PT_NULL =    0
PT_LOAD =    1
PT_DYNAMIC = 2
PT_INTERP =  3
PT_NOTE =    4
PT_SHLIB =   5
PT_PHDR =    6
PT_TLS =     7     
PT_LOOS =    0x60000000  
PT_HIOS =    0x6fffffff 
PT_LOPROC =  0x70000000
PT_HIPROC = 0x7fffffff
PT_GNU_EH_FRAME	= 0x6474e550
PT_GNU_STACK = PT_LOOS + 0x474e551

PT_X = 0x1
PT_W = 0x2
PT_R = 0x4
