ipv6: convert fib6_ref to refcount_t

We suspect some issues involving fib6_ref 0 -> 1 transitions might
cause strange syzbot reports.

Lets convert fib6_ref to refcount_t to catch them earlier.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2019-04-22 18:35:03 -07:00 committed by David S. Miller
parent 5ea715289a
commit f05713e091
3 changed files with 8 additions and 8 deletions

View File

@ -146,7 +146,7 @@ struct fib6_info {
struct list_head fib6_siblings;
unsigned int fib6_nsiblings;
atomic_t fib6_ref;
refcount_t fib6_ref;
unsigned long expires;
struct dst_metrics *fib6_metrics;
#define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
@ -284,17 +284,17 @@ void fib6_info_destroy_rcu(struct rcu_head *head);
static inline void fib6_info_hold(struct fib6_info *f6i)
{
atomic_inc(&f6i->fib6_ref);
refcount_inc(&f6i->fib6_ref);
}
static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
{
return atomic_inc_not_zero(&f6i->fib6_ref);
return refcount_inc_not_zero(&f6i->fib6_ref);
}
static inline void fib6_info_release(struct fib6_info *f6i)
{
if (f6i && atomic_dec_and_test(&f6i->fib6_ref))
if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
}

View File

@ -162,7 +162,7 @@ struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
}
INIT_LIST_HEAD(&f6i->fib6_siblings);
atomic_set(&f6i->fib6_ref, 1);
refcount_set(&f6i->fib6_ref, 1);
return f6i;
}
@ -929,7 +929,7 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
{
struct fib6_table *table = rt->fib6_table;
if (atomic_read(&rt->fib6_ref) != 1) {
if (refcount_read(&rt->fib6_ref) != 1) {
/* This route is used as dummy address holder in some split
* nodes. It is not leaked, but it still holds other resources,
* which must be released in time. So, scan ascendant nodes
@ -2311,7 +2311,7 @@ static int ipv6_route_seq_show(struct seq_file *seq, void *v)
dev = rt->fib6_nh.fib_nh_dev;
seq_printf(seq, " %08x %08x %08x %08x %8s\n",
rt->fib6_metric, atomic_read(&rt->fib6_ref), 0,
rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
flags, dev ? dev->name : "");
iter->w.leaf = NULL;
return 0;

View File

@ -296,7 +296,7 @@ static const struct fib6_info fib6_null_entry_template = {
.fib6_flags = (RTF_REJECT | RTF_NONEXTHOP),
.fib6_protocol = RTPROT_KERNEL,
.fib6_metric = ~(u32)0,
.fib6_ref = ATOMIC_INIT(1),
.fib6_ref = REFCOUNT_INIT(1),
.fib6_type = RTN_UNREACHABLE,
.fib6_metrics = (struct dst_metrics *)&dst_default_metrics,
};