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>
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dst_metadata.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_DST_METADATA_H
#define __NET_DST_METADATA_H 1
#include <linux/skbuff.h>
#include <net/ip_tunnels.h>
#include <net/dst.h>
enum metadata_type {
METADATA_IP_TUNNEL,
METADATA_HW_PORT_MUX,
};
struct hw_port_info {
struct net_device *lower_dev;
u32 port_id;
};
struct metadata_dst {
struct dst_entry dst;
enum metadata_type type;
union {
struct ip_tunnel_info tun_info;
struct hw_port_info port_info;
} u;
};
static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
{
struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
if (md_dst && md_dst->dst.flags & DST_METADATA)
return md_dst;
return NULL;
}
static inline struct ip_tunnel_info *
skb_tunnel_info(const struct sk_buff *skb)
{
struct metadata_dst *md_dst = skb_metadata_dst(skb);
struct dst_entry *dst;
if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
return &md_dst->u.tun_info;
dst = skb_dst(skb);
if (dst && dst->lwtstate)
return lwt_tun_info(dst->lwtstate);
return NULL;
}
static inline bool skb_valid_dst(const struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
return dst && !(dst->flags & DST_METADATA);
}
static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
const struct sk_buff *skb_b)
{
const struct metadata_dst *a, *b;
if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
return 0;
a = (const struct metadata_dst *) skb_dst(skb_a);
b = (const struct metadata_dst *) skb_dst(skb_b);
if (!a != !b || a->type != b->type)
return 1;
switch (a->type) {
case METADATA_HW_PORT_MUX:
return memcmp(&a->u.port_info, &b->u.port_info,
sizeof(a->u.port_info));
case METADATA_IP_TUNNEL:
return memcmp(&a->u.tun_info, &b->u.tun_info,
sizeof(a->u.tun_info) +
a->u.tun_info.options_len);
default:
return 1;
}
}
void metadata_dst_free(struct metadata_dst *);
struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
gfp_t flags);
void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
struct metadata_dst __percpu *
metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
static inline struct metadata_dst *tun_rx_dst(int md_size)
{
struct metadata_dst *tun_dst;
tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
if (!tun_dst)
return NULL;
tun_dst->u.tun_info.options_len = 0;
tun_dst->u.tun_info.mode = 0;
return tun_dst;
}
static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
{
struct metadata_dst *md_dst = skb_metadata_dst(skb);
int md_size;
struct metadata_dst *new_md;
if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
return ERR_PTR(-EINVAL);
md_size = md_dst->u.tun_info.options_len;
new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
if (!new_md)
return ERR_PTR(-ENOMEM);
memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
sizeof(struct ip_tunnel_info) + md_size);
skb_dst_drop(skb);
dst_hold(&new_md->dst);
skb_dst_set(skb, &new_md->dst);
return new_md;
}
static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
{
struct metadata_dst *dst;
dst = tun_dst_unclone(skb);
if (IS_ERR(dst))
return NULL;
return &dst->u.tun_info;
}
static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
__be32 daddr,
__u8 tos, __u8 ttl,
__be16 tp_dst,
__be16 flags,
__be64 tunnel_id,
int md_size)
{
struct metadata_dst *tun_dst;
tun_dst = tun_rx_dst(md_size);
if (!tun_dst)
return NULL;
ip_tunnel_key_init(&tun_dst->u.tun_info.key,
saddr, daddr, tos, ttl,
0, 0, tp_dst, tunnel_id, flags);
return tun_dst;
}
static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
__be16 flags,
__be64 tunnel_id,
int md_size)
{
const struct iphdr *iph = ip_hdr(skb);
return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
0, flags, tunnel_id, md_size);
}
static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u8 tos, __u8 ttl,
__be16 tp_dst,
__be32 label,
__be16 flags,
__be64 tunnel_id,
int md_size)
{
struct metadata_dst *tun_dst;
struct ip_tunnel_info *info;
tun_dst = tun_rx_dst(md_size);
if (!tun_dst)
return NULL;
info = &tun_dst->u.tun_info;
info->mode = IP_TUNNEL_INFO_IPV6;
info->key.tun_flags = flags;
info->key.tun_id = tunnel_id;
info->key.tp_src = 0;
info->key.tp_dst = tp_dst;
info->key.u.ipv6.src = *saddr;
info->key.u.ipv6.dst = *daddr;
info->key.tos = tos;
info->key.ttl = ttl;
info->key.label = label;
return tun_dst;
}
static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
__be16 flags,
__be64 tunnel_id,
int md_size)
{
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
ipv6_get_dsfield(ip6h), ip6h->hop_limit,
0, ip6_flowlabel(ip6h), flags, tunnel_id,
md_size);
}
#endif /* __NET_DST_METADATA_H */
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