linux-toradex.git/lib/refcount.c, branch v4.13-rc4

locking/refcount: Create unchecked atomic_t implementation

2017-06-28T16:54:46+00:00

Many subsystems will not use refcount_t unless there is a way to build the
kernel so that there is no regression in speed compared to atomic_t. This
adds CONFIG_REFCOUNT_FULL to enable the full refcount_t implementation
which has the validation but is slightly slower. When not enabled,
refcount_t uses the basic unchecked atomic_t routines, which results in
no code changes compared to just using atomic_t directly.

Signed-off-by: Kees Cook 
Acked-by: Greg Kroah-Hartman 
Cc: Alexey Dobriyan 
Cc: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Christoph Hellwig 
Cc: David S. Miller 
Cc: David Windsor 
Cc: Davidlohr Bueso 
Cc: Elena Reshetova 
Cc: Eric Biggers 
Cc: Eric W. Biederman 
Cc: Hans Liljestrand 
Cc: James Bottomley 
Cc: Jann Horn 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Manfred Spraul 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Serge E. Hallyn 
Cc: Thomas Gleixner 
Cc: arozansk@redhat.com
Cc: axboe@kernel.dk
Cc: linux-arch 
Link: http://lkml.kernel.org/r/20170621200026.GA115679@beast
Signed-off-by: Ingo Molnar

refcount: change EXPORT_SYMBOL markings

2017-05-06T18:01:34+00:00

Now that kref is using the refcount apis, the _GPL markings are getting
exported to places that it previously wasn't.  Now kref.h is GPLv2
licensed, so any non-GPL code using it better be talking to some
lawyers, but changing api markings isn't considered "nice", so let's fix
this up.

Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Linus Torvalds

locking/refcounts: Use atomic_try_cmpxchg()

2017-03-23T07:54:41+00:00

Generates better code (GCC-6.2.1):

  text        filename
  1576        defconfig-build/lib/refcount.o.pre
  1488        defconfig-build/lib/refcount.o.post

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/refcount: Add refcount_t API kernel-doc comments

2017-03-13T06:41:08+00:00

Signed-off-by: David Windsor 
Acked-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Thomas Gleixner 
Cc: elena.reshetova@intel.com
Cc: kernel-hardening@lists.openwall.com
Link: http://lkml.kernel.org/r/1489160052-20293-1-git-send-email-dwindsor@gmail.com
Signed-off-by: Ingo Molnar

locking/refcounts: Change WARN() to WARN_ONCE()

2017-03-01T08:25:55+00:00

Linus noticed that the new refcount.h APIs used WARN(), which would turn
into a dmesg DoS if it triggers frequently on some buggy driver.

So make sure we only warn once. These warnings are never supposed to happen,
so it's typically not a problem to lose subsequent warnings.

Suggested-by: Linus Torvalds 
Cc: Peter Zijlstra (Intel) 
Cc: Elena Reshetova 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/CA+55aFzbYUTZ=oqZ2YgDjY0C2_n6ODhTfqj6V+m5xWmDxsuB0w@mail.gmail.com
Signed-off-by: Ingo Molnar

locking/refcounts: Out-of-line everything

2017-02-24T08:02:10+00:00

Linus asked to please make this real C code.

And since size then isn't an issue what so ever anymore, remove the
debug knob and make all WARN()s unconditional.

Suggested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: dwindsor@gmail.com
Cc: elena.reshetova@intel.com
Cc: gregkh@linuxfoundation.org
Cc: ishkamiel@gmail.com
Cc: keescook@chromium.org
Signed-off-by: Ingo Molnar