arm64: uaccess: Implement unsafe accessors
Current implementation of get/put_user_unsafe default to get/put_user which toggle PAN before each access, despite having been told by the caller that multiple accesses to user memory were about to happen. Provide implementations for user_access_begin/end to turn PAN off/on and implement unsafe accessors that assume PAN was already turned off. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>hifive-unleashed-5.1
Julien Thierry
Catalin Marinas
parent
13e4cdd785
commit
0bd3ef34d2
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@ -270,31 +270,26 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
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#define __raw_get_user(x, ptr, err) \
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do { \
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unsigned long __gu_val; \
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__chk_user_ptr(ptr); \
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uaccess_enable_not_uao(); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
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__get_user_asm("ldrb", "ldtrb", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 2: \
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__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr), \
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__get_user_asm("ldrh", "ldtrh", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 4: \
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__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr), \
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__get_user_asm("ldr", "ldtr", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 8: \
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__get_user_asm("ldr", "ldtr", "%x", __gu_val, (ptr), \
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__get_user_asm("ldr", "ldtr", "%x", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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default: \
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BUILD_BUG(); \
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} \
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uaccess_disable_not_uao(); \
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(x) = (__force __typeof__(*(ptr)))__gu_val; \
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} while (0)
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#define __get_user_error(x, ptr, err) \
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@ -302,8 +297,13 @@ do { \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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might_fault(); \
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if (access_ok(__p, sizeof(*__p))) { \
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unsigned long __gu_val; \
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__chk_user_ptr(__p); \
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__p = uaccess_mask_ptr(__p); \
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__raw_get_user((x), __p, (err)); \
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uaccess_enable_not_uao(); \
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__raw_get_user(__gu_val, __p, (err)); \
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uaccess_disable_not_uao(); \
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(x) = (__force __typeof__(*__p)) __gu_val; \
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} else { \
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(x) = 0; (err) = -EFAULT; \
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} \
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@ -334,30 +334,26 @@ do { \
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#define __raw_put_user(x, ptr, err) \
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do { \
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__typeof__(*(ptr)) __pu_val = (x); \
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__chk_user_ptr(ptr); \
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uaccess_enable_not_uao(); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
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__put_user_asm("strb", "sttrb", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 2: \
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__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr), \
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__put_user_asm("strh", "sttrh", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 4: \
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__put_user_asm("str", "sttr", "%w", __pu_val, (ptr), \
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__put_user_asm("str", "sttr", "%w", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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case 8: \
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__put_user_asm("str", "sttr", "%x", __pu_val, (ptr), \
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__put_user_asm("str", "sttr", "%x", (x), (ptr), \
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(err), ARM64_HAS_UAO); \
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break; \
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default: \
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BUILD_BUG(); \
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} \
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uaccess_disable_not_uao(); \
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} while (0)
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#define __put_user_error(x, ptr, err) \
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@ -365,9 +361,13 @@ do { \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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might_fault(); \
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if (access_ok(__p, sizeof(*__p))) { \
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__typeof__(*(ptr)) __pu_val = (x); \
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__chk_user_ptr(__p); \
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__p = uaccess_mask_ptr(__p); \
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__raw_put_user((x), __p, (err)); \
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} else { \
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uaccess_enable_not_uao(); \
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__raw_put_user(__pu_val, __p, (err)); \
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uaccess_disable_not_uao(); \
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} else { \
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(err) = -EFAULT; \
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} \
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} while (0)
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@ -381,6 +381,45 @@ do { \
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#define put_user __put_user
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static __must_check inline bool user_access_begin(const void __user *ptr,
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size_t len)
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{
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if (unlikely(!access_ok(ptr, len)))
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return false;
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uaccess_enable_not_uao();
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return true;
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}
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#define user_access_begin(ptr, len) user_access_begin(ptr, len)
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#define user_access_end() uaccess_disable_not_uao()
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#define unsafe_get_user(x, ptr, err) \
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do { \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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unsigned long __gu_val; \
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int __gu_err = 0; \
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might_fault(); \
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__chk_user_ptr(__p); \
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__p = uaccess_mask_ptr(__p); \
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__raw_get_user(__gu_val, __p, __gu_err); \
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(x) = (__force __typeof__(*__p)) __gu_val; \
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if (__gu_err != 0) \
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goto err; \
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} while (0)
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#define unsafe_put_user(x, ptr, err) \
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do { \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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__typeof__(*(ptr)) __pu_val = (x); \
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int __pu_err = 0; \
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might_fault(); \
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__chk_user_ptr(__p); \
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__p = uaccess_mask_ptr(__p); \
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__raw_put_user(__pu_val, __p, __pu_err); \
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if (__pu_err != 0) \
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goto err; \
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} while (0)
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extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
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#define raw_copy_from_user(to, from, n) \
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({ \
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