[PATCH RFC rebase 2/9] powerpc: Use barrier_nospec in copy_from_user

From: Michal Suchanek
Date: Thu Mar 15 2018 - 15:18:41 EST


This is based on x86 patch doing the same.

Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
---
arch/powerpc/include/asm/uaccess.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 51bfeb8777f0..af9b0e731f46 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -248,6 +248,7 @@ do { \
__chk_user_ptr(ptr); \
if (!is_kernel_addr((unsigned long)__gu_addr)) \
might_fault(); \
+ barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
@@ -258,8 +259,10 @@ do { \
long __gu_err = -EFAULT; \
unsigned long __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
+ int can_access = access_ok(VERIFY_READ, __gu_addr, (size)); \
might_fault(); \
- if (access_ok(VERIFY_READ, __gu_addr, (size))) \
+ barrier_nospec(); \
+ if (can_access) \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
@@ -271,6 +274,7 @@ do { \
unsigned long __gu_val; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
__chk_user_ptr(ptr); \
+ barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
@@ -298,15 +302,19 @@ static inline unsigned long raw_copy_from_user(void *to,

switch (n) {
case 1:
+ barrier_nospec();
__get_user_size(*(u8 *)to, from, 1, ret);
break;
case 2:
+ barrier_nospec();
__get_user_size(*(u16 *)to, from, 2, ret);
break;
case 4:
+ barrier_nospec();
__get_user_size(*(u32 *)to, from, 4, ret);
break;
case 8:
+ barrier_nospec();
__get_user_size(*(u64 *)to, from, 8, ret);
break;
}
@@ -314,6 +322,7 @@ static inline unsigned long raw_copy_from_user(void *to,
return 0;
}

+ barrier_nospec();
return __copy_tofrom_user((__force void __user *)to, from, n);
}

--
2.13.6