Commit 2df4c9a7 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Russell King (Oracle)
Browse files

ARM: 9112/1: uaccess: add __{get,put}_kernel_nofault 



These mimic the behavior of get_user and put_user, except
for domain switching, address limit checking and handling
of mismatched sizes, none of which are relevant here.

To work with pre-Armv6 kernels, this has to avoid TUSER()
inside of the new macros, the new approach passes the "t"
string along with the opcode, which is a bit uglier but
avoids duplicating more code.

As there is no __get_user_asm_dword(), I work around it
by copying 32 bit at a time, which is possible because
the output size is known.

Acked-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
parent 7e2d8c29

arch/arm/include/asm/uaccess.h

+83 −40
Original line number Diff line number Diff line
@@ -308,11 +308,11 @@ static inline void set_fs(mm_segment_t fs) 
#define __get_user(x, ptr)						\

({									\

	long __gu_err = 0;						\

	__get_user_err((x), (ptr), __gu_err);				\

	__get_user_err((x), (ptr), __gu_err, TUSER());			\

	__gu_err;							\

})



#define __get_user_err(x, ptr, err)					\

#define __get_user_err(x, ptr, err, __t)				\

do {									\

	unsigned long __gu_addr = (unsigned long)(ptr);			\

	unsigned long __gu_val;						\
@@ -321,18 +321,19 @@ do { \ 
	might_fault();							\

	__ua_flags = uaccess_save_and_enable();				\

	switch (sizeof(*(ptr))) {					\

	case 1:	__get_user_asm_byte(__gu_val, __gu_addr, err);	break;	\

	case 2:	__get_user_asm_half(__gu_val, __gu_addr, err);	break;	\

	case 4:	__get_user_asm_word(__gu_val, __gu_addr, err);	break;	\

	case 1:	__get_user_asm_byte(__gu_val, __gu_addr, err, __t); break;	\

	case 2:	__get_user_asm_half(__gu_val, __gu_addr, err, __t); break;	\

	case 4:	__get_user_asm_word(__gu_val, __gu_addr, err, __t); break;	\

	default: (__gu_val) = __get_user_bad();				\

	}								\

	uaccess_restore(__ua_flags);					\

	(x) = (__typeof__(*(ptr)))__gu_val;				\

} while (0)

#endif



#define __get_user_asm(x, addr, err, instr)			\

	__asm__ __volatile__(					\

	"1:	" TUSER(instr) " %1, [%2], #0\n"		\

	"1:	" instr " %1, [%2], #0\n"			\

	"2:\n"							\

	"	.pushsection .text.fixup,\"ax\"\n"		\

	"	.align	2\n"					\
@@ -348,40 +349,38 @@ do { \ 
	: "r" (addr), "i" (-EFAULT)				\

	: "cc")



#define __get_user_asm_byte(x, addr, err)			\

	__get_user_asm(x, addr, err, ldrb)

#define __get_user_asm_byte(x, addr, err, __t)			\

	__get_user_asm(x, addr, err, "ldrb" __t)



#if __LINUX_ARM_ARCH__ >= 6



#define __get_user_asm_half(x, addr, err)			\

	__get_user_asm(x, addr, err, ldrh)

#define __get_user_asm_half(x, addr, err, __t)			\

	__get_user_asm(x, addr, err, "ldrh" __t)



#else



#ifndef __ARMEB__

#define __get_user_asm_half(x, __gu_addr, err)			\

#define __get_user_asm_half(x, __gu_addr, err, __t)		\

({								\

	unsigned long __b1, __b2;				\

	__get_user_asm_byte(__b1, __gu_addr, err);		\

	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\

	__get_user_asm_byte(__b1, __gu_addr, err, __t);		\

	__get_user_asm_byte(__b2, __gu_addr + 1, err, __t);	\

	(x) = __b1 | (__b2 << 8);				\

})

#else

#define __get_user_asm_half(x, __gu_addr, err)			\

#define __get_user_asm_half(x, __gu_addr, err, __t)		\

({								\

	unsigned long __b1, __b2;				\

	__get_user_asm_byte(__b1, __gu_addr, err);		\

	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\

	__get_user_asm_byte(__b1, __gu_addr, err, __t);		\

	__get_user_asm_byte(__b2, __gu_addr + 1, err, __t);	\

	(x) = (__b1 << 8) | __b2;				\

})

#endif



#endif /* __LINUX_ARM_ARCH__ >= 6 */



#define __get_user_asm_word(x, addr, err)			\

	__get_user_asm(x, addr, err, ldr)

#endif



#define __get_user_asm_word(x, addr, err, __t)			\

	__get_user_asm(x, addr, err, "ldr" __t)



#define __put_user_switch(x, ptr, __err, __fn)				\

	do {								\
@@ -425,7 +424,7 @@ do { \ 
#define __put_user_nocheck(x, __pu_ptr, __err, __size)			\

	do {								\

		unsigned long __pu_addr = (unsigned long)__pu_ptr;	\

		__put_user_nocheck_##__size(x, __pu_addr, __err);	\

		__put_user_nocheck_##__size(x, __pu_addr, __err, TUSER());\

	} while (0)



#define __put_user_nocheck_1 __put_user_asm_byte
@@ -433,9 +432,11 @@ do { \ 
#define __put_user_nocheck_4 __put_user_asm_word

#define __put_user_nocheck_8 __put_user_asm_dword



#endif /* !CONFIG_CPU_SPECTRE */



#define __put_user_asm(x, __pu_addr, err, instr)		\

	__asm__ __volatile__(					\

	"1:	" TUSER(instr) " %1, [%2], #0\n"		\

	"1:	" instr " %1, [%2], #0\n"		\

	"2:\n"							\

	"	.pushsection .text.fixup,\"ax\"\n"		\

	"	.align	2\n"					\
@@ -450,36 +451,36 @@ do { \ 
	: "r" (x), "r" (__pu_addr), "i" (-EFAULT)		\

	: "cc")



#define __put_user_asm_byte(x, __pu_addr, err)			\

	__put_user_asm(x, __pu_addr, err, strb)

#define __put_user_asm_byte(x, __pu_addr, err, __t)		\

	__put_user_asm(x, __pu_addr, err, "strb" __t)



#if __LINUX_ARM_ARCH__ >= 6



#define __put_user_asm_half(x, __pu_addr, err)			\

	__put_user_asm(x, __pu_addr, err, strh)

#define __put_user_asm_half(x, __pu_addr, err, __t)		\

	__put_user_asm(x, __pu_addr, err, "strh" __t)



#else



#ifndef __ARMEB__

#define __put_user_asm_half(x, __pu_addr, err)			\

#define __put_user_asm_half(x, __pu_addr, err, __t)		\

({								\

	unsigned long __temp = (__force unsigned long)(x);	\

	__put_user_asm_byte(__temp, __pu_addr, err);		\

	__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err);	\

	__put_user_asm_byte(__temp, __pu_addr, err, __t);	\

	__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err, __t);\

})

#else

#define __put_user_asm_half(x, __pu_addr, err)			\

#define __put_user_asm_half(x, __pu_addr, err, __t)		\

({								\

	unsigned long __temp = (__force unsigned long)(x);	\

	__put_user_asm_byte(__temp >> 8, __pu_addr, err);	\

	__put_user_asm_byte(__temp, __pu_addr + 1, err);	\

	__put_user_asm_byte(__temp >> 8, __pu_addr, err, __t);	\

	__put_user_asm_byte(__temp, __pu_addr + 1, err, __t);	\

})

#endif



#endif /* __LINUX_ARM_ARCH__ >= 6 */



#define __put_user_asm_word(x, __pu_addr, err)			\

	__put_user_asm(x, __pu_addr, err, str)

#define __put_user_asm_word(x, __pu_addr, err, __t)		\

	__put_user_asm(x, __pu_addr, err, "str" __t)



#ifndef __ARMEB__

#define	__reg_oper0	"%R2"
@@ -489,12 +490,12 @@ do { \ 
#define	__reg_oper1	"%R2"

#endif



#define __put_user_asm_dword(x, __pu_addr, err)			\

#define __put_user_asm_dword(x, __pu_addr, err, __t)		\

	__asm__ __volatile__(					\

 ARM(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1], #4\n"	) \

 ARM(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1]\n"	) \

 THUMB(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1]\n"	) \

 THUMB(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1, #4]\n"	) \

 ARM(	"1:	str" __t "	" __reg_oper1 ", [%1], #4\n"  ) \

 ARM(	"2:	str" __t "	" __reg_oper0 ", [%1]\n"      ) \

 THUMB(	"1:	str" __t "	" __reg_oper1 ", [%1]\n"      ) \

 THUMB(	"2:	str" __t "	" __reg_oper0 ", [%1, #4]\n"  ) \

	"3:\n"							\

	"	.pushsection .text.fixup,\"ax\"\n"		\

	"	.align	2\n"					\
@@ -510,7 +511,49 @@ do { \ 
	: "r" (x), "i" (-EFAULT)				\

	: "cc")



#endif /* !CONFIG_CPU_SPECTRE */

#define HAVE_GET_KERNEL_NOFAULT



#define __get_kernel_nofault(dst, src, type, err_label)			\

do {									\

	const type *__pk_ptr = (src);					\

	unsigned long __src = (unsigned long)(__pk_ptr);		\

	type __val;							\

	int __err = 0;							\

	switch (sizeof(type)) {						\

	case 1:	__get_user_asm_byte(__val, __src, __err, ""); break;	\

	case 2: __get_user_asm_half(__val, __src, __err, ""); break;	\

	case 4: __get_user_asm_word(__val, __src, __err, ""); break;	\

	case 8: {							\

		u32 *__v32 = (u32*)&__val;				\

		__get_user_asm_word(__v32[0], __src, __err, "");	\

		if (__err)						\

			break;						\

		__get_user_asm_word(__v32[1], __src+4, __err, "");	\

		break;							\

	}								\

	default: __err = __get_user_bad(); break;			\

	}								\

	*(type *)(dst) = __val;						\

	if (__err)							\

		goto err_label;						\

} while (0)



#define __put_kernel_nofault(dst, src, type, err_label)			\

do {									\

	const type *__pk_ptr = (dst);					\

	unsigned long __dst = (unsigned long)__pk_ptr;			\

	int __err = 0;							\

	type __val = *(type *)src;					\

	switch (sizeof(type)) {						\

	case 1: __put_user_asm_byte(__val, __dst, __err, ""); break;	\

	case 2:	__put_user_asm_half(__val, __dst, __err, ""); break;	\

	case 4:	__put_user_asm_word(__val, __dst, __err, ""); break;	\

	case 8:	__put_user_asm_dword(__val, __dst, __err, ""); break;	\

	default: __err = __put_user_bad(); break;			\

	}								\

	if (__err)							\

		goto err_label;						\

} while (0)



#ifdef CONFIG_MMU

extern unsigned long __must_check