The only reason uaccess routines might sleep
is if they fault. Make this explicit.
Arnd Bergmann suggested that the following code
if (!is_kernel_addr((unsigned long)__pu_addr))
might_fault();
can be further simplified by adding a version of might_fault
that includes the kernel addr check.
Will be considered as a further optimization in future.
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
arch/powerpc/include/asm/uaccess.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/uaccess.h
b/arch/powerpc/include/asm/uaccess.h
index 4db4959..9485b43 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -178,7 +178,7 @@ do {
\
long __pu_err; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
if (!is_kernel_addr((unsigned long)__pu_addr)) \
- might_sleep(); \
+ might_fault(); \
__chk_user_ptr(ptr); \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
@@ -188,7 +188,7 @@ do {
\
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
- might_sleep(); \
+ might_fault(); \
if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
@@ -268,7 +268,7 @@ do {
\
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
__chk_user_ptr(ptr); \
if (!is_kernel_addr((unsigned long)__gu_addr)) \
- might_sleep(); \
+ might_fault(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
@@ -282,7 +282,7 @@ do {
\
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
__chk_user_ptr(ptr); \
if (!is_kernel_addr((unsigned long)__gu_addr)) \
- might_sleep(); \
+ might_fault(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
@@ -294,7 +294,7 @@ do {
\
long __gu_err = -EFAULT; \
unsigned long __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
- might_sleep(); \
+ might_fault(); \
if (access_ok(VERIFY_READ, __gu_addr, (size))) \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
@@ -419,14 +419,14 @@ static inline unsigned long __copy_to_user_inatomic(void
__user *to,
static inline unsigned long __copy_from_user(void *to,
const void __user *from, unsigned long size)
{
- might_sleep();
+ might_fault();
return __copy_from_user_inatomic(to, from, size);
}
static inline unsigned long __copy_to_user(void __user *to,
const void *from, unsigned long size)
{
- might_sleep();
+ might_fault();
return __copy_to_user_inatomic(to, from, size);
}
@@ -434,7 +434,7 @@ extern unsigned long __clear_user(void __user *addr,
unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)
{
- might_sleep();
+ might_fault();
if (likely(access_ok(VERIFY_WRITE, addr, size)))
return __clear_user(addr, size);
if ((unsigned long)addr < TASK_SIZE) {
--
MST
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