hardened_malloc/memtag.h

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#ifndef MEMTAG_H
#define MEMTAG_H
#include "util.h"
#ifdef HAS_ARM_MTE
#include "arm_mte.h"
#define MEMTAG 1
#define RESERVED_TAG 15
#define TAG_WIDTH 4
#endif
static inline void *untag_pointer(void *ptr) {
#ifdef HAS_ARM_MTE
const uintptr_t mask = UINTPTR_MAX >> 8;
return (void *) ((uintptr_t) ptr & mask);
#else
return ptr;
#endif
}
static inline void *set_pointer_tag(void *ptr, u8 tag) {
#ifdef HAS_ARM_MTE
return (void *) (((uintptr_t) tag << 56) | (uintptr_t) untag_pointer(ptr));
#else
(void) tag;
return ptr;
#endif
}
static inline u8 get_pointer_tag(void *ptr) {
#ifdef HAS_ARM_MTE
return (((uintptr_t) ptr) >> 56) & 0xf;
#else
(void) ptr;
return 0;
#endif
}
#endif