Commit e508af8a authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'debug-net' 



Eric Dumazet says:

====================
net: CONFIG_DEBUG_NET and friends

This patch series is inspired by some syzbot reports
hinting that skb transport_header might be not set
in places we expect it being set.

Add a new CONFIG_DEBUG_NET option
and DEBUG_NET_WARN_ON_ONCE() helper, so that we can start
adding more sanity checks in the future.

Replace two BUG() in skb_checksum_help()
with less risky code.

v2: make first patch compile on more arches/compilers
    add the 5th patch to add more debugging in skb_checksum_help()
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents dc3a2001 eeee4b77

include/linux/netdevice.h

+1 −140
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ 
#include <linux/hashtable.h>

#include <linux/rbtree.h>

#include <net/net_trackers.h>

#include <net/net_debug.h>



struct netpoll_info;

struct device;
@@ -5071,81 +5072,9 @@ static inline const char *netdev_reg_state(const struct net_device *dev) 
	return " (unknown)";

}



__printf(3, 4) __cold

void netdev_printk(const char *level, const struct net_device *dev,

		   const char *format, ...);

__printf(2, 3) __cold

void netdev_emerg(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_alert(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_crit(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_err(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_warn(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_notice(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_info(const struct net_device *dev, const char *format, ...);



#define netdev_level_once(level, dev, fmt, ...)			\

do {								\

	static bool __section(".data.once") __print_once;	\

								\

	if (!__print_once) {					\

		__print_once = true;				\

		netdev_printk(level, dev, fmt, ##__VA_ARGS__);	\

	}							\

} while (0)



#define netdev_emerg_once(dev, fmt, ...) \

	netdev_level_once(KERN_EMERG, dev, fmt, ##__VA_ARGS__)

#define netdev_alert_once(dev, fmt, ...) \

	netdev_level_once(KERN_ALERT, dev, fmt, ##__VA_ARGS__)

#define netdev_crit_once(dev, fmt, ...) \

	netdev_level_once(KERN_CRIT, dev, fmt, ##__VA_ARGS__)

#define netdev_err_once(dev, fmt, ...) \

	netdev_level_once(KERN_ERR, dev, fmt, ##__VA_ARGS__)

#define netdev_warn_once(dev, fmt, ...) \

	netdev_level_once(KERN_WARNING, dev, fmt, ##__VA_ARGS__)

#define netdev_notice_once(dev, fmt, ...) \

	netdev_level_once(KERN_NOTICE, dev, fmt, ##__VA_ARGS__)

#define netdev_info_once(dev, fmt, ...) \

	netdev_level_once(KERN_INFO, dev, fmt, ##__VA_ARGS__)



#define MODULE_ALIAS_NETDEV(device) \

	MODULE_ALIAS("netdev-" device)



#if defined(CONFIG_DYNAMIC_DEBUG) || \

	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

#define netdev_dbg(__dev, format, args...)			\

do {								\

	dynamic_netdev_dbg(__dev, format, ##args);		\

} while (0)

#elif defined(DEBUG)

#define netdev_dbg(__dev, format, args...)			\

	netdev_printk(KERN_DEBUG, __dev, format, ##args)

#else

#define netdev_dbg(__dev, format, args...)			\

({								\

	if (0)							\

		netdev_printk(KERN_DEBUG, __dev, format, ##args); \

})

#endif



#if defined(VERBOSE_DEBUG)

#define netdev_vdbg	netdev_dbg

#else



#define netdev_vdbg(dev, format, args...)			\

({								\

	if (0)							\

		netdev_printk(KERN_DEBUG, dev, format, ##args);	\

	0;							\

})

#endif



/*

 * netdev_WARN() acts like dev_printk(), but with the key difference

 * of using a WARN/WARN_ON to get the message out, including the
@@ -5159,74 +5088,6 @@ do { \ 
	WARN_ONCE(1, "netdevice: %s%s: " format, netdev_name(dev),	\

		  netdev_reg_state(dev), ##args)



/* netif printk helpers, similar to netdev_printk */



#define netif_printk(priv, type, level, dev, fmt, args...)	\

do {					  			\

	if (netif_msg_##type(priv))				\

		netdev_printk(level, (dev), fmt, ##args);	\

} while (0)



#define netif_level(level, priv, type, dev, fmt, args...)	\

do {								\

	if (netif_msg_##type(priv))				\

		netdev_##level(dev, fmt, ##args);		\

} while (0)



#define netif_emerg(priv, type, dev, fmt, args...)		\

	netif_level(emerg, priv, type, dev, fmt, ##args)

#define netif_alert(priv, type, dev, fmt, args...)		\

	netif_level(alert, priv, type, dev, fmt, ##args)

#define netif_crit(priv, type, dev, fmt, args...)		\

	netif_level(crit, priv, type, dev, fmt, ##args)

#define netif_err(priv, type, dev, fmt, args...)		\

	netif_level(err, priv, type, dev, fmt, ##args)

#define netif_warn(priv, type, dev, fmt, args...)		\

	netif_level(warn, priv, type, dev, fmt, ##args)

#define netif_notice(priv, type, dev, fmt, args...)		\

	netif_level(notice, priv, type, dev, fmt, ##args)

#define netif_info(priv, type, dev, fmt, args...)		\

	netif_level(info, priv, type, dev, fmt, ##args)



#if defined(CONFIG_DYNAMIC_DEBUG) || \

	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

#define netif_dbg(priv, type, netdev, format, args...)		\

do {								\

	if (netif_msg_##type(priv))				\

		dynamic_netdev_dbg(netdev, format, ##args);	\

} while (0)

#elif defined(DEBUG)

#define netif_dbg(priv, type, dev, format, args...)		\

	netif_printk(priv, type, KERN_DEBUG, dev, format, ##args)

#else

#define netif_dbg(priv, type, dev, format, args...)			\

({									\

	if (0)								\

		netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \

	0;								\

})

#endif



/* if @cond then downgrade to debug, else print at @level */

#define netif_cond_dbg(priv, type, netdev, cond, level, fmt, args...)     \

	do {                                                              \

		if (cond)                                                 \

			netif_dbg(priv, type, netdev, fmt, ##args);       \

		else                                                      \

			netif_ ## level(priv, type, netdev, fmt, ##args); \

	} while (0)



#if defined(VERBOSE_DEBUG)

#define netif_vdbg	netif_dbg

#else

#define netif_vdbg(priv, type, dev, format, args...)		\

({								\

	if (0)							\

		netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \

	0;							\

})

#endif



/*

 *	The list of packet types we will receive (as opposed to discard)

 *	and the routines to invoke.

include/linux/skbuff.h

+2 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#if IS_ENABLED(CONFIG_NF_CONNTRACK)

#include <linux/netfilter/nf_conntrack_common.h>

#endif

#include <net/net_debug.h>



/**

 * DOC: skb checksums
@@ -2904,6 +2905,7 @@ static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 


static inline unsigned char *skb_transport_header(const struct sk_buff *skb)

{

	DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));

	return skb->head + skb->transport_header;

}

include/net/net_debug.h

0 → 100644
+157 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _LINUX_NET_DEBUG_H

#define _LINUX_NET_DEBUG_H



#include <linux/bug.h>

#include <linux/kern_levels.h>



struct net_device;



__printf(3, 4) __cold

void netdev_printk(const char *level, const struct net_device *dev,

		   const char *format, ...);

__printf(2, 3) __cold

void netdev_emerg(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_alert(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_crit(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_err(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_warn(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_notice(const struct net_device *dev, const char *format, ...);

__printf(2, 3) __cold

void netdev_info(const struct net_device *dev, const char *format, ...);



#define netdev_level_once(level, dev, fmt, ...)			\

do {								\

	static bool __section(".data.once") __print_once;	\

								\

	if (!__print_once) {					\

		__print_once = true;				\

		netdev_printk(level, dev, fmt, ##__VA_ARGS__);	\

	}							\

} while (0)



#define netdev_emerg_once(dev, fmt, ...) \

	netdev_level_once(KERN_EMERG, dev, fmt, ##__VA_ARGS__)

#define netdev_alert_once(dev, fmt, ...) \

	netdev_level_once(KERN_ALERT, dev, fmt, ##__VA_ARGS__)

#define netdev_crit_once(dev, fmt, ...) \

	netdev_level_once(KERN_CRIT, dev, fmt, ##__VA_ARGS__)

#define netdev_err_once(dev, fmt, ...) \

	netdev_level_once(KERN_ERR, dev, fmt, ##__VA_ARGS__)

#define netdev_warn_once(dev, fmt, ...) \

	netdev_level_once(KERN_WARNING, dev, fmt, ##__VA_ARGS__)

#define netdev_notice_once(dev, fmt, ...) \

	netdev_level_once(KERN_NOTICE, dev, fmt, ##__VA_ARGS__)

#define netdev_info_once(dev, fmt, ...) \

	netdev_level_once(KERN_INFO, dev, fmt, ##__VA_ARGS__)



#if defined(CONFIG_DYNAMIC_DEBUG) || \

	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

#define netdev_dbg(__dev, format, args...)			\

do {								\

	dynamic_netdev_dbg(__dev, format, ##args);		\

} while (0)

#elif defined(DEBUG)

#define netdev_dbg(__dev, format, args...)			\

	netdev_printk(KERN_DEBUG, __dev, format, ##args)

#else

#define netdev_dbg(__dev, format, args...)			\

({								\

	if (0)							\

		netdev_printk(KERN_DEBUG, __dev, format, ##args); \

})

#endif



#if defined(VERBOSE_DEBUG)

#define netdev_vdbg	netdev_dbg

#else



#define netdev_vdbg(dev, format, args...)			\

({								\

	if (0)							\

		netdev_printk(KERN_DEBUG, dev, format, ##args);	\

	0;							\

})

#endif



/* netif printk helpers, similar to netdev_printk */



#define netif_printk(priv, type, level, dev, fmt, args...)	\

do {					  			\

	if (netif_msg_##type(priv))				\

		netdev_printk(level, (dev), fmt, ##args);	\

} while (0)



#define netif_level(level, priv, type, dev, fmt, args...)	\

do {								\

	if (netif_msg_##type(priv))				\

		netdev_##level(dev, fmt, ##args);		\

} while (0)



#define netif_emerg(priv, type, dev, fmt, args...)		\

	netif_level(emerg, priv, type, dev, fmt, ##args)

#define netif_alert(priv, type, dev, fmt, args...)		\

	netif_level(alert, priv, type, dev, fmt, ##args)

#define netif_crit(priv, type, dev, fmt, args...)		\

	netif_level(crit, priv, type, dev, fmt, ##args)

#define netif_err(priv, type, dev, fmt, args...)		\

	netif_level(err, priv, type, dev, fmt, ##args)

#define netif_warn(priv, type, dev, fmt, args...)		\

	netif_level(warn, priv, type, dev, fmt, ##args)

#define netif_notice(priv, type, dev, fmt, args...)		\

	netif_level(notice, priv, type, dev, fmt, ##args)

#define netif_info(priv, type, dev, fmt, args...)		\

	netif_level(info, priv, type, dev, fmt, ##args)



#if defined(CONFIG_DYNAMIC_DEBUG) || \

	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

#define netif_dbg(priv, type, netdev, format, args...)		\

do {								\

	if (netif_msg_##type(priv))				\

		dynamic_netdev_dbg(netdev, format, ##args);	\

} while (0)

#elif defined(DEBUG)

#define netif_dbg(priv, type, dev, format, args...)		\

	netif_printk(priv, type, KERN_DEBUG, dev, format, ##args)

#else

#define netif_dbg(priv, type, dev, format, args...)			\

({									\

	if (0)								\

		netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \

	0;								\

})

#endif



/* if @cond then downgrade to debug, else print at @level */

#define netif_cond_dbg(priv, type, netdev, cond, level, fmt, args...)     \

	do {                                                              \

		if (cond)                                                 \

			netif_dbg(priv, type, netdev, fmt, ##args);       \

		else                                                      \

			netif_ ## level(priv, type, netdev, fmt, ##args); \

	} while (0)



#if defined(VERBOSE_DEBUG)

#define netif_vdbg	netif_dbg

#else

#define netif_vdbg(priv, type, dev, format, args...)		\

({								\

	if (0)							\

		netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \

	0;							\

})

#endif





#if defined(CONFIG_DEBUG_NET)

#define DEBUG_NET_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)

#else

#define DEBUG_NET_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)

#endif



#endif	/* _LINUX_NET_DEBUG_H */

net/Kconfig.debug

+7 −0
Original line number Diff line number Diff line
@@ -17,3 +17,10 @@ config NET_NS_REFCNT_TRACKER 
	help

	  Enable debugging feature to track netns references.

	  This adds memory and cpu costs.



config DEBUG_NET

	bool "Add generic networking debug"

	depends on DEBUG_KERNEL

	help

	  Enable extra sanity checks in networking.

	  This is mostly used by fuzzers, but is safe to select.

net/core/dev.c

+9 −3
Original line number Diff line number Diff line
@@ -3265,12 +3265,18 @@ int skb_checksum_help(struct sk_buff *skb) 
	}



	offset = skb_checksum_start_offset(skb);

	BUG_ON(offset >= skb_headlen(skb));

	ret = -EINVAL;

	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {

		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);

		goto out;

	}

	csum = skb_checksum(skb, offset, skb->len - offset, 0);



	offset += skb->csum_offset;

	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));



	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {

		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);

		goto out;

	}

	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));

	if (ret)

		goto out;