[PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends

[PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

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()

Eric Dumazet (5):
  net: add include/net/net_debug.h
  net: add CONFIG_DEBUG_NET
  net: warn if transport header was not set
  net: remove two BUG() from skb_checksum_help()
  net: add more debug info in skb_checksum_help()

 include/linux/netdevice.h | 141 +---------------------------------
 include/linux/skbuff.h    |   2 +
 include/net/net_debug.h   | 157 ++++++++++++++++++++++++++++++++++++++
 net/Kconfig.debug         |   7 ++
 net/core/dev.c            |  12 ++-
 5 files changed, 176 insertions(+), 143 deletions(-)
 create mode 100644 include/net/net_debug.h

-- 
2.36.0.512.ge40c2bad7a-goog

[PATCH v2 net-next 1/5] net: add include/net/net_debug.h

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

Remove from include/linux/netdevice.h helpers
that send debug/info/warnings to syslog.

We plan adding more helpers in following patches.

v2: added two includes, and 'struct net_device' forward declaration
    to avoid compile errors (kernel bots)

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/netdevice.h | 141 +----------------------------------
 include/net/net_debug.h   | 151 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 152 insertions(+), 140 deletions(-)
 create mode 100644 include/net/net_debug.h

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 74c97a34921d48c593c08e2bed72e099f42520a3..5fb1de931bcb9d0caaa5449169012b192d69d892 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -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;
@@ -5050,81 +5051,9 @@ 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
@@ -5138,74 +5067,6 @@ 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.
diff --git a/include/net/net_debug.h b/include/net/net_debug.h
new file mode 100644
index 0000000000000000000000000000000000000000..19cd2700c20ea9945ae7662bacfa50f5d2bed398
--- /dev/null
+++ b/include/net/net_debug.h
@@ -0,0 +1,151 @@
+/* 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
+
+
+#endif	/* _LINUX_NET_DEBUG_H */
-- 
2.36.0.512.ge40c2bad7a-goog

[PATCH v2 net-next 2/5] net: add CONFIG_DEBUG_NET

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

This config option enables network debugging checks.

This patch adds DEBUG_NET_WARN_ON_ONCE(cond)
Note that this is not a replacement for WARN_ON_ONCE(cond)
as (cond) is not evaluated if CONFIG_DEBUG_NET is not set.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/net_debug.h | 6 ++++++
 net/Kconfig.debug       | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/include/net/net_debug.h b/include/net/net_debug.h
index 19cd2700c20ea9945ae7662bacfa50f5d2bed398..1e74684cbbdbcd5ba304b935e76376a72d6ba3f2 100644
--- a/include/net/net_debug.h
+++ b/include/net/net_debug.h
@@ -148,4 +148,10 @@ do {								\
 #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 */
diff --git a/net/Kconfig.debug b/net/Kconfig.debug
index 2f50611df858911cf5190a361e4e9316e543ed3a..a5781cf63b16b32e5360df1ca26a753b6505d81f 100644
--- a/net/Kconfig.debug
+++ b/net/Kconfig.debug
@@ -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.
-- 
2.36.0.512.ge40c2bad7a-goog

[PATCH v2 net-next 3/5] net: warn if transport header was not set

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

Make sure skb_transport_header() and skb_transport_offset() uses
are not fooled if the transport header has not been set.

This change will likely expose existing bugs in linux networking stacks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/skbuff.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d58669d6cb91aa30edc70d59a0a7e9d4e2298842..a1c73fccccc68641fe46066e6d1195b31483ca4c 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -42,6 +42,7 @@
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 #include <linux/netfilter/nf_conntrack_common.h>
 #endif
+#include <net/net_debug.h>
 
 /* The interface for checksum offload between the stack and networking drivers
  * is as follows...
@@ -2804,6 +2805,7 @@ 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;
 }
 
-- 
2.36.0.512.ge40c2bad7a-goog

[PATCH v2 net-next 4/5] net: remove two BUG() from skb_checksum_help()

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

I have a syzbot report that managed to get a crash in skb_checksum_help()

If syzbot can trigger these BUG(), it makes sense to replace
them with more friendly WARN_ON_ONCE() since skb_checksum_help()
can instead return an error code.

Note that syzbot will still crash there, until real bug is fixed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/core/dev.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index f036ccb61da4da3ffc52c4f2402427054b831e8a..e12f8310dd86b312092c5d8fd50fa2ab60fce310 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3265,11 +3265,15 @@ 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)))
+		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)))
+		goto out;
 
 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
 	if (ret)
-- 
2.36.0.512.ge40c2bad7a-goog

[PATCH v2 net-next 5/5] net: add more debug info in skb_checksum_help()

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

This is a followup of previous patch.

Dumping the stack trace is a good start, but printing
basic skb information is probably better.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/core/dev.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index e12f8310dd86b312092c5d8fd50fa2ab60fce310..d3221ea4aab3bfded1d3d9e2b0d861afc1c2eed6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3266,15 +3266,17 @@ int skb_checksum_help(struct sk_buff *skb)
 
 	offset = skb_checksum_start_offset(skb);
 	ret = -EINVAL;
-	if (WARN_ON_ONCE(offset >= skb_headlen(skb)))
+	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;
-	if (WARN_ON_ONCE(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;
-- 
2.36.0.512.ge40c2bad7a-goog

Re: [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Mon,  9 May 2022 20:57:36 -0700 you wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> 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.
> 
> [...]

Here is the summary with links:
  - [v2,net-next,1/5] net: add include/net/net_debug.h
    https://git.kernel.org/netdev/net-next/c/5b87be9e4978
  - [v2,net-next,2/5] net: add CONFIG_DEBUG_NET
    https://git.kernel.org/netdev/net-next/c/d268c1f5cfc9
  - [v2,net-next,3/5] net: warn if transport header was not set
    (no matching commit)
  - [v2,net-next,4/5] net: remove two BUG() from skb_checksum_help()
    https://git.kernel.org/netdev/net-next/c/d7ea0d9df2a6
  - [v2,net-next,5/5] net: add more debug info in skb_checksum_help()
    https://git.kernel.org/netdev/net-next/c/eeee4b77dc52

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html