-- Binary file execute in memory handler. -- Copyright (C) 2006 - 2015 Tristan Gingold -- -- This program is free software: you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation, either version 2 of the License, or -- (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with this program. If not, see . with Ada.Text_IO; use Ada.Text_IO; package body Binary_File.Memory is -- Absolute section. Sect_Abs : Section_Acc; -- PLT section (for x86-64). Sect_Plt : Section_Acc; procedure Set_Symbol_Address (Sym : Symbol; Addr : System.Address) is begin if Arch = Arch_X86_64 and then Is_Symbol_Code (Sym) then -- Branches are limited on x86-64 to a 32 bit offset. Create a -- trampoline so that functions created outside of the module could -- be reached using the standard ABI. -- -- This works only for code, not for data. Therefore we assume that -- data symbols are correctly handled. declare V : Unsigned_64; Pc : constant Pc_Type := Sect_Plt.Pc; begin Set_Current_Section (Sect_Plt); Prealloc (16); -- Emit: movabs $ADDR, %r11 V := Unsigned_64 (To_Pc_Type (Addr)); Sect_Plt.Data (Pc + 0) := 16#49#; Sect_Plt.Data (Pc + 1) := 16#BB#; for I in Pc_Type range 0 .. 7 loop Sect_Plt.Data (Pc + 2 + I) := Byte (V and 16#ff#); V := Shift_Right (V, 8); end loop; -- Emit: jmp *%r11 Sect_Plt.Data (Pc + 10) := 16#41#; Sect_Plt.Data (Pc + 11) := 16#FF#; Sect_Plt.Data (Pc + 12) := 16#E3#; Sect_Plt.Pc := Pc + 13; Set_Symbol_Value (Sym, Pc); Set_Section (Sym, Sect_Plt); end; else Set_Symbol_Value (Sym, To_Pc_Type (Addr)); Set_Section (Sym, Sect_Abs); end if; -- Symbol is not anymore undefined. Set_Scope (Sym, Sym_Global); end Set_Symbol_Address; procedure Write_Memory_Init is begin Create_Section (Sect_Abs, "*ABS*", Section_Exec); Sect_Abs.Vaddr := 0; if Arch = Arch_X86_64 then Create_Section (Sect_Plt, ".plt", Section_Exec); end if; end Write_Memory_Init; type Segment_Kind is (Seg_Text, Seg_Ro, Seg_Data, Seg_None); function Get_Segment (Sect : Section_Acc) return Segment_Kind is begin if Sect = Sect_Abs then return Seg_None; end if; if (Sect.Flags and Section_Exec) /= 0 then return Seg_Text; elsif (Sect.Flags and Section_Write) /= 0 then return Seg_Data; elsif (Sect.Flags and Section_Read) /= 0 then return Seg_Ro; else return Seg_None; end if; end Get_Segment; procedure Write_Memory_Relocate (Error : out Boolean) is Log_Pagesize : constant := 12; type Seg_Size_Array is array (Segment_Kind) of Pc_Type; Seg_Size : Seg_Size_Array; Seg_Offs : Seg_Size_Array; Size : Pc_Type; Program_Seg : Memsegs.Memseg_Type; Program : Byte_Array_Acc; Sect : Section_Acc; Rel : Reloc_Acc; N_Rel : Reloc_Acc; begin -- Compute sizes. Seg_Size := (others => 0); Sect := Section_Chain; while Sect /= null loop declare Seg : constant Segment_Kind := Get_Segment (Sect); begin -- Currently, offset in the segment. Sect.Img_Off := Pow_Align (Seg_Size (Seg), Sect.Align); Seg_Size (Seg) := Sect.Img_Off + Sect.Pc; end; Sect := Sect.Next; end loop; -- Align. for I in Seg_Text .. Seg_Data loop Seg_Size (I) := Pow_Align (Seg_Size (I), Log_Pagesize); end loop; -- Whole size. Size := 0; for I in Seg_Text .. Seg_Data loop Size := Size + Seg_Size (I); end loop; -- Allocate and copy. Program_Seg := Memsegs.Create; Memsegs.Resize (Program_Seg, Natural (Size)); Program := To_Byte_Array_Acc (Memsegs.Get_Address (Program_Seg)); Seg_Offs (Seg_Text) := 0; Seg_Offs (Seg_Ro) := Seg_Size (Seg_Text); Seg_Offs (Seg_Data) := Seg_Size (Seg_Text) + Seg_Size (Seg_Ro); Sect := Section_Chain; while Sect /= null loop declare Seg : constant Segment_Kind := Get_Segment (Sect); Off : Pc_Type renames Seg_Offs (Seg); begin if Seg /= Seg_None then -- From segment offset to image offset. Sect.Img_Off := Sect.Img_Off + Seg_Offs (Seg); if Sect.Pc > 0 then Off := Pow_Align (Off, Sect.Align); if Sect.Data = null then -- For bss. Program (Off .. Off + Sect.Pc - 1) := (others => 0); else Program (Off .. Off + Sect.Pc - 1) := Sect.Data (0 .. Sect.Pc - 1); Memsegs.Delete (Sect.Seg); end if; Sect.Data := To_Byte_Array_Acc (Program (Off)'Address); -- Set virtual address. Sect.Vaddr := To_Pc_Type (Program (Off)'Address); Off := Off + Sect.Pc; end if; end if; end; Sect := Sect.Next; end loop; -- Do all relocations. Sect := Section_Chain; Error := False; while Sect /= null loop -- Put_Line ("Section: " & Sect.Name.all & ", Flags:" -- & Section_Flags'Image (Sect.Flags)); Rel := Sect.First_Reloc; while Rel /= null loop N_Rel := Rel.Sect_Next; if Get_Scope (Rel.Sym) = Sym_Undef then Put_Line ("symbol " & Get_Symbol_Name (Rel.Sym) & " is undefined"); Error := True; else Apply_Reloc (Sect, Rel); end if; Free (Rel); Rel := N_Rel; end loop; Sect.First_Reloc := null; Sect.Last_Reloc := null; Sect.Nbr_Relocs := 0; Sect := Sect.Next; end loop; if Seg_Size (Seg_Text) /= 0 then Memsegs.Set_Rx (Program_Seg, 0, Natural (Seg_Size (Seg_Text))); end if; end Write_Memory_Relocate; function Get_Section_Addr (Sect : Section_Acc) return System.Address is begin return Sect.Data (0)'Address; end Get_Section_Addr; function Get_Section_Size (Sect : Section_Acc) return Pc_Type is begin return Sect.Pc; end Get_Section_Size; end Binary_File.Memory; 24 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243