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* [PATCH 12/12] netfilter: xt_connmark: do not cast xt_connmark_tginfo1 to xt_connmark_tginfo2
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

These structures have different layout, fill xt_connmark_tginfo2 with
old fields in xt_connmark_tginfo1. Based on patch from Jack Ma.

Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_connmark.c | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index 4b424e6caf3e..94df000abb92 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -36,9 +36,7 @@ MODULE_ALIAS("ipt_connmark");
 MODULE_ALIAS("ip6t_connmark");
 
 static unsigned int
-connmark_tg_shift(struct sk_buff *skb,
-		const struct xt_connmark_tginfo1 *info,
-		u8 shift_bits, u8 shift_dir)
+connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
 {
 	enum ip_conntrack_info ctinfo;
 	u_int32_t new_targetmark;
@@ -52,10 +50,11 @@ connmark_tg_shift(struct sk_buff *skb,
 	switch (info->mode) {
 	case XT_CONNMARK_SET:
 		newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
-		if (shift_dir == D_SHIFT_RIGHT)
-			newmark >>= shift_bits;
+		if (info->shift_dir == D_SHIFT_RIGHT)
+			newmark >>= info->shift_bits;
 		else
-			newmark <<= shift_bits;
+			newmark <<= info->shift_bits;
+
 		if (ct->mark != newmark) {
 			ct->mark = newmark;
 			nf_conntrack_event_cache(IPCT_MARK, ct);
@@ -63,10 +62,11 @@ connmark_tg_shift(struct sk_buff *skb,
 		break;
 	case XT_CONNMARK_SAVE:
 		new_targetmark = (skb->mark & info->nfmask);
-		if (shift_dir == D_SHIFT_RIGHT)
-			new_targetmark >>= shift_bits;
+		if (info->shift_dir == D_SHIFT_RIGHT)
+			new_targetmark >>= info->shift_bits;
 		else
-			new_targetmark <<= shift_bits;
+			new_targetmark <<= info->shift_bits;
+
 		newmark = (ct->mark & ~info->ctmask) ^
 			  new_targetmark;
 		if (ct->mark != newmark) {
@@ -76,10 +76,11 @@ connmark_tg_shift(struct sk_buff *skb,
 		break;
 	case XT_CONNMARK_RESTORE:
 		new_targetmark = (ct->mark & info->ctmask);
-		if (shift_dir == D_SHIFT_RIGHT)
-			new_targetmark >>= shift_bits;
+		if (info->shift_dir == D_SHIFT_RIGHT)
+			new_targetmark >>= info->shift_bits;
 		else
-			new_targetmark <<= shift_bits;
+			new_targetmark <<= info->shift_bits;
+
 		newmark = (skb->mark & ~info->nfmask) ^
 			  new_targetmark;
 		skb->mark = newmark;
@@ -92,8 +93,14 @@ static unsigned int
 connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	const struct xt_connmark_tginfo1 *info = par->targinfo;
-
-	return connmark_tg_shift(skb, info, 0, 0);
+	const struct xt_connmark_tginfo2 info2 = {
+		.ctmark	= info->ctmark,
+		.ctmask	= info->ctmask,
+		.nfmask	= info->nfmask,
+		.mode	= info->mode,
+	};
+
+	return connmark_tg_shift(skb, &info2);
 }
 
 static unsigned int
@@ -101,8 +108,7 @@ connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	const struct xt_connmark_tginfo2 *info = par->targinfo;
 
-	return connmark_tg_shift(skb, (const struct xt_connmark_tginfo1 *)info,
-				 info->shift_bits, info->shift_dir);
+	return connmark_tg_shift(skb, info);
 }
 
 static int connmark_tg_check(const struct xt_tgchk_param *par)
-- 
2.11.0

^ permalink raw reply related

* [PATCH 11/12] netfilter: nf_tables: fix out-of-bounds in nft_chain_commit_update
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Taehee Yoo <ap420073@gmail.com>

When chain name is changed, nft_chain_commit_update is called.
In the nft_chain_commit_update, trans->ctx.chain->name has old chain name
and nft_trans_chain_name(trans) has new chain name.
If new chain name is longer than old chain name, KASAN warns
slab-out-of-bounds.

[  175.015012] BUG: KASAN: slab-out-of-bounds in strcpy+0x9e/0xb0
[  175.022735] Write of size 1 at addr ffff880114e022da by task iptables-compat/1458

[  175.031353] CPU: 0 PID: 1458 Comm: iptables-compat Not tainted 4.16.0-rc7+ #146
[  175.031353] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[  175.031353] Call Trace:
[  175.031353]  dump_stack+0x68/0xa0
[  175.031353]  print_address_description+0xd0/0x260
[  175.031353]  ? strcpy+0x9e/0xb0
[  175.031353]  kasan_report+0x234/0x350
[  175.031353]  __asan_report_store1_noabort+0x1c/0x20
[  175.031353]  strcpy+0x9e/0xb0
[  175.031353]  nf_tables_commit+0x1ccc/0x2990
[  175.031353]  nfnetlink_rcv+0x141e/0x16c0
[  175.031353]  ? nfnetlink_net_init+0x150/0x150
[  175.031353]  ? lock_acquire+0x370/0x370
[  175.031353]  ? lock_acquire+0x370/0x370
[  175.031353]  netlink_unicast+0x444/0x640
[  175.031353]  ? netlink_attachskb+0x700/0x700
[  175.031353]  ? _copy_from_iter_full+0x180/0x740
[  175.031353]  ? kasan_check_write+0x14/0x20
[  175.031353]  ? _copy_from_user+0x9b/0xd0
[  175.031353]  netlink_sendmsg+0x845/0xc70
[ ... ]

Steps to reproduce:
   iptables-compat -N 1
   iptables-compat -E 1 aaaaaaaaa

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 102ad873acb4..04d4e3772584 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5745,7 +5745,7 @@ static void nft_chain_commit_update(struct nft_trans *trans)
 	struct nft_base_chain *basechain;
 
 	if (nft_trans_chain_name(trans))
-		strcpy(trans->ctx.chain->name, nft_trans_chain_name(trans));
+		swap(trans->ctx.chain->name, nft_trans_chain_name(trans));
 
 	if (!nft_is_base_chain(trans->ctx.chain))
 		return;
-- 
2.11.0

^ permalink raw reply related

* [PATCH 09/12] netfilter: conntrack: include kmemleak.h for kmemleak_not_leak()
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Stephen Rothwell <sfr@canb.auug.org.au>

After merging the netfilter tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

net/netfilter/nf_conntrack_extend.c: In function 'nf_ct_ext_add':
net/netfilter/nf_conntrack_extend.c:74:2: error: implicit declaration of function 'kmemleak_not_leak' [-Werror=implicit-function-declaration]
  kmemleak_not_leak(old);
  ^~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

Fixes: 114aa35d06d4 ("netfilter: conntrack: silent a memory leak warning")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_extend.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index bd71a828ebde..277bbfe26478 100644
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -9,6 +9,7 @@
  *      2 of the License, or (at your option) any later version.
  */
 #include <linux/kernel.h>
+#include <linux/kmemleak.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/rcupdate.h>
-- 
2.11.0

^ permalink raw reply related

* [PATCH 10/12] netfilter: nf_tables: NAT chain and extensions require NF_TABLES
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

Move these options inside the scope of the 'if' NF_TABLES and
NF_TABLES_IPV6 dependencies. This patch fixes:

   net/ipv6/netfilter/nft_chain_nat_ipv6.o: In function `nft_nat_do_chain':
>> net/ipv6/netfilter/nft_chain_nat_ipv6.c:37: undefined reference to `nft_do_chain'
   net/ipv6/netfilter/nft_chain_nat_ipv6.o: In function `nft_chain_nat_ipv6_exit':
>> net/ipv6/netfilter/nft_chain_nat_ipv6.c:94: undefined reference to `nft_unregister_chain_type'
   net/ipv6/netfilter/nft_chain_nat_ipv6.o: In function `nft_chain_nat_ipv6_init':
>> net/ipv6/netfilter/nft_chain_nat_ipv6.c:87: undefined reference to `nft_register_chain_type'

that happens with:

CONFIG_NF_TABLES=m
CONFIG_NFT_CHAIN_NAT_IPV6=y

Fixes: 02c7b25e5f54 ("netfilter: nf_tables: build-in filter chain type")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv6/netfilter/Kconfig | 55 +++++++++++++++++++++++-----------------------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index ccbfa83e4bb0..ce77bcc2490c 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -48,6 +48,34 @@ config NFT_CHAIN_ROUTE_IPV6
 	  fields such as the source, destination, flowlabel, hop-limit and
 	  the packet mark.
 
+if NF_NAT_IPV6
+
+config NFT_CHAIN_NAT_IPV6
+	tristate "IPv6 nf_tables nat chain support"
+	help
+	  This option enables the "nat" chain for IPv6 in nf_tables. This
+	  chain type is used to perform Network Address Translation (NAT)
+	  packet transformations such as the source, destination address and
+	  source and destination ports.
+
+config NFT_MASQ_IPV6
+	tristate "IPv6 masquerade support for nf_tables"
+	depends on NFT_MASQ
+	select NF_NAT_MASQUERADE_IPV6
+	help
+	  This is the expression that provides IPv4 masquerading support for
+	  nf_tables.
+
+config NFT_REDIR_IPV6
+	tristate "IPv6 redirect support for nf_tables"
+	depends on NFT_REDIR
+	select NF_NAT_REDIRECT
+	help
+	  This is the expression that provides IPv4 redirect support for
+	  nf_tables.
+
+endif # NF_NAT_IPV6
+
 config NFT_REJECT_IPV6
 	select NF_REJECT_IPV6
 	default NFT_REJECT
@@ -107,39 +135,12 @@ config NF_NAT_IPV6
 
 if NF_NAT_IPV6
 
-config NFT_CHAIN_NAT_IPV6
-	depends on NF_TABLES_IPV6
-	tristate "IPv6 nf_tables nat chain support"
-	help
-	  This option enables the "nat" chain for IPv6 in nf_tables. This
-	  chain type is used to perform Network Address Translation (NAT)
-	  packet transformations such as the source, destination address and
-	  source and destination ports.
-
 config NF_NAT_MASQUERADE_IPV6
 	tristate "IPv6 masquerade support"
 	help
 	  This is the kernel functionality to provide NAT in the masquerade
 	  flavour (automatic source address selection) for IPv6.
 
-config NFT_MASQ_IPV6
-	tristate "IPv6 masquerade support for nf_tables"
-	depends on NF_TABLES_IPV6
-	depends on NFT_MASQ
-	select NF_NAT_MASQUERADE_IPV6
-	help
-	  This is the expression that provides IPv4 masquerading support for
-	  nf_tables.
-
-config NFT_REDIR_IPV6
-	tristate "IPv6 redirect support for nf_tables"
-	depends on NF_TABLES_IPV6
-	depends on NFT_REDIR
-	select NF_NAT_REDIRECT
-	help
-	  This is the expression that provides IPv4 redirect support for
-	  nf_tables.
-
 endif # NF_NAT_IPV6
 
 config IP6_NF_IPTABLES
-- 
2.11.0

^ permalink raw reply related

* [PATCH 08/12] netfilter: nf_tables: free set name in error path
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Florian Westphal <fw@strlen.de>

set->name must be free'd here in case ops->init fails.

Fixes: 387454901bd6 ("netfilter: nf_tables: Allow set names of up to 255 chars")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index b1984f8f7253..102ad873acb4 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3212,18 +3212,20 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 
 	err = ops->init(set, &desc, nla);
 	if (err < 0)
-		goto err2;
+		goto err3;
 
 	err = nft_trans_set_add(&ctx, NFT_MSG_NEWSET, set);
 	if (err < 0)
-		goto err3;
+		goto err4;
 
 	list_add_tail_rcu(&set->list, &table->sets);
 	table->use++;
 	return 0;
 
-err3:
+err4:
 	ops->destroy(set);
+err3:
+	kfree(set->name);
 err2:
 	kvfree(set);
 err1:
-- 
2.11.0

^ permalink raw reply related

* [PATCH 06/12] netfilter: fix CONFIG_NF_REJECT_IPV6=m link error
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Arnd Bergmann <arnd@arndb.de>

We get a new link error with CONFIG_NFT_REJECT_INET=y and CONFIG_NF_REJECT_IPV6=m
after larger parts of the nftables modules are linked together:

net/netfilter/nft_reject_inet.o: In function `nft_reject_inet_eval':
nft_reject_inet.c:(.text+0x17c): undefined reference to `nf_send_unreach6'
nft_reject_inet.c:(.text+0x190): undefined reference to `nf_send_reset6'

The problem is that with NF_TABLES_INET set, we implicitly try to use
the ipv6 version as well for NFT_REJECT, but when CONFIG_IPV6 is set to
a loadable module, it's impossible to reach that.

The best workaround I found is to express the above as a Kconfig
dependency, forcing NFT_REJECT itself to be 'm' in that particular
configuration.

Fixes: 02c7b25e5f54 ("netfilter: nf_tables: build-in filter chain type")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 704b3832dbad..44d8a55e9721 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -594,6 +594,7 @@ config NFT_QUOTA
 config NFT_REJECT
 	default m if NETFILTER_ADVANCED=n
 	tristate "Netfilter nf_tables reject support"
+	depends on !NF_TABLES_INET || (IPV6!=m || m)
 	help
 	  This option adds the "reject" expression that you can use to
 	  explicitly deny and notify via TCP reset/ICMP informational errors
-- 
2.11.0

^ permalink raw reply related

* [PATCH 05/12] netfilter: conntrack: silent a memory leak warning
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Cong Wang <xiyou.wangcong@gmail.com>

The following memory leak is false postive:

unreferenced object 0xffff8f37f156fb38 (size 128):
  comm "softirq", pid 0, jiffies 4294899665 (age 11.292s)
  hex dump (first 32 bytes):
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    00 00 00 00 30 00 20 00 48 6b 6b 6b 6b 6b 6b 6b  ....0. .Hkkkkkkk
  backtrace:
    [<000000004fda266a>] __kmalloc_track_caller+0x10d/0x141
    [<000000007b0a7e3c>] __krealloc+0x45/0x62
    [<00000000d08e0bfb>] nf_ct_ext_add+0xdc/0x133
    [<0000000099b47fd8>] init_conntrack+0x1b1/0x392
    [<0000000086dc36ec>] nf_conntrack_in+0x1ee/0x34b
    [<00000000940592de>] nf_hook_slow+0x36/0x95
    [<00000000d1bd4da7>] nf_hook.constprop.43+0x1c3/0x1dd
    [<00000000c3673266>] __ip_local_out+0xae/0xb4
    [<000000003e4192a6>] ip_local_out+0x17/0x33
    [<00000000b64356de>] igmp_ifc_timer_expire+0x23e/0x26f
    [<000000006a8f3032>] call_timer_fn+0x14c/0x2a5
    [<00000000650c1725>] __run_timers.part.34+0x150/0x182
    [<0000000090e6946e>] run_timer_softirq+0x2a/0x4c
    [<000000004d1e7293>] __do_softirq+0x1d1/0x3c2
    [<000000004643557d>] irq_exit+0x53/0xa2
    [<0000000029ddee8f>] smp_apic_timer_interrupt+0x22a/0x235

because __krealloc() is not supposed to release the old
memory and it is released later via kfree_rcu(). Since this is
the only external user of __krealloc(), just mark it as not leak
here.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_extend.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index 9fe0ddc333fb..bd71a828ebde 100644
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -71,6 +71,7 @@ void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 	rcu_read_unlock();
 
 	alloc = max(newlen, NF_CT_EXT_PREALLOC);
+	kmemleak_not_leak(old);
 	new = __krealloc(old, alloc, gfp);
 	if (!new)
 		return NULL;
-- 
2.11.0

^ permalink raw reply related

* [PATCH 07/12] netfilter: nf_tables: can't fail after linking rule into active rule list
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Florian Westphal <fw@strlen.de>

rules in nftables a free'd using kfree, but protected by rcu, i.e. we
must wait for a grace period to elapse.

Normal removal patch does this, but nf_tables_newrule() doesn't obey
this rule during error handling.

It calls nft_trans_rule_add() *after* linking rule, and, if that
fails to allocate memory, it unlinks the rule and then kfree() it --
this is unsafe.

Switch order -- first add rule to transaction list, THEN link it
to public list.

Note: nft_trans_rule_add() uses GFP_KERNEL; it will not fail so this
is not a problem in practice (spotted only during code review).

Fixes: 0628b123c96d12 ("netfilter: nfnetlink: add batch support and use it from nf_tables")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 59 +++++++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 9134cc429ad4..b1984f8f7253 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2361,41 +2361,46 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
 	}
 
 	if (nlh->nlmsg_flags & NLM_F_REPLACE) {
-		if (nft_is_active_next(net, old_rule)) {
-			trans = nft_trans_rule_add(&ctx, NFT_MSG_DELRULE,
-						   old_rule);
-			if (trans == NULL) {
-				err = -ENOMEM;
-				goto err2;
-			}
-			nft_deactivate_next(net, old_rule);
-			chain->use--;
-			list_add_tail_rcu(&rule->list, &old_rule->list);
-		} else {
+		if (!nft_is_active_next(net, old_rule)) {
 			err = -ENOENT;
 			goto err2;
 		}
-	} else if (nlh->nlmsg_flags & NLM_F_APPEND)
-		if (old_rule)
-			list_add_rcu(&rule->list, &old_rule->list);
-		else
-			list_add_tail_rcu(&rule->list, &chain->rules);
-	else {
-		if (old_rule)
-			list_add_tail_rcu(&rule->list, &old_rule->list);
-		else
-			list_add_rcu(&rule->list, &chain->rules);
-	}
+		trans = nft_trans_rule_add(&ctx, NFT_MSG_DELRULE,
+					   old_rule);
+		if (trans == NULL) {
+			err = -ENOMEM;
+			goto err2;
+		}
+		nft_deactivate_next(net, old_rule);
+		chain->use--;
 
-	if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) {
-		err = -ENOMEM;
-		goto err3;
+		if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) {
+			err = -ENOMEM;
+			goto err2;
+		}
+
+		list_add_tail_rcu(&rule->list, &old_rule->list);
+	} else {
+		if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) {
+			err = -ENOMEM;
+			goto err2;
+		}
+
+		if (nlh->nlmsg_flags & NLM_F_APPEND) {
+			if (old_rule)
+				list_add_rcu(&rule->list, &old_rule->list);
+			else
+				list_add_tail_rcu(&rule->list, &chain->rules);
+		 } else {
+			if (old_rule)
+				list_add_tail_rcu(&rule->list, &old_rule->list);
+			else
+				list_add_rcu(&rule->list, &chain->rules);
+		}
 	}
 	chain->use++;
 	return 0;
 
-err3:
-	list_del_rcu(&rule->list);
 err2:
 	nf_tables_rule_destroy(&ctx, rule);
 err1:
-- 
2.11.0

^ permalink raw reply related

* [PATCH 04/12] netfilter: xt_connmark: Add bit mapping for bit-shift operation.
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Jack Ma <jack.ma@alliedtelesis.co.nz>

With the addition of bit-shift operations, we are able to shift
ct/skbmark based on user requirements. However, this change might also
cause the most left/right hand- side mark to be accidentially lost
during shift operations.

This patch adds the ability to 'grep' certain bits based on ctmask or
nfmask out of the original mark. Then, apply shift operations to achieve
a new mapping between ctmark and skb->mark.

For example: If someone would like save the fourth F bits of ctmark
0xFFF(F)000F into the seventh hexadecimal (0) skb->mark 0xABC000(0)E.

	new_targetmark = (ctmark & ctmask) >> 12;
	(new) skb->mark = (skb->mark &~nfmask) ^
        	           new_targetmark;

This will preserve the other bits that are not related to this
operation.

Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.")
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jack Ma <jack.ma@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_connmark.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index 773da82190dc..4b424e6caf3e 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -41,6 +41,7 @@ connmark_tg_shift(struct sk_buff *skb,
 		u8 shift_bits, u8 shift_dir)
 {
 	enum ip_conntrack_info ctinfo;
+	u_int32_t new_targetmark;
 	struct nf_conn *ct;
 	u_int32_t newmark;
 
@@ -61,24 +62,26 @@ connmark_tg_shift(struct sk_buff *skb,
 		}
 		break;
 	case XT_CONNMARK_SAVE:
-		newmark = (ct->mark & ~info->ctmask) ^
-			  (skb->mark & info->nfmask);
+		new_targetmark = (skb->mark & info->nfmask);
 		if (shift_dir == D_SHIFT_RIGHT)
-			newmark >>= shift_bits;
+			new_targetmark >>= shift_bits;
 		else
-			newmark <<= shift_bits;
+			new_targetmark <<= shift_bits;
+		newmark = (ct->mark & ~info->ctmask) ^
+			  new_targetmark;
 		if (ct->mark != newmark) {
 			ct->mark = newmark;
 			nf_conntrack_event_cache(IPCT_MARK, ct);
 		}
 		break;
 	case XT_CONNMARK_RESTORE:
-		newmark = (skb->mark & ~info->nfmask) ^
-			  (ct->mark & info->ctmask);
+		new_targetmark = (ct->mark & info->ctmask);
 		if (shift_dir == D_SHIFT_RIGHT)
-			newmark >>= shift_bits;
+			new_targetmark >>= shift_bits;
 		else
-			newmark <<= shift_bits;
+			new_targetmark <<= shift_bits;
+		newmark = (skb->mark & ~info->nfmask) ^
+			  new_targetmark;
 		skb->mark = newmark;
 		break;
 	}
-- 
2.11.0

^ permalink raw reply related

* [PATCH 02/12] ipvs: fix rtnl_lock lockups caused by start_sync_thread
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Julian Anastasov <ja@ssi.bg>

syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]

We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:

1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).

2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.

Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.

Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.

[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(rtnl_mutex);
   lock(rtnl_mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

2 locks held by syzkaller688027/4497:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388

stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
  check_deadlock kernel/locking/lockdep.c:1805 [inline]
  validate_chain kernel/locking/lockdep.c:2401 [inline]
  __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
  lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
  __mutex_lock_common kernel/locking/mutex.c:756 [inline]
  __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
  mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
  rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
  ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
  inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
  sock_release+0x8d/0x1e0 net/socket.c:595
  start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
  do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
  udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
  SYSC_setsockopt net/socket.c:1849 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1828
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60

[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
       Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D23688 25421   4408 0x00000004
Call Trace:
  context_switch kernel/sched/core.c:2862 [inline]
  __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
  schedule+0xf5/0x430 kernel/sched/core.c:3499
  schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
  do_wait_for_common kernel/sched/completion.c:86 [inline]
  __wait_for_common kernel/sched/completion.c:107 [inline]
  wait_for_common kernel/sched/completion.c:118 [inline]
  wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
  kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
  stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
  do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
  sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
  SYSC_setsockopt net/socket.c:1850 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1829
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001

Showing all locks held in the system:
2 locks held by khungtaskd/868:
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
  #1:  (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
  #0:  (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
  #2:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
  #0:  (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/ipvs/ip_vs_ctl.c  |   8 ---
 net/netfilter/ipvs/ip_vs_sync.c | 155 +++++++++++++++++++++-------------------
 2 files changed, 80 insertions(+), 83 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 5ebde4b15810..f36098887ad0 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2384,11 +2384,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
 			strlcpy(cfg.mcast_ifn, dm->mcast_ifn,
 				sizeof(cfg.mcast_ifn));
 			cfg.syncid = dm->syncid;
-			rtnl_lock();
-			mutex_lock(&ipvs->sync_mutex);
 			ret = start_sync_thread(ipvs, &cfg, dm->state);
-			mutex_unlock(&ipvs->sync_mutex);
-			rtnl_unlock();
 		} else {
 			mutex_lock(&ipvs->sync_mutex);
 			ret = stop_sync_thread(ipvs, dm->state);
@@ -3481,12 +3477,8 @@ static int ip_vs_genl_new_daemon(struct netns_ipvs *ipvs, struct nlattr **attrs)
 	if (ipvs->mixed_address_family_dests > 0)
 		return -EINVAL;
 
-	rtnl_lock();
-	mutex_lock(&ipvs->sync_mutex);
 	ret = start_sync_thread(ipvs, &c,
 				nla_get_u32(attrs[IPVS_DAEMON_ATTR_STATE]));
-	mutex_unlock(&ipvs->sync_mutex);
-	rtnl_unlock();
 	return ret;
 }
 
diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index fbaf3bd05b2e..001501e25625 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -49,6 +49,7 @@
 #include <linux/kthread.h>
 #include <linux/wait.h>
 #include <linux/kernel.h>
+#include <linux/sched/signal.h>
 
 #include <asm/unaligned.h>		/* Used for ntoh_seq and hton_seq */
 
@@ -1360,15 +1361,9 @@ static void set_mcast_pmtudisc(struct sock *sk, int val)
 /*
  *      Specifiy default interface for outgoing multicasts
  */
-static int set_mcast_if(struct sock *sk, char *ifname)
+static int set_mcast_if(struct sock *sk, struct net_device *dev)
 {
-	struct net_device *dev;
 	struct inet_sock *inet = inet_sk(sk);
-	struct net *net = sock_net(sk);
-
-	dev = __dev_get_by_name(net, ifname);
-	if (!dev)
-		return -ENODEV;
 
 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
 		return -EINVAL;
@@ -1396,19 +1391,14 @@ static int set_mcast_if(struct sock *sk, char *ifname)
  *      in the in_addr structure passed in as a parameter.
  */
 static int
-join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
+join_mcast_group(struct sock *sk, struct in_addr *addr, struct net_device *dev)
 {
-	struct net *net = sock_net(sk);
 	struct ip_mreqn mreq;
-	struct net_device *dev;
 	int ret;
 
 	memset(&mreq, 0, sizeof(mreq));
 	memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
 
-	dev = __dev_get_by_name(net, ifname);
-	if (!dev)
-		return -ENODEV;
 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
 		return -EINVAL;
 
@@ -1423,15 +1413,10 @@ join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
 
 #ifdef CONFIG_IP_VS_IPV6
 static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
-			     char *ifname)
+			     struct net_device *dev)
 {
-	struct net *net = sock_net(sk);
-	struct net_device *dev;
 	int ret;
 
-	dev = __dev_get_by_name(net, ifname);
-	if (!dev)
-		return -ENODEV;
 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
 		return -EINVAL;
 
@@ -1443,24 +1428,18 @@ static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
 }
 #endif
 
-static int bind_mcastif_addr(struct socket *sock, char *ifname)
+static int bind_mcastif_addr(struct socket *sock, struct net_device *dev)
 {
-	struct net *net = sock_net(sock->sk);
-	struct net_device *dev;
 	__be32 addr;
 	struct sockaddr_in sin;
 
-	dev = __dev_get_by_name(net, ifname);
-	if (!dev)
-		return -ENODEV;
-
 	addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
 	if (!addr)
 		pr_err("You probably need to specify IP address on "
 		       "multicast interface.\n");
 
 	IP_VS_DBG(7, "binding socket with (%s) %pI4\n",
-		  ifname, &addr);
+		  dev->name, &addr);
 
 	/* Now bind the socket with the address of multicast interface */
 	sin.sin_family	     = AF_INET;
@@ -1493,7 +1472,8 @@ static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
 /*
  *      Set up sending multicast socket over UDP
  */
-static struct socket *make_send_sock(struct netns_ipvs *ipvs, int id)
+static int make_send_sock(struct netns_ipvs *ipvs, int id,
+			  struct net_device *dev, struct socket **sock_ret)
 {
 	/* multicast addr */
 	union ipvs_sockaddr mcast_addr;
@@ -1505,9 +1485,10 @@ static struct socket *make_send_sock(struct netns_ipvs *ipvs, int id)
 				  IPPROTO_UDP, &sock);
 	if (result < 0) {
 		pr_err("Error during creation of socket; terminating\n");
-		return ERR_PTR(result);
+		goto error;
 	}
-	result = set_mcast_if(sock->sk, ipvs->mcfg.mcast_ifn);
+	*sock_ret = sock;
+	result = set_mcast_if(sock->sk, dev);
 	if (result < 0) {
 		pr_err("Error setting outbound mcast interface\n");
 		goto error;
@@ -1522,7 +1503,7 @@ static struct socket *make_send_sock(struct netns_ipvs *ipvs, int id)
 		set_sock_size(sock->sk, 1, result);
 
 	if (AF_INET == ipvs->mcfg.mcast_af)
-		result = bind_mcastif_addr(sock, ipvs->mcfg.mcast_ifn);
+		result = bind_mcastif_addr(sock, dev);
 	else
 		result = 0;
 	if (result < 0) {
@@ -1538,19 +1519,18 @@ static struct socket *make_send_sock(struct netns_ipvs *ipvs, int id)
 		goto error;
 	}
 
-	return sock;
+	return 0;
 
 error:
-	sock_release(sock);
-	return ERR_PTR(result);
+	return result;
 }
 
 
 /*
  *      Set up receiving multicast socket over UDP
  */
-static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id,
-					int ifindex)
+static int make_receive_sock(struct netns_ipvs *ipvs, int id,
+			     struct net_device *dev, struct socket **sock_ret)
 {
 	/* multicast addr */
 	union ipvs_sockaddr mcast_addr;
@@ -1562,8 +1542,9 @@ static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id,
 				  IPPROTO_UDP, &sock);
 	if (result < 0) {
 		pr_err("Error during creation of socket; terminating\n");
-		return ERR_PTR(result);
+		goto error;
 	}
+	*sock_ret = sock;
 	/* it is equivalent to the REUSEADDR option in user-space */
 	sock->sk->sk_reuse = SK_CAN_REUSE;
 	result = sysctl_sync_sock_size(ipvs);
@@ -1571,7 +1552,7 @@ static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id,
 		set_sock_size(sock->sk, 0, result);
 
 	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
-	sock->sk->sk_bound_dev_if = ifindex;
+	sock->sk->sk_bound_dev_if = dev->ifindex;
 	result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen);
 	if (result < 0) {
 		pr_err("Error binding to the multicast addr\n");
@@ -1582,21 +1563,20 @@ static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id,
 #ifdef CONFIG_IP_VS_IPV6
 	if (ipvs->bcfg.mcast_af == AF_INET6)
 		result = join_mcast_group6(sock->sk, &mcast_addr.in6.sin6_addr,
-					   ipvs->bcfg.mcast_ifn);
+					   dev);
 	else
 #endif
 		result = join_mcast_group(sock->sk, &mcast_addr.in.sin_addr,
-					  ipvs->bcfg.mcast_ifn);
+					  dev);
 	if (result < 0) {
 		pr_err("Error joining to the multicast group\n");
 		goto error;
 	}
 
-	return sock;
+	return 0;
 
 error:
-	sock_release(sock);
-	return ERR_PTR(result);
+	return result;
 }
 
 
@@ -1778,13 +1758,12 @@ static int sync_thread_backup(void *data)
 int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 		      int state)
 {
-	struct ip_vs_sync_thread_data *tinfo;
+	struct ip_vs_sync_thread_data *tinfo = NULL;
 	struct task_struct **array = NULL, *task;
-	struct socket *sock;
 	struct net_device *dev;
 	char *name;
 	int (*threadfn)(void *data);
-	int id, count, hlen;
+	int id = 0, count, hlen;
 	int result = -ENOMEM;
 	u16 mtu, min_mtu;
 
@@ -1792,6 +1771,18 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %zd bytes\n",
 		  sizeof(struct ip_vs_sync_conn_v0));
 
+	/* Do not hold one mutex and then to block on another */
+	for (;;) {
+		rtnl_lock();
+		if (mutex_trylock(&ipvs->sync_mutex))
+			break;
+		rtnl_unlock();
+		mutex_lock(&ipvs->sync_mutex);
+		if (rtnl_trylock())
+			break;
+		mutex_unlock(&ipvs->sync_mutex);
+	}
+
 	if (!ipvs->sync_state) {
 		count = clamp(sysctl_sync_ports(ipvs), 1, IPVS_SYNC_PORTS_MAX);
 		ipvs->threads_mask = count - 1;
@@ -1810,7 +1801,8 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	dev = __dev_get_by_name(ipvs->net, c->mcast_ifn);
 	if (!dev) {
 		pr_err("Unknown mcast interface: %s\n", c->mcast_ifn);
-		return -ENODEV;
+		result = -ENODEV;
+		goto out_early;
 	}
 	hlen = (AF_INET6 == c->mcast_af) ?
 	       sizeof(struct ipv6hdr) + sizeof(struct udphdr) :
@@ -1827,26 +1819,30 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 		c->sync_maxlen = mtu - hlen;
 
 	if (state == IP_VS_STATE_MASTER) {
+		result = -EEXIST;
 		if (ipvs->ms)
-			return -EEXIST;
+			goto out_early;
 
 		ipvs->mcfg = *c;
 		name = "ipvs-m:%d:%d";
 		threadfn = sync_thread_master;
 	} else if (state == IP_VS_STATE_BACKUP) {
+		result = -EEXIST;
 		if (ipvs->backup_threads)
-			return -EEXIST;
+			goto out_early;
 
 		ipvs->bcfg = *c;
 		name = "ipvs-b:%d:%d";
 		threadfn = sync_thread_backup;
 	} else {
-		return -EINVAL;
+		result = -EINVAL;
+		goto out_early;
 	}
 
 	if (state == IP_VS_STATE_MASTER) {
 		struct ipvs_master_sync_state *ms;
 
+		result = -ENOMEM;
 		ipvs->ms = kcalloc(count, sizeof(ipvs->ms[0]), GFP_KERNEL);
 		if (!ipvs->ms)
 			goto out;
@@ -1862,39 +1858,38 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	} else {
 		array = kcalloc(count, sizeof(struct task_struct *),
 				GFP_KERNEL);
+		result = -ENOMEM;
 		if (!array)
 			goto out;
 	}
 
-	tinfo = NULL;
 	for (id = 0; id < count; id++) {
-		if (state == IP_VS_STATE_MASTER)
-			sock = make_send_sock(ipvs, id);
-		else
-			sock = make_receive_sock(ipvs, id, dev->ifindex);
-		if (IS_ERR(sock)) {
-			result = PTR_ERR(sock);
-			goto outtinfo;
-		}
+		result = -ENOMEM;
 		tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL);
 		if (!tinfo)
-			goto outsocket;
+			goto out;
 		tinfo->ipvs = ipvs;
-		tinfo->sock = sock;
+		tinfo->sock = NULL;
 		if (state == IP_VS_STATE_BACKUP) {
 			tinfo->buf = kmalloc(ipvs->bcfg.sync_maxlen,
 					     GFP_KERNEL);
 			if (!tinfo->buf)
-				goto outtinfo;
+				goto out;
 		} else {
 			tinfo->buf = NULL;
 		}
 		tinfo->id = id;
+		if (state == IP_VS_STATE_MASTER)
+			result = make_send_sock(ipvs, id, dev, &tinfo->sock);
+		else
+			result = make_receive_sock(ipvs, id, dev, &tinfo->sock);
+		if (result < 0)
+			goto out;
 
 		task = kthread_run(threadfn, tinfo, name, ipvs->gen, id);
 		if (IS_ERR(task)) {
 			result = PTR_ERR(task);
-			goto outtinfo;
+			goto out;
 		}
 		tinfo = NULL;
 		if (state == IP_VS_STATE_MASTER)
@@ -1911,20 +1906,20 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	ipvs->sync_state |= state;
 	spin_unlock_bh(&ipvs->sync_buff_lock);
 
+	mutex_unlock(&ipvs->sync_mutex);
+	rtnl_unlock();
+
 	/* increase the module use count */
 	ip_vs_use_count_inc();
 
 	return 0;
 
-outsocket:
-	sock_release(sock);
-
-outtinfo:
-	if (tinfo) {
-		sock_release(tinfo->sock);
-		kfree(tinfo->buf);
-		kfree(tinfo);
-	}
+out:
+	/* We do not need RTNL lock anymore, release it here so that
+	 * sock_release below and in the kthreads can use rtnl_lock
+	 * to leave the mcast group.
+	 */
+	rtnl_unlock();
 	count = id;
 	while (count-- > 0) {
 		if (state == IP_VS_STATE_MASTER)
@@ -1932,13 +1927,23 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 		else
 			kthread_stop(array[count]);
 	}
-	kfree(array);
-
-out:
 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
 		kfree(ipvs->ms);
 		ipvs->ms = NULL;
 	}
+	mutex_unlock(&ipvs->sync_mutex);
+	if (tinfo) {
+		if (tinfo->sock)
+			sock_release(tinfo->sock);
+		kfree(tinfo->buf);
+		kfree(tinfo);
+	}
+	kfree(array);
+	return result;
+
+out_early:
+	mutex_unlock(&ipvs->sync_mutex);
+	rtnl_unlock();
 	return result;
 }
 
-- 
2.11.0

^ permalink raw reply related

* [PATCH 03/12] netfilter: ebtables: don't attempt to allocate 0-sized compat array
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Florian Westphal <fw@strlen.de>

Dmitry reports 32bit ebtables on 64bit kernel got broken by
a recent change that returns -EINVAL when ruleset has no entries.

ebtables however only counts user-defined chains, so for the
initial table nentries will be 0.

Don't try to allocate the compat array in this case, as no user
defined rules exist no rule will need 64bit translation.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 7d7d7e02111e9 ("netfilter: compat: reject huge allocation requests")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/bridge/netfilter/ebtables.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 032e0fe45940..28a4c3490359 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1825,13 +1825,14 @@ static int compat_table_info(const struct ebt_table_info *info,
 {
 	unsigned int size = info->entries_size;
 	const void *entries = info->entries;
-	int ret;
 
 	newinfo->entries_size = size;
-
-	ret = xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
-	if (ret)
-		return ret;
+	if (info->nentries) {
+		int ret = xt_compat_init_offsets(NFPROTO_BRIDGE,
+						 info->nentries);
+		if (ret)
+			return ret;
+	}
 
 	return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
 							entries, newinfo);
-- 
2.11.0

^ permalink raw reply related

* [PATCH 01/12] netfilter: nf_conntrack_sip: allow duplicate SDP expectations
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev
In-Reply-To: <20180423175714.9794-1-pablo@netfilter.org>

From: Florian Westphal <fw@strlen.de>

Callum Sinclair reported SIP IP Phone errors that he tracked down to
such phones sending session descriptions for different media types but
with same port numbers.

The expect core will only 'refresh' existing expectation if it is
from same master AND same expectation class (media type).
As expectation class is different, we get an error.

The SIP connection tracking code will then

1). drop the SDP packet
2). if an rtp expectation was already installed successfully,
    error on rtcp expectation will cancel the rtp one.

Make the expect core report back to caller when the conflict is due
to different expectation class and have SIP tracker ignore soft-error.

Reported-by: Callum Sinclair <Callum.Sinclair@alliedtelesis.co.nz>
Tested-by: Callum Sinclair <Callum.Sinclair@alliedtelesis.co.nz>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_expect.c |  5 ++++-
 net/netfilter/nf_conntrack_sip.c    | 16 ++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 8ef21d9f9a00..4b2b3d53acfc 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -252,7 +252,7 @@ static inline int expect_clash(const struct nf_conntrack_expect *a,
 static inline int expect_matches(const struct nf_conntrack_expect *a,
 				 const struct nf_conntrack_expect *b)
 {
-	return a->master == b->master && a->class == b->class &&
+	return a->master == b->master &&
 	       nf_ct_tuple_equal(&a->tuple, &b->tuple) &&
 	       nf_ct_tuple_mask_equal(&a->mask, &b->mask) &&
 	       net_eq(nf_ct_net(a->master), nf_ct_net(b->master)) &&
@@ -421,6 +421,9 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect)
 	h = nf_ct_expect_dst_hash(net, &expect->tuple);
 	hlist_for_each_entry_safe(i, next, &nf_ct_expect_hash[h], hnode) {
 		if (expect_matches(i, expect)) {
+			if (i->class != expect->class)
+				return -EALREADY;
+
 			if (nf_ct_remove_expect(i))
 				break;
 		} else if (expect_clash(i, expect)) {
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 4dbb5bad4363..908e51e2dc2b 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -938,11 +938,19 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff,
 				       datalen, rtp_exp, rtcp_exp,
 				       mediaoff, medialen, daddr);
 	else {
-		if (nf_ct_expect_related(rtp_exp) == 0) {
-			if (nf_ct_expect_related(rtcp_exp) != 0)
-				nf_ct_unexpect_related(rtp_exp);
-			else
+		/* -EALREADY handling works around end-points that send
+		 * SDP messages with identical port but different media type,
+		 * we pretend expectation was set up.
+		 */
+		int errp = nf_ct_expect_related(rtp_exp);
+
+		if (errp == 0 || errp == -EALREADY) {
+			int errcp = nf_ct_expect_related(rtcp_exp);
+
+			if (errcp == 0 || errcp == -EALREADY)
 				ret = NF_ACCEPT;
+			else if (errp == 0)
+				nf_ct_unexpect_related(rtp_exp);
 		}
 	}
 	nf_ct_expect_put(rtcp_exp);
-- 
2.11.0

^ permalink raw reply related

* [PATCH 00/12] Netfilter/IPVS fixes for net
From: Pablo Neira Ayuso @ 2018-04-23 17:57 UTC (permalink / raw)
  To: netfilter-devel; +Cc: davem, netdev

Hi David,

The following patchset contains Netfilter/IPVS fixes for your net tree,
they are:

1) Fix SIP conntrack with phones sending session descriptions for different
   media types but same port numbers, from Florian Westphal.

2) Fix incorrect rtnl_lock mutex logic from IPVS sync thread, from Julian
   Anastasov.

3) Skip compat array allocation in ebtables if there is no entries, also
   from Florian.

4) Do not lose left/right bits when shifting marks from xt_connmark, from
   Jack Ma.

5) Silence false positive memleak in conntrack extensions, from Cong Wang.

6) Fix CONFIG_NF_REJECT_IPV6=m link problems, from Arnd Bergmann.

7) Cannot kfree rule that is already in list in nf_tables, switch order
   so this error handling is not required, from Florian Westphal.

8) Release set name in error path, from Florian.

9) include kmemleak.h in nf_conntrack_extend.c, from Stepheh Rothwell.

10) NAT chain and extensions depend on NF_TABLES.

11) Out of bound access when renaming chains, from Taehee Yoo.

12) Incorrect casting in xt_connmark leads to wrong bitshifting.

You can pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thanks.

----------------------------------------------------------------

The following changes since commit a2ac99905f1ea8b15997a6ec39af69aa28a3653b:

  vhost-net: set packet weight of tx polling to 2 * vq size (2018-04-09 11:01:37 -0400)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to 5a786232eb69a1f870ddc0cfd69d5bdef241a2ea:

  netfilter: xt_connmark: do not cast xt_connmark_tginfo1 to xt_connmark_tginfo2 (2018-04-19 16:19:28 +0200)

----------------------------------------------------------------
Arnd Bergmann (1):
      netfilter: fix CONFIG_NF_REJECT_IPV6=m link error

Cong Wang (1):
      netfilter: conntrack: silent a memory leak warning

Florian Westphal (4):
      netfilter: nf_conntrack_sip: allow duplicate SDP expectations
      netfilter: ebtables: don't attempt to allocate 0-sized compat array
      netfilter: nf_tables: can't fail after linking rule into active rule list
      netfilter: nf_tables: free set name in error path

Jack Ma (1):
      netfilter: xt_connmark: Add bit mapping for bit-shift operation.

Julian Anastasov (1):
      ipvs: fix rtnl_lock lockups caused by start_sync_thread

Pablo Neira Ayuso (2):
      netfilter: nf_tables: NAT chain and extensions require NF_TABLES
      netfilter: xt_connmark: do not cast xt_connmark_tginfo1 to xt_connmark_tginfo2

Stephen Rothwell (1):
      netfilter: conntrack: include kmemleak.h for kmemleak_not_leak()

Taehee Yoo (1):
      netfilter: nf_tables: fix out-of-bounds in nft_chain_commit_update

 net/bridge/netfilter/ebtables.c     |  11 +--
 net/ipv6/netfilter/Kconfig          |  55 ++++++-------
 net/netfilter/Kconfig               |   1 +
 net/netfilter/ipvs/ip_vs_ctl.c      |   8 --
 net/netfilter/ipvs/ip_vs_sync.c     | 155 +++++++++++++++++++-----------------
 net/netfilter/nf_conntrack_expect.c |   5 +-
 net/netfilter/nf_conntrack_extend.c |   2 +
 net/netfilter/nf_conntrack_sip.c    |  16 +++-
 net/netfilter/nf_tables_api.c       |  69 ++++++++--------
 net/netfilter/xt_connmark.c         |  49 +++++++-----
 10 files changed, 200 insertions(+), 171 deletions(-)

^ permalink raw reply

* Re: [PATCH v7 net-next 4/4] netvsc: refactor notifier/event handling code to use the failover framework
From: Michael S. Tsirkin @ 2018-04-23 17:56 UTC (permalink / raw)
  To: Stephen Hemminger
  Cc: Jiri Pirko, Sridhar Samudrala, davem, netdev, virtualization,
	virtio-dev, jesse.brandeburg, alexander.h.duyck, kubakici,
	jasowang, loseweigh
In-Reply-To: <20180423104440.2fe6cfd2@xeon-e3>

On Mon, Apr 23, 2018 at 10:44:40AM -0700, Stephen Hemminger wrote:
> On Mon, 23 Apr 2018 20:24:56 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > On Mon, Apr 23, 2018 at 10:04:06AM -0700, Stephen Hemminger wrote:
> > > > >
> > > > >I will NAK patches to change to common code for netvsc especially the
> > > > >three device model.  MS worked hard with distro vendors to support transparent
> > > > >mode, ans we really can't have a new model; or do backport.
> > > > >
> > > > >Plus, DPDK is now dependent on existing model.    
> > > > 
> > > > Sorry, but nobody here cares about dpdk or other similar oddities.  
> > > 
> > > The network device model is a userspace API, and DPDK is a userspace application.  
> > 
> > It is userspace but are you sure dpdk is actually poking at netdevs?
> > AFAIK it's normally banging device registers directly.
> > 
> > > You can't go breaking userspace even if you don't like the application.  
> > 
> > Could you please explain how is the proposed patchset breaking
> > userspace? Ignoring DPDK for now, I don't think it changes the userspace
> > API at all.
> > 
> 
> The DPDK has a device driver vdev_netvsc which scans the Linux network devices
> to look for Linux netvsc device and the paired VF device and setup the
> DPDK environment.  This setup creates a DPDK failsafe (bondingish) instance
> and sets up TAP support over the Linux netvsc device as well as the Mellanox
> VF device.
> 
> So it depends on existing 2 device model. You can't go to a 3 device model
> or start hiding devices from userspace.

Okay so how does the existing patch break that? IIUC does not go to
a 3 device model since netvsc calls failover_register directly.

> Also, I am working on associating netvsc and VF device based on serial number
> rather than MAC address. The serial number is how Windows works now, and it makes
> sense for Linux and Windows to use the same mechanism if possible.

Maybe we should support same for virtio ...
Which serial do you mean? From vpd?

I guess you will want to keep supporting MAC for old hypervisors?

It all seems like a reasonable thing to support in the generic core.

-- 
MST

^ permalink raw reply

* [PATCH bpf-next v5 05/10] bpf/verifier: improve register value range tracking with ARSH
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

When helpers like bpf_get_stack returns an int value
and later on used for arithmetic computation, the LSH and ARSH
operations are often required to get proper sign extension into
64-bit. For example, without this patch:
    54: R0=inv(id=0,umax_value=800)
    54: (bf) r8 = r0
    55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800)
    55: (67) r8 <<= 32
    56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000))
    56: (c7) r8 s>>= 32
    57: R8=inv(id=0)
With this patch:
    54: R0=inv(id=0,umax_value=800)
    54: (bf) r8 = r0
    55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800)
    55: (67) r8 <<= 32
    56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000))
    56: (c7) r8 s>>= 32
    57: R8=inv(id=0, umax_value=800,var_off=(0x0; 0x3ff))
With better range of "R8", later on when "R8" is added to other register,
e.g., a map pointer or scalar-value register, the better register
range can be derived and verifier failure may be avoided.

In our later example,
    ......
    usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
    if (usize < 0)
        return 0;
    ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
    ......
Without improving ARSH value range tracking, the register representing
"max_len - usize" will have smin_value equal to S64_MIN and will be
rejected by verifier.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 include/linux/tnum.h  |  4 +++-
 kernel/bpf/tnum.c     | 10 ++++++++++
 kernel/bpf/verifier.c | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/include/linux/tnum.h b/include/linux/tnum.h
index 0d2d3da..c7dc2b5 100644
--- a/include/linux/tnum.h
+++ b/include/linux/tnum.h
@@ -23,8 +23,10 @@ struct tnum tnum_range(u64 min, u64 max);
 /* Arithmetic and logical ops */
 /* Shift a tnum left (by a fixed shift) */
 struct tnum tnum_lshift(struct tnum a, u8 shift);
-/* Shift a tnum right (by a fixed shift) */
+/* Shift (rsh) a tnum right (by a fixed shift) */
 struct tnum tnum_rshift(struct tnum a, u8 shift);
+/* Shift (arsh) a tnum right (by a fixed min_shift) */
+struct tnum tnum_arshift(struct tnum a, u8 min_shift);
 /* Add two tnums, return @a + @b */
 struct tnum tnum_add(struct tnum a, struct tnum b);
 /* Subtract two tnums, return @a - @b */
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index 1f4bf68..938d412 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -43,6 +43,16 @@ struct tnum tnum_rshift(struct tnum a, u8 shift)
 	return TNUM(a.value >> shift, a.mask >> shift);
 }
 
+struct tnum tnum_arshift(struct tnum a, u8 min_shift)
+{
+	/* if a.value is negative, arithmetic shifting by minimum shift
+	 * will have larger negative offset compared to more shifting.
+	 * If a.value is nonnegative, arithmetic shifting by minimum shift
+	 * will have larger positive offset compare to more shifting.
+	 */
+	return TNUM((s64)a.value >> min_shift, (s64)a.mask >> min_shift);
+}
+
 struct tnum tnum_add(struct tnum a, struct tnum b)
 {
 	u64 sm, sv, sigma, chi, mu;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1bbb43d..7c09610 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2966,6 +2966,47 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		/* We may learn something more from the var_off */
 		__update_reg_bounds(dst_reg);
 		break;
+	case BPF_ARSH:
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
+			 */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			break;
+		}
+
+		/* BPF_ARSH is an arithmetic shift. The new range of
+		 * smin_value and smax_value should take the sign
+		 * into consideration.
+		 *
+		 * For example, if smin_value = -16, umin_val = 0
+		 * and umax_val = 2, the new smin_value should be
+		 * -16 >> 0 = -16 since -16 >> 2 = -4.
+		 * If smin_value = 16, umin_val = 0 and umax_val = 2,
+		 * the new smin_value should be 16 >> 2 = 4.
+		 *
+		 * Now suppose smax_value = -4, umin_val = 0 and
+		 * umax_val = 2, the new smax_value should be
+		 * -4 >> 2 = -1. If smax_value = 32 with the same
+		 * umin_val/umax_val, the new smax_value should remain 32.
+		 */
+		if (dst_reg->smin_value < 0)
+			dst_reg->smin_value >>= umin_val;
+		else
+			dst_reg->smin_value >>= umax_val;
+		if (dst_reg->smax_value < 0)
+			dst_reg->smax_value >>= umax_val;
+		else
+			dst_reg->smax_value >>= umin_val;
+		dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);
+
+		/* blow away the dst_reg umin_value/umax_value and rely on
+		 * dst_reg var_off to refine the result.
+		 */
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+		__update_reg_bounds(dst_reg);
+		break;
 	default:
 		mark_reg_unknown(env, regs, insn->dst_reg);
 		break;
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 02/10] bpf: add bpf_get_stack helper
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

Currently, stackmap and bpf_get_stackid helper are provided
for bpf program to get the stack trace. This approach has
a limitation though. If two stack traces have the same hash,
only one will get stored in the stackmap table,
so some stack traces are missing from user perspective.

This patch implements a new helper, bpf_get_stack, will
send stack traces directly to bpf program. The bpf program
is able to see all stack traces, and then can do in-kernel
processing or send stack traces to user space through
shared map or bpf_perf_event_output.

Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 include/linux/bpf.h      |  1 +
 include/linux/filter.h   |  3 ++-
 include/uapi/linux/bpf.h | 19 ++++++++++++--
 kernel/bpf/core.c        |  5 ++++
 kernel/bpf/stackmap.c    | 67 ++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/bpf/syscall.c     | 10 ++++++++
 kernel/bpf/verifier.c    |  3 +++
 kernel/trace/bpf_trace.c | 50 +++++++++++++++++++++++++++++++++++-
 8 files changed, 154 insertions(+), 4 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index ee5275e..2c520b4 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -690,6 +690,7 @@ extern const struct bpf_func_proto bpf_get_current_comm_proto;
 extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
 extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
 extern const struct bpf_func_proto bpf_get_stackid_proto;
+extern const struct bpf_func_proto bpf_get_stack_proto;
 extern const struct bpf_func_proto bpf_sock_map_update_proto;
 
 /* Shared helpers among cBPF and eBPF. */
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 4da8b23..044d30e 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -468,7 +468,8 @@ struct bpf_prog {
 				dst_needed:1,	/* Do we need dst entry? */
 				blinded:1,	/* Was blinded */
 				is_func:1,	/* program is a bpf function */
-				kprobe_override:1; /* Do we override a kprobe? */
+				kprobe_override:1, /* Do we override a kprobe? */
+				need_callchain_buf:1; /* Needs callchain buffer? */
 	enum bpf_prog_type	type;		/* Type of BPF program */
 	enum bpf_attach_type	expected_attach_type; /* For some prog types */
 	u32			len;		/* Number of filter blocks */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c8383a2..470f3a2 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -529,6 +529,17 @@ union bpf_attr {
  *             other bits - reserved
  *     Return: >= 0 stackid on success or negative error
  *
+ * int bpf_get_stack(ctx, buf, size, flags)
+ *     walk user or kernel stack and store the ips in buf
+ *     @ctx: struct pt_regs*
+ *     @buf: user buffer to fill stack
+ *     @size: the buf size
+ *     @flags: bits 0-7 - numer of stack frames to skip
+ *             bit 8 - collect user stack instead of kernel
+ *             bit 11 - get build-id as well if user stack
+ *             other bits - reserved
+ *     Return: >= 0 size copied on success or negative error
+ *
  * s64 bpf_csum_diff(from, from_size, to, to_size, seed)
  *     calculate csum diff
  *     @from: raw from buffer
@@ -841,7 +852,8 @@ union bpf_attr {
 	FN(msg_cork_bytes),		\
 	FN(msg_pull_data),		\
 	FN(bind),			\
-	FN(xdp_adjust_tail),
+	FN(xdp_adjust_tail),		\
+	FN(get_stack),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -875,11 +887,14 @@ enum bpf_func_id {
 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
 #define BPF_F_TUNINFO_IPV6		(1ULL << 0)
 
-/* BPF_FUNC_get_stackid flags. */
+/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
 #define BPF_F_SKIP_FIELD_MASK		0xffULL
 #define BPF_F_USER_STACK		(1ULL << 8)
+/* flags used by BPF_FUNC_get_stackid only. */
 #define BPF_F_FAST_STACK_CMP		(1ULL << 9)
 #define BPF_F_REUSE_STACKID		(1ULL << 10)
+/* flags used by BPF_FUNC_get_stack only. */
+#define BPF_F_USER_BUILD_ID		(1ULL << 11)
 
 /* BPF_FUNC_skb_set_tunnel_key flags. */
 #define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index d315b39..bf22eca 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -31,6 +31,7 @@
 #include <linux/rbtree_latch.h>
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
+#include <linux/perf_event.h>
 
 #include <asm/unaligned.h>
 
@@ -1709,6 +1710,10 @@ static void bpf_prog_free_deferred(struct work_struct *work)
 	aux = container_of(work, struct bpf_prog_aux, work);
 	if (bpf_prog_is_dev_bound(aux))
 		bpf_prog_offload_destroy(aux->prog);
+#ifdef CONFIG_PERF_EVENTS
+	if (aux->prog->need_callchain_buf)
+		put_callchain_buffers();
+#endif
 	for (i = 0; i < aux->func_cnt; i++)
 		bpf_jit_free(aux->func[i]);
 	if (aux->func_cnt) {
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 04f6ec1..4477cf6 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -402,6 +402,73 @@ const struct bpf_func_proto bpf_get_stackid_proto = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,
+	   u64, flags)
+{
+	u32 init_nr, trace_nr, copy_len, elem_size, num_elem;
+	bool user_build_id = flags & BPF_F_USER_BUILD_ID;
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	bool user = flags & BPF_F_USER_STACK;
+	struct perf_callchain_entry *trace;
+	bool kernel = !user;
+	int err = -EINVAL;
+	u64 *ips;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_USER_BUILD_ID)))
+		goto clear;
+	if (kernel && user_build_id)
+		goto clear;
+
+	elem_size = (user && user_build_id) ? sizeof(struct bpf_stack_build_id)
+					    : sizeof(u64);
+	if (unlikely(size % elem_size))
+		goto clear;
+
+	num_elem = size / elem_size;
+	if (sysctl_perf_event_max_stack < num_elem)
+		init_nr = 0;
+	else
+		init_nr = sysctl_perf_event_max_stack - num_elem;
+	trace = get_perf_callchain(regs, init_nr, kernel, user,
+				   sysctl_perf_event_max_stack, false, false);
+	if (unlikely(!trace))
+		goto err_fault;
+
+	trace_nr = trace->nr - init_nr;
+	if (trace_nr <= skip)
+		goto err_fault;
+
+	trace_nr -= skip;
+	trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem;
+	copy_len = trace_nr * elem_size;
+	ips = trace->ip + skip + init_nr;
+	if (user && user_build_id)
+		stack_map_get_build_id_offset(buf, ips, trace_nr, user);
+	else
+		memcpy(buf, ips, copy_len);
+
+	if (size > copy_len)
+		memset(buf + copy_len, 0, size - copy_len);
+	return copy_len;
+
+err_fault:
+	err = -EFAULT;
+clear:
+	memset(buf, 0, size);
+	return err;
+}
+
+const struct bpf_func_proto bpf_get_stack_proto = {
+	.func		= bpf_get_stack,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 /* Called from eBPF program */
 static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
 {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fe23dc5a..1ee71f6 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1360,6 +1360,16 @@ static int bpf_prog_load(union bpf_attr *attr)
 	if (err)
 		goto free_used_maps;
 
+	if (prog->need_callchain_buf) {
+#ifdef CONFIG_PERF_EVENTS
+		err = get_callchain_buffers(sysctl_perf_event_max_stack);
+#else
+		err = -ENOTSUPP;
+#endif
+		if (err)
+			goto free_used_maps;
+	}
+
 	err = bpf_prog_new_fd(prog);
 	if (err < 0) {
 		/* failed to allocate fd.
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5dd1dcb..aba9425 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2460,6 +2460,9 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 	if (err)
 		return err;
 
+	if (func_id == BPF_FUNC_get_stack)
+		env->prog->need_callchain_buf = true;
+
 	if (changes_data)
 		clear_all_pkt_pointers(env);
 	return 0;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d88e96d..fe8476f 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -20,6 +20,7 @@
 #include "trace.h"
 
 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 
 /**
  * trace_call_bpf - invoke BPF program
@@ -577,6 +578,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_perf_event_output_proto;
 	case BPF_FUNC_get_stackid:
 		return &bpf_get_stackid_proto;
+	case BPF_FUNC_get_stack:
+		return &bpf_get_stack_proto;
 	case BPF_FUNC_perf_event_read_value:
 		return &bpf_perf_event_read_value_proto;
 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
@@ -664,6 +667,25 @@ static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
+	   u64, flags)
+{
+	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
+
+	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
+			     (unsigned long) size, flags, 0);
+}
+
+static const struct bpf_func_proto bpf_get_stack_proto_tp = {
+	.func		= bpf_get_stack_tp,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -672,6 +694,8 @@ tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_perf_event_output_proto_tp;
 	case BPF_FUNC_get_stackid:
 		return &bpf_get_stackid_proto_tp;
+	case BPF_FUNC_get_stack:
+		return &bpf_get_stack_proto_tp;
 	default:
 		return tracing_func_proto(func_id, prog);
 	}
@@ -734,6 +758,8 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_perf_event_output_proto_tp;
 	case BPF_FUNC_get_stackid:
 		return &bpf_get_stackid_proto_tp;
+	case BPF_FUNC_get_stack:
+		return &bpf_get_stack_proto_tp;
 	case BPF_FUNC_perf_prog_read_value:
 		return &bpf_perf_prog_read_value_proto;
 	default:
@@ -744,7 +770,7 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 /*
  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
  * to avoid potential recursive reuse issue when/if tracepoints are added
- * inside bpf_*_event_output and/or bpf_get_stack_id
+ * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack
  */
 static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs);
 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
@@ -787,6 +813,26 @@ static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
 	.arg3_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
+	   void *, buf, u32, size, u64, flags)
+{
+	struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
+
+	perf_fetch_caller_regs(regs);
+	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
+			     (unsigned long) size, flags, 0);
+}
+
+static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
+	.func		= bpf_get_stack_raw_tp,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -795,6 +841,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_perf_event_output_proto_raw_tp;
 	case BPF_FUNC_get_stackid:
 		return &bpf_get_stackid_proto_raw_tp;
+	case BPF_FUNC_get_stack:
+		return &bpf_get_stack_proto_raw_tp;
 	default:
 		return tracing_func_proto(func_id, prog);
 	}
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 10/10] tools/bpf: add a test for bpf_get_stack with tracepoint prog
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

The test_stacktrace_map and test_stacktrace_build_id are
enhanced to call bpf_get_stack in the helper to get the
stack trace as well.  The stack traces from bpf_get_stack
and bpf_get_stackid are compared to ensure that for the
same stack as represented as the same hash, their ip addresses
or build id's must be the same.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/test_progs.c           | 70 ++++++++++++++++++++--
 .../selftests/bpf/test_stacktrace_build_id.c       | 20 ++++++-
 tools/testing/selftests/bpf/test_stacktrace_map.c  | 20 ++++++-
 3 files changed, 99 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index c148a55..664db67 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -897,11 +897,47 @@ static int compare_map_keys(int map1_fd, int map2_fd)
 	return 0;
 }
 
+static int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len)
+{
+	__u32 key, next_key, *cur_key_p, *next_key_p;
+	char *val_buf1, *val_buf2;
+	int i, err = 0;
+
+	val_buf1 = malloc(stack_trace_len);
+	val_buf2 = malloc(stack_trace_len);
+	cur_key_p = NULL;
+	next_key_p = &key;
+	while (bpf_map_get_next_key(smap_fd, cur_key_p, next_key_p) == 0) {
+		err = bpf_map_lookup_elem(smap_fd, next_key_p, val_buf1);
+		if (err)
+			goto out;
+		err = bpf_map_lookup_elem(amap_fd, next_key_p, val_buf2);
+		if (err)
+			goto out;
+		for (i = 0; i < stack_trace_len; i++) {
+			if (val_buf1[i] != val_buf2[i]) {
+				err = -1;
+				goto out;
+			}
+		}
+		key = *next_key_p;
+		cur_key_p = &key;
+		next_key_p = &next_key;
+	}
+	if (errno != ENOENT)
+		err = -1;
+
+out:
+	free(val_buf1);
+	free(val_buf2);
+	return err;
+}
+
 static void test_stacktrace_map()
 {
-	int control_map_fd, stackid_hmap_fd, stackmap_fd;
+	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
 	const char *file = "./test_stacktrace_map.o";
-	int bytes, efd, err, pmu_fd, prog_fd;
+	int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len;
 	struct perf_event_attr attr = {};
 	__u32 key, val, duration = 0;
 	struct bpf_object *obj;
@@ -957,6 +993,10 @@ static void test_stacktrace_map()
 	if (stackmap_fd < 0)
 		goto disable_pmu;
 
+	stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
+	if (stack_amap_fd < 0)
+		goto disable_pmu;
+
 	/* give some time for bpf program run */
 	sleep(1);
 
@@ -978,6 +1018,12 @@ static void test_stacktrace_map()
 		  "err %d errno %d\n", err, errno))
 		goto disable_pmu_noerr;
 
+	stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
+	err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
+	if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu_noerr;
+
 	goto disable_pmu_noerr;
 disable_pmu:
 	error_cnt++;
@@ -1071,9 +1117,9 @@ static int extract_build_id(char *build_id, size_t size)
 
 static void test_stacktrace_build_id(void)
 {
-	int control_map_fd, stackid_hmap_fd, stackmap_fd;
+	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
 	const char *file = "./test_stacktrace_build_id.o";
-	int bytes, efd, err, pmu_fd, prog_fd;
+	int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len;
 	struct perf_event_attr attr = {};
 	__u32 key, previous_key, val, duration = 0;
 	struct bpf_object *obj;
@@ -1138,6 +1184,11 @@ static void test_stacktrace_build_id(void)
 		  err, errno))
 		goto disable_pmu;
 
+	stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
+	if (CHECK(stack_amap_fd < 0, "bpf_find_map stack_amap",
+		  "err %d errno %d\n", err, errno))
+		goto disable_pmu;
+
 	assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")
 	       == 0);
 	assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0);
@@ -1189,8 +1240,15 @@ static void test_stacktrace_build_id(void)
 		previous_key = key;
 	} while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
 
-	CHECK(build_id_matches < 1, "build id match",
-	      "Didn't find expected build ID from the map");
+	if (CHECK(build_id_matches < 1, "build id match",
+		  "Didn't find expected build ID from the map"))
+		goto disable_pmu;
+
+	stack_trace_len = PERF_MAX_STACK_DEPTH
+		* sizeof(struct bpf_stack_build_id);
+	err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
+	CHECK(err, "compare_stack_ips stackmap vs. stack_amap",
+	      "err %d errno %d\n", err, errno);
 
 disable_pmu:
 	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
diff --git a/tools/testing/selftests/bpf/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
index b755bd7..d86c281 100644
--- a/tools/testing/selftests/bpf/test_stacktrace_build_id.c
+++ b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
@@ -19,7 +19,7 @@ struct bpf_map_def SEC("maps") stackid_hmap = {
 	.type = BPF_MAP_TYPE_HASH,
 	.key_size = sizeof(__u32),
 	.value_size = sizeof(__u32),
-	.max_entries = 10000,
+	.max_entries = 16384,
 };
 
 struct bpf_map_def SEC("maps") stackmap = {
@@ -31,6 +31,14 @@ struct bpf_map_def SEC("maps") stackmap = {
 	.map_flags = BPF_F_STACK_BUILD_ID,
 };
 
+struct bpf_map_def SEC("maps") stack_amap = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(struct bpf_stack_build_id)
+		* PERF_MAX_STACK_DEPTH,
+	.max_entries = 128,
+};
+
 /* taken from /sys/kernel/debug/tracing/events/random/urandom_read/format */
 struct random_urandom_args {
 	unsigned long long pad;
@@ -42,7 +50,10 @@ struct random_urandom_args {
 SEC("tracepoint/random/urandom_read")
 int oncpu(struct random_urandom_args *args)
 {
+	__u32 max_len = sizeof(struct bpf_stack_build_id)
+			* PERF_MAX_STACK_DEPTH;
 	__u32 key = 0, val = 0, *value_p;
+	void *stack_p;
 
 	value_p = bpf_map_lookup_elem(&control_map, &key);
 	if (value_p && *value_p)
@@ -50,8 +61,13 @@ int oncpu(struct random_urandom_args *args)
 
 	/* The size of stackmap and stackid_hmap should be the same */
 	key = bpf_get_stackid(args, &stackmap, BPF_F_USER_STACK);
-	if ((int)key >= 0)
+	if ((int)key >= 0) {
 		bpf_map_update_elem(&stackid_hmap, &key, &val, 0);
+		stack_p = bpf_map_lookup_elem(&stack_amap, &key);
+		if (stack_p)
+			bpf_get_stack(args, stack_p, max_len,
+				      BPF_F_USER_STACK | BPF_F_USER_BUILD_ID);
+	}
 
 	return 0;
 }
diff --git a/tools/testing/selftests/bpf/test_stacktrace_map.c b/tools/testing/selftests/bpf/test_stacktrace_map.c
index 76d85c5d..f83c7b6 100644
--- a/tools/testing/selftests/bpf/test_stacktrace_map.c
+++ b/tools/testing/selftests/bpf/test_stacktrace_map.c
@@ -19,14 +19,21 @@ struct bpf_map_def SEC("maps") stackid_hmap = {
 	.type = BPF_MAP_TYPE_HASH,
 	.key_size = sizeof(__u32),
 	.value_size = sizeof(__u32),
-	.max_entries = 10000,
+	.max_entries = 16384,
 };
 
 struct bpf_map_def SEC("maps") stackmap = {
 	.type = BPF_MAP_TYPE_STACK_TRACE,
 	.key_size = sizeof(__u32),
 	.value_size = sizeof(__u64) * PERF_MAX_STACK_DEPTH,
-	.max_entries = 10000,
+	.max_entries = 16384,
+};
+
+struct bpf_map_def SEC("maps") stack_amap = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(__u64) * PERF_MAX_STACK_DEPTH,
+	.max_entries = 16384,
 };
 
 /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
@@ -44,7 +51,10 @@ struct sched_switch_args {
 SEC("tracepoint/sched/sched_switch")
 int oncpu(struct sched_switch_args *ctx)
 {
+	__u32 max_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
 	__u32 key = 0, val = 0, *value_p;
+	void *stack_p;
+
 
 	value_p = bpf_map_lookup_elem(&control_map, &key);
 	if (value_p && *value_p)
@@ -52,8 +62,12 @@ int oncpu(struct sched_switch_args *ctx)
 
 	/* The size of stackmap and stackid_hmap should be the same */
 	key = bpf_get_stackid(ctx, &stackmap, 0);
-	if ((int)key >= 0)
+	if ((int)key >= 0) {
 		bpf_map_update_elem(&stackid_hmap, &key, &val, 0);
+		stack_p = bpf_map_lookup_elem(&stack_amap, &key);
+		if (stack_p)
+			bpf_get_stack(ctx, stack_p, max_len, 0);
+	}
 
 	return 0;
 }
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 06/10] tools/bpf: add bpf_get_stack helper to tools headers
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/include/uapi/linux/bpf.h            | 19 +++++++++++++++++--
 tools/testing/selftests/bpf/bpf_helpers.h |  3 ++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 7f7fbb9..116eb5f 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -529,6 +529,17 @@ union bpf_attr {
  *             other bits - reserved
  *     Return: >= 0 stackid on success or negative error
  *
+ * int bpf_get_stack(ctx, buf, size, flags)
+ *     walk user or kernel stack and store the ips in buf
+ *     @ctx: struct pt_regs*
+ *     @buf: user buffer to fill stack
+ *     @size: the buf size
+ *     @flags: bits 0-7 - numer of stack frames to skip
+ *             bit 8 - collect user stack instead of kernel
+ *             bit 11 - get build-id as well if user stack
+ *             other bits - reserved
+ *     Return: >= 0 size copied on success or negative error
+ *
  * s64 bpf_csum_diff(from, from_size, to, to_size, seed)
  *     calculate csum diff
  *     @from: raw from buffer
@@ -841,7 +852,8 @@ union bpf_attr {
 	FN(msg_cork_bytes),		\
 	FN(msg_pull_data),		\
 	FN(bind),			\
-	FN(xdp_adjust_tail),
+	FN(xdp_adjust_tail),		\
+	FN(get_stack),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -875,11 +887,14 @@ enum bpf_func_id {
 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
 #define BPF_F_TUNINFO_IPV6		(1ULL << 0)
 
-/* BPF_FUNC_get_stackid flags. */
+/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
 #define BPF_F_SKIP_FIELD_MASK		0xffULL
 #define BPF_F_USER_STACK		(1ULL << 8)
+/* flags used by BPF_FUNC_get_stackid only. */
 #define BPF_F_FAST_STACK_CMP		(1ULL << 9)
 #define BPF_F_REUSE_STACKID		(1ULL << 10)
+/* flags used by BPF_FUNC_get_stack only. */
+#define BPF_F_USER_BUILD_ID		(1ULL << 11)
 
 /* BPF_FUNC_skb_set_tunnel_key flags. */
 #define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index 9271576..2d9d650 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -98,7 +98,8 @@ static int (*bpf_bind)(void *ctx, void *addr, int addr_len) =
 	(void *) BPF_FUNC_bind;
 static int (*bpf_xdp_adjust_tail)(void *ctx, int offset) =
 	(void *) BPF_FUNC_xdp_adjust_tail;
-
+static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) =
+	(void *) BPF_FUNC_get_stack;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 09/10] tools/bpf: add a test for bpf_get_stack with raw tracepoint prog
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

The test attached a raw_tracepoint program to sched/sched_switch.
It tested to get stack for user space, kernel space and user
space with build_id request. It also tested to get user
and kernel stack into the same buffer with back-to-back
bpf_get_stack helper calls.

Whenever the kernel stack is available, the user space
application will check to ensure that the kernel function
for raw_tracepoint ___bpf_prog_run is part of the stack.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/Makefile               |   3 +-
 tools/testing/selftests/bpf/test_get_stack_rawtp.c | 102 +++++++++++++++++
 tools/testing/selftests/bpf/test_progs.c           | 122 +++++++++++++++++++++
 3 files changed, 226 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/test_get_stack_rawtp.c

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 0b72cc7..54e9e74 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -32,7 +32,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
 	test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \
 	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
 	sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
-	test_btf_haskv.o test_btf_nokv.o
+	test_btf_haskv.o test_btf_nokv.o test_get_stack_rawtp.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
@@ -56,6 +56,7 @@ $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a
 $(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
 $(OUTPUT)/test_sock: cgroup_helpers.c
 $(OUTPUT)/test_sock_addr: cgroup_helpers.c
+$(OUTPUT)/test_progs: trace_helpers.c
 
 .PHONY: force
 
diff --git a/tools/testing/selftests/bpf/test_get_stack_rawtp.c b/tools/testing/selftests/bpf/test_get_stack_rawtp.c
new file mode 100644
index 0000000..ba1dcf9
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_get_stack_rawtp.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+/* Permit pretty deep stack traces */
+#define MAX_STACK_RAWTP 100
+struct stack_trace_t {
+	int pid;
+	int kern_stack_size;
+	int user_stack_size;
+	int user_stack_buildid_size;
+	__u64 kern_stack[MAX_STACK_RAWTP];
+	__u64 user_stack[MAX_STACK_RAWTP];
+	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
+};
+
+struct bpf_map_def SEC("maps") perfmap = {
+	.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(__u32),
+	.max_entries = 2,
+};
+
+struct bpf_map_def SEC("maps") stackdata_map = {
+	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = sizeof(struct stack_trace_t),
+	.max_entries = 1,
+};
+
+/* Allocate per-cpu space twice the needed. For the code below
+ *   usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
+ *   if (usize < 0)
+ *     return 0;
+ *   ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
+ *
+ * If we have value_size = MAX_STACK_RAWTP * sizeof(__u64),
+ * verifier will complain that access "raw_data + usize"
+ * with size "max_len - usize" may be out of bound.
+ * The maximum "raw_data + usize" is "raw_data + max_len"
+ * and the maximum "max_len - usize" is "max_len", verifier
+ * concludes that the maximum buffer access range is
+ * "raw_data[0...max_len * 2 - 1]" and hence reject the program.
+ *
+ * Doubling the to-be-used max buffer size can fix this verifier
+ * issue and avoid complicated C programming massaging.
+ * This is an acceptable workaround since there is one entry here.
+ */
+struct bpf_map_def SEC("maps") rawdata_map = {
+	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size = sizeof(__u32),
+	.value_size = MAX_STACK_RAWTP * sizeof(__u64) * 2,
+	.max_entries = 1,
+};
+
+SEC("tracepoint/sched/sched_switch")
+int bpf_prog1(void *ctx)
+{
+	int max_len, max_buildid_len, usize, ksize, total_size;
+	struct stack_trace_t *data;
+	void *raw_data;
+	__u32 key = 0;
+
+	data = bpf_map_lookup_elem(&stackdata_map, &key);
+	if (!data)
+		return 0;
+
+	max_len = MAX_STACK_RAWTP * sizeof(__u64);
+	max_buildid_len = MAX_STACK_RAWTP * sizeof(struct bpf_stack_build_id);
+	data->pid = bpf_get_current_pid_tgid();
+	data->kern_stack_size = bpf_get_stack(ctx, data->kern_stack,
+					      max_len, 0);
+	data->user_stack_size = bpf_get_stack(ctx, data->user_stack, max_len,
+					    BPF_F_USER_STACK);
+	data->user_stack_buildid_size = bpf_get_stack(
+		ctx, data->user_stack_buildid, max_buildid_len,
+		BPF_F_USER_STACK | BPF_F_USER_BUILD_ID);
+	bpf_perf_event_output(ctx, &perfmap, 0, data, sizeof(*data));
+
+	/* write both kernel and user stacks to the same buffer */
+	raw_data = bpf_map_lookup_elem(&rawdata_map, &key);
+	if (!raw_data)
+		return 0;
+
+	usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
+	if (usize < 0)
+		return 0;
+
+	ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
+	if (ksize < 0)
+		return 0;
+
+	total_size = usize + ksize;
+	if (total_size > 0 && total_size <= max_len)
+		bpf_perf_event_output(ctx, &perfmap, 0, raw_data, total_size);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index eedda98..c148a55 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -38,6 +38,7 @@ typedef __u16 __sum16;
 #include "bpf_util.h"
 #include "bpf_endian.h"
 #include "bpf_rlimit.h"
+#include "trace_helpers.h"
 
 static int error_cnt, pass_cnt;
 
@@ -1204,6 +1205,126 @@ static void test_stacktrace_build_id(void)
 	return;
 }
 
+#define MAX_CNT_RAWTP	10ull
+#define MAX_STACK_RAWTP	100
+struct get_stack_trace_t {
+	int pid;
+	int kern_stack_size;
+	int user_stack_size;
+	int user_stack_buildid_size;
+	__u64 kern_stack[MAX_STACK_RAWTP];
+	__u64 user_stack[MAX_STACK_RAWTP];
+	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
+};
+
+static void get_stack_raw_tp_action(void)
+{
+	FILE *f;
+
+	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+	(void) f;
+}
+
+static int get_stack_print_output(void *data, int size)
+{
+	bool good_kern_stack = false, good_user_stack = false;
+	const char *expected_func = "___bpf_prog_run";
+	struct get_stack_trace_t *e = data;
+	int i, num_stack;
+	static __u64 cnt;
+	struct ksym *ks;
+
+	cnt++;
+
+	if (size < sizeof(struct get_stack_trace_t)) {
+		__u64 *raw_data = data;
+
+		num_stack = size / sizeof(__u64);
+		for (i = 0; i < num_stack; i++) {
+			ks = ksym_search(raw_data[i]);
+			if (ks && (strcmp(ks->name, expected_func) == 0)) {
+				good_kern_stack = true;
+				good_user_stack = (i > 0);
+			}
+		}
+	} else {
+		if (e->kern_stack_size > 0) {
+			num_stack = e->kern_stack_size / sizeof(__u64);
+			for (i = 0; i < num_stack; i++) {
+				ks = ksym_search(e->kern_stack[i]);
+				if (ks && (strcmp(ks->name, expected_func) == 0))
+					good_kern_stack = true;
+			}
+		}
+		if (e->user_stack_size > 0 && e->user_stack_buildid_size > 0)
+			good_user_stack = true;
+	}
+	if (!good_kern_stack || !good_user_stack)
+		return PERF_EVENT_ERROR;
+
+	if (cnt == MAX_CNT_RAWTP)
+		return PERF_EVENT_DONE;
+
+	return PERF_EVENT_CONT;
+}
+
+static void test_get_stack_raw_tp(void)
+{
+	const char *file = "./test_get_stack_rawtp.o";
+	int efd, err, prog_fd, pmu_fd, perfmap_fd;
+	struct perf_event_attr attr = {};
+	__u32 key = 0, duration = 0;
+	struct bpf_object *obj;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
+	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
+		return;
+
+	efd = bpf_raw_tracepoint_open("sched_switch", prog_fd);
+	if (CHECK(efd < 0, "raw_tp_open", "err %d errno %d\n", efd, errno))
+		goto close_prog;
+
+	perfmap_fd = bpf_find_map(__func__, obj, "perfmap");
+	if (CHECK(perfmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
+		  perfmap_fd, errno))
+		goto close_prog;
+
+	err = load_kallsyms();
+	if (CHECK(err < 0, "load_kallsyms", "err %d errno %d\n", err, errno))
+		goto close_prog;
+
+	attr.sample_type = PERF_SAMPLE_RAW;
+	attr.type = PERF_TYPE_SOFTWARE;
+	attr.config = PERF_COUNT_SW_BPF_OUTPUT;
+	pmu_fd = syscall(__NR_perf_event_open, &attr, -1/*pid*/, 0/*cpu*/,
+			 -1/*group_fd*/, 0);
+	if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
+		  errno))
+		goto close_prog;
+
+	err = bpf_map_update_elem(perfmap_fd, &key, &pmu_fd, BPF_ANY);
+	if (CHECK(err < 0, "bpf_map_update_elem", "err %d errno %d\n", err,
+		  errno))
+		goto close_prog;
+
+	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
+	if (CHECK(err < 0, "ioctl PERF_EVENT_IOC_ENABLE", "err %d errno %d\n",
+		  err, errno))
+		goto close_prog;
+
+	err = perf_event_poller(pmu_fd, get_stack_raw_tp_action,
+				get_stack_print_output);
+	if (CHECK(err < 0, "perf_event_poller", "err %d errno %d\n", err,
+		  errno))
+		goto close_prog;
+
+	goto close_prog_noerr;
+close_prog:
+	error_cnt++;
+close_prog_noerr:
+	bpf_object__close(obj);
+}
+
 int main(void)
 {
 	test_pkt_access();
@@ -1219,6 +1340,7 @@ int main(void)
 	test_stacktrace_map();
 	test_stacktrace_build_id();
 	test_stacktrace_map_raw_tp();
+	test_get_stack_raw_tp();
 
 	printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
 	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 08/10] tools/bpf: add a verifier test case for bpf_get_stack helper and ARSH
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

The test_verifier already has a few ARSH test cases.
This patch adds a new test case which takes advantage of newly
improved verifier behavior for bpf_get_stack and ARSH.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/test_verifier.c | 45 +++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 3e7718b..cd595ba 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -11423,6 +11423,51 @@ static struct bpf_test tests[] = {
 		.errstr = "BPF_XADD stores into R2 packet",
 		.prog_type = BPF_PROG_TYPE_XDP,
 	},
+	{
+		"bpf_get_stack return R0 within range",
+		.insns = {
+			BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+			BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+			BPF_LD_MAP_FD(BPF_REG_1, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_map_lookup_elem),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 28),
+			BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+			BPF_MOV64_IMM(BPF_REG_9, sizeof(struct test_val)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+			BPF_MOV64_IMM(BPF_REG_3, sizeof(struct test_val)),
+			BPF_MOV64_IMM(BPF_REG_4, 256),
+			BPF_EMIT_CALL(BPF_FUNC_get_stack),
+			BPF_MOV64_IMM(BPF_REG_1, 0),
+			BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_8, 32),
+			BPF_ALU64_IMM(BPF_ARSH, BPF_REG_8, 32),
+			BPF_JMP_REG(BPF_JSLT, BPF_REG_1, BPF_REG_8, 16),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_8),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
+			BPF_ALU64_IMM(BPF_ARSH, BPF_REG_1, 32),
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_1),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+			BPF_MOV64_IMM(BPF_REG_5, sizeof(struct test_val)),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_5),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 4),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_9),
+			BPF_MOV64_IMM(BPF_REG_4, 0),
+			BPF_EMIT_CALL(BPF_FUNC_get_stack),
+			BPF_EXIT_INSN(),
+		},
+		.fixup_map2 = { 4 },
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	},
 };
 
 static int probe_filter_length(const struct bpf_insn *fp)
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 00/10] bpf: add bpf_get_stack helper
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team

Currently, stackmap and bpf_get_stackid helper are provided
for bpf program to get the stack trace. This approach has
a limitation though. If two stack traces have the same hash,
only one will get stored in the stackmap table regardless of
whether BPF_F_REUSE_STACKID is specified or not,
so some stack traces may be missing from user perspective.

This patch implements a new helper, bpf_get_stack, will
send stack traces directly to bpf program. The bpf program
is able to see all stack traces, and then can do in-kernel
processing or send stack traces to user space through
shared map or bpf_perf_event_output.

Patches #1 and #2 implemented the core kernel support.
Patch #3 removes two never-hit branches in verifier.
Patches #4 and #5 are two verifier improves to make
bpf programming easier. Patch #6 synced the new helper
to tools headers. Patch #7 moved perf_event polling code
and ksym lookup code from samples/bpf to
tools/testing/selftests/bpf. Patch #8 added a verifier
test in tools/bpf for new verifier change.
Patches #9 and #10 added tests for raw tracepoint prog
and tracepoint prog respectively.

Changelogs:
  v4 -> v5:
    . relied on dst_reg->var_off to refine umin_val/umax_val
      in verifier handling BPF_ARSH value range tracking,
      suggested by Edward.
  v3 -> v4:
    . fixed a bug when meta ptr is set to NULL in check_func_arg.
    . introduced tnum_arshift and added detailed comments for
      the underlying implementation
    . avoided using VLA in tools/bpf test_progs.
  v2 -> v3:
    . used meta to track helper memory size argument
    . implemented range checking for ARSH in verifier
    . moved perf event polling and ksym related functions
      from samples/bpf to tools/bpf
    . added test to compare build id's between bpf_get_stackid
      and bpf_get_stack
  v1 -> v2:
    . fixed compilation error when CONFIG_PERF_EVENTS is not enabled

Yonghong Song (10):
  bpf: change prototype for stack_map_get_build_id_offset
  bpf: add bpf_get_stack helper
  bpf/verifier: refine retval R0 state for bpf_get_stack helper
  bpf: remove never-hit branches in verifier adjust_scalar_min_max_vals
  bpf/verifier: improve register value range tracking with ARSH
  tools/bpf: add bpf_get_stack helper to tools headers
  samples/bpf: move common-purpose trace functions to selftests
  tools/bpf: add a verifier test case for bpf_get_stack helper and ARSH
  tools/bpf: add a test for bpf_get_stack with raw tracepoint prog
  tools/bpf: add a test for bpf_get_stack with tracepoint prog

 include/linux/bpf.h                                |   1 +
 include/linux/filter.h                             |   3 +-
 include/linux/tnum.h                               |   4 +-
 include/uapi/linux/bpf.h                           |  19 +-
 kernel/bpf/core.c                                  |   5 +
 kernel/bpf/stackmap.c                              |  80 ++++++++-
 kernel/bpf/syscall.c                               |  10 ++
 kernel/bpf/tnum.c                                  |  10 ++
 kernel/bpf/verifier.c                              |  80 ++++++++-
 kernel/trace/bpf_trace.c                           |  50 +++++-
 samples/bpf/Makefile                               |  11 +-
 samples/bpf/bpf_load.c                             |  63 -------
 samples/bpf/bpf_load.h                             |   7 -
 samples/bpf/offwaketime_user.c                     |   1 +
 samples/bpf/sampleip_user.c                        |   1 +
 samples/bpf/spintest_user.c                        |   1 +
 samples/bpf/trace_event_user.c                     |   1 +
 samples/bpf/trace_output_user.c                    | 125 ++------------
 tools/include/uapi/linux/bpf.h                     |  19 +-
 tools/testing/selftests/bpf/Makefile               |   3 +-
 tools/testing/selftests/bpf/bpf_helpers.h          |   3 +-
 tools/testing/selftests/bpf/test_get_stack_rawtp.c | 102 +++++++++++
 tools/testing/selftests/bpf/test_progs.c           | 192 ++++++++++++++++++++-
 .../selftests/bpf/test_stacktrace_build_id.c       |  20 ++-
 tools/testing/selftests/bpf/test_stacktrace_map.c  |  20 ++-
 tools/testing/selftests/bpf/test_verifier.c        |  45 +++++
 tools/testing/selftests/bpf/trace_helpers.c        | 186 ++++++++++++++++++++
 tools/testing/selftests/bpf/trace_helpers.h        |  24 +++
 28 files changed, 867 insertions(+), 219 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/test_get_stack_rawtp.c
 create mode 100644 tools/testing/selftests/bpf/trace_helpers.c
 create mode 100644 tools/testing/selftests/bpf/trace_helpers.h

-- 
2.9.5

^ permalink raw reply

* [PATCH bpf-next v5 07/10] samples/bpf: move common-purpose trace functions to selftests
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

There is no functionality change in this patch. The common-purpose
trace functions, including perf_event polling and ksym lookup,
are moved from trace_output_user.c and bpf_load.c to
selftests/bpf/trace_helpers.c so that these function can
be reused later in selftests.

Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 samples/bpf/Makefile                        |  11 +-
 samples/bpf/bpf_load.c                      |  63 ----------
 samples/bpf/bpf_load.h                      |   7 --
 samples/bpf/offwaketime_user.c              |   1 +
 samples/bpf/sampleip_user.c                 |   1 +
 samples/bpf/spintest_user.c                 |   1 +
 samples/bpf/trace_event_user.c              |   1 +
 samples/bpf/trace_output_user.c             | 125 +++----------------
 tools/testing/selftests/bpf/trace_helpers.c | 186 ++++++++++++++++++++++++++++
 tools/testing/selftests/bpf/trace_helpers.h |  24 ++++
 10 files changed, 238 insertions(+), 182 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/trace_helpers.c
 create mode 100644 tools/testing/selftests/bpf/trace_helpers.h

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index aa8c392..d36444c 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -49,6 +49,7 @@ hostprogs-y += xdp_adjust_tail
 # Libbpf dependencies
 LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o
 CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
+TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
 
 test_lru_dist-objs := test_lru_dist.o $(LIBBPF)
 sock_example-objs := sock_example.o $(LIBBPF)
@@ -65,10 +66,10 @@ tracex6-objs := bpf_load.o $(LIBBPF) tracex6_user.o
 tracex7-objs := bpf_load.o $(LIBBPF) tracex7_user.o
 load_sock_ops-objs := bpf_load.o $(LIBBPF) load_sock_ops.o
 test_probe_write_user-objs := bpf_load.o $(LIBBPF) test_probe_write_user_user.o
-trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o
+trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o $(TRACE_HELPERS)
 lathist-objs := bpf_load.o $(LIBBPF) lathist_user.o
-offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o
-spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o
+offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o $(TRACE_HELPERS)
+spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o $(TRACE_HELPERS)
 map_perf_test-objs := bpf_load.o $(LIBBPF) map_perf_test_user.o
 test_overhead-objs := bpf_load.o $(LIBBPF) test_overhead_user.o
 test_cgrp2_array_pin-objs := $(LIBBPF) test_cgrp2_array_pin.o
@@ -82,8 +83,8 @@ xdp2-objs := bpf_load.o $(LIBBPF) xdp1_user.o
 xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o
 test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \
 				       test_current_task_under_cgroup_user.o
-trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o
-sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o
+trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o $(TRACE_HELPERS)
+sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o $(TRACE_HELPERS)
 tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o
 lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o
 xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index bebe418..529972e 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -650,66 +650,3 @@ void read_trace_pipe(void)
 		}
 	}
 }
-
-#define MAX_SYMS 300000
-static struct ksym syms[MAX_SYMS];
-static int sym_cnt;
-
-static int ksym_cmp(const void *p1, const void *p2)
-{
-	return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
-}
-
-int load_kallsyms(void)
-{
-	FILE *f = fopen("/proc/kallsyms", "r");
-	char func[256], buf[256];
-	char symbol;
-	void *addr;
-	int i = 0;
-
-	if (!f)
-		return -ENOENT;
-
-	while (!feof(f)) {
-		if (!fgets(buf, sizeof(buf), f))
-			break;
-		if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
-			break;
-		if (!addr)
-			continue;
-		syms[i].addr = (long) addr;
-		syms[i].name = strdup(func);
-		i++;
-	}
-	sym_cnt = i;
-	qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
-	return 0;
-}
-
-struct ksym *ksym_search(long key)
-{
-	int start = 0, end = sym_cnt;
-	int result;
-
-	while (start < end) {
-		size_t mid = start + (end - start) / 2;
-
-		result = key - syms[mid].addr;
-		if (result < 0)
-			end = mid;
-		else if (result > 0)
-			start = mid + 1;
-		else
-			return &syms[mid];
-	}
-
-	if (start >= 1 && syms[start - 1].addr < key &&
-	    key < syms[start].addr)
-		/* valid ksym */
-		return &syms[start - 1];
-
-	/* out of range. return _stext */
-	return &syms[0];
-}
-
diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h
index 453c200..2c3d0b4 100644
--- a/samples/bpf/bpf_load.h
+++ b/samples/bpf/bpf_load.h
@@ -54,12 +54,5 @@ int load_bpf_file(char *path);
 int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map);
 
 void read_trace_pipe(void);
-struct ksym {
-	long addr;
-	char *name;
-};
-
-int load_kallsyms(void);
-struct ksym *ksym_search(long key);
 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
 #endif
diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
index 512f87a..f06063a 100644
--- a/samples/bpf/offwaketime_user.c
+++ b/samples/bpf/offwaketime_user.c
@@ -17,6 +17,7 @@
 #include <sys/resource.h>
 #include "libbpf.h"
 #include "bpf_load.h"
+#include "trace_helpers.h"
 
 #define PRINT_RAW_ADDR 0
 
diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
index 4ed690b..60c2b73 100644
--- a/samples/bpf/sampleip_user.c
+++ b/samples/bpf/sampleip_user.c
@@ -22,6 +22,7 @@
 #include "libbpf.h"
 #include "bpf_load.h"
 #include "perf-sys.h"
+#include "trace_helpers.h"
 
 #define DEFAULT_FREQ	99
 #define DEFAULT_SECS	5
diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c
index 3d73621..8d3e9cf 100644
--- a/samples/bpf/spintest_user.c
+++ b/samples/bpf/spintest_user.c
@@ -7,6 +7,7 @@
 #include <sys/resource.h>
 #include "libbpf.h"
 #include "bpf_load.h"
+#include "trace_helpers.h"
 
 int main(int ac, char **argv)
 {
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index 56f7a25..1fa1bec 100644
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c
@@ -21,6 +21,7 @@
 #include "libbpf.h"
 #include "bpf_load.h"
 #include "perf-sys.h"
+#include "trace_helpers.h"
 
 #define SAMPLE_FREQ 50
 
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index ccca1e3..cc4b383 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -21,100 +21,10 @@
 #include "libbpf.h"
 #include "bpf_load.h"
 #include "perf-sys.h"
+#include "trace_helpers.h"
 
 static int pmu_fd;
 
-int page_size;
-int page_cnt = 8;
-volatile struct perf_event_mmap_page *header;
-
-typedef void (*print_fn)(void *data, int size);
-
-static int perf_event_mmap(int fd)
-{
-	void *base;
-	int mmap_size;
-
-	page_size = getpagesize();
-	mmap_size = page_size * (page_cnt + 1);
-
-	base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (base == MAP_FAILED) {
-		printf("mmap err\n");
-		return -1;
-	}
-
-	header = base;
-	return 0;
-}
-
-static int perf_event_poll(int fd)
-{
-	struct pollfd pfd = { .fd = fd, .events = POLLIN };
-
-	return poll(&pfd, 1, 1000);
-}
-
-struct perf_event_sample {
-	struct perf_event_header header;
-	__u32 size;
-	char data[];
-};
-
-static void perf_event_read(print_fn fn)
-{
-	__u64 data_tail = header->data_tail;
-	__u64 data_head = header->data_head;
-	__u64 buffer_size = page_cnt * page_size;
-	void *base, *begin, *end;
-	char buf[256];
-
-	asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
-	if (data_head == data_tail)
-		return;
-
-	base = ((char *)header) + page_size;
-
-	begin = base + data_tail % buffer_size;
-	end = base + data_head % buffer_size;
-
-	while (begin != end) {
-		struct perf_event_sample *e;
-
-		e = begin;
-		if (begin + e->header.size > base + buffer_size) {
-			long len = base + buffer_size - begin;
-
-			assert(len < e->header.size);
-			memcpy(buf, begin, len);
-			memcpy(buf + len, base, e->header.size - len);
-			e = (void *) buf;
-			begin = base + e->header.size - len;
-		} else if (begin + e->header.size == base + buffer_size) {
-			begin = base;
-		} else {
-			begin += e->header.size;
-		}
-
-		if (e->header.type == PERF_RECORD_SAMPLE) {
-			fn(e->data, e->size);
-		} else if (e->header.type == PERF_RECORD_LOST) {
-			struct {
-				struct perf_event_header header;
-				__u64 id;
-				__u64 lost;
-			} *lost = (void *) e;
-			printf("lost %lld events\n", lost->lost);
-		} else {
-			printf("unknown event type=%d size=%d\n",
-			       e->header.type, e->header.size);
-		}
-	}
-
-	__sync_synchronize(); /* smp_mb() */
-	header->data_tail = data_head;
-}
-
 static __u64 time_get_ns(void)
 {
 	struct timespec ts;
@@ -127,7 +37,7 @@ static __u64 start_time;
 
 #define MAX_CNT 100000ll
 
-static void print_bpf_output(void *data, int size)
+static int print_bpf_output(void *data, int size)
 {
 	static __u64 cnt;
 	struct {
@@ -138,7 +48,7 @@ static void print_bpf_output(void *data, int size)
 	if (e->cookie != 0x12345678) {
 		printf("BUG pid %llx cookie %llx sized %d\n",
 		       e->pid, e->cookie, size);
-		kill(0, SIGINT);
+		return PERF_EVENT_ERROR;
 	}
 
 	cnt++;
@@ -146,8 +56,10 @@ static void print_bpf_output(void *data, int size)
 	if (cnt == MAX_CNT) {
 		printf("recv %lld events per sec\n",
 		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
-		kill(0, SIGINT);
+		return PERF_EVENT_DONE;
 	}
+
+	return PERF_EVENT_CONT;
 }
 
 static void test_bpf_perf_event(void)
@@ -166,10 +78,18 @@ static void test_bpf_perf_event(void)
 	ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
 }
 
+static void exec_action(void)
+{
+	FILE *f;
+
+	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+	(void) f;
+}
+
 int main(int argc, char **argv)
 {
 	char filename[256];
-	FILE *f;
+	int ret;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 
@@ -180,17 +100,8 @@ int main(int argc, char **argv)
 
 	test_bpf_perf_event();
 
-	if (perf_event_mmap(pmu_fd) < 0)
-		return 1;
-
-	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
-	(void) f;
-
 	start_time = time_get_ns();
-	for (;;) {
-		perf_event_poll(pmu_fd);
-		perf_event_read(print_bpf_output);
-	}
-
-	return 0;
+	ret = perf_event_poller(pmu_fd, exec_action, print_bpf_output);
+	kill(0, SIGINT);
+	return ret;
 }
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
new file mode 100644
index 0000000..00954e3
--- /dev/null
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <poll.h>
+#include <unistd.h>
+#include <linux/perf_event.h>
+#include <sys/mman.h>
+#include "trace_helpers.h"
+
+#define MAX_SYMS 300000
+static struct ksym syms[MAX_SYMS];
+static int sym_cnt;
+
+static int ksym_cmp(const void *p1, const void *p2)
+{
+	return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
+}
+
+int load_kallsyms(void)
+{
+	FILE *f = fopen("/proc/kallsyms", "r");
+	char func[256], buf[256];
+	char symbol;
+	void *addr;
+	int i = 0;
+
+	if (!f)
+		return -ENOENT;
+
+	while (!feof(f)) {
+		if (!fgets(buf, sizeof(buf), f))
+			break;
+		if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
+			break;
+		if (!addr)
+			continue;
+		syms[i].addr = (long) addr;
+		syms[i].name = strdup(func);
+		i++;
+	}
+	sym_cnt = i;
+	qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
+	return 0;
+}
+
+struct ksym *ksym_search(long key)
+{
+	int start = 0, end = sym_cnt;
+	int result;
+
+	while (start < end) {
+		size_t mid = start + (end - start) / 2;
+
+		result = key - syms[mid].addr;
+		if (result < 0)
+			end = mid;
+		else if (result > 0)
+			start = mid + 1;
+		else
+			return &syms[mid];
+	}
+
+	if (start >= 1 && syms[start - 1].addr < key &&
+	    key < syms[start].addr)
+		/* valid ksym */
+		return &syms[start - 1];
+
+	/* out of range. return _stext */
+	return &syms[0];
+}
+
+static int page_size;
+static int page_cnt = 8;
+static volatile struct perf_event_mmap_page *header;
+
+static int perf_event_mmap(int fd)
+{
+	void *base;
+	int mmap_size;
+
+	page_size = getpagesize();
+	mmap_size = page_size * (page_cnt + 1);
+
+	base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (base == MAP_FAILED) {
+		printf("mmap err\n");
+		return -1;
+	}
+
+	header = base;
+	return 0;
+}
+
+static int perf_event_poll(int fd)
+{
+	struct pollfd pfd = { .fd = fd, .events = POLLIN };
+
+	return poll(&pfd, 1, 1000);
+}
+
+struct perf_event_sample {
+	struct perf_event_header header;
+	__u32 size;
+	char data[];
+};
+
+static int perf_event_read(perf_event_print_fn fn)
+{
+	__u64 data_tail = header->data_tail;
+	__u64 data_head = header->data_head;
+	__u64 buffer_size = page_cnt * page_size;
+	void *base, *begin, *end;
+	char buf[256];
+	int ret;
+
+	asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
+	if (data_head == data_tail)
+		return PERF_EVENT_CONT;
+
+	base = ((char *)header) + page_size;
+
+	begin = base + data_tail % buffer_size;
+	end = base + data_head % buffer_size;
+
+	while (begin != end) {
+		struct perf_event_sample *e;
+
+		e = begin;
+		if (begin + e->header.size > base + buffer_size) {
+			long len = base + buffer_size - begin;
+
+			assert(len < e->header.size);
+			memcpy(buf, begin, len);
+			memcpy(buf + len, base, e->header.size - len);
+			e = (void *) buf;
+			begin = base + e->header.size - len;
+		} else if (begin + e->header.size == base + buffer_size) {
+			begin = base;
+		} else {
+			begin += e->header.size;
+		}
+
+		if (e->header.type == PERF_RECORD_SAMPLE) {
+			ret = fn(e->data, e->size);
+			if (ret != PERF_EVENT_CONT)
+				return ret;
+		} else if (e->header.type == PERF_RECORD_LOST) {
+			struct {
+				struct perf_event_header header;
+				__u64 id;
+				__u64 lost;
+			} *lost = (void *) e;
+			printf("lost %lld events\n", lost->lost);
+		} else {
+			printf("unknown event type=%d size=%d\n",
+			       e->header.type, e->header.size);
+		}
+	}
+
+	__sync_synchronize(); /* smp_mb() */
+	header->data_tail = data_head;
+	return PERF_EVENT_CONT;
+}
+
+int perf_event_poller(int fd, perf_event_exec_fn exec_fn,
+		      perf_event_print_fn output_fn)
+{
+	int ret;
+
+	if (perf_event_mmap(fd) < 0)
+		return PERF_EVENT_ERROR;
+
+	exec_fn();
+
+	for (;;) {
+		perf_event_poll(fd);
+		ret = perf_event_read(output_fn);
+		if (ret != PERF_EVENT_CONT)
+			return ret;
+	}
+
+	return PERF_EVENT_DONE;
+}
diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
new file mode 100644
index 0000000..8750778
--- /dev/null
+++ b/tools/testing/selftests/bpf/trace_helpers.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TRACE_HELPER_H
+#define __TRACE_HELPER_H
+
+struct ksym {
+	long addr;
+	char *name;
+};
+
+int load_kallsyms(void);
+struct ksym *ksym_search(long key);
+
+typedef void (*perf_event_exec_fn)(void);
+typedef int (*perf_event_print_fn)(void *data, int size);
+
+/* return code for perf_event_print_fn */
+#define PERF_EVENT_DONE		0
+#define PERF_EVENT_ERROR	1
+#define PERF_EVENT_CONT		2
+
+/* return PERF_EVENT_DONE or PERF_EVENT_ERROR */
+int perf_event_poller(int fd, perf_event_exec_fn exec_fn,
+		      perf_event_print_fn output_fn);
+#endif
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 03/10] bpf/verifier: refine retval R0 state for bpf_get_stack helper
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

The special property of return values for helpers bpf_get_stack
and bpf_probe_read_str are captured in verifier.
Both helpers return a negative error code or
a length, which is equal to or smaller than the buffer
size argument. This additional information in the
verifier can avoid the condition such as "retval > bufsize"
in the bpf program. For example, for the code blow,
    usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
    if (usize < 0 || usize > max_len)
        return 0;
The verifier may have the following errors:
    52: (85) call bpf_get_stack#65
     R0=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R1_w=ctx(id=0,off=0,imm=0)
     R2_w=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R3_w=inv800 R4_w=inv256
     R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0)
     R9_w=inv800 R10=fp0,call_-1
    53: (bf) r8 = r0
    54: (bf) r1 = r8
    55: (67) r1 <<= 32
    56: (bf) r2 = r1
    57: (77) r2 >>= 32
    58: (25) if r2 > 0x31f goto pc+33
     R0=inv(id=0) R1=inv(id=0,smax_value=9223372032559808512,
                         umax_value=18446744069414584320,
                         var_off=(0x0; 0xffffffff00000000))
     R2=inv(id=0,umax_value=799,var_off=(0x0; 0x3ff))
     R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0)
     R8=inv(id=0) R9=inv800 R10=fp0,call_-1
    59: (1f) r9 -= r8
    60: (c7) r1 s>>= 32
    61: (bf) r2 = r7
    62: (0f) r2 += r1
    math between map_value pointer and register with unbounded
    min value is not allowed
The failure is due to llvm compiler optimization where register "r2",
which is a copy of "r1", is tested for condition while later on "r1"
is used for map_ptr operation. The verifier is not able to track such
inst sequence effectively.

Without the "usize > max_len" condition, there is no llvm optimization
and the below generated code passed verifier:
    52: (85) call bpf_get_stack#65
     R0=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R1_w=ctx(id=0,off=0,imm=0)
     R2_w=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R3_w=inv800 R4_w=inv256
     R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0)
     R9_w=inv800 R10=fp0,call_-1
    53: (b7) r1 = 0
    54: (bf) r8 = r0
    55: (67) r8 <<= 32
    56: (c7) r8 s>>= 32
    57: (6d) if r1 s> r8 goto pc+24
     R0=inv(id=0,umax_value=800) R1=inv0 R6=ctx(id=0,off=0,imm=0)
     R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0)
     R8=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R9=inv800
     R10=fp0,call_-1
    58: (bf) r2 = r7
    59: (0f) r2 += r8
    60: (1f) r9 -= r8
    61: (bf) r1 = r6

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/bpf/verifier.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index aba9425..d00bf53 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -164,6 +164,8 @@ struct bpf_call_arg_meta {
 	bool pkt_access;
 	int regno;
 	int access_size;
+	s64 msize_smax_value;
+	u64 msize_umax_value;
 };
 
 static DEFINE_MUTEX(bpf_verifier_lock);
@@ -1994,6 +1996,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 	} else if (arg_type_is_mem_size(arg_type)) {
 		bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO);
 
+		/* remember the mem_size which may be used later
+		 * to refine return values.
+		 */
+		meta->msize_smax_value = reg->smax_value;
+		meta->msize_umax_value = reg->umax_value;
+
 		/* The register is SCALAR_VALUE; the access check
 		 * happens using its boundaries.
 		 */
@@ -2333,6 +2341,21 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
 	return 0;
 }
 
+static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
+				   int func_id,
+				   struct bpf_call_arg_meta *meta)
+{
+	struct bpf_reg_state *ret_reg = &regs[BPF_REG_0];
+
+	if (ret_type != RET_INTEGER ||
+	    (func_id != BPF_FUNC_get_stack &&
+	     func_id != BPF_FUNC_probe_read_str))
+		return;
+
+	ret_reg->smax_value = meta->msize_smax_value;
+	ret_reg->umax_value = meta->msize_umax_value;
+}
+
 static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
 {
 	const struct bpf_func_proto *fn = NULL;
@@ -2456,6 +2479,8 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		return -EINVAL;
 	}
 
+	do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
+
 	err = check_map_func_compatibility(env, meta.map_ptr, func_id);
 	if (err)
 		return err;
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 04/10] bpf: remove never-hit branches in verifier adjust_scalar_min_max_vals
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

In verifier function adjust_scalar_min_max_vals,
when src_known is false and the opcode is BPF_LSH/BPF_RSH,
early return will happen in the function. So remove
the branch in handling BPF_LSH/BPF_RSH when src_known is false.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/bpf/verifier.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d00bf53..1bbb43d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2932,10 +2932,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value <<= umin_val;
 			dst_reg->umax_value <<= umax_val;
 		}
-		if (src_known)
-			dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
-		else
-			dst_reg->var_off = tnum_lshift(tnum_unknown, umin_val);
+		dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
 		/* We may learn something more from the var_off */
 		__update_reg_bounds(dst_reg);
 		break;
@@ -2963,11 +2960,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 		 */
 		dst_reg->smin_value = S64_MIN;
 		dst_reg->smax_value = S64_MAX;
-		if (src_known)
-			dst_reg->var_off = tnum_rshift(dst_reg->var_off,
-						       umin_val);
-		else
-			dst_reg->var_off = tnum_rshift(tnum_unknown, umin_val);
+		dst_reg->var_off = tnum_rshift(dst_reg->var_off, umin_val);
 		dst_reg->umin_value >>= umax_val;
 		dst_reg->umax_value >>= umin_val;
 		/* We may learn something more from the var_off */
-- 
2.9.5

^ permalink raw reply related

* [PATCH bpf-next v5 01/10] bpf: change prototype for stack_map_get_build_id_offset
From: Yonghong Song @ 2018-04-23 17:54 UTC (permalink / raw)
  To: ast, daniel, netdev, ecree; +Cc: kernel-team
In-Reply-To: <20180423175417.4104464-1-yhs@fb.com>

This patch didn't incur functionality change. The function prototype
got changed so that the same function can be reused later.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 kernel/bpf/stackmap.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 57eeb12..04f6ec1 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -262,16 +262,11 @@ static int stack_map_get_build_id(struct vm_area_struct *vma,
 	return ret;
 }
 
-static void stack_map_get_build_id_offset(struct bpf_map *map,
-					  struct stack_map_bucket *bucket,
+static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
 					  u64 *ips, u32 trace_nr, bool user)
 {
 	int i;
 	struct vm_area_struct *vma;
-	struct bpf_stack_build_id *id_offs;
-
-	bucket->nr = trace_nr;
-	id_offs = (struct bpf_stack_build_id *)bucket->data;
 
 	/*
 	 * We cannot do up_read() in nmi context, so build_id lookup is
@@ -361,8 +356,10 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
 			pcpu_freelist_pop(&smap->freelist);
 		if (unlikely(!new_bucket))
 			return -ENOMEM;
-		stack_map_get_build_id_offset(map, new_bucket, ips,
-					      trace_nr, user);
+		new_bucket->nr = trace_nr;
+		stack_map_get_build_id_offset(
+			(struct bpf_stack_build_id *)new_bucket->data,
+			ips, trace_nr, user);
 		trace_len = trace_nr * sizeof(struct bpf_stack_build_id);
 		if (hash_matches && bucket->nr == trace_nr &&
 		    memcmp(bucket->data, new_bucket->data, trace_len) == 0) {
-- 
2.9.5

^ permalink raw reply related


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