arch/alpha/include/asm/uaccess.h

Source file repositories/reference/linux-study-clean/arch/alpha/include/asm/uaccess.h

File Facts

System
Linux kernel
Corpus path
arch/alpha/include/asm/uaccess.h
Extension
.h
Size
6135 bytes
Lines
213
Domain
Architecture Layer
Bucket
arch/alpha
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))

#define __get_user_64(addr)				\
	__asm__("1: ldq %0,%2\n"			\
	"2:\n"						\
	EXC(1b,2b,%0,%1)				\
		: "=r"(__gu_val), "=r"(__gu_err)	\
		: "m"(__m(addr)), "1"(__gu_err))

#define __get_user_32(addr)				\
	__asm__("1: ldl %0,%2\n"			\
	"2:\n"						\
	EXC(1b,2b,%0,%1)				\
		: "=r"(__gu_val), "=r"(__gu_err)	\
		: "m"(__m(addr)), "1"(__gu_err))

#define __get_user_16(addr)				\
	__asm__("1: ldwu %0,%2\n"			\
	"2:\n"						\
	EXC(1b,2b,%0,%1)				\
		: "=r"(__gu_val), "=r"(__gu_err)	\
		: "m"(__m(addr)), "1"(__gu_err))

#define __get_user_8(addr)				\
	__asm__("1: ldbu %0,%2\n"			\
	"2:\n"						\
	EXC(1b,2b,%0,%1)				\
		: "=r"(__gu_val), "=r"(__gu_err)	\
		: "m"(__m(addr)), "1"(__gu_err))

extern void __put_user_unknown(void);

#define __put_user_nocheck(x, ptr, size)			\
({								\
	long __pu_err = 0;					\
	__chk_user_ptr(ptr);					\
	switch (size) {						\
	  case 1: __put_user_8(x, ptr); break;			\
	  case 2: __put_user_16(x, ptr); break;			\
	  case 4: __put_user_32(x, ptr); break;			\
	  case 8: __put_user_64(x, ptr); break;			\
	  default: __put_user_unknown(); break;			\
	}							\
	__pu_err;						\
})

#define __put_user_check(x, ptr, size)				\
({								\
	long __pu_err = -EFAULT;				\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
	if (__access_ok(__pu_addr, size)) {			\
		__pu_err = 0;					\
		switch (size) {					\
		  case 1: __put_user_8(x, __pu_addr); break;	\
		  case 2: __put_user_16(x, __pu_addr); break;	\
		  case 4: __put_user_32(x, __pu_addr); break;	\
		  case 8: __put_user_64(x, __pu_addr); break;	\
		  default: __put_user_unknown(); break;		\
		}						\
	}							\
	__pu_err;						\
})

/*
 * The "__put_user_xx()" macros tell gcc they read from memory
 * instead of writing: this is because they do not write to
 * any memory gcc knows about, so there are no aliasing issues
 */
#define __put_user_64(x, addr)					\
__asm__ __volatile__("1: stq %r2,%1\n"				\
	"2:\n"							\
	EXC(1b,2b,$31,%0)					\
		: "=r"(__pu_err)				\
		: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))

#define __put_user_32(x, addr)					\
__asm__ __volatile__("1: stl %r2,%1\n"				\
	"2:\n"							\
	EXC(1b,2b,$31,%0)					\
		: "=r"(__pu_err)				\
		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))

#define __put_user_16(x, addr)					\
__asm__ __volatile__("1: stw %r2,%1\n"				\
	"2:\n"							\
	EXC(1b,2b,$31,%0)					\
		: "=r"(__pu_err)				\
		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))

Annotation

Implementation Notes