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authorKuniyuki Iwashima <kuniyu@amazon.com>2024-01-29 11:04:35 -0800
committerJakub Kicinski <kuba@kernel.org>2024-01-31 16:41:16 -0800
commit99a7a5b9943ea2d05fb0dee38e4ae2290477ed83 (patch)
tree6f47f81313dea6d075f8a90be3a9e71b55c9601d /net
parent11498715f266a3fb4caabba9dd575636cbcaa8f1 (diff)
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af_unix: Remove CONFIG_UNIX_SCM.
Originally, the code related to garbage collection was all in garbage.c. Commit f4e65870e5ce ("net: split out functions related to registering inflight socket files") moved some functions to scm.c for io_uring and added CONFIG_UNIX_SCM just in case AF_UNIX was built as module. However, since commit 97154bcf4d1b ("af_unix: Kconfig: make CONFIG_UNIX bool"), AF_UNIX is no longer built separately. Also, io_uring does not support SCM_RIGHTS now. Let's move the functions back to garbage.c Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20240129190435.57228-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/Makefile2
-rw-r--r--net/unix/Kconfig5
-rw-r--r--net/unix/Makefile2
-rw-r--r--net/unix/af_unix.c63
-rw-r--r--net/unix/garbage.c73
-rw-r--r--net/unix/scm.c150
-rw-r--r--net/unix/scm.h10
7 files changed, 133 insertions, 172 deletions
diff --git a/net/Makefile b/net/Makefile
index b06b5539e7a6..65bb8c72a35e 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -17,7 +17,7 @@ obj-$(CONFIG_NETFILTER) += netfilter/
obj-$(CONFIG_INET) += ipv4/
obj-$(CONFIG_TLS) += tls/
obj-$(CONFIG_XFRM) += xfrm/
-obj-$(CONFIG_UNIX_SCM) += unix/
+obj-$(CONFIG_UNIX) += unix/
obj-y += ipv6/
obj-$(CONFIG_PACKET) += packet/
obj-$(CONFIG_NET_KEY) += key/
diff --git a/net/unix/Kconfig b/net/unix/Kconfig
index 28b232f281ab..8b5d04210d7c 100644
--- a/net/unix/Kconfig
+++ b/net/unix/Kconfig
@@ -16,11 +16,6 @@ config UNIX
Say Y unless you know what you are doing.
-config UNIX_SCM
- bool
- depends on UNIX
- default y
-
config AF_UNIX_OOB
bool
depends on UNIX
diff --git a/net/unix/Makefile b/net/unix/Makefile
index 20491825b4d0..4ddd125c4642 100644
--- a/net/unix/Makefile
+++ b/net/unix/Makefile
@@ -11,5 +11,3 @@ unix-$(CONFIG_BPF_SYSCALL) += unix_bpf.o
obj-$(CONFIG_UNIX_DIAG) += unix_diag.o
unix_diag-y := diag.o
-
-obj-$(CONFIG_UNIX_SCM) += scm.o
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 1720419d93d6..1cfbc586adb4 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -118,8 +118,6 @@
#include <linux/btf_ids.h>
#include <linux/bpf-cgroup.h>
-#include "scm.h"
-
static atomic_long_t unix_nr_socks;
static struct hlist_head bsd_socket_buckets[UNIX_HASH_SIZE / 2];
static spinlock_t bsd_socket_locks[UNIX_HASH_SIZE / 2];
@@ -1790,6 +1788,52 @@ out:
return err;
}
+/* The "user->unix_inflight" variable is protected by the garbage
+ * collection lock, and we just read it locklessly here. If you go
+ * over the limit, there might be a tiny race in actually noticing
+ * it across threads. Tough.
+ */
+static inline bool too_many_unix_fds(struct task_struct *p)
+{
+ struct user_struct *user = current_user();
+
+ if (unlikely(READ_ONCE(user->unix_inflight) > task_rlimit(p, RLIMIT_NOFILE)))
+ return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return false;
+}
+
+static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+
+ if (too_many_unix_fds(current))
+ return -ETOOMANYREFS;
+
+ /* Need to duplicate file references for the sake of garbage
+ * collection. Otherwise a socket in the fps might become a
+ * candidate for GC while the skb is not yet queued.
+ */
+ UNIXCB(skb).fp = scm_fp_dup(scm->fp);
+ if (!UNIXCB(skb).fp)
+ return -ENOMEM;
+
+ for (i = scm->fp->count - 1; i >= 0; i--)
+ unix_inflight(scm->fp->user, scm->fp->fp[i]);
+
+ return 0;
+}
+
+static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+
+ scm->fp = UNIXCB(skb).fp;
+ UNIXCB(skb).fp = NULL;
+
+ for (i = scm->fp->count - 1; i >= 0; i--)
+ unix_notinflight(scm->fp->user, scm->fp->fp[i]);
+}
+
static void unix_peek_fds(struct scm_cookie *scm, struct sk_buff *skb)
{
scm->fp = scm_fp_dup(UNIXCB(skb).fp);
@@ -1837,6 +1881,21 @@ static void unix_peek_fds(struct scm_cookie *scm, struct sk_buff *skb)
spin_unlock(&unix_gc_lock);
}
+static void unix_destruct_scm(struct sk_buff *skb)
+{
+ struct scm_cookie scm;
+
+ memset(&scm, 0, sizeof(scm));
+ scm.pid = UNIXCB(skb).pid;
+ if (UNIXCB(skb).fp)
+ unix_detach_fds(&scm, skb);
+
+ /* Alas, it calls VFS */
+ /* So fscking what? fput() had been SMP-safe since the last Summer */
+ scm_destroy(&scm);
+ sock_wfree(skb);
+}
+
static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
{
int err = 0;
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index ce5b5f87b16e..9b8473dd79a4 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -81,11 +81,80 @@
#include <net/scm.h>
#include <net/tcp_states.h>
-#include "scm.h"
+struct unix_sock *unix_get_socket(struct file *filp)
+{
+ struct inode *inode = file_inode(filp);
+
+ /* Socket ? */
+ if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
+ struct socket *sock = SOCKET_I(inode);
+ const struct proto_ops *ops;
+ struct sock *sk = sock->sk;
-/* Internal data structures and random procedures: */
+ ops = READ_ONCE(sock->ops);
+ /* PF_UNIX ? */
+ if (sk && ops && ops->family == PF_UNIX)
+ return unix_sk(sk);
+ }
+
+ return NULL;
+}
+
+DEFINE_SPINLOCK(unix_gc_lock);
+unsigned int unix_tot_inflight;
static LIST_HEAD(gc_candidates);
+static LIST_HEAD(gc_inflight_list);
+
+/* Keep the number of times in flight count for the file
+ * descriptor if it is for an AF_UNIX socket.
+ */
+void unix_inflight(struct user_struct *user, struct file *filp)
+{
+ struct unix_sock *u = unix_get_socket(filp);
+
+ spin_lock(&unix_gc_lock);
+
+ if (u) {
+ if (!u->inflight) {
+ WARN_ON_ONCE(!list_empty(&u->link));
+ list_add_tail(&u->link, &gc_inflight_list);
+ } else {
+ WARN_ON_ONCE(list_empty(&u->link));
+ }
+ u->inflight++;
+
+ /* Paired with READ_ONCE() in wait_for_unix_gc() */
+ WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + 1);
+ }
+
+ WRITE_ONCE(user->unix_inflight, user->unix_inflight + 1);
+
+ spin_unlock(&unix_gc_lock);
+}
+
+void unix_notinflight(struct user_struct *user, struct file *filp)
+{
+ struct unix_sock *u = unix_get_socket(filp);
+
+ spin_lock(&unix_gc_lock);
+
+ if (u) {
+ WARN_ON_ONCE(!u->inflight);
+ WARN_ON_ONCE(list_empty(&u->link));
+
+ u->inflight--;
+ if (!u->inflight)
+ list_del_init(&u->link);
+
+ /* Paired with READ_ONCE() in wait_for_unix_gc() */
+ WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - 1);
+ }
+
+ WRITE_ONCE(user->unix_inflight, user->unix_inflight - 1);
+
+ spin_unlock(&unix_gc_lock);
+}
static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *),
struct sk_buff_head *hitlist)
diff --git a/net/unix/scm.c b/net/unix/scm.c
deleted file mode 100644
index db65b0ab5947..000000000000
--- a/net/unix/scm.c
+++ /dev/null
@@ -1,150 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/socket.h>
-#include <linux/net.h>
-#include <linux/fs.h>
-#include <net/af_unix.h>
-#include <net/scm.h>
-#include <linux/init.h>
-#include <linux/io_uring.h>
-
-#include "scm.h"
-
-unsigned int unix_tot_inflight;
-EXPORT_SYMBOL(unix_tot_inflight);
-
-LIST_HEAD(gc_inflight_list);
-EXPORT_SYMBOL(gc_inflight_list);
-
-DEFINE_SPINLOCK(unix_gc_lock);
-EXPORT_SYMBOL(unix_gc_lock);
-
-struct unix_sock *unix_get_socket(struct file *filp)
-{
- struct inode *inode = file_inode(filp);
-
- /* Socket ? */
- if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
- struct socket *sock = SOCKET_I(inode);
- const struct proto_ops *ops = READ_ONCE(sock->ops);
- struct sock *s = sock->sk;
-
- /* PF_UNIX ? */
- if (s && ops && ops->family == PF_UNIX)
- return unix_sk(s);
- }
-
- return NULL;
-}
-EXPORT_SYMBOL(unix_get_socket);
-
-/* Keep the number of times in flight count for the file
- * descriptor if it is for an AF_UNIX socket.
- */
-void unix_inflight(struct user_struct *user, struct file *fp)
-{
- struct unix_sock *u = unix_get_socket(fp);
-
- spin_lock(&unix_gc_lock);
-
- if (u) {
- if (!u->inflight) {
- WARN_ON_ONCE(!list_empty(&u->link));
- list_add_tail(&u->link, &gc_inflight_list);
- } else {
- WARN_ON_ONCE(list_empty(&u->link));
- }
- u->inflight++;
- /* Paired with READ_ONCE() in wait_for_unix_gc() */
- WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + 1);
- }
- WRITE_ONCE(user->unix_inflight, user->unix_inflight + 1);
- spin_unlock(&unix_gc_lock);
-}
-
-void unix_notinflight(struct user_struct *user, struct file *fp)
-{
- struct unix_sock *u = unix_get_socket(fp);
-
- spin_lock(&unix_gc_lock);
-
- if (u) {
- WARN_ON_ONCE(!u->inflight);
- WARN_ON_ONCE(list_empty(&u->link));
-
- u->inflight--;
- if (!u->inflight)
- list_del_init(&u->link);
- /* Paired with READ_ONCE() in wait_for_unix_gc() */
- WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - 1);
- }
- WRITE_ONCE(user->unix_inflight, user->unix_inflight - 1);
- spin_unlock(&unix_gc_lock);
-}
-
-/*
- * The "user->unix_inflight" variable is protected by the garbage
- * collection lock, and we just read it locklessly here. If you go
- * over the limit, there might be a tiny race in actually noticing
- * it across threads. Tough.
- */
-static inline bool too_many_unix_fds(struct task_struct *p)
-{
- struct user_struct *user = current_user();
-
- if (unlikely(READ_ONCE(user->unix_inflight) > task_rlimit(p, RLIMIT_NOFILE)))
- return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
- return false;
-}
-
-int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
-{
- int i;
-
- if (too_many_unix_fds(current))
- return -ETOOMANYREFS;
-
- /*
- * Need to duplicate file references for the sake of garbage
- * collection. Otherwise a socket in the fps might become a
- * candidate for GC while the skb is not yet queued.
- */
- UNIXCB(skb).fp = scm_fp_dup(scm->fp);
- if (!UNIXCB(skb).fp)
- return -ENOMEM;
-
- for (i = scm->fp->count - 1; i >= 0; i--)
- unix_inflight(scm->fp->user, scm->fp->fp[i]);
- return 0;
-}
-EXPORT_SYMBOL(unix_attach_fds);
-
-void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
-{
- int i;
-
- scm->fp = UNIXCB(skb).fp;
- UNIXCB(skb).fp = NULL;
-
- for (i = scm->fp->count-1; i >= 0; i--)
- unix_notinflight(scm->fp->user, scm->fp->fp[i]);
-}
-EXPORT_SYMBOL(unix_detach_fds);
-
-void unix_destruct_scm(struct sk_buff *skb)
-{
- struct scm_cookie scm;
-
- memset(&scm, 0, sizeof(scm));
- scm.pid = UNIXCB(skb).pid;
- if (UNIXCB(skb).fp)
- unix_detach_fds(&scm, skb);
-
- /* Alas, it calls VFS */
- /* So fscking what? fput() had been SMP-safe since the last Summer */
- scm_destroy(&scm);
- sock_wfree(skb);
-}
-EXPORT_SYMBOL(unix_destruct_scm);
diff --git a/net/unix/scm.h b/net/unix/scm.h
deleted file mode 100644
index 5a255a477f16..000000000000
--- a/net/unix/scm.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef NET_UNIX_SCM_H
-#define NET_UNIX_SCM_H
-
-extern struct list_head gc_inflight_list;
-extern spinlock_t unix_gc_lock;
-
-int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb);
-void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb);
-
-#endif