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| author | Al Viro <viro@zeniv.linux.org.uk> | 2017-03-25 23:36:22 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2017-03-29 00:24:04 +0200 |
| commit | 122b05ddf506e637336dcf64b5a129825f7bf6d4 (patch) | |
| tree | e8addfa4b5747e198698c0d54789b077cf2a92a0 /arch/x86/include | |
| parent | generic ...copy_..._user primitives (diff) | |
| download | linux-122b05ddf506e637336dcf64b5a129825f7bf6d4.tar.xz linux-122b05ddf506e637336dcf64b5a129825f7bf6d4.zip | |
amd64: get rid of zeroing
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 12 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 16 |
2 files changed, 20 insertions, 8 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 0522d88a7f90..26410afcb8b0 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -379,6 +379,18 @@ do { \ : "=r" (err), ltype(x) \ : "m" (__m(addr)), "i" (errret), "0" (err)) +#define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \ + asm volatile("\n" \ + "1: mov"itype" %2,%"rtype"1\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: mov %3,%0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(1b, 3b) \ + : "=r" (err), ltype(x) \ + : "m" (__m(addr)), "i" (errret), "0" (err)) + /* * This doesn't do __uaccess_begin/end - the exception handling * around it must do that. diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 8ddadd93639e..142f0f1230be 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -59,44 +59,44 @@ int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size) switch (size) { case 1: __uaccess_begin(); - __get_user_asm(*(u8 *)dst, (u8 __user *)src, + __get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src, ret, "b", "b", "=q", 1); __uaccess_end(); return ret; case 2: __uaccess_begin(); - __get_user_asm(*(u16 *)dst, (u16 __user *)src, + __get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src, ret, "w", "w", "=r", 2); __uaccess_end(); return ret; case 4: __uaccess_begin(); - __get_user_asm(*(u32 *)dst, (u32 __user *)src, + __get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src, ret, "l", "k", "=r", 4); __uaccess_end(); return ret; case 8: __uaccess_begin(); - __get_user_asm(*(u64 *)dst, (u64 __user *)src, + __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, ret, "q", "", "=r", 8); __uaccess_end(); return ret; case 10: __uaccess_begin(); - __get_user_asm(*(u64 *)dst, (u64 __user *)src, + __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, ret, "q", "", "=r", 10); if (likely(!ret)) - __get_user_asm(*(u16 *)(8 + (char *)dst), + __get_user_asm_nozero(*(u16 *)(8 + (char *)dst), (u16 __user *)(8 + (char __user *)src), ret, "w", "w", "=r", 2); __uaccess_end(); return ret; case 16: __uaccess_begin(); - __get_user_asm(*(u64 *)dst, (u64 __user *)src, + __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, ret, "q", "", "=r", 16); if (likely(!ret)) - __get_user_asm(*(u64 *)(8 + (char *)dst), + __get_user_asm_nozero(*(u64 *)(8 + (char *)dst), (u64 __user *)(8 + (char __user *)src), ret, "q", "", "=r", 8); __uaccess_end(); |