arch/mips/include/asm/uaccess.h

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

File Facts

System
Linux kernel
Corpus path
arch/mips/include/asm/uaccess.h
Extension
.h
Size
14995 bytes
Lines
564
Domain
Architecture Layer
Bucket
arch/mips
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))

#ifdef CONFIG_32BIT
#define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
#endif
#ifdef CONFIG_64BIT
#define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
#endif

#define __get_data_asm(val, insn, addr)					\
{									\
	long __gu_tmp;							\
									\
	__asm__ __volatile__(						\
	"1:	"insn("%1", "%3")"				\n"	\
	"2:							\n"	\
	"	.insn						\n"	\
	"	.section .fixup,\"ax\"				\n"	\
	"3:	li	%0, %4					\n"	\
	"	move	%1, $0					\n"	\
	"	j	2b					\n"	\
	"	.previous					\n"	\
	"	.section __ex_table,\"a\"			\n"	\
	"	"__UA_ADDR "\t1b, 3b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=r" (__gu_tmp)				\
	: "0" (0), "o" (__m(addr)), "i" (-EFAULT));			\
									\
	(val) = (__typeof__(*(addr))) __gu_tmp;				\
}

/*
 * Get a long long 64 using 32 bit registers.
 */
#define __get_data_asm_ll32(val, insn, addr)				\
{									\
	union {								\
		unsigned long long	l;				\
		__typeof__(*(addr))	t;				\
	} __gu_tmp;							\
									\
	__asm__ __volatile__(						\
	"1:	" insn("%1", "(%3)")"				\n"	\
	"2:	" insn("%D1", "4(%3)")"				\n"	\
	"3:							\n"	\
	"	.insn						\n"	\
	"	.section	.fixup,\"ax\"			\n"	\
	"4:	li	%0, %4					\n"	\
	"	move	%1, $0					\n"	\
	"	move	%D1, $0					\n"	\
	"	j	3b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 4b				\n"	\
	"	" __UA_ADDR "	2b, 4b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=&r" (__gu_tmp.l)				\
	: "0" (0), "r" (addr), "i" (-EFAULT));				\
									\
	(val) = __gu_tmp.t;						\
}

#define __get_kernel_nofault(dst, src, type, err_label)			\
do {									\
	int __gu_err;							\
									\
	switch (sizeof(type)) {						\
	case 1:								\
		__get_data_asm(*(type *)(dst), kernel_lb,		\
			       (__force type *)(src));			\
		break;							\
	case 2:								\
		__get_data_asm(*(type *)(dst), kernel_lh,		\
			       (__force type *)(src));			\
		break;							\
	case 4:								\
		 __get_data_asm(*(type *)(dst), kernel_lw,		\
			       (__force type *)(src));			\
		break;							\
	case 8:								\
		__GET_DW(*(type *)(dst), kernel_ld,			\
			 (__force type *)(src));			\
		break;							\
	default:							\
		BUILD_BUG();						\
		break;							\
	}								\
	if (unlikely(__gu_err))						\
		goto err_label;						\

Annotation

Implementation Notes