From: lic121 lic121@chinatelecom.cn
[ 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@chinatelecom.cn Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20220301132623.GA19995@vscode.7~ Signed-off-by: Sasha Levin sashal@kernel.org --- 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 edafe56664f3..32a2f5749c71 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);