René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Problem on RPI5 with Python13","articleBody":"Hi,\nusing the last version of P4D on RPI 5 leads to Exception External SIGSEGV. \nProblem is in method function  GetCallBack(Self: TObject; Method: Pointer; ArgNum: Integer;\n  CallType: TCallType): Pointer; \n\nnmap didn't allocate the memory.\n\n\nI have solved this problem changing the method code in way\n```pascal\n{$IFDEF CPUARM64}\nfunction  GetCallBack(Self: TObject; Method: Pointer; ArgNum: Integer;\n  CallType: TCallType): Pointer;\nconst\n  S1: array[0..79] of byte = (\n//big-endian\n//offset  \u003c_start\u003e:\n  $fd, $7b, $bf, $a9,  //\tstp\tx29, x30, [sp, #-16]!\n  $fd, $03, $00, $91,  //\tmov\tx29, sp\n  $e0, $07, $bf, $a9,  //\tstp\tx0, x1, [sp, #-16]!\n  $e2, $0f, $bf, $a9,  //\tstp\tx2, x3, [sp, #-16]!\n  $e4, $17, $bf, $a9,  //\tstp\tx4, x5, [sp, #-16]!\n  $e6, $1f, $bf, $a9,  //\tstp\tx6, x7, [sp, #-16]!\n  $0a, $00, $00, $10,  //\tadr\tx10, #0 \u003c_start+0x18\u003e\n  $40, $15, $40, $f9,  //\tldr\tx0, [x10, #40]\n  $49, $19, $40, $f9,  //\tldr\tx9, [x10, #48]\n  $e7, $2f, $c1, $a8,  //\tldp\tx7, x11, [sp], #16\n  $e5, $1b, $c1, $a8,  //\tldp\tx5, x6, [sp], #16\n  $e3, $13, $c1, $a8,  //\tldp\tx3, x4, [sp], #16\n  $e1, $0b, $c1, $a8,  //\tldp\tx1, x2, [sp], #16\n  $20, $01, $3f, $d6,  //\tblr\tx9\n  $fd, $7b, $c1, $a8,  //\tldp\tx29, x30, [sp], #16\n  $c0, $03, $5f, $d6,  //\tret\n  $00, $00, $00, $00,  //\t.word\t0x00000000 //Self\n  $00, $00, $00, $00,  //\t.word\t0x00000000\n  $00, $00, $00, $00,  //\t.word\t0x00000000 //Method\n  $00, $00, $00, $00   //\t.word\t0x00000000\n);\nconst\n  PageSize = 4096;\nvar\n  P, Q: PByte;\n  LLiteralPool: TArray\u003cpointer\u003e;\n  I: Integer;\n  addr: Pointer;\nbegin\n  GetCodeMem(Q, SizeOf(S1));\n  if Q = nil then\n  begin\n    addr := fpMmap(nil, PageSize, PROT_READ or PROT_WRITE or PROT_EXEC, MAP_PRIVATE or MAP_ANONYMOUS, -1, 0);\n    if addr = Pointer(-1) then\n    \t{$IFDEF UNIX}\n      raise Exception.Create('mmap failed: ' + SysErrorMessage(GetLastOSError));\n    \t{$ENDIF}\n    Q := PByte(addr);\n  end;\n\n  P := Q;\n  Move(S1, P^, SizeOf(S1));\n\n  LLiteralPool := TArray\u003cpointer\u003e.Create(Self, Method);\n\n  Inc(P, Length(S1) - (Length(LLiteralPool) * SizeOf(pointer)));\n  for I := Low(LLiteralPool) to High(LLiteralPool) do begin\n    Move(LLiteralPool[I], P^, SizeOf(pointer));\n    Inc(P, SizeOf(pointer));\n  end;\n  {$IFDEF UNIX}\n  if fpMprotect(Pointer(Q), SizeOf(S1), PROT_READ or PROT_EXEC) \u003c\u003e 0 then\n    raise Exception.Create('mprotect failed: ' + SysErrorMessage(GetLastOSError));\n  {$ENDIF}\n\n  {$IF DEFINED(OSX) AND DEFINED(CPUARM64)}\n    {\n      macOS for M1 has a bug (Apple Feedback FB8994773) in which mprotect\n      rejects a permission change from NONE -\u003e RWX.\n      Solution: give RW permission, make memory changes, then change RW to X\n    }\n    //X permission to the entire page for executions...\n    if mprotect(CodeMemPages, PageSize, PROT_EXEC) \u003c\u003e 0 then\n      raise EMProtectError.CreateFmt('MProtect error: %s', [\n        SysErrorMessage({$IFDEF FPC}GetLastOSError{$ELSE}GetLastError{$ENDIF}())]);\n  {$IFEND}\n\n  Result := Pointer(Q); //set arm mode\nend;\n{$ENDIF CPUARM64}      \n```\nMaybe that will help to someone.\n\nBest regards\nBojan\n\n","author":{"url":"https://github.com/comdora","@type":"Person","name":"comdora"},"datePublished":"2025-11-22T11:59:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/510/python4delphi/issues/510"}