2 files changed, 153 insertions, 12 deletions

diff --git a/arch/i386/lib/usercopy.c b/arch/i386/lib/usercopy.c
index 6979297ce278..c5aa65f7c02a 100644
--- a/arch/i386/lib/usercopy.c
+++ b/arch/i386/lib/usercopy.c
@@ -528,6 +528,97 @@ static unsigned long __copy_user_zeroing_intel_nocache(void *to,
         return size;
 }
 
+static unsigned long __copy_user_intel_nocache(void *to,
+                                const void __user *from, unsigned long size)
+{
+        int d0, d1;
+
+        __asm__ __volatile__(
+               "        .align 2,0x90\n"
+               "0:      movl 32(%4), %%eax\n"
+               "        cmpl $67, %0\n"
+               "        jbe 2f\n"
+               "1:      movl 64(%4), %%eax\n"
+               "        .align 2,0x90\n"
+               "2:      movl 0(%4), %%eax\n"
+               "21:     movl 4(%4), %%edx\n"
+               "        movnti %%eax, 0(%3)\n"
+               "        movnti %%edx, 4(%3)\n"
+               "3:      movl 8(%4), %%eax\n"
+               "31:     movl 12(%4),%%edx\n"
+               "        movnti %%eax, 8(%3)\n"
+               "        movnti %%edx, 12(%3)\n"
+               "4:      movl 16(%4), %%eax\n"
+               "41:     movl 20(%4), %%edx\n"
+               "        movnti %%eax, 16(%3)\n"
+               "        movnti %%edx, 20(%3)\n"
+               "10:     movl 24(%4), %%eax\n"
+               "51:     movl 28(%4), %%edx\n"
+               "        movnti %%eax, 24(%3)\n"
+               "        movnti %%edx, 28(%3)\n"
+               "11:     movl 32(%4), %%eax\n"
+               "61:     movl 36(%4), %%edx\n"
+               "        movnti %%eax, 32(%3)\n"
+               "        movnti %%edx, 36(%3)\n"
+               "12:     movl 40(%4), %%eax\n"
+               "71:     movl 44(%4), %%edx\n"
+               "        movnti %%eax, 40(%3)\n"
+               "        movnti %%edx, 44(%3)\n"
+               "13:     movl 48(%4), %%eax\n"
+               "81:     movl 52(%4), %%edx\n"
+               "        movnti %%eax, 48(%3)\n"
+               "        movnti %%edx, 52(%3)\n"
+               "14:     movl 56(%4), %%eax\n"
+               "91:     movl 60(%4), %%edx\n"
+               "        movnti %%eax, 56(%3)\n"
+               "        movnti %%edx, 60(%3)\n"
+               "        addl $-64, %0\n"
+               "        addl $64, %4\n"
+               "        addl $64, %3\n"
+               "        cmpl $63, %0\n"
+               "        ja  0b\n"
+               "        sfence \n"
+               "5:      movl  %0, %%eax\n"
+               "        shrl  $2, %0\n"
+               "        andl $3, %%eax\n"
+               "        cld\n"
+               "6:      rep; movsl\n"
+               "        movl %%eax,%0\n"
+               "7:      rep; movsb\n"
+               "8:\n"
+               ".section .fixup,\"ax\"\n"
+               "9:      lea 0(%%eax,%0,4),%0\n"
+               "16:     jmp 8b\n"
+               ".previous\n"
+               ".section __ex_table,\"a\"\n"
+               "        .align 4\n"
+               "        .long 0b,16b\n"
+               "        .long 1b,16b\n"
+               "        .long 2b,16b\n"
+               "        .long 21b,16b\n"
+               "        .long 3b,16b\n"
+               "        .long 31b,16b\n"
+               "        .long 4b,16b\n"
+               "        .long 41b,16b\n"
+               "        .long 10b,16b\n"
+               "        .long 51b,16b\n"
+               "        .long 11b,16b\n"
+               "        .long 61b,16b\n"
+               "        .long 12b,16b\n"
+               "        .long 71b,16b\n"
+               "        .long 13b,16b\n"
+               "        .long 81b,16b\n"
+               "        .long 14b,16b\n"
+               "        .long 91b,16b\n"
+               "        .long 6b,9b\n"
+               "        .long 7b,16b\n"
+               ".previous"
+               : "=&c"(size), "=&D" (d0), "=&S" (d1)
+               :  "1"(to), "2"(from), "0"(size)
+               : "eax", "edx", "memory");
+        return size;
+}
+
 #else
 
 /*
@@ -694,6 +785,19 @@ unsigned long __copy_from_user_ll(void *to, const void __user *from,
 }
 EXPORT_SYMBOL(__copy_from_user_ll);
 
+unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
+                                         unsigned long n)
+{
+        BUG_ON((long)n < 0);
+        if (movsl_is_ok(to, from, n))
+                __copy_user(to, from, n);
+        else
+                n = __copy_user_intel((void __user *)to,
+                                      (const void *)from, n);
+        return n;
+}
+EXPORT_SYMBOL(__copy_from_user_ll_nozero);
+
 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
                                         unsigned long n)
 {
@@ -709,6 +813,21 @@ unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
         return n;
 }
 
+unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
+                                        unsigned long n)
+{
+        BUG_ON((long)n < 0);
+#ifdef CONFIG_X86_INTEL_USERCOPY
+        if ( n > 64 && cpu_has_xmm2)
+                n = __copy_user_intel_nocache(to, from, n);
+        else
+                __copy_user(to, from, n);
+#else
+        __copy_user(to, from, n);
+#endif
+        return n;
+}
+
 /**
  * copy_to_user: - Copy a block of data into user space.
  * @to:   Destination address, in user space.
diff --git a/include/asm-i386/uaccess.h b/include/asm-i386/uaccess.h
index d0d253277be5..54d905ebc63d 100644
--- a/include/asm-i386/uaccess.h
+++ b/include/asm-i386/uaccess.h
@@ -390,8 +390,12 @@ unsigned long __must_check __copy_to_user_ll(void __user *to,
                                 const void *from, unsigned long n);
 unsigned long __must_check __copy_from_user_ll(void *to,
                                 const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nozero(void *to,
+                                const void __user *from, unsigned long n);
 unsigned long __must_check __copy_from_user_ll_nocache(void *to,
                                 const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to,
+                                const void __user *from, unsigned long n);
 
 /*
  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
@@ -463,11 +467,36 @@ __copy_to_user(void __user *to, const void *from, unsigned long n)
  * atomic context and will fail rather than sleep.  In this case the
  * uncopied bytes will *NOT* be padded with zeros.  See fs/filemap.h
  * for explanation of why this is needed.
- * FIXME this isn't implimented yet EMXIF
  */
 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:
+                        __get_user_size(*(u8 *)to, from, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __get_user_size(*(u16 *)to, from, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __get_user_size(*(u32 *)to, from, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_from_user_ll_nozero(to, from, n);
+}
+static __always_inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+        might_sleep();
         if (__builtin_constant_p(n)) {
                 unsigned long ret;
 
@@ -488,9 +517,10 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
 
 #define ARCH_HAS_NOCACHE_UACCESS
 
-static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to,
+static __always_inline unsigned long __copy_from_user_nocache(void *to,
                                 const void __user *from, unsigned long n)
 {
+        might_sleep();
         if (__builtin_constant_p(n)) {
                 unsigned long ret;
 
@@ -510,17 +540,9 @@ static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to,
 }
 
 static __always_inline unsigned long
-__copy_from_user(void *to, const void __user *from, unsigned long n)
+__copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n)
 {
-       might_sleep();
-       return __copy_from_user_inatomic(to, from, n);
-}
-
-static __always_inline unsigned long
-__copy_from_user_nocache(void *to, const void __user *from, unsigned long n)
-{
-       might_sleep();
-       return __copy_from_user_inatomic_nocache(to, from, n);
+       return __copy_from_user_ll_nocache_nozero(to, from, n);
 }
 
 unsigned long __must_check copy_to_user(void __user *to,