[PATCH v2 1/3] tracing: document "string_size" [ku]probe type

From: Omar Sandoval <osandov@osandov.com>
To: Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Namhyung Kim <namhyung@gmail.com>
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	Omar Sandoval <osandov@fb.com>
Subject: [PATCH v2 1/3] tracing: document "string_size" [ku]probe type
Date: Thu,  2 Jun 2016 18:11:01 -0700	[thread overview]
Message-ID: <afa35ca13fd30802d0d307a71570f8fc46e919a4.1464916142.git.osandov@fb.com> (raw)
In-Reply-To: <cover.1464916142.git.osandov@fb.com>
In-Reply-To: <cover.1464916142.git.osandov@fb.com>

From: Omar Sandoval <osandov@fb.com>

It has been undocumented since it was introduced in commit e09c8614b329
("tracing/kprobes: Support "string" type").

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 Documentation/trace/kprobetrace.txt  | 11 ++++++-----
 Documentation/trace/uprobetracer.txt |  9 +++++----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index d68ea5fc812b..4b3f5293b7bf 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -43,8 +43,8 @@ Synopsis of kprobe_events
   +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
   NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
   FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
-		  (u8/u16/u32/u64/s8/s16/s32/s64), "string" and bitfield
-		  are supported.
+		  (u8/u16/u32/u64/s8/s16/s32/s64), "string", "string_size", and
+		  bitfield are supported.
 
   (*) only for return probe.
   (**) this is useful for fetching a field of data structures.
@@ -54,9 +54,10 @@ Types
 Several types are supported for fetch-args. Kprobe tracer will access memory
 by given type. Prefix 's' and 'u' means those types are signed and unsigned
 respectively. Traced arguments are shown in decimal (signed) or hex (unsigned).
-String type is a special type, which fetches a "null-terminated" string from
-kernel space. This means it will fail and store NULL if the string container
-has been paged out.
+"string" is a special type which fetches a null-terminated string from kernel
+space. This means it will fail and store NULL if the string container has been
+paged out. "string_size" is the length of a null-terminated string including
+the NUL byte.
 Bitfield is another special type, which takes 3 parameters, bit-width, bit-
 offset, and container-size (usually 32). The syntax is;
 
diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt
index f1cf9a34ad9d..7e0480263c2f 100644
--- a/Documentation/trace/uprobetracer.txt
+++ b/Documentation/trace/uprobetracer.txt
@@ -39,8 +39,8 @@ Synopsis of uprobe_tracer
    +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
    NAME=FETCHARG     : Set NAME as the argument name of FETCHARG.
    FETCHARG:TYPE     : Set TYPE as the type of FETCHARG. Currently, basic types
-		       (u8/u16/u32/u64/s8/s16/s32/s64), "string" and bitfield
-		       are supported.
+		       (u8/u16/u32/u64/s8/s16/s32/s64), "string",
+		       "string_size", and bitfield are supported.
 
   (*) only for return probe.
   (**) this is useful for fetching a field of data structures.
@@ -50,8 +50,9 @@ Types
 Several types are supported for fetch-args. Uprobe tracer will access memory
 by given type. Prefix 's' and 'u' means those types are signed and unsigned
 respectively. Traced arguments are shown in decimal (signed) or hex (unsigned).
-String type is a special type, which fetches a "null-terminated" string from
-user space.
+"string" is a special type which fetches a null-terminated string from user
+space. "string_size" is the length of a null-terminated string including the
+NUL byte.
 Bitfield is another special type, which takes 3 parameters, bit-width, bit-
 offset, and container-size (usually 32). The syntax is;
 
-- 
2.8.3
