printk: synchronize %p formatting documentation

Move all pointer-formatting documentation to one place in the code and one
place in the documentation instead of keeping it in three places with
different level of completeness.  Documentation/printk-formats.txt has
detailed information about each modifier, docstring above pointer() has
short descriptions of them (as that is the function dealing with %p) and
docstring above vsprintf() is removed as redundant.  Both docstrings in
the code that were modified are updated with a reminder of updating the
documentation upon any further change.

[akpm@linux-foundation.org: fix comment]
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 2216eb1..9b8d7f7 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -119,6 +119,7 @@ Raw buffer as an escaped string:
 	If field width is omitted the 1 byte only will be escaped.
 
 Raw buffer as a hex string:
+
 	%*ph	00 01 02  ...  3f
 	%*phC	00:01:02: ... :3f
 	%*phD	00-01-02- ... -3f
@@ -234,6 +235,7 @@ UUID/GUID addresses:
 	Passed by reference.
 
 dentry names:
+
 	%pd{,2,3,4}
 	%pD{,2,3,4}
 
@@ -256,6 +258,8 @@ struct va_format:
 		va_list *va;
 	};
 
+	Implements a "recursive vsnprintf".
+
 	Do not use this feature without some mechanism to verify the
 	correctness of the format string and va_list arguments.
 
@@ -284,6 +288,31 @@ bitmap and its derivatives such as cpumask and nodemask:
 
 	Passed by reference.
 
+Network device features:
+
+	%pNF	0x000000000000c000
+
+	For printing netdev_features_t.
+
+	Passed by reference.
+
+Command from struct task_struct
+
+	%pT	ls
+
+	For printing executable name excluding path from struct
+	task_struct.
+
+	Passed by reference.
+
+Ignored argument:
+
+	%n	%n
+
+	The argument passed will be ignored.  In other words, literal "%n" will
+	be in the output and the argument will be considered for next format
+	specifier.
+
 Thank you for your cooperation and attention.