mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 00:40:03 +00:00
0dbffbb533
sk_ll_usec is read locklessly from sk_can_busy_loop() while another thread can change its value in sock_setsockopt() This is correct but needs annotations. BUG: KCSAN: data-race in __skb_try_recv_datagram / sock_setsockopt write to 0xffff88814eb5f904 of 4 bytes by task 14011 on cpu 0: sock_setsockopt+0x1287/0x2090 net/core/sock.c:1175 __sys_setsockopt+0x14f/0x200 net/socket.c:2100 __do_sys_setsockopt net/socket.c:2115 [inline] __se_sys_setsockopt net/socket.c:2112 [inline] __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88814eb5f904 of 4 bytes by task 14001 on cpu 1: sk_can_busy_loop include/net/busy_poll.h:41 [inline] __skb_try_recv_datagram+0x14f/0x320 net/core/datagram.c:273 unix_dgram_recvmsg+0x14c/0x870 net/unix/af_unix.c:2101 unix_seqpacket_recvmsg+0x5a/0x70 net/unix/af_unix.c:2067 ____sys_recvmsg+0x15d/0x310 include/linux/uio.h:244 ___sys_recvmsg net/socket.c:2598 [inline] do_recvmmsg+0x35c/0x9f0 net/socket.c:2692 __sys_recvmmsg net/socket.c:2771 [inline] __do_sys_recvmmsg net/socket.c:2794 [inline] __se_sys_recvmmsg net/socket.c:2787 [inline] __x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2787 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0x00000101 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 14001 Comm: syz-executor.3 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
163 lines
3.9 KiB
C
163 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* net busy poll support
|
|
* Copyright(c) 2013 Intel Corporation.
|
|
*
|
|
* Author: Eliezer Tamir
|
|
*
|
|
* Contact Information:
|
|
* e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
|
|
*/
|
|
|
|
#ifndef _LINUX_NET_BUSY_POLL_H
|
|
#define _LINUX_NET_BUSY_POLL_H
|
|
|
|
#include <linux/netdevice.h>
|
|
#include <linux/sched/clock.h>
|
|
#include <linux/sched/signal.h>
|
|
#include <net/ip.h>
|
|
|
|
/* 0 - Reserved to indicate value not set
|
|
* 1..NR_CPUS - Reserved for sender_cpu
|
|
* NR_CPUS+1..~0 - Region available for NAPI IDs
|
|
*/
|
|
#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
|
|
|
|
#define BUSY_POLL_BUDGET 8
|
|
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
|
|
struct napi_struct;
|
|
extern unsigned int sysctl_net_busy_read __read_mostly;
|
|
extern unsigned int sysctl_net_busy_poll __read_mostly;
|
|
|
|
static inline bool net_busy_loop_on(void)
|
|
{
|
|
return sysctl_net_busy_poll;
|
|
}
|
|
|
|
static inline bool sk_can_busy_loop(const struct sock *sk)
|
|
{
|
|
return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);
|
|
}
|
|
|
|
bool sk_busy_loop_end(void *p, unsigned long start_time);
|
|
|
|
void napi_busy_loop(unsigned int napi_id,
|
|
bool (*loop_end)(void *, unsigned long),
|
|
void *loop_end_arg, bool prefer_busy_poll, u16 budget);
|
|
|
|
#else /* CONFIG_NET_RX_BUSY_POLL */
|
|
static inline unsigned long net_busy_loop_on(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline bool sk_can_busy_loop(struct sock *sk)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
#endif /* CONFIG_NET_RX_BUSY_POLL */
|
|
|
|
static inline unsigned long busy_loop_current_time(void)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
return (unsigned long)(local_clock() >> 10);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/* in poll/select we use the global sysctl_net_ll_poll value */
|
|
static inline bool busy_loop_timeout(unsigned long start_time)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
|
|
|
|
if (bp_usec) {
|
|
unsigned long end_time = start_time + bp_usec;
|
|
unsigned long now = busy_loop_current_time();
|
|
|
|
return time_after(now, end_time);
|
|
}
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
static inline bool sk_busy_loop_timeout(struct sock *sk,
|
|
unsigned long start_time)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
|
|
|
|
if (bp_usec) {
|
|
unsigned long end_time = start_time + bp_usec;
|
|
unsigned long now = busy_loop_current_time();
|
|
|
|
return time_after(now, end_time);
|
|
}
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
static inline void sk_busy_loop(struct sock *sk, int nonblock)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
|
|
|
|
if (napi_id >= MIN_NAPI_ID)
|
|
napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
|
|
READ_ONCE(sk->sk_prefer_busy_poll),
|
|
READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);
|
|
#endif
|
|
}
|
|
|
|
/* used in the NIC receive handler to mark the skb */
|
|
static inline void skb_mark_napi_id(struct sk_buff *skb,
|
|
struct napi_struct *napi)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
/* If the skb was already marked with a valid NAPI ID, avoid overwriting
|
|
* it.
|
|
*/
|
|
if (skb->napi_id < MIN_NAPI_ID)
|
|
skb->napi_id = napi->napi_id;
|
|
#endif
|
|
}
|
|
|
|
/* used in the protocol hanlder to propagate the napi_id to the socket */
|
|
static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
|
|
#endif
|
|
sk_rx_queue_set(sk, skb);
|
|
}
|
|
|
|
static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
if (!READ_ONCE(sk->sk_napi_id))
|
|
WRITE_ONCE(sk->sk_napi_id, napi_id);
|
|
#endif
|
|
}
|
|
|
|
/* variant used for unconnected sockets */
|
|
static inline void sk_mark_napi_id_once(struct sock *sk,
|
|
const struct sk_buff *skb)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
__sk_mark_napi_id_once(sk, skb->napi_id);
|
|
#endif
|
|
}
|
|
|
|
static inline void sk_mark_napi_id_once_xdp(struct sock *sk,
|
|
const struct xdp_buff *xdp)
|
|
{
|
|
#ifdef CONFIG_NET_RX_BUSY_POLL
|
|
__sk_mark_napi_id_once(sk, xdp->rxq->napi_id);
|
|
#endif
|
|
}
|
|
|
|
#endif /* _LINUX_NET_BUSY_POLL_H */
|