Messages in this thread | | | Date | Tue, 17 Sep 2019 17:28:59 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] lockdep: Make print_lock() address visible |
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On Mon, Sep 16, 2019 at 08:07:55PM -0700, Kees Cook wrote: > On Mon, Sep 16, 2019 at 06:39:46PM -0700, keescook@chromium.org wrote: > > commit 519248f36d6f3c80e176f6fa844c10d94f1f5990 > > Author: Paul E. McKenney <paulmck@linux.ibm.com> > > Date: Thu May 30 05:39:25 2019 -0700 > > > > lockdep: Make print_lock() address visible > > > > Security is a wonderful thing, but so is the ability to debug based on > > lockdep warnings. This commit therefore makes lockdep lock addresses > > visible in the clear. > > > > Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > index 4861cf8e274b..4aca3f4379d2 100644 > > --- a/kernel/locking/lockdep.c > > +++ b/kernel/locking/lockdep.c > > @@ -620,7 +620,7 @@ static void print_lock(struct held_lock *hlock) > > return; > > } > > > > - printk(KERN_CONT "%p", hlock->instance); > > + printk(KERN_CONT "%px", hlock->instance); > > print_lock_name(lock); > > printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip); > > } > > Just to clarify: this is only visible under CONFIG_LOCKDEP, yes? That's > not a state anyone would run a production system under, I'd hope.
Yes, by my reading of kernel/locking/Makefile, the entire kernel/locking/lockdep.c file is completely ignored unless CONFIG_LOCKDEP=y.
So yes, it would be silly for this code to be in a production system.
Thanx, Paul
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