From: Peter Zijlstra <peterz@infradead.org>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: g@hirez.programming.kicks-ass.net, Qian Cai <cai@redhat.com>,
Waiman Long <longman@redhat.com>, Ingo Molnar <mingo@redhat.com>,
Will Deacon <will@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: lockdep null-ptr-deref
Date: Fri, 2 Oct 2020 15:09:29 +0200 [thread overview]
Message-ID: <20201002130929.GW2628@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20201002123602.GE17810@debian-boqun.qqnc3lrjykvubdpftowmye0fmh.lx.internal.cloudapp.net>
On Fri, Oct 02, 2020 at 08:36:02PM +0800, Boqun Feng wrote:
> But what if f2() is called with interrupt disabled? Or f2() disables
> interrupt inside the function, like:
>
> void f2(...)
> {
> local_irq_disable();
> spin_lock(&B);
> g(...);
> ...
> local_irq_enable();
> }
>
> In this case, there wouldn't be any LOCK_ENABLED_*_READ usage for
> rwlock_t A. As a result, we won't see it in the lockdep splat.
Hurm, fair enough. So just to make sure, you're arguing for:
-#define LOCK_TRACE_STATES (XXX_LOCK_USAGE_STATES*4 + 1)
+#define LOCK_TRACE_STATES (XXX_LOCK_USAGE_STATES*4 + 2)
On top of my earlier patch, right?
next prev parent reply other threads:[~2020-10-02 13:09 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-29 14:31 lockdep null-ptr-deref Qian Cai
2020-09-29 23:08 ` Boqun Feng
2020-09-30 9:16 ` Peter Zijlstra
2020-09-30 9:49 ` Peter Zijlstra
2020-09-30 12:18 ` Boqun Feng
2020-09-30 19:02 ` Peter Zijlstra
2020-10-02 12:36 ` Boqun Feng
2020-10-02 13:09 ` Peter Zijlstra [this message]
2020-10-02 13:35 ` Boqun Feng
2020-10-02 10:06 ` Peter Zijlstra
2020-10-02 13:40 ` Qian Cai
2020-10-07 16:20 ` [tip: locking/core] lockdep: Fix usage_traceoverflow tip-bot2 for Peter Zijlstra
2020-10-27 11:29 ` Chris Wilson
2020-10-27 11:59 ` Peter Zijlstra
2020-10-27 12:30 ` Peter Zijlstra
2020-10-27 12:48 ` Peter Zijlstra
2020-10-27 14:13 ` Chris Wilson
2020-10-31 11:30 ` [tip: locking/urgent] lockdep: Fix nr_unused_locks accounting tip-bot2 for Peter Zijlstra
2020-10-27 13:29 ` [tip: locking/core] lockdep: Fix usage_traceoverflow Chris Wilson
2020-10-27 15:45 ` Peter Zijlstra
2020-10-27 16:34 ` Chris Wilson
2020-10-28 17:40 ` Chris Wilson
2020-10-28 18:06 ` Chris Wilson
2020-10-28 19:42 ` Peter Zijlstra
2020-10-28 19:59 ` Peter Zijlstra
2020-10-30 3:51 ` Boqun Feng
2020-10-30 9:38 ` Peter Zijlstra
2020-10-30 9:55 ` Peter Zijlstra
2020-11-02 5:37 ` [PATCH 1/2] lockdep: Avoid to modify chain keys in validate_chain() Boqun Feng
2020-11-02 5:37 ` [PATCH 2/2] lockdep/selftest: Add spin_nest_lock test Boqun Feng
2020-12-03 10:35 ` [tip: locking/core] " tip-bot2 for Boqun Feng
2020-11-05 6:25 ` [PATCH 1/2] lockdep: Avoid to modify chain keys in validate_chain() Boqun Feng
2020-11-10 17:28 ` Peter Zijlstra
2020-11-11 8:23 ` [tip: locking/urgent] " tip-bot2 for Boqun Feng
2020-10-09 7:58 ` [tip: locking/core] lockdep: Fix usage_traceoverflow tip-bot2 for Peter Zijlstra
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