netdev_printk/dynamic_netdev_dbg: Directly call printk_emit

A lot of stack is used in recursive printks with %pV.

Using multiple levels of %pV (a logging function with %pV
that calls another logging function with %pV) can consume
more stack than necessary.

Avoid excessive stack use by not calling dev_printk from
netdev_printk and dynamic_netdev_dbg.  Duplicate the logic
and form of dev_printk instead.

Make __netdev_printk static.
Remove EXPORT_SYMBOL(__netdev_printk)
Whitespace and brace style neatening.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 17 insertions, 7 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index d7fe32c946c1..ac890f14613a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6423,22 +6423,30 @@ const char *netdev_drivername(const struct net_device *dev)
         return empty;
 }
 
-int __netdev_printk(const char *level, const struct net_device *dev,
+static int __netdev_printk(const char *level, const struct net_device *dev,
                            struct va_format *vaf)
 {
         int r;
 
-        if (dev && dev->dev.parent)
-                r = dev_printk(level, dev->dev.parent, "%s: %pV",
-                               netdev_name(dev), vaf);
-        else if (dev)
+        if (dev && dev->dev.parent) {
+                char dict[128];
+                size_t dictlen = create_syslog_header(dev->dev.parent,
+                                                      dict, sizeof(dict));
+
+                r = printk_emit(0, level[1] - '0',
+                                dictlen ? dict : NULL, dictlen,
+                                "%s %s: %s: %pV",
+                                dev_driver_string(dev->dev.parent),
+                                dev_name(dev->dev.parent),
+                                netdev_name(dev), vaf);
+        } else if (dev) {
                 r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
-        else
+        } else {
                 r = printk("%s(NULL net_device): %pV", level, vaf);
+        }
 
         return r;
 }
-EXPORT_SYMBOL(__netdev_printk);
 
 int netdev_printk(const char *level, const struct net_device *dev,
                   const char *format, ...)
@@ -6453,6 +6461,7 @@ int netdev_printk(const char *level, const struct net_device *dev,
         vaf.va = &args;
 
         r = __netdev_printk(level, dev, &vaf);
+
         va_end(args);
 
         return r;
@@ -6472,6 +6481,7 @@ int func(const struct net_device *dev, const char *fmt, ...)	\
         vaf.va = &args;                                         \
                                                                 \
         r = __netdev_printk(level, dev, &vaf);                  \
+                                                                \
         va_end(args);                                           \
                                                                 \
         return r;                                               \