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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-22 23:19:37 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-22 23:19:37 +0200 |
commit | 5b09c3edecd37ec1a52fbd5ae97a19734edc7a77 (patch) | |
tree | 899fbf0a4255f76ae18d280b216b8ddede02512b /arch | |
parent | Merge tag 'for-f2fs-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jae... (diff) | |
download | linux-5b09c3edecd37ec1a52fbd5ae97a19734edc7a77.tar.xz linux-5b09c3edecd37ec1a52fbd5ae97a19734edc7a77.zip |
x86: remove pointless 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_to_user_inatomic()" is mostly
the special cases for the constant size, and it's actually never
relevant. Every user except for one aren't actually using a constant
size anyway, and the one user that uses it is better off just using
__put_user() instead.
So get rid of the unnecessary complexity.
[ The same cleanup should likely happen to __copy_from_user_inatomic()
as well, but that one has a lot more users that I need to take a look
at first ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 36 |
1 files changed, 0 insertions, 36 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 3fe0eac59462..537cc883ea29 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -33,46 +33,10 @@ unsigned long __must_check __copy_from_user_ll_nocache_nozero * the specified block with access_ok() before calling this function. * The caller should also make sure he pins the user space address * so that we don't result in page fault and sleep. - * - * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault - * we return the initial request size (1, 2 or 4), as copy_*_user should do. - * If a store crosses a page boundary and gets a fault, the x86 will not write - * anything, so this is accurate. */ - static __always_inline unsigned long __must_check __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { - if (__builtin_constant_p(n)) { - unsigned long ret; - - switch (n) { - case 1: - __uaccess_begin(); - __put_user_size(*(u8 *)from, (u8 __user *)to, - 1, ret, 1); - __uaccess_end(); - return ret; - case 2: - __uaccess_begin(); - __put_user_size(*(u16 *)from, (u16 __user *)to, - 2, ret, 2); - __uaccess_end(); - return ret; - case 4: - __uaccess_begin(); - __put_user_size(*(u32 *)from, (u32 __user *)to, - 4, ret, 4); - __uaccess_end(); - return ret; - case 8: - __uaccess_begin(); - __put_user_size(*(u64 *)from, (u64 __user *)to, - 8, ret, 8); - __uaccess_end(); - return ret; - } - } return __copy_to_user_ll(to, from, n); } |