Revision c403f6a3a792a6601185497c12b0bdf4be880439 authored by Qian Cai on 15 August 2020, 00:31:53 UTC, committed by Linus Torvalds on 15 August 2020, 02:56:57 UTC
 BUG: KCSAN: data-race in page_cpupid_xchg_last / put_page

 write (marked) to 0xfffffc0d48ec1a00 of 8 bytes by task 91442 on cpu 3:
  page_cpupid_xchg_last+0x51/0x80
  page_cpupid_xchg_last at mm/mmzone.c:109 (discriminator 11)
  wp_page_reuse+0x3e/0xc0
  wp_page_reuse at mm/memory.c:2453
  do_wp_page+0x472/0x7b0
  do_wp_page at mm/memory.c:2798
  __handle_mm_fault+0xcb0/0xd00
  handle_pte_fault at mm/memory.c:4049
  (inlined by) __handle_mm_fault at mm/memory.c:4163
  handle_mm_fault+0xfc/0x2f0
  handle_mm_fault at mm/memory.c:4200
  do_page_fault+0x263/0x6f9
  do_user_addr_fault at arch/x86/mm/fault.c:1465
  (inlined by) do_page_fault at arch/x86/mm/fault.c:1539
  page_fault+0x34/0x40

 read to 0xfffffc0d48ec1a00 of 8 bytes by task 94817 on cpu 69:
  put_page+0x15a/0x1f0
  page_zonenum at include/linux/mm.h:923
  (inlined by) is_zone_device_page at include/linux/mm.h:929
  (inlined by) page_is_devmap_managed at include/linux/mm.h:948
  (inlined by) put_page at include/linux/mm.h:1023
  wp_page_copy+0x571/0x930
  wp_page_copy at mm/memory.c:2615
  do_wp_page+0x107/0x7b0
  __handle_mm_fault+0xcb0/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 69 PID: 94817 Comm: systemd-udevd Tainted: G        W  O L 5.5.0-next-20200204+ #6
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

A page never changes its zone number. The zone number happens to be
stored in the same word as other bits which are modified, but the zone
number bits will never be modified by any other write, so it can accept
a reload of the zone bits after an intervening write and it don't need
to use READ_ONCE(). Thus, annotate this data race using
ASSERT_EXCLUSIVE_BITS() to also assert that there are no concurrent
writes to it.

Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/1581619089-14472-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 7e0cc01
Raw File
rose.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *	Declarations of Rose type objects.
 *
 *	Jonathan Naylor G4KLX	25/8/96
 */

#ifndef _ROSE_H
#define _ROSE_H 

#include <linux/rose.h>
#include <net/sock.h>

#define	ROSE_ADDR_LEN			5

#define	ROSE_MIN_LEN			3

#define	ROSE_CALL_REQ_ADDR_LEN_OFF	3
#define	ROSE_CALL_REQ_ADDR_LEN_VAL	0xAA	/* each address is 10 digits */
#define	ROSE_CALL_REQ_DEST_ADDR_OFF	4
#define	ROSE_CALL_REQ_SRC_ADDR_OFF	9
#define	ROSE_CALL_REQ_FACILITIES_OFF	14

#define	ROSE_GFI			0x10
#define	ROSE_Q_BIT			0x80
#define	ROSE_D_BIT			0x40
#define	ROSE_M_BIT			0x10

#define	ROSE_CALL_REQUEST		0x0B
#define	ROSE_CALL_ACCEPTED		0x0F
#define	ROSE_CLEAR_REQUEST		0x13
#define	ROSE_CLEAR_CONFIRMATION		0x17
#define	ROSE_DATA			0x00
#define	ROSE_INTERRUPT			0x23
#define	ROSE_INTERRUPT_CONFIRMATION	0x27
#define	ROSE_RR				0x01
#define	ROSE_RNR			0x05
#define	ROSE_REJ			0x09
#define	ROSE_RESET_REQUEST		0x1B
#define	ROSE_RESET_CONFIRMATION		0x1F
#define	ROSE_REGISTRATION_REQUEST	0xF3
#define	ROSE_REGISTRATION_CONFIRMATION	0xF7
#define	ROSE_RESTART_REQUEST		0xFB
#define	ROSE_RESTART_CONFIRMATION	0xFF
#define	ROSE_DIAGNOSTIC			0xF1
#define	ROSE_ILLEGAL			0xFD

/* Define Link State constants. */

enum {
	ROSE_STATE_0,			/* Ready */
	ROSE_STATE_1,			/* Awaiting Call Accepted */
	ROSE_STATE_2,			/* Awaiting Clear Confirmation */
	ROSE_STATE_3,			/* Data Transfer */
	ROSE_STATE_4,			/* Awaiting Reset Confirmation */
	ROSE_STATE_5			/* Deferred Call Acceptance */
};

#define ROSE_DEFAULT_T0			180000		/* Default T10 T20 value */
#define ROSE_DEFAULT_T1			200000		/* Default T11 T21 value */
#define ROSE_DEFAULT_T2			180000		/* Default T12 T22 value */
#define	ROSE_DEFAULT_T3			180000		/* Default T13 T23 value */
#define	ROSE_DEFAULT_HB			5000		/* Default Holdback value */
#define	ROSE_DEFAULT_IDLE		0		/* No Activity Timeout - none */
#define	ROSE_DEFAULT_ROUTING		1		/* Default routing flag */
#define	ROSE_DEFAULT_FAIL_TIMEOUT	120000		/* Time until link considered usable */
#define	ROSE_DEFAULT_MAXVC		50		/* Maximum number of VCs per neighbour */
#define	ROSE_DEFAULT_WINDOW_SIZE	7		/* Default window size */

#define ROSE_MODULUS 			8
#define	ROSE_MAX_PACKET_SIZE		251		/* Maximum packet size */

#define	ROSE_COND_ACK_PENDING		0x01
#define	ROSE_COND_PEER_RX_BUSY		0x02
#define	ROSE_COND_OWN_RX_BUSY		0x04

#define	FAC_NATIONAL			0x00
#define	FAC_CCITT			0x0F

#define	FAC_NATIONAL_RAND		0x7F
#define	FAC_NATIONAL_FLAGS		0x3F
#define	FAC_NATIONAL_DEST_DIGI		0xE9
#define	FAC_NATIONAL_SRC_DIGI		0xEB
#define	FAC_NATIONAL_FAIL_CALL		0xED
#define	FAC_NATIONAL_FAIL_ADD		0xEE
#define	FAC_NATIONAL_DIGIS			0xEF

#define	FAC_CCITT_DEST_NSAP		0xC9
#define	FAC_CCITT_SRC_NSAP		0xCB

struct rose_neigh {
	struct rose_neigh	*next;
	ax25_address		callsign;
	ax25_digi		*digipeat;
	ax25_cb			*ax25;
	struct net_device		*dev;
	unsigned short		count;
	unsigned short		use;
	unsigned int		number;
	char			restarted;
	char			dce_mode;
	char			loopback;
	struct sk_buff_head	queue;
	struct timer_list	t0timer;
	struct timer_list	ftimer;
};

struct rose_node {
	struct rose_node	*next;
	rose_address		address;
	unsigned short		mask;
	unsigned char		count;
	char			loopback;
	struct rose_neigh	*neighbour[3];
};

struct rose_route {
	struct rose_route	*next;
	unsigned int		lci1, lci2;
	rose_address		src_addr, dest_addr;
	ax25_address		src_call, dest_call;
	struct rose_neigh 	*neigh1, *neigh2;
	unsigned int		rand;
};

struct rose_sock {
	struct sock		sock;
	rose_address		source_addr,   dest_addr;
	ax25_address		source_call,   dest_call;
	unsigned char		source_ndigis, dest_ndigis;
	ax25_address		source_digis[ROSE_MAX_DIGIS];
	ax25_address		dest_digis[ROSE_MAX_DIGIS];
	struct rose_neigh	*neighbour;
	struct net_device		*device;
	unsigned int		lci, rand;
	unsigned char		state, condition, qbitincl, defer;
	unsigned char		cause, diagnostic;
	unsigned short		vs, vr, va, vl;
	unsigned long		t1, t2, t3, hb, idle;
#ifdef M_BIT
	unsigned short		fraglen;
	struct sk_buff_head	frag_queue;
#endif
	struct sk_buff_head	ack_queue;
	struct rose_facilities_struct facilities;
	struct timer_list	timer;
	struct timer_list	idletimer;
};

#define rose_sk(sk) ((struct rose_sock *)(sk))

/* af_rose.c */
extern ax25_address rose_callsign;
extern int  sysctl_rose_restart_request_timeout;
extern int  sysctl_rose_call_request_timeout;
extern int  sysctl_rose_reset_request_timeout;
extern int  sysctl_rose_clear_request_timeout;
extern int  sysctl_rose_no_activity_timeout;
extern int  sysctl_rose_ack_hold_back_timeout;
extern int  sysctl_rose_routing_control;
extern int  sysctl_rose_link_fail_timeout;
extern int  sysctl_rose_maximum_vcs;
extern int  sysctl_rose_window_size;

int rosecmp(rose_address *, rose_address *);
int rosecmpm(rose_address *, rose_address *, unsigned short);
char *rose2asc(char *buf, const rose_address *);
struct sock *rose_find_socket(unsigned int, struct rose_neigh *);
void rose_kill_by_neigh(struct rose_neigh *);
unsigned int rose_new_lci(struct rose_neigh *);
int rose_rx_call_request(struct sk_buff *, struct net_device *,
			 struct rose_neigh *, unsigned int);
void rose_destroy_socket(struct sock *);

/* rose_dev.c */
void rose_setup(struct net_device *);

/* rose_in.c */
int rose_process_rx_frame(struct sock *, struct sk_buff *);

/* rose_link.c */
void rose_start_ftimer(struct rose_neigh *);
void rose_stop_ftimer(struct rose_neigh *);
void rose_stop_t0timer(struct rose_neigh *);
int rose_ftimer_running(struct rose_neigh *);
void rose_link_rx_restart(struct sk_buff *, struct rose_neigh *,
			  unsigned short);
void rose_transmit_clear_request(struct rose_neigh *, unsigned int,
				 unsigned char, unsigned char);
void rose_transmit_link(struct sk_buff *, struct rose_neigh *);

/* rose_loopback.c */
void rose_loopback_init(void);
void rose_loopback_clear(void);
int rose_loopback_queue(struct sk_buff *, struct rose_neigh *);

/* rose_out.c */
void rose_kick(struct sock *);
void rose_enquiry_response(struct sock *);

/* rose_route.c */
extern struct rose_neigh *rose_loopback_neigh;
extern const struct seq_operations rose_neigh_seqops;
extern const struct seq_operations rose_node_seqops;
extern struct seq_operations rose_route_seqops;

void rose_add_loopback_neigh(void);
int __must_check rose_add_loopback_node(rose_address *);
void rose_del_loopback_node(rose_address *);
void rose_rt_device_down(struct net_device *);
void rose_link_device_down(struct net_device *);
struct net_device *rose_dev_first(void);
struct net_device *rose_dev_get(rose_address *);
struct rose_route *rose_route_free_lci(unsigned int, struct rose_neigh *);
struct rose_neigh *rose_get_neigh(rose_address *, unsigned char *,
				  unsigned char *, int);
int rose_rt_ioctl(unsigned int, void __user *);
void rose_link_failed(ax25_cb *, int);
int rose_route_frame(struct sk_buff *, ax25_cb *);
void rose_rt_free(void);

/* rose_subr.c */
void rose_clear_queues(struct sock *);
void rose_frames_acked(struct sock *, unsigned short);
void rose_requeue_frames(struct sock *);
int rose_validate_nr(struct sock *, unsigned short);
void rose_write_internal(struct sock *, int);
int rose_decode(struct sk_buff *, int *, int *, int *, int *, int *);
int rose_parse_facilities(unsigned char *, unsigned int,
			  struct rose_facilities_struct *);
void rose_disconnect(struct sock *, int, int, int);

/* rose_timer.c */
void rose_start_heartbeat(struct sock *);
void rose_start_t1timer(struct sock *);
void rose_start_t2timer(struct sock *);
void rose_start_t3timer(struct sock *);
void rose_start_hbtimer(struct sock *);
void rose_start_idletimer(struct sock *);
void rose_stop_heartbeat(struct sock *);
void rose_stop_timer(struct sock *);
void rose_stop_idletimer(struct sock *);

/* sysctl_net_rose.c */
void rose_register_sysctl(void);
void rose_unregister_sysctl(void);

#endif
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