diff options
| author | Kees Cook <keescook@chromium.org> | 2017-06-21 13:00:26 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-06-28 18:54:46 +0200 |
| commit | fd25d19f6b8da315332bb75936605fb45d3ea981 (patch) | |
| tree | 526af3a06699d0a2570b04402548a6edc61c07bf /arch/Kconfig | |
| parent | f9e169883164390a15b56d00cb7e22c2e72f4dba (diff) | |
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>
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 6c00e5b00f8b..f76b214cf7ad 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -867,4 +867,13 @@ config STRICT_MODULE_RWX config ARCH_WANT_RELAX_ORDER bool +config REFCOUNT_FULL + bool "Perform full reference count validation at the expense of speed" + help + Enabling this switches the refcounting infrastructure from a fast + unchecked atomic_t implementation to a fully state checked + implementation, which can be (slightly) slower but provides protections + against various use-after-free conditions that can be used in + security flaw exploits. + source "kernel/gcov/Kconfig" |