From: tip-bot for Christine Chan <cschan@codeaurora.org>
To: linux-tip-commits@vger.kernel.org
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
Subject: [tip:core/debugobjects] timer: Use debugobjects to catch deletion of uninitialized timers
Date: Mon, 28 Nov 2011 06:21:11 -0800 [thread overview]
Message-ID: <tip-dc4218bd0fe499fce2896f88101ea42dac1f60fc@git.kernel.org> (raw)
In-Reply-To: <1320724108-20788-4-git-send-email-sboyd@codeaurora.org>
Commit-ID: dc4218bd0fe499fce2896f88101ea42dac1f60fc
Gitweb: http://git.kernel.org/tip/dc4218bd0fe499fce2896f88101ea42dac1f60fc
Author: Christine Chan <cschan@codeaurora.org>
AuthorDate: Mon, 7 Nov 2011 19:48:28 -0800
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 23 Nov 2011 18:49:23 +0100
timer: Use debugobjects to catch deletion of uninitialized timers
del_timer_sync() calls debug_object_assert_init() to assert that
a timer has been initialized before calling lock_timer_base().
lock_timer_base() would spin forever on a NULL(uninit-ed) base.
The check is added to del_timer() to prevent silent failure, even
though it would not get stuck in an infinite loop.
[ sboyd@codeaurora.org: Remove WARN, intialize timer function]
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/1320724108-20788-4-git-send-email-sboyd@codeaurora.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/timer.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/kernel/timer.c b/kernel/timer.c
index 317087d..5fc5a76 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -487,12 +487,40 @@ static int timer_fixup_free(void *addr, enum debug_obj_state state)
}
}
+/*
+ * fixup_assert_init is called when:
+ * - an untracked/uninit-ed object is found
+ */
+static int timer_fixup_assert_init(void *addr, enum debug_obj_state state)
+{
+ struct timer_list *timer = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_NOTAVAILABLE:
+ if (timer->entry.prev == TIMER_ENTRY_STATIC) {
+ /*
+ * This is not really a fixup. The timer was
+ * statically initialized. We just make sure that it
+ * is tracked in the object tracker.
+ */
+ debug_object_init(timer, &timer_debug_descr);
+ return 0;
+ } else {
+ setup_timer(timer, stub_timer, 0);
+ return 1;
+ }
+ default:
+ return 0;
+ }
+}
+
static struct debug_obj_descr timer_debug_descr = {
- .name = "timer_list",
- .debug_hint = timer_debug_hint,
- .fixup_init = timer_fixup_init,
- .fixup_activate = timer_fixup_activate,
- .fixup_free = timer_fixup_free,
+ .name = "timer_list",
+ .debug_hint = timer_debug_hint,
+ .fixup_init = timer_fixup_init,
+ .fixup_activate = timer_fixup_activate,
+ .fixup_free = timer_fixup_free,
+ .fixup_assert_init = timer_fixup_assert_init,
};
static inline void debug_timer_init(struct timer_list *timer)
@@ -515,6 +543,11 @@ static inline void debug_timer_free(struct timer_list *timer)
debug_object_free(timer, &timer_debug_descr);
}
+static inline void debug_timer_assert_init(struct timer_list *timer)
+{
+ debug_object_assert_init(timer, &timer_debug_descr);
+}
+
static void __init_timer(struct timer_list *timer,
const char *name,
struct lock_class_key *key);
@@ -538,6 +571,7 @@ EXPORT_SYMBOL_GPL(destroy_timer_on_stack);
static inline void debug_timer_init(struct timer_list *timer) { }
static inline void debug_timer_activate(struct timer_list *timer) { }
static inline void debug_timer_deactivate(struct timer_list *timer) { }
+static inline void debug_timer_assert_init(struct timer_list *timer) { }
#endif
static inline void debug_init(struct timer_list *timer)
@@ -559,6 +593,11 @@ static inline void debug_deactivate(struct timer_list *timer)
trace_timer_cancel(timer);
}
+static inline void debug_assert_init(struct timer_list *timer)
+{
+ debug_timer_assert_init(timer);
+}
+
static void __init_timer(struct timer_list *timer,
const char *name,
struct lock_class_key *key)
@@ -909,6 +948,8 @@ int del_timer(struct timer_list *timer)
unsigned long flags;
int ret = 0;
+ debug_assert_init(timer);
+
timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
@@ -939,6 +980,8 @@ int try_to_del_timer_sync(struct timer_list *timer)
unsigned long flags;
int ret = -1;
+ debug_assert_init(timer);
+
base = lock_timer_base(timer, &flags);
if (base->running_timer == timer)
prev parent reply other threads:[~2011-11-28 14:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-08 3:48 [PATCHv2 0/3] Catching del_timer_sync() on uninitialized timers Stephen Boyd
2011-11-08 3:48 ` [PATCHv2 1/3] debugobjects: Be smarter about static objects Stephen Boyd
2011-11-28 14:18 ` [tip:core/debugobjects] " tip-bot for Stephen Boyd
2011-12-13 10:38 ` Thomas Gleixner
2011-12-13 19:36 ` Stephen Boyd
2011-12-13 20:37 ` Thomas Gleixner
2011-12-14 4:59 ` [PATCH] debugobjects: Fix selftest for static warnings Stephen Boyd
2011-11-28 14:20 ` [tip:core/debugobjects] timer: Setup uninitialized timer with a stub callback tip-bot for Stephen Boyd
2011-11-08 3:48 ` [PATCHv2 2/3] debugobjects: Extend to assert that an object is initialized Stephen Boyd
2011-11-28 14:19 ` [tip:core/debugobjects] " tip-bot for Christine Chan
2011-11-08 3:48 ` [PATCHv2 3/3] kernel/timer.c: Use debugobjects to catch deletion of uninitialized timers Stephen Boyd
2011-11-28 14:21 ` tip-bot for Christine Chan [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tip-dc4218bd0fe499fce2896f88101ea42dac1f60fc@git.kernel.org \
--to=cschan@codeaurora.org \
--cc=akpm@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=sboyd@codeaurora.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).