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Commit ad72907a authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

ARM: 7528/1: uaccess: annotate [__]{get,put}_user functions with might_fault() 



The user access functions may generate a fault, resulting in invocation
of a handler that may sleep.

This patch annotates the accessors with might_fault() so that we print a
warning if they are invoked from atomic context and help lockdep keep
track of mmap_sem.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 8404663f

arch/arm/include/asm/uaccess.h

+16 −2
Original line number Original line Diff line number Diff line
@@ -118,7 +118,7 @@ extern int __get_user_4(void *); 
		: "0" (__p), "r" (__l)					\

		: "0" (__p), "r" (__l)					\

		: __GUP_CLOBBER_##__s)

		: __GUP_CLOBBER_##__s)





#define get_user(x,p)							\

#define __get_user_check(x,p)							\

	({								\

	({								\

		unsigned long __limit = current_thread_info()->addr_limit - 1; \

		unsigned long __limit = current_thread_info()->addr_limit - 1; \

		register const typeof(*(p)) __user *__p asm("r0") = (p);\

		register const typeof(*(p)) __user *__p asm("r0") = (p);\
@@ -141,6 +141,12 @@ extern int __get_user_4(void *); 
		__e;							\

		__e;							\

	})

	})





#define get_user(x,p)							\

	({								\

		might_fault();						\

		__get_user_check(x,p);					\

	 })



extern int __put_user_1(void *, unsigned int);

extern int __put_user_1(void *, unsigned int);

extern int __put_user_2(void *, unsigned int);

extern int __put_user_2(void *, unsigned int);

extern int __put_user_4(void *, unsigned int);

extern int __put_user_4(void *, unsigned int);
@@ -155,7 +161,7 @@ extern int __put_user_8(void *, unsigned long long); 
		: "0" (__p), "r" (__r2), "r" (__l)			\

		: "0" (__p), "r" (__r2), "r" (__l)			\

		: "ip", "lr", "cc")

		: "ip", "lr", "cc")





#define put_user(x,p)							\

#define __put_user_check(x,p)							\

	({								\

	({								\

		unsigned long __limit = current_thread_info()->addr_limit - 1; \

		unsigned long __limit = current_thread_info()->addr_limit - 1; \

		register const typeof(*(p)) __r2 asm("r2") = (x);	\

		register const typeof(*(p)) __r2 asm("r2") = (x);	\
@@ -180,6 +186,12 @@ extern int __put_user_8(void *, unsigned long long); 
		__e;							\

		__e;							\

	})

	})





#define put_user(x,p)							\

	({								\

		might_fault();						\

		__put_user_check(x,p);					\

	 })



#else /* CONFIG_MMU */

#else /* CONFIG_MMU */





/*

/*
@@ -233,6 +245,7 @@ do { \ 
	unsigned long __gu_addr = (unsigned long)(ptr);			\

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

	unsigned long __gu_val;						\

	unsigned long __gu_val;						\

	__chk_user_ptr(ptr);						\

	__chk_user_ptr(ptr);						\

	might_fault();							\

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

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

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

	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 2:	__get_user_asm_half(__gu_val,__gu_addr,err);	break;	\
@@ -314,6 +327,7 @@ do { \ 
	unsigned long __pu_addr = (unsigned long)(ptr);			\

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

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

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

	__chk_user_ptr(ptr);						\

	__chk_user_ptr(ptr);						\

	might_fault();							\

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

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

	case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);	break;	\

	case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);	break;	\

	case 2: __put_user_asm_half(__pu_val,__pu_addr,err);	break;	\

	case 2: __put_user_asm_half(__pu_val,__pu_addr,err);	break;	\