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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 ARM Ltd.
*/
#ifndef __ASM_MTE_KASAN_H
#define __ASM_MTE_KASAN_H
#include <asm/mte-def.h>
#ifndef __ASSEMBLY__
#include <linux/types.h>
#ifdef CONFIG_ARM64_MTE
/*
* These functions are meant to be only used from KASAN runtime through
* the arch_*() interface defined in asm/memory.h.
* These functions don't include system_supports_mte() checks,
* as KASAN only calls them when MTE is supported and enabled.
*/
static inline u8 mte_get_ptr_tag(void *ptr)
{
/* Note: The format of KASAN tags is 0xF<x> */
u8 tag = 0xF0 | (u8)(((u64)(ptr)) >> MTE_TAG_SHIFT);
return tag;
}
/* Get allocation tag for the address. */
static inline u8 mte_get_mem_tag(void *addr)
{
asm(__MTE_PREAMBLE "ldg %0, [%0]"
: "+r" (addr));
return mte_get_ptr_tag(addr);
}
/* Generate a random tag. */
static inline u8 mte_get_random_tag(void)
{
void *addr;
asm(__MTE_PREAMBLE "irg %0, %0"
: "=r" (addr));
return mte_get_ptr_tag(addr);
}
/*
* Assign allocation tags for a region of memory based on the pointer tag.
* Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and
* size must be non-zero and MTE_GRANULE_SIZE aligned.
*/
static inline void mte_set_mem_tag_range(void *addr, size_t size,
u8 tag, bool init)
{
u64 curr, end;
if (!size)
return;
curr = (u64)__tag_set(addr, tag);
end = curr + size;
/*
* 'asm volatile' is required to prevent the compiler to move
* the statement outside of the loop.
*/
if (init) {
do {
asm volatile(__MTE_PREAMBLE "stzg %0, [%0]"
:
: "r" (curr)
: "memory");
curr += MTE_GRANULE_SIZE;
} while (curr != end);
} else {
do {
asm volatile(__MTE_PREAMBLE "stg %0, [%0]"
:
: "r" (curr)
: "memory");
curr += MTE_GRANULE_SIZE;
} while (curr != end);
}
}
void mte_enable_kernel_sync(void);
void mte_enable_kernel_async(void);
void mte_init_tags(u64 max_tag);
void mte_set_report_once(bool state);
bool mte_report_once(void);
#else /* CONFIG_ARM64_MTE */
static inline u8 mte_get_ptr_tag(void *ptr)
{
return 0xFF;
}
static inline u8 mte_get_mem_tag(void *addr)
{
return 0xFF;
}
static inline u8 mte_get_random_tag(void)
{
return 0xFF;
}
static inline void mte_set_mem_tag_range(void *addr, size_t size,
u8 tag, bool init)
{
}
static inline void mte_enable_kernel_sync(void)
{
}
static inline void mte_enable_kernel_async(void)
{
}
static inline void mte_init_tags(u64 max_tag)
{
}
static inline void mte_set_report_once(bool state)
{
}
static inline bool mte_report_once(void)
{
return false;
}
#endif /* CONFIG_ARM64_MTE */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_MTE_KASAN_H */
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