diff options
Diffstat (limited to 'net/netfilter/x_tables.c')
| -rw-r--r-- | net/netfilter/x_tables.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index c83a3b5e1c6c..a164e5123d59 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1153,6 +1153,7 @@ xt_replace_table(struct xt_table *table, int *error) { struct xt_table_info *private; + unsigned int cpu; int ret; ret = xt_jumpstack_alloc(newinfo); @@ -1182,14 +1183,28 @@ xt_replace_table(struct xt_table *table, smp_wmb(); table->private = newinfo; + /* make sure all cpus see new ->private value */ + smp_wmb(); + /* * Even though table entries have now been swapped, other CPU's - * may still be using the old entries. This is okay, because - * resynchronization happens because of the locking done - * during the get_counters() routine. + * may still be using the old entries... */ local_bh_enable(); + /* ... so wait for even xt_recseq on all cpus */ + for_each_possible_cpu(cpu) { + seqcount_t *s = &per_cpu(xt_recseq, cpu); + u32 seq = raw_read_seqcount(s); + + if (seq & 1) { + do { + cond_resched(); + cpu_relax(); + } while (seq == raw_read_seqcount(s)); + } + } + #ifdef CONFIG_AUDIT if (audit_enabled) { audit_log(current->audit_context, GFP_KERNEL, |