On Tue, Mar 1, 2022 at 6:57 PM lic121 <lic121@xxxxxxxxxxxxxxx> wrote: > > xsk_umem__create() does mmap for fill/comp rings, but xsk_umem__delete() > doesn't do the unmap. This works fine for regular cases, because > xsk_socket__delete() does unmap for the rings. But for the case that > xsk_socket__create_shared() fails, umem rings are not unmapped. > > fill_save/comp_save are checked to determine if rings have already be > unmapped by xsk. If fill_save and comp_save are NULL, it means that the > rings have already been used by xsk. Then they are supposed to be > unmapped by xsk_socket__delete(). Otherwise, xsk_umem__delete() does the > unmap. Thanks for the fix. Please note that the AF_XDP support in libbpf has been deprecated and moved to libxdp (https://github.com/xdp-project/xdp-tools). The code will be completely removed in the libbpf 1.0 release. Could I take your patch and apply it to libxdp instead and fix the bug there? I have not checked, but it is likely present there as well. And that is the code base we will be using going forward. > Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") > Signed-off-by: lic121 <lic121@xxxxxxxxxxxxxxx> > --- > tools/lib/bpf/xsk.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > index edafe56..32a2f57 100644 > --- a/tools/lib/bpf/xsk.c > +++ b/tools/lib/bpf/xsk.c > @@ -1193,12 +1193,23 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, > > int xsk_umem__delete(struct xsk_umem *umem) > { > + struct xdp_mmap_offsets off; > + int err; > + > if (!umem) > return 0; > > if (umem->refcount) > return -EBUSY; > > + err = xsk_get_mmap_offsets(umem->fd, &off); > + if (!err && umem->fill_save && umem->comp_save) { > + munmap(umem->fill_save->ring - off.fr.desc, > + off.fr.desc + umem->config.fill_size * sizeof(__u64)); > + munmap(umem->comp_save->ring - off.cr.desc, > + off.cr.desc + umem->config.comp_size * sizeof(__u64)); > + } > + > close(umem->fd); > free(umem); > > -- > 1.8.3.1 >
