From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 29/32] netfilter: x_tables: remove XT_TABLE_INFO_SZ and a dereference. Date: Mon, 15 Jun 2015 23:26:26 +0200 Message-ID: <1434403589-24796-30-git-send-email-pablo@netfilter.org> References: <1434403589-24796-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: In-Reply-To: <1434403589-24796-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Eric Dumazet 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 Cc: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- 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