Commit 2e903b91 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan, arm64: implement HW_TAGS runtime 

Provide implementation of KASAN functions required for the hardware
tag-based mode.  Those include core functions for memory and pointer
tagging (tags_hw.c) and bug reporting (report_tags_hw.c).  Also adapt
common KASAN code to support the new mode.

Link: https://lkml.kernel.org/r/cfd0fbede579a6b66755c98c88c108e54f9c56bf.1606161801.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Tested-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0fea6e9a

arch/arm64/include/asm/memory.h

+2 −2
Original line number Diff line number Diff line
@@ -214,7 +214,7 @@ static inline unsigned long kaslr_offset(void) 
	(__force __typeof__(addr))__addr;				\

})



#ifdef CONFIG_KASAN_SW_TAGS

#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)

#define __tag_shifted(tag)	((u64)(tag) << 56)

#define __tag_reset(addr)	__untagged_addr(addr)

#define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
@@ -222,7 +222,7 @@ static inline unsigned long kaslr_offset(void) 
#define __tag_shifted(tag)	0UL

#define __tag_reset(addr)	(addr)

#define __tag_get(addr)		0

#endif /* CONFIG_KASAN_SW_TAGS */

#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */



static inline const void *__tag_set(const void *addr, u8 tag)

{

arch/arm64/kernel/cpufeature.c

+3 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ 
#include <linux/types.h>

#include <linux/mm.h>

#include <linux/cpu.h>

#include <linux/kasan.h>

#include <asm/cpu.h>

#include <asm/cpufeature.h>

#include <asm/cpu_ops.h>
@@ -1710,6 +1711,8 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) 
		cleared_zero_page = true;

		mte_clear_page_tags(lm_alias(empty_zero_page));

	}



	kasan_init_hw_tags_cpu();

}

#endif /* CONFIG_ARM64_MTE */

arch/arm64/kernel/smp.c

+2 −0
Original line number Diff line number Diff line
@@ -462,6 +462,8 @@ void __init smp_prepare_boot_cpu(void) 
	/* Conditionally switch to GIC PMR for interrupt masking */

	if (system_uses_irq_prio_masking())

		init_gic_priority_masking();



	kasan_init_hw_tags();

}



static u64 __init of_get_cpu_mpidr(struct device_node *dn)

include/linux/kasan.h

+17 −7
Original line number Diff line number Diff line
@@ -190,25 +190,35 @@ static inline void kasan_record_aux_stack(void *ptr) {} 


#endif /* CONFIG_KASAN_GENERIC */



#ifdef CONFIG_KASAN_SW_TAGS



void __init kasan_init_sw_tags(void);

#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)



void *kasan_reset_tag(const void *addr);



bool kasan_report(unsigned long addr, size_t size,

		bool is_write, unsigned long ip);



#else /* CONFIG_KASAN_SW_TAGS */



static inline void kasan_init_sw_tags(void) { }

#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */



static inline void *kasan_reset_tag(const void *addr)

{

	return (void *)addr;

}



#endif /* CONFIG_KASAN_SW_TAGS */

#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/



#ifdef CONFIG_KASAN_SW_TAGS

void __init kasan_init_sw_tags(void);

#else

static inline void kasan_init_sw_tags(void) { }

#endif



#ifdef CONFIG_KASAN_HW_TAGS

void kasan_init_hw_tags_cpu(void);

void __init kasan_init_hw_tags(void);

#else

static inline void kasan_init_hw_tags_cpu(void) { }

static inline void kasan_init_hw_tags(void) { }

#endif



#ifdef CONFIG_KASAN_VMALLOC

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -1421,7 +1421,7 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid) 
}

#endif /* CONFIG_NUMA_BALANCING */



#ifdef CONFIG_KASAN_SW_TAGS

#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)

static inline u8 page_kasan_tag(const struct page *page)

{

	return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;