summaryrefslogtreecommitdiff
path: root/Documentation/DocBook
diff options
context:
space:
mode:
authorChristine Chan <cschan@codeaurora.org>2011-11-08 07:48:27 +0400
committerThomas Gleixner <tglx@linutronix.de>2011-11-23 21:49:22 +0400
commitb84d435cc228e87951f3bbabf6cc4a5f25d5fb16 (patch)
tree4a43e7224c49f1ef9b3f25d38a80c29c2692b8dc /Documentation/DocBook
parentfeac18dda25134005909e7770c77464e65608bd8 (diff)
downloadlinux-b84d435cc228e87951f3bbabf6cc4a5f25d5fb16.tar.xz
debugobjects: Extend to assert that an object is initialized
Calling del_timer_sync() on an uninitialized timer leads to a never ending loop in lock_timer_base() that spins checking for a non-NULL timer base. Add an assertion to debugobjects to catch usage of uninitialized objects so that we can initialize timers in the del_timer_sync() path before it calls lock_timer_base(). [ sboyd@codeaurora.org: Clarify commit message ] Signed-off-by: Christine Chan <cschan@codeaurora.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/1320724108-20788-3-git-send-email-sboyd@codeaurora.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r--Documentation/DocBook/debugobjects.tmpl50
1 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl
index 08ff908aa7a2..24979f691e3e 100644
--- a/Documentation/DocBook/debugobjects.tmpl
+++ b/Documentation/DocBook/debugobjects.tmpl
@@ -96,6 +96,7 @@
<listitem><para>debug_object_deactivate</para></listitem>
<listitem><para>debug_object_destroy</para></listitem>
<listitem><para>debug_object_free</para></listitem>
+ <listitem><para>debug_object_assert_init</para></listitem>
</itemizedlist>
Each of these functions takes the address of the real object and
a pointer to the object type specific debug description
@@ -273,6 +274,26 @@
debug checks.
</para>
</sect1>
+
+ <sect1 id="debug_object_assert_init">
+ <title>debug_object_assert_init</title>
+ <para>
+ This function is called to assert that an object has been
+ initialized.
+ </para>
+ <para>
+ When the real object is not tracked by debugobjects, it calls
+ fixup_assert_init of the object type description structure
+ provided by the caller, with the hardcoded object state
+ ODEBUG_NOT_AVAILABLE. The fixup function can correct the problem
+ by calling debug_object_init and other specific initializing
+ functions.
+ </para>
+ <para>
+ When the real object is already tracked by debugobjects it is
+ ignored.
+ </para>
+ </sect1>
</chapter>
<chapter id="fixupfunctions">
<title>Fixup functions</title>
@@ -381,6 +402,35 @@
statistics.
</para>
</sect1>
+ <sect1 id="fixup_assert_init">
+ <title>fixup_assert_init</title>
+ <para>
+ This function is called from the debug code whenever a problem
+ in debug_object_assert_init is detected.
+ </para>
+ <para>
+ Called from debug_object_assert_init() with a hardcoded state
+ ODEBUG_STATE_NOTAVAILABLE when the object is not found in the
+ debug bucket.
+ </para>
+ <para>
+ The function returns 1 when the fixup was successful,
+ otherwise 0. The return value is used to update the
+ statistics.
+ </para>
+ <para>
+ Note, this function should make sure debug_object_init() is
+ called before returning.
+ </para>
+ <para>
+ The handling of statically initialized objects is a special
+ case. The fixup function should check if this is a legitimate
+ case of a statically initialized object or not. In this case only
+ debug_object_init() should be called to make the object known to
+ the tracker. Then the function should return 0 because this is not
+ a real fixup.
+ </para>
+ </sect1>
</chapter>
<chapter id="bugs">
<title>Known Bugs And Assumptions</title>