NAK. Please On Thu, Feb 08, 2024 at 08:05:52PM -0800, Alexei Starovoitov wrote: > From: Alexei Starovoitov <ast@xxxxxxxxxx> > > BPF would like to use the vmap API to implement a lazily-populated > memory space which can be shared by multiple userspace threads. > The vmap API is generally public and has functions to request and What is "the vmap API"? > For example, there is the public ioremap_page_range(), which is used > to map device memory into addressable kernel space. It's not really public. It's a helper for the ioremap implementation which really should not be arch specific to start with and are in the process of beeing consolidatd into common code. > The new BPF code needs the functionality of vmap_pages_range() in > order to incrementally map privately managed arrays of pages into its > vmap area. Indeed this function used to be public, but became private > when usecases other than vmalloc happened to disappear. Yes, for a freaking good reason. The vmap area is not for general abuse by random callers. We have a few of those left, but we need to get rid of that and not add more.