diff options
| author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2020-12-22 12:01:45 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-22 12:55:07 -0800 |
| commit | bad1e1c663e0a72f9cf7b230a00d821678f80455 (patch) | |
| tree | cd623e54bc02bc56da1fe75bd71c3adcb7eab75e /arch/arm64/include | |
| parent | 620954a67bcec6ca6b902baaaa1e3f2601b371a7 (diff) | |
arm64: mte: switch GCR_EL1 in kernel entry and exit
When MTE is present, the GCR_EL1 register contains the tags mask that
allows to exclude tags from the random generation via the IRG instruction.
With the introduction of the new Tag-Based KASAN API that provides a
mechanism to reserve tags for special reasons, the MTE implementation has
to make sure that the GCR_EL1 setting for the kernel does not affect the
userspace processes and viceversa.
Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit.
Link: https://lkml.kernel.org/r/578b03294708cc7258fad0dc9c2a2e809e5a8214.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/mte-def.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mte-kasan.h | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mte.h | 2 |
3 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/mte-def.h b/arch/arm64/include/asm/mte-def.h index 8401ac5840c7..2d73a1612f09 100644 --- a/arch/arm64/include/asm/mte-def.h +++ b/arch/arm64/include/asm/mte-def.h @@ -10,6 +10,5 @@ #define MTE_TAG_SHIFT 56 #define MTE_TAG_SIZE 4 #define MTE_TAG_MASK GENMASK((MTE_TAG_SHIFT + (MTE_TAG_SIZE - 1)), MTE_TAG_SHIFT) -#define MTE_TAG_MAX (MTE_TAG_MASK >> MTE_TAG_SHIFT) #endif /* __ASM_MTE_DEF_H */ diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index 71ff6c6786ac..26349a4b5e2e 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -30,6 +30,7 @@ u8 mte_get_random_tag(void); void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag); void mte_enable_kernel(void); +void mte_init_tags(u64 max_tag); #else /* CONFIG_ARM64_MTE */ @@ -55,6 +56,10 @@ static inline void mte_enable_kernel(void) { } +static inline void mte_init_tags(u64 max_tag) +{ +} + #endif /* CONFIG_ARM64_MTE */ #endif /* __ASSEMBLY__ */ diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index cf1cd181dcb2..d02aff9f493d 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -18,6 +18,8 @@ #include <asm/pgtable-types.h> +extern u64 gcr_kernel_excl; + void mte_clear_page_tags(void *addr); unsigned long mte_copy_tags_from_user(void *to, const void __user *from, unsigned long n); |