📄 uaccess.h
字号:
"jal\t" #destination "\n\t"
#endif
extern size_t __copy_user(void *__to, const void *__from, size_t __n);
#define __invoke_copy_to_user(to,from,n) \
({ \
register void __user *__cu_to_r __asm__ ("$4"); \
register const void *__cu_from_r __asm__ ("$5"); \
register long __cu_len_r __asm__ ("$6"); \
\
__cu_to_r = (to); \
__cu_from_r = (from); \
__cu_len_r = (n); \
__asm__ __volatile__( \
__MODULE_JAL(__copy_user) \
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
: \
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
"memory"); \
__cu_len_r; \
})
/*
* __copy_to_user: - Copy a block of data into user space, with less checking.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
#define __copy_to_user(to,from,n) \
({ \
void __user __user *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
might_sleep(); \
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
__cu_len; \
})
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
/*
* copy_to_user: - Copy a block of data into user space.
* @to: Destination address, in user space.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from kernel space to user space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
#define copy_to_user(to,from,n) \
({ \
void __user *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
might_sleep(); \
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
__cu_len); \
__cu_len; \
})
#define __invoke_copy_from_user(to,from,n) \
({ \
register void *__cu_to_r __asm__ ("$4"); \
register const void __user *__cu_from_r __asm__ ("$5"); \
register long __cu_len_r __asm__ ("$6"); \
\
__cu_to_r = (to); \
__cu_from_r = (from); \
__cu_len_r = (n); \
__asm__ __volatile__( \
".set\tnoreorder\n\t" \
__MODULE_JAL(__copy_user) \
".set\tnoat\n\t" \
__UA_ADDU "\t$1, %1, %2\n\t" \
".set\tat\n\t" \
".set\treorder" \
: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
: \
: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
"memory"); \
__cu_len_r; \
})
/*
* __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
#define __copy_from_user(to,from,n) \
({ \
void *__cu_to; \
const void __user *__cu_from; \
long __cu_len; \
\
might_sleep(); \
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
__cu_len); \
__cu_len; \
})
/*
* copy_from_user: - Copy a block of data from user space.
* @to: Destination address, in kernel space.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
* Context: User context only. This function may sleep.
*
* Copy data from user space to kernel space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
#define copy_from_user(to,from,n) \
({ \
void *__cu_to; \
const void __user *__cu_from; \
long __cu_len; \
\
might_sleep(); \
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
__cu_len); \
__cu_len; \
})
#define __copy_in_user(to, from, n) __copy_from_user(to, from, n)
#define copy_in_user(to,from,n) \
({ \
void __user *__cu_to; \
const void __user *__cu_from; \
long __cu_len; \
\
might_sleep(); \
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \
__cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
__cu_len); \
__cu_len; \
})
/*
* __clear_user: - Zero a block of memory in user space, with less checking.
* @to: Destination address, in user space.
* @n: Number of bytes to zero.
*
* Zero a block of memory in user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be cleared.
* On success, this will be zero.
*/
static inline __kernel_size_t
__clear_user(void __user *addr, __kernel_size_t size)
{
__kernel_size_t res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, $0\n\t"
"move\t$6, %2\n\t"
__MODULE_JAL(__bzero)
"move\t%0, $6"
: "=r" (res)
: "r" (addr), "r" (size)
: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
return res;
}
#define clear_user(addr,n) \
({ \
void __user * __cl_addr = (addr); \
unsigned long __cl_size = (n); \
if (__cl_size && access_ok(VERIFY_WRITE, \
((unsigned long)(__cl_addr)), __cl_size)) \
__cl_size = __clear_user(__cl_addr, __cl_size); \
__cl_size; \
})
/*
* __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
* @dst: Destination address, in kernel space. This buffer must be at
* least @count bytes long.
* @src: Source address, in user space.
* @count: Maximum number of bytes to copy, including the trailing NUL.
*
* Copies a NUL-terminated string from userspace to kernel space.
* Caller must check the specified block with access_ok() before calling
* this function.
*
* On success, returns the length of the string (not including the trailing
* NUL).
*
* If access to userspace fails, returns -EFAULT (some data may have been
* copied).
*
* If @count is smaller than the length of the string, copies @count bytes
* and returns @count.
*/
static inline long
__strncpy_from_user(char *__to, const char __user *__from, long __len)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
"move\t$6, %3\n\t"
__MODULE_JAL(__strncpy_from_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (__to), "r" (__from), "r" (__len)
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
return res;
}
/*
* strncpy_from_user: - Copy a NUL terminated string from userspace.
* @dst: Destination address, in kernel space. This buffer must be at
* least @count bytes long.
* @src: Source address, in user space.
* @count: Maximum number of bytes to copy, including the trailing NUL.
*
* Copies a NUL-terminated string from userspace to kernel space.
*
* On success, returns the length of the string (not including the trailing
* NUL).
*
* If access to userspace fails, returns -EFAULT (some data may have been
* copied).
*
* If @count is smaller than the length of the string, copies @count bytes
* and returns @count.
*/
static inline long
strncpy_from_user(char *__to, const char __user *__from, long __len)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
"move\t$6, %3\n\t"
__MODULE_JAL(__strncpy_from_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (__to), "r" (__from), "r" (__len)
: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
return res;
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strlen_user(const char __user *s)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
__MODULE_JAL(__strlen_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s)
: "$2", "$4", __UA_t0, "$31");
return res;
}
/*
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
* Context: User context only. This function may sleep.
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* On exception, returns 0.
*
* If there is a limit on the length of a valid string, you may wish to
* consider using strnlen_user() instead.
*/
static inline long strlen_user(const char __user *s)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
__MODULE_JAL(__strlen_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s)
: "$2", "$4", __UA_t0, "$31");
return res;
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
static inline long __strnlen_user(const char __user *s, long n)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
__MODULE_JAL(__strnlen_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s), "r" (n)
: "$2", "$4", "$5", __UA_t0, "$31");
return res;
}
/*
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
* Context: User context only. This function may sleep.
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* On exception, returns 0.
*
* If there is a limit on the length of a valid string, you may wish to
* consider using strnlen_user() instead.
*/
static inline long strnlen_user(const char __user *s, long n)
{
long res;
might_sleep();
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
__MODULE_JAL(__strnlen_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s), "r" (n)
: "$2", "$4", "$5", __UA_t0, "$31");
return res;
}
struct exception_table_entry
{
unsigned long insn;
unsigned long nextinsn;
};
extern int fixup_exception(struct pt_regs *regs);
#endif /* _ASM_UACCESS_H */
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