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authorWill Deacon <will.deacon@arm.com>2012-09-07 18:24:10 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-09-09 17:28:48 +0100
commitad72907acd2943304c292ae36960bb66e6dc23c9 (patch)
treed9f09ddcb8c4bc8d5a3885c89bc28942bd2e33bd /arch/arm/include/asm/uaccess.h
parent8404663f81d212918ff85f493649a7991209fa04 (diff)
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: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/uaccess.h')
-rw-r--r--arch/arm/include/asm/uaccess.h18
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 6f83ad6e4d3..77bd79f2ffd 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -118,7 +118,7 @@ extern int __get_user_4(void *);
: "0" (__p), "r" (__l) \
: __GUP_CLOBBER_##__s)
-#define get_user(x,p) \
+#define __get_user_check(x,p) \
({ \
unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
@@ -141,6 +141,12 @@ extern int __get_user_4(void *);
__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_2(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) \
: "ip", "lr", "cc")
-#define put_user(x,p) \
+#define __put_user_check(x,p) \
({ \
unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __r2 asm("r2") = (x); \
@@ -180,6 +186,12 @@ extern int __put_user_8(void *, unsigned long long);
__e; \
})
+#define put_user(x,p) \
+ ({ \
+ might_fault(); \
+ __put_user_check(x,p); \
+ })
+
#else /* CONFIG_MMU */
/*
@@ -233,6 +245,7 @@ do { \
unsigned long __gu_addr = (unsigned long)(ptr); \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
+ might_fault(); \
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; \
@@ -314,6 +327,7 @@ do { \
unsigned long __pu_addr = (unsigned long)(ptr); \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
+ might_fault(); \
switch (sizeof(*(ptr))) { \
case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \