysfs, char device, etc.) I just don't want to invent the wheel. How do you do it ? Thanks. Ramon