diff options
| -rw-r--r-- | include/net/af_unix.h | 2 | ||||
| -rw-r--r-- | include/net/scm.h | 1 | ||||
| -rw-r--r-- | net/core/scm.c | 2 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 8 | ||||
| -rw-r--r-- | net/unix/garbage.c | 90 |
5 files changed, 100 insertions, 3 deletions
diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 55c4abc26a71..f31ad1166346 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -22,6 +22,8 @@ extern unsigned int unix_tot_inflight; void unix_inflight(struct user_struct *user, struct file *fp); void unix_notinflight(struct user_struct *user, struct file *fp); +void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver); +void unix_del_edges(struct scm_fp_list *fpl); int unix_prepare_fpl(struct scm_fp_list *fpl); void unix_destroy_fpl(struct scm_fp_list *fpl); void unix_gc(void); diff --git a/include/net/scm.h b/include/net/scm.h index 5f5154e5096d..bbc5527809d1 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -32,6 +32,7 @@ struct scm_fp_list { short count_unix; short max; #ifdef CONFIG_UNIX + bool inflight; struct list_head vertices; struct unix_edge *edges; #endif diff --git a/net/core/scm.c b/net/core/scm.c index 1bcc8a2d65e3..5763f3320358 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -90,6 +90,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) fpl->max = SCM_MAX_FD; fpl->user = NULL; #if IS_ENABLED(CONFIG_UNIX) + fpl->inflight = false; fpl->edges = NULL; INIT_LIST_HEAD(&fpl->vertices); #endif @@ -384,6 +385,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl) new_fpl->max = new_fpl->count; new_fpl->user = get_uid(fpl->user); #if IS_ENABLED(CONFIG_UNIX) + new_fpl->inflight = false; new_fpl->edges = NULL; INIT_LIST_HEAD(&new_fpl->vertices); #endif diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index a3b25d311560..24adbc4d5188 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1943,8 +1943,10 @@ static void scm_stat_add(struct sock *sk, struct sk_buff *skb) struct scm_fp_list *fp = UNIXCB(skb).fp; struct unix_sock *u = unix_sk(sk); - if (unlikely(fp && fp->count)) + if (unlikely(fp && fp->count)) { atomic_add(fp->count, &u->scm_stat.nr_fds); + unix_add_edges(fp, u); + } } static void scm_stat_del(struct sock *sk, struct sk_buff *skb) @@ -1952,8 +1954,10 @@ static void scm_stat_del(struct sock *sk, struct sk_buff *skb) struct scm_fp_list *fp = UNIXCB(skb).fp; struct unix_sock *u = unix_sk(sk); - if (unlikely(fp && fp->count)) + if (unlikely(fp && fp->count)) { atomic_sub(fp->count, &u->scm_stat.nr_fds); + unix_del_edges(fp); + } } /* diff --git a/net/unix/garbage.c b/net/unix/garbage.c index f31917683288..36d665936096 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -101,6 +101,38 @@ struct unix_sock *unix_get_socket(struct file *filp) return NULL; } +static LIST_HEAD(unix_unvisited_vertices); + +static void unix_add_edge(struct scm_fp_list *fpl, struct unix_edge *edge) +{ + struct unix_vertex *vertex = edge->predecessor->vertex; + + if (!vertex) { + vertex = list_first_entry(&fpl->vertices, typeof(*vertex), entry); + vertex->out_degree = 0; + INIT_LIST_HEAD(&vertex->edges); + + list_move_tail(&vertex->entry, &unix_unvisited_vertices); + edge->predecessor->vertex = vertex; + } + + vertex->out_degree++; + list_add_tail(&edge->vertex_entry, &vertex->edges); +} + +static void unix_del_edge(struct scm_fp_list *fpl, struct unix_edge *edge) +{ + struct unix_vertex *vertex = edge->predecessor->vertex; + + list_del(&edge->vertex_entry); + vertex->out_degree--; + + if (!vertex->out_degree) { + edge->predecessor->vertex = NULL; + list_move_tail(&vertex->entry, &fpl->vertices); + } +} + static void unix_free_vertices(struct scm_fp_list *fpl) { struct unix_vertex *vertex, *next_vertex; @@ -111,6 +143,60 @@ static void unix_free_vertices(struct scm_fp_list *fpl) } } +DEFINE_SPINLOCK(unix_gc_lock); + +void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver) +{ + int i = 0, j = 0; + + spin_lock(&unix_gc_lock); + + if (!fpl->count_unix) + goto out; + + do { + struct unix_sock *inflight = unix_get_socket(fpl->fp[j++]); + struct unix_edge *edge; + + if (!inflight) + continue; + + edge = fpl->edges + i++; + edge->predecessor = inflight; + edge->successor = receiver; + + unix_add_edge(fpl, edge); + } while (i < fpl->count_unix); + +out: + spin_unlock(&unix_gc_lock); + + fpl->inflight = true; + + unix_free_vertices(fpl); +} + +void unix_del_edges(struct scm_fp_list *fpl) +{ + int i = 0; + + spin_lock(&unix_gc_lock); + + if (!fpl->count_unix) + goto out; + + do { + struct unix_edge *edge = fpl->edges + i++; + + unix_del_edge(fpl, edge); + } while (i < fpl->count_unix); + +out: + spin_unlock(&unix_gc_lock); + + fpl->inflight = false; +} + int unix_prepare_fpl(struct scm_fp_list *fpl) { struct unix_vertex *vertex; @@ -141,11 +227,13 @@ err: void unix_destroy_fpl(struct scm_fp_list *fpl) { + if (fpl->inflight) + unix_del_edges(fpl); + kvfree(fpl->edges); unix_free_vertices(fpl); } -DEFINE_SPINLOCK(unix_gc_lock); unsigned int unix_tot_inflight; static LIST_HEAD(gc_candidates); static LIST_HEAD(gc_inflight_list); |