From: Eric Dumazet <edumazet@xxxxxxxxxx>
After Florian patches, there is no need for XT_TABLE_INFO_SZ anymore :
Only one copy of table is kept, instead of one copy per cpu.
We also can avoid a dereference if we put table data right after
xt_table_info. It reduces register pressure and helps compiler.
Then, we attempt a kmalloc() if total size is under order-3 allocation,
to reduce TLB pressure, as in many cases, rules fit in 32 KB.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/linux/netfilter/x_tables.h | 5 +----
net/ipv4/netfilter/arp_tables.c | 4 ++--
net/ipv4/netfilter/ip_tables.c | 4 ++--
net/ipv6/netfilter/ip6_tables.c | 4 ++--
net/netfilter/x_tables.c | 32 ++++++++++++--------------------
5 files changed, 19 insertions(+), 30 deletions(-)
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 9969d79..95693c4 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -225,12 +225,9 @@ struct xt_table_info {
unsigned int __percpu *stackptr;
void ***jumpstack;
- /* Note : this field MUST be the last one, see XT_TABLE_INFO_SZ */
- void *entries;
+ unsigned char entries[0] __aligned(8);
};
-#define XT_TABLE_INFO_SZ (offsetof(struct xt_table_info, entries) \
- + nr_cpu_ids * sizeof(char *))
int xt_register_target(struct xt_target *target);
void xt_unregister_target(struct xt_target *target);
int xt_register_targets(struct xt_target *target, unsigned int n);
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index d75c139..95c9b6e 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -256,7 +256,7 @@ unsigned int arpt_do_table(struct sk_buff *skb,
const struct arphdr *arp;
struct arpt_entry *e, *back;
const char *indev, *outdev;
- void *table_base;
+ const void *table_base;
const struct xt_table_info *private;
struct xt_action_param acpar;
unsigned int addend;
@@ -868,7 +868,7 @@ static int compat_table_info(const struct xt_table_info *info,
struct xt_table_info *newinfo)
{
struct arpt_entry *iter;
- void *loc_cpu_entry;
+ const void *loc_cpu_entry;
int ret;
if (!newinfo || !info)
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 6151500..6c72fbb 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -938,7 +938,7 @@ copy_entries_to_user(unsigned int total_size,
struct xt_counters *counters;
const struct xt_table_info *private = table->private;
int ret = 0;
- void *loc_cpu_entry;
+ const void *loc_cpu_entry;
counters = alloc_counters(table);
if (IS_ERR(counters))
@@ -1052,7 +1052,7 @@ static int compat_table_info(const struct xt_table_info *info,
struct xt_table_info *newinfo)
{
struct ipt_entry *iter;
- void *loc_cpu_entry;
+ const void *loc_cpu_entry;
int ret;
if (!newinfo || !info)
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 80a7f0d..3c35ced 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -951,7 +951,7 @@ copy_entries_to_user(unsigned int total_size,
struct xt_counters *counters;
const struct xt_table_info *private = table->private;
int ret = 0;
- void *loc_cpu_entry;
+ const void *loc_cpu_entry;
counters = alloc_counters(table);
if (IS_ERR(counters))
@@ -1065,7 +1065,7 @@ static int compat_table_info(const struct xt_table_info *info,
struct xt_table_info *newinfo)
{
struct ip6t_entry *iter;
- void *loc_cpu_entry;
+ const void *loc_cpu_entry;
int ret;
if (!newinfo || !info)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 6062ce3..d324fe7 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -658,29 +658,23 @@ EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
struct xt_table_info *xt_alloc_table_info(unsigned int size)
{
- struct xt_table_info *newinfo;
+ struct xt_table_info *info = NULL;
+ size_t sz = sizeof(*info) + size;
/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
return NULL;
- newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
- if (!newinfo)
- return NULL;
-
- newinfo->size = size;
-
- if (size <= PAGE_SIZE)
- newinfo->entries = kmalloc(size, GFP_KERNEL);
- else
- newinfo->entries = vmalloc(size);
-
- if (newinfo->entries == NULL) {
- xt_free_table_info(newinfo);
- return NULL;
+ if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
+ info = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+ if (!info) {
+ info = vmalloc(sz);
+ if (!info)
+ return NULL;
}
-
- return newinfo;
+ memset(info, 0, sizeof(*info));
+ info->size = size;
+ return info;
}
EXPORT_SYMBOL(xt_alloc_table_info);
@@ -688,8 +682,6 @@ void xt_free_table_info(struct xt_table_info *info)
{
int cpu;
- kvfree(info->entries);
-
if (info->jumpstack != NULL) {
for_each_possible_cpu(cpu)
kvfree(info->jumpstack[cpu]);
@@ -698,7 +690,7 @@ void xt_free_table_info(struct xt_table_info *info)
free_percpu(info->stackptr);
- kfree(info);
+ kvfree(info);
}
EXPORT_SYMBOL(xt_free_table_info);
--
1.7.10.4
--
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