This is a note to let you know that I've just added the patch titled libbpf: Unmap rings when umem deleted to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: libbpf-unmap-rings-when-umem-deleted.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 58608c982b62cff7a8ec49a1a04f95c2ddb7d348 Author: lic121 <lic121@xxxxxxxxxxxxxxx> Date: Tue Mar 1 13:26:23 2022 +0000 libbpf: Unmap rings when umem deleted [ Upstream commit 9c6e6a80ee741adf6cb3cfd8eef7d1554f91fceb ] 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. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Cheng Li <lic121@xxxxxxxxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Link: https://lore.kernel.org/bpf/20220301132623.GA19995@vscode.7~ Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index e9b619aa0cdf..a27b3141463a 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -1210,12 +1210,23 @@ 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);