* Re: [PATCH] lockdep: Make print_lock() address visible [not found] <20190917013946.9EC51C60479@www.outflux.net> @ 2019-09-17 3:07 ` Kees Cook 2019-09-18 0:28 ` Paul E. McKenney 0 siblings, 1 reply; 2+ messages in thread From: Kees Cook @ 2019-09-17 3:07 UTC (permalink / raw) To: Paul E. McKenney; +Cc: linux-kernel 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. -- Kees Cook ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] lockdep: Make print_lock() address visible 2019-09-17 3:07 ` [PATCH] lockdep: Make print_lock() address visible Kees Cook @ 2019-09-18 0:28 ` Paul E. McKenney 0 siblings, 0 replies; 2+ messages in thread From: Paul E. McKenney @ 2019-09-18 0:28 UTC (permalink / raw) To: Kees Cook; +Cc: Paul E. McKenney, linux-kernel 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 ^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-09-17 3:07 ` [PATCH] lockdep: Make print_lock() address visible Kees Cook
2019-09-18 0:28 ` Paul E. McKenney
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