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@@ -1,8 +1,10 @@
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-/* Copyright 2002 Andi Kleen, SuSE Labs.
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+/*
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+ * Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com>
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+ * Copyright 2002 Andi Kleen, SuSE Labs.
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* Subject to the GNU Public License v2.
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- *
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- * Functions to copy from and to user space.
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- */
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+ *
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+ * Functions to copy from and to user space.
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+ */
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#include <linux/linkage.h>
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#include <asm/dwarf2.h>
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@@ -20,60 +22,88 @@
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.long \orig-1f /* by default jump to orig */
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1:
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.section .altinstr_replacement,"ax"
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-2: .byte 0xe9 /* near jump with 32bit immediate */
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+2: .byte 0xe9 /* near jump with 32bit immediate */
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.long \alt-1b /* offset */ /* or alternatively to alt */
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.previous
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.section .altinstructions,"a"
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.align 8
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.quad 0b
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.quad 2b
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- .byte \feature /* when feature is set */
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+ .byte \feature /* when feature is set */
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.byte 5
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.byte 5
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.previous
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.endm
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-/* Standard copy_to_user with segment limit checking */
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+ .macro ALIGN_DESTINATION
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+#ifdef FIX_ALIGNMENT
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+ /* check for bad alignment of destination */
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+ movl %edi,%ecx
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+ andl $7,%ecx
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+ jz 102f /* already aligned */
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+ subl $8,%ecx
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+ negl %ecx
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+ subl %ecx,%edx
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+100: movb (%rsi),%al
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+101: movb %al,(%rdi)
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+ incq %rsi
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+ incq %rdi
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+ decl %ecx
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+ jnz 100b
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+102:
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+ .section .fixup,"ax"
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+103: addl %r8d,%edx /* ecx is zerorest also */
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+ jmp copy_user_handle_tail
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+ .previous
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+
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+ .section __ex_table,"a"
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+ .align 8
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+ .quad 100b,103b
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+ .quad 101b,103b
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+ .previous
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+#endif
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+ .endm
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+
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+/* Standard copy_to_user with segment limit checking */
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ENTRY(copy_to_user)
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CFI_STARTPROC
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GET_THREAD_INFO(%rax)
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movq %rdi,%rcx
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addq %rdx,%rcx
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- jc bad_to_user
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+ jc bad_to_user
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cmpq TI_addr_limit(%rax),%rcx
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jae bad_to_user
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- xorl %eax,%eax /* clear zero flag */
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ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
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CFI_ENDPROC
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-ENTRY(copy_user_generic)
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+/* Standard copy_from_user with segment limit checking */
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+ENTRY(copy_from_user)
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CFI_STARTPROC
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- movl $1,%ecx /* set zero flag */
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+ GET_THREAD_INFO(%rax)
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+ movq %rsi,%rcx
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+ addq %rdx,%rcx
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+ jc bad_from_user
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+ cmpq TI_addr_limit(%rax),%rcx
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+ jae bad_from_user
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ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
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CFI_ENDPROC
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+ENDPROC(copy_from_user)
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-ENTRY(__copy_from_user_inatomic)
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+ENTRY(copy_user_generic)
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CFI_STARTPROC
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- xorl %ecx,%ecx /* clear zero flag */
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ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
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CFI_ENDPROC
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+ENDPROC(copy_user_generic)
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-/* Standard copy_from_user with segment limit checking */
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-ENTRY(copy_from_user)
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+ENTRY(__copy_from_user_inatomic)
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CFI_STARTPROC
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- GET_THREAD_INFO(%rax)
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- movq %rsi,%rcx
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- addq %rdx,%rcx
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- jc bad_from_user
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- cmpq TI_addr_limit(%rax),%rcx
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- jae bad_from_user
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- movl $1,%ecx /* set zero flag */
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ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
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CFI_ENDPROC
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-ENDPROC(copy_from_user)
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-
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+ENDPROC(__copy_from_user_inatomic)
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+
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.section .fixup,"ax"
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/* must zero dest */
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+ENTRY(bad_from_user)
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bad_from_user:
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CFI_STARTPROC
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movl %edx,%ecx
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@@ -81,271 +111,158 @@ bad_from_user:
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rep
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stosb
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bad_to_user:
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- movl %edx,%eax
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+ movl %edx,%eax
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ret
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CFI_ENDPROC
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-END(bad_from_user)
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+ENDPROC(bad_from_user)
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.previous
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-
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-
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+
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/*
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* copy_user_generic_unrolled - memory copy with exception handling.
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- * This version is for CPUs like P4 that don't have efficient micro code for rep movsq
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- *
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- * Input:
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+ * This version is for CPUs like P4 that don't have efficient micro
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+ * code for rep movsq
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+ *
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+ * Input:
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* rdi destination
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* rsi source
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* rdx count
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- * ecx zero flag -- if true zero destination on error
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*
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- * Output:
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- * eax uncopied bytes or 0 if successful.
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+ * Output:
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+ * eax uncopied bytes or 0 if successfull.
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*/
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ENTRY(copy_user_generic_unrolled)
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CFI_STARTPROC
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- pushq %rbx
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- CFI_ADJUST_CFA_OFFSET 8
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- CFI_REL_OFFSET rbx, 0
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- pushq %rcx
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- CFI_ADJUST_CFA_OFFSET 8
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- CFI_REL_OFFSET rcx, 0
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- xorl %eax,%eax /*zero for the exception handler */
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-
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-#ifdef FIX_ALIGNMENT
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- /* check for bad alignment of destination */
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- movl %edi,%ecx
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- andl $7,%ecx
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- jnz .Lbad_alignment
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-.Lafter_bad_alignment:
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-#endif
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-
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- movq %rdx,%rcx
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-
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- movl $64,%ebx
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- shrq $6,%rdx
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- decq %rdx
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- js .Lhandle_tail
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-
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- .p2align 4
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-.Lloop:
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-.Ls1: movq (%rsi),%r11
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-.Ls2: movq 1*8(%rsi),%r8
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-.Ls3: movq 2*8(%rsi),%r9
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-.Ls4: movq 3*8(%rsi),%r10
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-.Ld1: movq %r11,(%rdi)
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-.Ld2: movq %r8,1*8(%rdi)
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-.Ld3: movq %r9,2*8(%rdi)
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-.Ld4: movq %r10,3*8(%rdi)
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-
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-.Ls5: movq 4*8(%rsi),%r11
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-.Ls6: movq 5*8(%rsi),%r8
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-.Ls7: movq 6*8(%rsi),%r9
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-.Ls8: movq 7*8(%rsi),%r10
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-.Ld5: movq %r11,4*8(%rdi)
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-.Ld6: movq %r8,5*8(%rdi)
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-.Ld7: movq %r9,6*8(%rdi)
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-.Ld8: movq %r10,7*8(%rdi)
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-
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- decq %rdx
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-
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+ cmpl $8,%edx
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+ jb 20f /* less then 8 bytes, go to byte copy loop */
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+ ALIGN_DESTINATION
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+ movl %edx,%ecx
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+ andl $63,%edx
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+ shrl $6,%ecx
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+ jz 17f
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+1: movq (%rsi),%r8
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+2: movq 1*8(%rsi),%r9
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+3: movq 2*8(%rsi),%r10
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+4: movq 3*8(%rsi),%r11
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+5: movq %r8,(%rdi)
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+6: movq %r9,1*8(%rdi)
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+7: movq %r10,2*8(%rdi)
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+8: movq %r11,3*8(%rdi)
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+9: movq 4*8(%rsi),%r8
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+10: movq 5*8(%rsi),%r9
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+11: movq 6*8(%rsi),%r10
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+12: movq 7*8(%rsi),%r11
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+13: movq %r8,4*8(%rdi)
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+14: movq %r9,5*8(%rdi)
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+15: movq %r10,6*8(%rdi)
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+16: movq %r11,7*8(%rdi)
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leaq 64(%rsi),%rsi
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leaq 64(%rdi),%rdi
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-
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- jns .Lloop
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-
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- .p2align 4
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-.Lhandle_tail:
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- movl %ecx,%edx
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- andl $63,%ecx
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- shrl $3,%ecx
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- jz .Lhandle_7
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- movl $8,%ebx
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- .p2align 4
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-.Lloop_8:
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-.Ls9: movq (%rsi),%r8
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-.Ld9: movq %r8,(%rdi)
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decl %ecx
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- leaq 8(%rdi),%rdi
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+ jnz 1b
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+17: movl %edx,%ecx
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+ andl $7,%edx
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+ shrl $3,%ecx
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+ jz 20f
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+18: movq (%rsi),%r8
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+19: movq %r8,(%rdi)
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leaq 8(%rsi),%rsi
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- jnz .Lloop_8
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-
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-.Lhandle_7:
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+ leaq 8(%rdi),%rdi
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+ decl %ecx
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+ jnz 18b
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+20: andl %edx,%edx
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+ jz 23f
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movl %edx,%ecx
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- andl $7,%ecx
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- jz .Lende
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- .p2align 4
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-.Lloop_1:
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-.Ls10: movb (%rsi),%bl
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-.Ld10: movb %bl,(%rdi)
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- incq %rdi
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+21: movb (%rsi),%al
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+22: movb %al,(%rdi)
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incq %rsi
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+ incq %rdi
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decl %ecx
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- jnz .Lloop_1
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-
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- CFI_REMEMBER_STATE
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-.Lende:
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- popq %rcx
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- CFI_ADJUST_CFA_OFFSET -8
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- CFI_RESTORE rcx
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- popq %rbx
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- CFI_ADJUST_CFA_OFFSET -8
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- CFI_RESTORE rbx
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+ jnz 21b
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+23: xor %eax,%eax
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ret
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- CFI_RESTORE_STATE
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-#ifdef FIX_ALIGNMENT
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- /* align destination */
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- .p2align 4
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-.Lbad_alignment:
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- movl $8,%r9d
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- subl %ecx,%r9d
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- movl %r9d,%ecx
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- cmpq %r9,%rdx
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- jz .Lhandle_7
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- js .Lhandle_7
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-.Lalign_1:
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-.Ls11: movb (%rsi),%bl
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-.Ld11: movb %bl,(%rdi)
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- incq %rsi
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- incq %rdi
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- decl %ecx
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- jnz .Lalign_1
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- subq %r9,%rdx
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- jmp .Lafter_bad_alignment
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-#endif
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+ .section .fixup,"ax"
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+30: shll $6,%ecx
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+ addl %ecx,%edx
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+ jmp 60f
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+40: leal (%edx,%ecx,8),%edx
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+ jmp 60f
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+50: movl %ecx,%edx
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+60: jmp copy_user_handle_tail /* ecx is zerorest also */
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+ .previous
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- /* table sorted by exception address */
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.section __ex_table,"a"
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.align 8
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- .quad .Ls1,.Ls1e /* Ls1-Ls4 have copied zero bytes */
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- .quad .Ls2,.Ls1e
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- .quad .Ls3,.Ls1e
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- .quad .Ls4,.Ls1e
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- .quad .Ld1,.Ls1e /* Ld1-Ld4 have copied 0-24 bytes */
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- .quad .Ld2,.Ls2e
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- .quad .Ld3,.Ls3e
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- .quad .Ld4,.Ls4e
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- .quad .Ls5,.Ls5e /* Ls5-Ls8 have copied 32 bytes */
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- .quad .Ls6,.Ls5e
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- .quad .Ls7,.Ls5e
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- .quad .Ls8,.Ls5e
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- .quad .Ld5,.Ls5e /* Ld5-Ld8 have copied 32-56 bytes */
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- .quad .Ld6,.Ls6e
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- .quad .Ld7,.Ls7e
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- .quad .Ld8,.Ls8e
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- .quad .Ls9,.Le_quad
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- .quad .Ld9,.Le_quad
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- .quad .Ls10,.Le_byte
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- .quad .Ld10,.Le_byte
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-#ifdef FIX_ALIGNMENT
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- .quad .Ls11,.Lzero_rest
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- .quad .Ld11,.Lzero_rest
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-#endif
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- .quad .Le5,.Le_zero
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+ .quad 1b,30b
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+ .quad 2b,30b
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+ .quad 3b,30b
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+ .quad 4b,30b
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+ .quad 5b,30b
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+ .quad 6b,30b
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+ .quad 7b,30b
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+ .quad 8b,30b
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+ .quad 9b,30b
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+ .quad 10b,30b
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+ .quad 11b,30b
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+ .quad 12b,30b
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+ .quad 13b,30b
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+ .quad 14b,30b
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+ .quad 15b,30b
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+ .quad 16b,30b
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+ .quad 18b,40b
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+ .quad 19b,40b
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+ .quad 21b,50b
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+ .quad 22b,50b
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.previous
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-
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- /* eax: zero, ebx: 64 */
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-.Ls1e: addl $8,%eax /* eax is bytes left uncopied within the loop (Ls1e: 64 .. Ls8e: 8) */
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-.Ls2e: addl $8,%eax
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-.Ls3e: addl $8,%eax
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-.Ls4e: addl $8,%eax
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-.Ls5e: addl $8,%eax
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-.Ls6e: addl $8,%eax
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-.Ls7e: addl $8,%eax
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-.Ls8e: addl $8,%eax
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- addq %rbx,%rdi /* +64 */
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- subq %rax,%rdi /* correct destination with computed offset */
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-
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- shlq $6,%rdx /* loop counter * 64 (stride length) */
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- addq %rax,%rdx /* add offset to loopcnt */
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- andl $63,%ecx /* remaining bytes */
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- addq %rcx,%rdx /* add them */
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- jmp .Lzero_rest
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-
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- /* exception on quad word loop in tail handling */
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- /* ecx: loopcnt/8, %edx: length, rdi: correct */
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-.Le_quad:
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- shll $3,%ecx
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- andl $7,%edx
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- addl %ecx,%edx
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- /* edx: bytes to zero, rdi: dest, eax:zero */
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-.Lzero_rest:
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- cmpl $0,(%rsp)
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- jz .Le_zero
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- movq %rdx,%rcx
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-.Le_byte:
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- xorl %eax,%eax
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-.Le5: rep
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- stosb
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- /* when there is another exception while zeroing the rest just return */
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-.Le_zero:
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- movq %rdx,%rax
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- jmp .Lende
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CFI_ENDPROC
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-ENDPROC(copy_user_generic)
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+ENDPROC(copy_user_generic_unrolled)
|
|
|
|
|
|
-
|
|
|
- /* Some CPUs run faster using the string copy instructions.
|
|
|
- This is also a lot simpler. Use them when possible.
|
|
|
- Patch in jmps to this code instead of copying it fully
|
|
|
- to avoid unwanted aliasing in the exception tables. */
|
|
|
-
|
|
|
- /* rdi destination
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|
|
- * rsi source
|
|
|
- * rdx count
|
|
|
- * ecx zero flag
|
|
|
- *
|
|
|
- * Output:
|
|
|
- * eax uncopied bytes or 0 if successfull.
|
|
|
- *
|
|
|
- * Only 4GB of copy is supported. This shouldn't be a problem
|
|
|
- * because the kernel normally only writes from/to page sized chunks
|
|
|
- * even if user space passed a longer buffer.
|
|
|
- * And more would be dangerous because both Intel and AMD have
|
|
|
- * errata with rep movsq > 4GB. If someone feels the need to fix
|
|
|
- * this please consider this.
|
|
|
- */
|
|
|
+/* Some CPUs run faster using the string copy instructions.
|
|
|
+ * This is also a lot simpler. Use them when possible.
|
|
|
+ *
|
|
|
+ * Only 4GB of copy is supported. This shouldn't be a problem
|
|
|
+ * because the kernel normally only writes from/to page sized chunks
|
|
|
+ * even if user space passed a longer buffer.
|
|
|
+ * And more would be dangerous because both Intel and AMD have
|
|
|
+ * errata with rep movsq > 4GB. If someone feels the need to fix
|
|
|
+ * this please consider this.
|
|
|
+ *
|
|
|
+ * Input:
|
|
|
+ * rdi destination
|
|
|
+ * rsi source
|
|
|
+ * rdx count
|
|
|
+ *
|
|
|
+ * Output:
|
|
|
+ * eax uncopied bytes or 0 if successful.
|
|
|
+ */
|
|
|
ENTRY(copy_user_generic_string)
|
|
|
CFI_STARTPROC
|
|
|
- movl %ecx,%r8d /* save zero flag */
|
|
|
+ andl %edx,%edx
|
|
|
+ jz 4f
|
|
|
+ cmpl $8,%edx
|
|
|
+ jb 2f /* less than 8 bytes, go to byte copy loop */
|
|
|
+ ALIGN_DESTINATION
|
|
|
movl %edx,%ecx
|
|
|
shrl $3,%ecx
|
|
|
- andl $7,%edx
|
|
|
- jz 10f
|
|
|
-1: rep
|
|
|
- movsq
|
|
|
- movl %edx,%ecx
|
|
|
-2: rep
|
|
|
- movsb
|
|
|
-9: movl %ecx,%eax
|
|
|
- ret
|
|
|
-
|
|
|
- /* multiple of 8 byte */
|
|
|
-10: rep
|
|
|
+ andl $7,%edx
|
|
|
+1: rep
|
|
|
movsq
|
|
|
- xor %eax,%eax
|
|
|
+2: movl %edx,%ecx
|
|
|
+3: rep
|
|
|
+ movsb
|
|
|
+4: xorl %eax,%eax
|
|
|
ret
|
|
|
|
|
|
- /* exception handling */
|
|
|
-3: lea (%rdx,%rcx,8),%rax /* exception on quad loop */
|
|
|
- jmp 6f
|
|
|
-5: movl %ecx,%eax /* exception on byte loop */
|
|
|
- /* eax: left over bytes */
|
|
|
-6: testl %r8d,%r8d /* zero flag set? */
|
|
|
- jz 7f
|
|
|
- movl %eax,%ecx /* initialize x86 loop counter */
|
|
|
- push %rax
|
|
|
- xorl %eax,%eax
|
|
|
-8: rep
|
|
|
- stosb /* zero the rest */
|
|
|
-11: pop %rax
|
|
|
-7: ret
|
|
|
- CFI_ENDPROC
|
|
|
-END(copy_user_generic_c)
|
|
|
+ .section .fixup,"ax"
|
|
|
+11: leal (%edx,%ecx,8),%ecx
|
|
|
+12: movl %ecx,%edx /* ecx is zerorest also */
|
|
|
+ jmp copy_user_handle_tail
|
|
|
+ .previous
|
|
|
|
|
|
.section __ex_table,"a"
|
|
|
- .quad 1b,3b
|
|
|
- .quad 2b,5b
|
|
|
- .quad 8b,11b
|
|
|
- .quad 10b,3b
|
|
|
+ .align 8
|
|
|
+ .quad 1b,11b
|
|
|
+ .quad 3b,12b
|
|
|
.previous
|
|
|
+ CFI_ENDPROC
|
|
|
+ENDPROC(copy_user_generic_string)
|