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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-23 02:21:27 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-23 02:21:27 +0200
commitbd28b14591b98f696bc9f94c5ba2e598ca487dfd (patch)
tree5cd165412fa7dec2dbbac28ff6d8d5b12d3011f4 /arch
parentx86: remove pointless uaccess_32.h complexity (diff)
downloadlinux-bd28b14591b98f696bc9f94c5ba2e598ca487dfd.tar.xz
linux-bd28b14591b98f696bc9f94c5ba2e598ca487dfd.zip
x86: remove more uaccess_32.h complexity
I'm looking at trying to possibly merge the 32-bit and 64-bit versions of the x86 uaccess.h implementation, but first this needs to be cleaned up. For example, the 32-bit version of "__copy_from_user_inatomic()" is mostly the special cases for the constant size, and it's actually almost never relevant. Most users aren't actually using a constant size anyway, and the few cases that do small constant copies are better off just using __get_user() instead. So get rid of the unnecessary complexity. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/uaccess_32.h26
1 files changed, 0 insertions, 26 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 537cc883ea29..4b32da24faaf 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -65,32 +65,6 @@ __copy_to_user(void __user *to, const void *from, unsigned long n)
static __always_inline unsigned long
__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
{
- /* Avoid zeroing the tail if the copy fails..
- * If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
- * but as the zeroing behaviour is only significant when n is not
- * constant, that shouldn't be a problem.
- */
- if (__builtin_constant_p(n)) {
- unsigned long ret;
-
- switch (n) {
- case 1:
- __uaccess_begin();
- __get_user_size(*(u8 *)to, from, 1, ret, 1);
- __uaccess_end();
- return ret;
- case 2:
- __uaccess_begin();
- __get_user_size(*(u16 *)to, from, 2, ret, 2);
- __uaccess_end();
- return ret;
- case 4:
- __uaccess_begin();
- __get_user_size(*(u32 *)to, from, 4, ret, 4);
- __uaccess_end();
- return ret;
- }
- }
return __copy_from_user_ll_nozero(to, from, n);
}