diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 9 | ||||
| -rw-r--r-- | arch/tile/lib/atomic_asm_32.S | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/atomic.h | 13 |
3 files changed, 10 insertions, 15 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" diff --git a/arch/tile/lib/atomic_asm_32.S b/arch/tile/lib/atomic_asm_32.S index 1a70e6c0f259..94709ab41ed8 100644 --- a/arch/tile/lib/atomic_asm_32.S +++ b/arch/tile/lib/atomic_asm_32.S @@ -24,8 +24,7 @@ * has an opportunity to return -EFAULT to the user if needed. * The 64-bit routines just return a "long long" with the value, * since they are only used from kernel space and don't expect to fault. - * Support for 16-bit ops is included in the framework but we don't provide - * any (x86_64 has an atomic_inc_short(), so we might want to some day). + * Support for 16-bit ops is included in the framework but we don't provide any. * * Note that the caller is advised to issue a suitable L1 or L2 * prefetch on the address being manipulated to avoid extra stalls. diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index caa5798c92f4..33380b871463 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -246,19 +246,6 @@ static __always_inline int __atomic_add_unless(atomic_t *v, int a, int u) return c; } -/** - * atomic_inc_short - increment of a short integer - * @v: pointer to type int - * - * Atomically adds 1 to @v - * Returns the new value of @u - */ -static __always_inline short int atomic_inc_short(short int *v) -{ - asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); - return *v; -} - #ifdef CONFIG_X86_32 # include <asm/atomic64_32.h> #else |