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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#
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#
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.text
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.text
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/** Syscall wrapper.
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/** Syscall wrapper - INT $0x30 version.
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 *
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 *
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 * Mind the order of arguments. First two arguments and the syscall number go to
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 * Mind the order of arguments. First two arguments and the syscall number go to
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 * scratch registers. An optimized version of this wrapper for fewer arguments
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 * scratch registers. An optimized version of this wrapper for fewer arguments
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 * could benefit from this and not save unused registers on the stack.
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 * could benefit from this and not save unused registers on the stack.
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 */
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 */
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.global __syscall
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.global __syscall_int
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__syscall:
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__syscall_int:
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	pushl %ebx
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	pushl %ebx
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	pushl %esi
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	pushl %esi
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	pushl %edi
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	pushl %edi
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	pushl %ebp
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	pushl %ebp
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	movl 20(%esp), %edx	# First argument.
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	movl 20(%esp), %edx	# First argument.
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	popl %ebp
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	popl %ebp
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	popl %edi
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	popl %edi
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	popl %esi
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	popl %esi
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	popl %ebx
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	popl %ebx
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	ret
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	ret
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/** Syscall wrapper - SYSENTER version.
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 *
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 * This is an optimized version of syscall for four or less arguments.  Note
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 * that EBP and EDI are used to remember user stack address and the return
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 * address. The kernel part doesn't save DS, ES and FS so the handler restores
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 * these to the selector immediately following CS (it must be the flat data
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 * segment, otherwise the SYSENTER wouldn't work in the first place).
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 */
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.global __syscall_sysenter
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__syscall_sysenter:
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	pushl %ebx
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	pushl %esi
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	pushl %edi
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	pushl %ebp
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	mov %esp, %ebp
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	lea ra, %edi
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	movl 20(%esp), %edx	# First argument.
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	movl 24(%esp), %ecx	# Second argument.
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	movl 28(%esp), %ebx	# Third argument.
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	movl 32(%esp), %esi	# Fourth argument.
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	movl 44(%esp), %eax	# Syscall number.
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	sysenter
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ra:
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	movw %cs, %cx
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	addw $8, %cx
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	movw %cx, %ds
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	movw %cx, %es
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	movw %cx, %fs
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	popl %ebp
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	popl %edi
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	popl %esi
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	popl %ebx
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	ret