@@ -4,6 +4,7 @@
#include <asm/types.h>
#include <linux/bits.h>
+#include <linux/typecheck.h>
#include <uapi/linux/kernel.h>
@@ -253,6 +254,24 @@ static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
__clear_bit(nr, addr);
}
+#define __ptr_set_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ __set_bit(nr, (unsigned long *)(addr)); \
+ })
+
+#define __ptr_clear_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ __clear_bit(nr, (unsigned long *)(addr)); \
+ })
+
+#define __ptr_test_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ test_bit(nr, (unsigned long *)(addr)); \
+ })
+
#ifdef __KERNEL__
#ifndef set_mask_bits
@@ -22,4 +22,14 @@
(void)__tmp; \
})
+/*
+ * Check at compile that something is a pointer type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck_pointer(x) \
+({ typeof(x) __dummy; \
+ (void)sizeof(*__dummy); \
+ 1; \
+})
+
#endif /* TYPECHECK_H_INCLUDED */
cpumap needs to set, clear, and test the lowest bit in skb pointer in various places. To make these checks less noisy, add pointer friendly bitop macros that also do some typechecking to sanitize the argument. These wrap the non-atomic bitops __set_bit, __clear_bit, and test_bit but for pointer arguments. Pointer's address has to be passed in and it is treated as an unsigned long *, since width and representation of pointer and unsigned long match on targets Linux supports. They are prefixed with double underscore to indicate lack of atomicity. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> --- include/linux/bitops.h | 19 +++++++++++++++++++ include/linux/typecheck.h | 10 ++++++++++ 2 files changed, 29 insertions(+)