Commit ddf35cf3 authored by Michael Ellerman's avatar Michael Ellerman

powerpc: Use barrier_nospec in copy_from_user()

Based on the x86 commit doing the same.

See commit 304ec1b0 ("x86/uaccess: Use __uaccess_begin_nospec()
and uaccess_try_nospec") and b3bbfb3f ("x86: Introduce
__uaccess_begin_nospec() and uaccess_try_nospec") for more detail.

In all cases we are ordering the load from the potentially
user-controlled pointer vs a previous branch based on an access_ok()
check or similar.

Base on a patch from Michal Suchanek.
Signed-off-by: default avatarMichal Suchanek <msuchanek@suse.de>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent cb3d6759
......@@ -258,6 +258,7 @@ 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; \
......@@ -269,8 +270,10 @@ do { \
unsigned long __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
might_fault(); \
if (access_ok(VERIFY_READ, __gu_addr, (size))) \
if (access_ok(VERIFY_READ, __gu_addr, (size))) { \
barrier_nospec(); \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
} \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
......@@ -281,6 +284,7 @@ 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; \
......@@ -308,15 +312,19 @@ 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;
}
......@@ -324,6 +332,7 @@ static inline unsigned long raw_copy_from_user(void *to,
return 0;
}
barrier_nospec();
return __copy_tofrom_user((__force void __user *)to, from, n);
}
......
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