debug_object_assert

From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753751Ab1K1OUH (ORCPT ); Mon, 28 Nov 2011 09:20:07 -0500 Received: from terminus.zytor.com ([198.137.202.10]:53505 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751143Ab1K1OUF (ORCPT ); Mon, 28 Nov 2011 09:20:05 -0500 Date: Mon, 28 Nov 2011 06:19:39 -0800 From: tip-bot for Christine Chan Message-ID: Cc: linux-kernel@vger.kernel.org, john.stultz@linaro.org, hpa@zytor.com, mingo@redhat.com, akpm@linux-foundation.org, cschan@codeaurora.org, tglx@linutronix.de, sboyd@codeaurora.org Reply-To: mingo@redhat.com, hpa@zytor.com, john.stultz@linaro.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, cschan@codeaurora.org, tglx@linutronix.de, sboyd@codeaurora.org In-Reply-To: <1320724108-20788-3-git-send-email-sboyd@codeaurora.org> References: <1320724108-20788-3-git-send-email-sboyd@codeaurora.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/debugobjects] debugobjects: Extend to assert that an object is initialized Git-Commit-ID: b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Mon, 28 Nov 2011 06:19:48 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 Gitweb: http://git.kernel.org/tip/b84d435cc228e87951f3bbabf6cc4a5f25d5fb16 Author: Christine Chan AuthorDate: Mon, 7 Nov 2011 19:48:27 -0800 Committer: Thomas Gleixner CommitDate: Wed, 23 Nov 2011 18:49:22 +0100 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 Signed-off-by: Stephen Boyd Cc: John Stultz Link: http://lkml.kernel.org/r/1320724108-20788-3-git-send-email-sboyd@codeaurora.org Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- Documentation/DocBook/debugobjects.tmpl | 50 +++++++++++++++++++++++++++++++ include/linux/debugobjects.h | 6 ++++ lib/debugobjects.c | 38 +++++++++++++++++++++++ 3 files changed, 94 insertions(+), 0 deletions(-) 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 @@ debug_object_deactivate debug_object_destroy debug_object_free + debug_object_assert_init 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. + + + debug_object_assert_init + + This function is called to assert that an object has been + initialized. + + + 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. + + + When the real object is already tracked by debugobjects it is + ignored. + + Fixup functions @@ -381,6 +402,35 @@ statistics. + + fixup_assert_init + + This function is called from the debug code whenever a problem + in debug_object_assert_init is detected. + + + Called from debug_object_assert_init() with a hardcoded state + ODEBUG_STATE_NOTAVAILABLE when the object is not found in the + debug bucket. + + + The function returns 1 when the fixup was successful, + otherwise 0. The return value is used to update the + statistics. + + + Note, this function should make sure debug_object_init() is + called before returning. + + + 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. + + Known Bugs And Assumptions diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h index 65970b8..0e5f578 100644 --- a/include/linux/debugobjects.h +++ b/include/linux/debugobjects.h @@ -46,6 +46,8 @@ struct debug_obj { * fails * @fixup_free: fixup function, which is called when the free check * fails + * @fixup_assert_init: fixup function, which is called when the assert_init + * check fails */ struct debug_obj_descr { const char *name; @@ -54,6 +56,7 @@ struct debug_obj_descr { int (*fixup_activate) (void *addr, enum debug_obj_state state); int (*fixup_destroy) (void *addr, enum debug_obj_state state); int (*fixup_free) (void *addr, enum debug_obj_state state); + int (*fixup_assert_init)(void *addr, enum debug_obj_state state); }; #ifdef CONFIG_DEBUG_OBJECTS @@ -64,6 +67,7 @@ extern void debug_object_activate (void *addr, struct debug_obj_descr *descr); extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr); extern void debug_object_destroy (void *addr, struct debug_obj_descr *descr); extern void debug_object_free (void *addr, struct debug_obj_descr *descr); +extern void debug_object_assert_init(void *addr, struct debug_obj_descr *descr); /* * Active state: @@ -89,6 +93,8 @@ static inline void debug_object_destroy (void *addr, struct debug_obj_descr *descr) { } static inline void debug_object_free (void *addr, struct debug_obj_descr *descr) { } +static inline void +debug_object_assert_init(void *addr, struct debug_obj_descr *descr) { } static inline void debug_objects_early_init(void) { } static inline void debug_objects_mem_init(void) { } diff --git a/lib/debugobjects.c b/lib/debugobjects.c index b7a5305..77cb245 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -571,6 +571,44 @@ out_unlock: } /** + * debug_object_assert_init - debug checks when object should be init-ed + * @addr: address of the object + * @descr: pointer to an object specific debug description structure + */ +void debug_object_assert_init(void *addr, struct debug_obj_descr *descr) +{ + struct debug_bucket *db; + struct debug_obj *obj; + unsigned long flags; + + if (!debug_objects_enabled) + return; + + db = get_bucket((unsigned long) addr); + + raw_spin_lock_irqsave(&db->lock, flags); + + obj = lookup_object(addr, db); + if (!obj) { + struct debug_obj o = { .object = addr, + .state = ODEBUG_STATE_NOTAVAILABLE, + .descr = descr }; + + raw_spin_unlock_irqrestore(&db->lock, flags); + /* + * Maybe the object is static. Let the type specific + * code decide what to do. + */ + if (debug_object_fixup(descr->fixup_assert_init, addr, + ODEBUG_STATE_NOTAVAILABLE)) + debug_print_object(&o, "assert_init"); + return; + } + + raw_spin_unlock_irqrestore(&db->lock, flags); +} + +/** * debug_object_active_state - debug checks object usage state machine * @addr: address of the object * @descr: pointer to an object specific debug description structure