Kees Cook
5d6dec6fba
locking/refcount: Remove the half-implemented refcount_sub() API
...
CONFIG_REFCOUNT_FULL=y (correctly) does not provide a refcount_sub(),
which should not be part of proper refcount design patterns.
Remove the erroneous extern and the later !CONFIG_REFCOUNT_FULL
accidental implementation.
Signed-off-by: Kees Cook <keescook@chromium.org >
Cc: Elena Reshetova <elena.reshetova@intel.com >
Cc: Josh Poimboeuf <jpoimboe@redhat.com >
Cc: Linus Torvalds <torvalds@linux-foundation.org >
Cc: Peter Zijlstra <peterz@infradead.org >
Cc: Thomas Gleixner <tglx@linutronix.de >
Fixes: 29dee3c03ahttp://lkml.kernel.org/r/20170701180129.GA17405@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org >
2017-07-02 11:24:36 +02:00
Kees Cook
fd25d19f6b
locking/refcount: Create unchecked atomic_t implementation
...
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 <keescook@chromium.org >
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org >
Cc: Alexey Dobriyan <adobriyan@gmail.com >
Cc: Andrew Morton <akpm@linux-foundation.org >
Cc: Arnd Bergmann <arnd@arndb.de >
Cc: Christoph Hellwig <hch@infradead.org >
Cc: David S. Miller <davem@davemloft.net >
Cc: David Windsor <dwindsor@gmail.com >
Cc: Davidlohr Bueso <dave@stgolabs.net >
Cc: Elena Reshetova <elena.reshetova@intel.com >
Cc: Eric Biggers <ebiggers3@gmail.com >
Cc: Eric W. Biederman <ebiederm@xmission.com >
Cc: Hans Liljestrand <ishkamiel@gmail.com >
Cc: James Bottomley <James.Bottomley@hansenpartnership.com >
Cc: Jann Horn <jannh@google.com >
Cc: Josh Poimboeuf <jpoimboe@redhat.com >
Cc: Linus Torvalds <torvalds@linux-foundation.org >
Cc: Manfred Spraul <manfred@colorfullife.com >
Cc: Peter Zijlstra <peterz@infradead.org >
Cc: Rik van Riel <riel@redhat.com >
Cc: Serge E. Hallyn <serge@hallyn.com >
Cc: Thomas Gleixner <tglx@linutronix.de >
Cc: arozansk@redhat.com
Cc: axboe@kernel.dk
Cc: linux-arch <linux-arch@vger.kernel.org >
Link: http://lkml.kernel.org/r/20170621200026.GA115679@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org >
2017-06-28 18:54:46 +02:00
David Windsor
bd174169c7
locking/refcount: Add refcount_t API kernel-doc comments
...
Signed-off-by: David Windsor <dwindsor@gmail.com >
Acked-by: Peter Zijlstra <peterz@infradead.org >
Cc: Linus Torvalds <torvalds@linux-foundation.org >
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com >
Cc: Thomas Gleixner <tglx@linutronix.de >
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 <mingo@kernel.org >
2017-03-13 07:41:08 +01:00
Elena Reshetova
318b1dedcd
locking/refcounts: Add missing kernel.h header to have UINT_MAX defined
...
Fix header dependency.
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com >
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com >
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org >
Cc: Linus Torvalds <torvalds@linux-foundation.org >
Cc: Peter Zijlstra <peterz@infradead.org >
Cc: Thomas Gleixner <tglx@linutronix.de >
Link: http://lkml.kernel.org/r/1487855374-21993-1-git-send-email-elena.reshetova@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org >
2017-02-24 09:02:10 +01:00
Peter Zijlstra
29dee3c03a
locking/refcounts: Out-of-line everything
...
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 <torvalds@linux-foundation.org >
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org >
Cc: Peter Zijlstra <peterz@infradead.org >
Cc: Thomas Gleixner <tglx@linutronix.de >
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 <mingo@kernel.org >
2017-02-24 09:02:10 +01:00
Peter Zijlstra
f405df5de3
refcount_t: Introduce a special purpose refcount type
...
Provide refcount_t, an atomic_t like primitive built just for
refcounting.
It provides saturation semantics such that overflow becomes impossible
and thereby 'spurious' use-after-free is avoided.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org >
Cc: Linus Torvalds <torvalds@linux-foundation.org >
Cc: Peter Zijlstra <peterz@infradead.org >
Cc: Thomas Gleixner <tglx@linutronix.de >
Signed-off-by: Ingo Molnar <mingo@kernel.org >
2017-02-10 09:04:19 +01:00
