60 lines
1 KiB
ArmAsm
60 lines
1 KiB
ArmAsm
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! OS X, unlike FreeBSD, requires us to provide our own signal
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! trampoline. We must change the new action from a struct sigaction
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! to a bigger struct that includes the trampoline.
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.sect .text
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.define _sigaction
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_sigaction:
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mov eax, esp
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mov ebx, 8(esp) ! ebx = ptr to new action
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cmp ebx, 0
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je 1f
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! push bigger struct
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push 8(ebx) ! sa_flags
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push 4(ebx) ! sa_mask
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push trampoline ! sa_tramp
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push 0(ebx) ! sa_handler
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mov ebx, esp
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jmp 2f
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1:
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sub esp, 16
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2:
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push 12(eax) ! ptr to old action
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push ebx ! ptr to bigger struct
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push 4(eax) ! sig
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call 3f
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add esp, 28
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ret
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3:
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mov eax, 46
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int 0x80
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jb .set_errno
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ret
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trampoline:
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! 4(esp) = handler
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! 8(esp) = info style
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! 12(esp) = sig
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! 16(esp) = info
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! 20(esp) = context
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! Call handler(sig, info, context)
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mov eax, esp
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push 20(eax)
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push 16(eax)
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push 12(eax)
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call 4(eax)
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add esp, 12
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! Return from trampoline.
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mov eax, esp
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push 8(eax) ! info style
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push 20(eax) ! context
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sub esp, 4
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mov eax, 184 ! sigreturn
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int 0x80
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! Only if sigreturn() fails:
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mov eax, 1 ! exit
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int 0x80
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