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>
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl
index 08ff908..24979f6 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>