[PATCH v2 1/3] powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user()

From: Christophe Leroy
Date: Tue Feb 09 2021 - 09:04:55 EST


Copied from commit 4b842e4e25b1 ("x86: get rid of small
constant size cases in raw_copy_{to,from}_user()")

Very few call sites where that would be triggered remain, and none
of those is anywhere near hot enough to bother.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/uaccess.h | 41 ------------------------------
1 file changed, 41 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 93d33f7e8b53..a4d2569173ac 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -398,26 +398,6 @@ static inline unsigned long raw_copy_from_user(void *to,
const void __user *from, unsigned long n)
{
unsigned long ret;
- if (__builtin_constant_p(n) && (n <= 8)) {
- ret = 1;
-
- switch (n) {
- case 1:
- __get_user_size(*(u8 *)to, from, 1, ret);
- break;
- case 2:
- __get_user_size(*(u16 *)to, from, 2, ret);
- break;
- case 4:
- __get_user_size(*(u32 *)to, from, 4, ret);
- break;
- case 8:
- __get_user_size(*(u64 *)to, from, 8, ret);
- break;
- }
- if (ret == 0)
- return 0;
- }

allow_read_from_user(from, n);
ret = __copy_tofrom_user((__force void __user *)to, from, n);
@@ -428,27 +408,6 @@ static inline unsigned long raw_copy_from_user(void *to,
static inline unsigned long
raw_copy_to_user_allowed(void __user *to, const void *from, unsigned long n)
{
- if (__builtin_constant_p(n) && (n <= 8)) {
- unsigned long ret = 1;
-
- switch (n) {
- case 1:
- __put_user_size_allowed(*(u8 *)from, (u8 __user *)to, 1, ret);
- break;
- case 2:
- __put_user_size_allowed(*(u16 *)from, (u16 __user *)to, 2, ret);
- break;
- case 4:
- __put_user_size_allowed(*(u32 *)from, (u32 __user *)to, 4, ret);
- break;
- case 8:
- __put_user_size_allowed(*(u64 *)from, (u64 __user *)to, 8, ret);
- break;
- }
- if (ret == 0)
- return 0;
- }
-
return __copy_tofrom_user(to, (__force const void __user *)from, n);
}

--
2.25.0