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
flow.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *
 *	Generic internet FLOW.
 *
 */

#ifndef _NET_FLOW_H
#define _NET_FLOW_H

#include <linux/socket.h>
#include <linux/in6.h>
#include <linux/atomic.h>
#include <net/flow_dissector.h>
#include <linux/uidgid.h>

/*
 * ifindex generation is per-net namespace, and loopback is
 * always the 1st device in ns (see net_dev_init), thus any
 * loopback device should get ifindex 1
 */

#define LOOPBACK_IFINDEX	1

struct flowi_tunnel {
	__be64			tun_id;
};

struct flowi_common {
	int	flowic_oif;
	int	flowic_iif;
	__u32	flowic_mark;
	__u8	flowic_tos;
	__u8	flowic_scope;
	__u8	flowic_proto;
	__u8	flowic_flags;
#define FLOWI_FLAG_ANYSRC		0x01
#define FLOWI_FLAG_KNOWN_NH		0x02
#define FLOWI_FLAG_SKIP_NH_OIF		0x04
	__u32	flowic_secid;
	kuid_t  flowic_uid;
	struct flowi_tunnel flowic_tun_key;
	__u32		flowic_multipath_hash;
};

union flowi_uli {
	struct {
		__be16	dport;
		__be16	sport;
	} ports;

	struct {
		__u8	type;
		__u8	code;
	} icmpt;

	struct {
		__le16	dport;
		__le16	sport;
	} dnports;

	__be32		spi;
	__be32		gre_key;

	struct {
		__u8	type;
	} mht;
};

struct flowi4 {
	struct flowi_common	__fl_common;
#define flowi4_oif		__fl_common.flowic_oif
#define flowi4_iif		__fl_common.flowic_iif
#define flowi4_mark		__fl_common.flowic_mark
#define flowi4_tos		__fl_common.flowic_tos
#define flowi4_scope		__fl_common.flowic_scope
#define flowi4_proto		__fl_common.flowic_proto
#define flowi4_flags		__fl_common.flowic_flags
#define flowi4_secid		__fl_common.flowic_secid
#define flowi4_tun_key		__fl_common.flowic_tun_key
#define flowi4_uid		__fl_common.flowic_uid
#define flowi4_multipath_hash	__fl_common.flowic_multipath_hash

	/* (saddr,daddr) must be grouped, same order as in IP header */
	__be32			saddr;
	__be32			daddr;

	union flowi_uli		uli;
#define fl4_sport		uli.ports.sport
#define fl4_dport		uli.ports.dport
#define fl4_icmp_type		uli.icmpt.type
#define fl4_icmp_code		uli.icmpt.code
#define fl4_ipsec_spi		uli.spi
#define fl4_mh_type		uli.mht.type
#define fl4_gre_key		uli.gre_key
} __attribute__((__aligned__(BITS_PER_LONG/8)));

static inline void flowi4_init_output(struct flowi4 *fl4, int oif,
				      __u32 mark, __u8 tos, __u8 scope,
				      __u8 proto, __u8 flags,
				      __be32 daddr, __be32 saddr,
				      __be16 dport, __be16 sport,
				      kuid_t uid)
{
	fl4->flowi4_oif = oif;
	fl4->flowi4_iif = LOOPBACK_IFINDEX;
	fl4->flowi4_mark = mark;
	fl4->flowi4_tos = tos;
	fl4->flowi4_scope = scope;
	fl4->flowi4_proto = proto;
	fl4->flowi4_flags = flags;
	fl4->flowi4_secid = 0;
	fl4->flowi4_tun_key.tun_id = 0;
	fl4->flowi4_uid = uid;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
	fl4->fl4_dport = dport;
	fl4->fl4_sport = sport;
}

/* Reset some input parameters after previous lookup */
static inline void flowi4_update_output(struct flowi4 *fl4, int oif, __u8 tos,
					__be32 daddr, __be32 saddr)
{
	fl4->flowi4_oif = oif;
	fl4->flowi4_tos = tos;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
}


struct flowi6 {
	struct flowi_common	__fl_common;
#define flowi6_oif		__fl_common.flowic_oif
#define flowi6_iif		__fl_common.flowic_iif
#define flowi6_mark		__fl_common.flowic_mark
#define flowi6_scope		__fl_common.flowic_scope
#define flowi6_proto		__fl_common.flowic_proto
#define flowi6_flags		__fl_common.flowic_flags
#define flowi6_secid		__fl_common.flowic_secid
#define flowi6_tun_key		__fl_common.flowic_tun_key
#define flowi6_uid		__fl_common.flowic_uid
	struct in6_addr		daddr;
	struct in6_addr		saddr;
	/* Note: flowi6_tos is encoded in flowlabel, too. */
	__be32			flowlabel;
	union flowi_uli		uli;
#define fl6_sport		uli.ports.sport
#define fl6_dport		uli.ports.dport
#define fl6_icmp_type		uli.icmpt.type
#define fl6_icmp_code		uli.icmpt.code
#define fl6_ipsec_spi		uli.spi
#define fl6_mh_type		uli.mht.type
#define fl6_gre_key		uli.gre_key
	__u32			mp_hash;
} __attribute__((__aligned__(BITS_PER_LONG/8)));

struct flowidn {
	struct flowi_common	__fl_common;
#define flowidn_oif		__fl_common.flowic_oif
#define flowidn_iif		__fl_common.flowic_iif
#define flowidn_mark		__fl_common.flowic_mark
#define flowidn_scope		__fl_common.flowic_scope
#define flowidn_proto		__fl_common.flowic_proto
#define flowidn_flags		__fl_common.flowic_flags
	__le16			daddr;
	__le16			saddr;
	union flowi_uli		uli;
#define fld_sport		uli.ports.sport
#define fld_dport		uli.ports.dport
} __attribute__((__aligned__(BITS_PER_LONG/8)));

struct flowi {
	union {
		struct flowi_common	__fl_common;
		struct flowi4		ip4;
		struct flowi6		ip6;
		struct flowidn		dn;
	} u;
#define flowi_oif	u.__fl_common.flowic_oif
#define flowi_iif	u.__fl_common.flowic_iif
#define flowi_mark	u.__fl_common.flowic_mark
#define flowi_tos	u.__fl_common.flowic_tos
#define flowi_scope	u.__fl_common.flowic_scope
#define flowi_proto	u.__fl_common.flowic_proto
#define flowi_flags	u.__fl_common.flowic_flags
#define flowi_secid	u.__fl_common.flowic_secid
#define flowi_tun_key	u.__fl_common.flowic_tun_key
#define flowi_uid	u.__fl_common.flowic_uid
} __attribute__((__aligned__(BITS_PER_LONG/8)));

static inline struct flowi *flowi4_to_flowi(struct flowi4 *fl4)
{
	return container_of(fl4, struct flowi, u.ip4);
}

static inline struct flowi *flowi6_to_flowi(struct flowi6 *fl6)
{
	return container_of(fl6, struct flowi, u.ip6);
}

static inline struct flowi *flowidn_to_flowi(struct flowidn *fldn)
{
	return container_of(fldn, struct flowi, u.dn);
}

__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys);

#endif
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