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Message-ID: <20240229114016.2995906-4-edumazet@google.com>
Date: Thu, 29 Feb 2024 11:40:13 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: Jiri Pirko <jiri@...dia.com>, David Ahern <dsahern@...nel.org>, netdev@...r.kernel.org,
Florian Westphal <fw@...len.de>, eric.dumazet@...il.com, Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 3/6] inet: annotate data-races around ifa->ifa_preferred_lft
ifa->ifa_preferred_lft can be read locklessly.
Add appropriate READ_ONCE()/WRITE_ONCE() annotations.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
net/ipv4/devinet.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 99f3e7c57d36ff028edadd4efd66d996ddc5d9b4..368fb56e1f1b2e3b7888f611a3f113f3bd5fc2af 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -714,11 +714,13 @@ static void check_lifetime(struct work_struct *work)
rcu_read_lock();
hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) {
unsigned long age, tstamp;
+ u32 preferred_lft;
u32 valid_lft;
if (ifa->ifa_flags & IFA_F_PERMANENT)
continue;
+ preferred_lft = READ_ONCE(ifa->ifa_preferred_lft);
valid_lft = READ_ONCE(ifa->ifa_valid_lft);
tstamp = READ_ONCE(ifa->ifa_tstamp);
/* We try to batch several events at once. */
@@ -728,20 +730,18 @@ static void check_lifetime(struct work_struct *work)
if (valid_lft != INFINITY_LIFE_TIME &&
age >= valid_lft) {
change_needed = true;
- } else if (ifa->ifa_preferred_lft ==
+ } else if (preferred_lft ==
INFINITY_LIFE_TIME) {
continue;
- } else if (age >= ifa->ifa_preferred_lft) {
+ } else if (age >= preferred_lft) {
if (time_before(tstamp + valid_lft * HZ, next))
next = tstamp + valid_lft * HZ;
if (!(ifa->ifa_flags & IFA_F_DEPRECATED))
change_needed = true;
- } else if (time_before(tstamp +
- ifa->ifa_preferred_lft * HZ,
+ } else if (time_before(tstamp + preferred_lft * HZ,
next)) {
- next = tstamp +
- ifa->ifa_preferred_lft * HZ;
+ next = tstamp + preferred_lft * HZ;
}
}
rcu_read_unlock();
@@ -818,7 +818,7 @@ static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft,
if (addrconf_finite_timeout(timeout)) {
if (timeout == 0)
ifa->ifa_flags |= IFA_F_DEPRECATED;
- ifa->ifa_preferred_lft = timeout;
+ WRITE_ONCE(ifa->ifa_preferred_lft, timeout);
}
WRITE_ONCE(ifa->ifa_tstamp, jiffies);
if (!ifa->ifa_cstamp)
@@ -1698,7 +1698,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
tstamp = READ_ONCE(ifa->ifa_tstamp);
if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {
- preferred = ifa->ifa_preferred_lft;
+ preferred = READ_ONCE(ifa->ifa_preferred_lft);
valid = READ_ONCE(ifa->ifa_valid_lft);
if (preferred != INFINITY_LIFE_TIME) {
long tval = (jiffies - tstamp) / HZ;
--
2.44.0.278.ge034bb2e1d-goog
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