Fixed kernel segfault in VTerm (referenced possible NULL value)

[tpg/acess2.git] / Kernel / drv / vterm.c

diff --git a/Kernel/drv/vterm.c b/Kernel/drv/vterm.c
index da82d67..252f292 100644 (file)
--- a/Kernel/drv/vterm.c
+++ b/Kernel/drv/vterm.c
@@ -39,7 +39,6 @@ enum eVT_InModes {
 typedef struct {
         int    Mode;   //!< Current Mode (see ::eTplTerminal_Modes)
         int    Flags;  //!< Flags (see VT_FLAG_*)
-        
        
        short   NewWidth;       //!< Un-applied dimensions (Width)
        short   NewHeight;      //!< Un-applied dimensions (Height)
@@ -52,6 +51,8 @@ typedef struct {
         int    WritePos;       //!< Write Buffer Offset (Text Only)
        Uint32  CurColour;      //!< Current Text Colour
        
+       tMutex  ReadingLock;    //!< Lock the VTerm when a process is reading from it
+       tTID    ReadingThread;  //!< Owner of the lock
         int    InputRead;      //!< Input buffer read position
         int    InputWrite;     //!< Input buffer write position
        char    InputBuffer[MAX_INPUT_CHARS8];
@@ -402,6 +403,9 @@ Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
         int    pos = 0;
        tVTerm  *term = &gVT_Terminals[ Node->Inode ];
        
+       Mutex_Acquire( &term->ReadingLock );
+       term->ReadingThread = Threads_GetTID();
+       
        // Check current mode
        switch(term->Mode)
        {
@@ -409,7 +413,8 @@ Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
        case TERM_MODE_TEXT:
                while(pos < Length)
                {
-                       while(term->InputRead == term->InputWrite)      Threads_Yield();
+                       //TODO: Sleep instead
+                       while(term->InputRead == term->InputWrite)      Threads_Sleep();
                        
                        ((char*)Buffer)[pos] = term->InputBuffer[term->InputRead];
                        pos ++;
@@ -423,7 +428,7 @@ Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
        default:
                while(pos < Length)
                {
-                       while(term->InputRead == term->InputWrite)      Threads_Yield();
+                       while(term->InputRead == term->InputWrite)      Threads_Sleep();
                        ((Uint32*)Buffer)[pos] = ((Uint32*)term->InputBuffer)[term->InputRead];
                        pos ++;
                        term->InputRead ++;
@@ -431,6 +436,10 @@ Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
                }
                break;
        }
+       
+       term->ReadingThread = -1;
+       Mutex_Release( &term->ReadingLock );
+       
        return 0;
 }
 
@@ -614,7 +623,7 @@ int VT_Terminal_IOCtl(tVFS_Node *Node, int Id, void *Data)
                if( term->NewHeight )
                        ret = term->NewHeight;
                else if( term->Mode == TERM_MODE_TEXT )
-                       ret = term->TextHeight = *iData;
+                       ret = term->TextHeight;
                else
                        ret = term->Height;
                LEAVE('i', ret);
@@ -648,7 +657,8 @@ void VT_SetTerminal(int ID)
                tVideo_IOCtl_Pos        pos;
                pos.x = (gpVT_CurTerm->WritePos - gpVT_CurTerm->ViewPos) % gpVT_CurTerm->TextWidth;
                pos.y = (gpVT_CurTerm->WritePos - gpVT_CurTerm->ViewPos) / gpVT_CurTerm->TextWidth;
-               VFS_IOCtl(giVT_OutputDevHandle, VIDEO_IOCTL_SETCURSOR, &pos);
+               if( pos.x < gpVT_CurTerm->TextHeight )
+                       VFS_IOCtl(giVT_OutputDevHandle, VIDEO_IOCTL_SETCURSOR, &pos);
        }
        
        if( gpVT_CurTerm->Mode == TERM_MODE_TEXT )
@@ -818,6 +828,11 @@ void VT_KBCallBack(Uint32 Codepoint)
                        term->InputRead %= MAX_INPUT_CHARS32;
                }
        }
+       
+       // Wake up the thread waiting on us
+       if( term->ReadingThread >= 0 ) {
+               Threads_WakeTID(term->ReadingThread);
+       }
 }
 
 /**
@@ -828,7 +843,7 @@ void VT_int_ClearLine(tVTerm *Term, int Num)
 {
         int    i;
        tVT_Char        *cell = &Term->Text[ Num*Term->TextWidth ];
-       if( Num < 0 || Num >= Term->TextHeight )        return ;
+       if( Num < 0 || Num >= Term->TextHeight * (giVT_Scrollback + 1) )        return ;
        //ENTER("pTerm iNum", Term, Num);
        for( i = Term->TextWidth; i--; )
        {
@@ -868,17 +883,6 @@ int VT_int_ParseEscape(tVTerm *Term, char *Buffer)
                        } while(c == ';');
                }
                
-               /*
-               // Get string (what does this do?)
-               if(c == '"') {
-                       c = Buffer[j++];
-                       while(c != '"')
-                               c = Buffer[j++];
-               }
-               */
-               
-               //Log_Debug("VTerm", "argc = %i", argc);
-               
                // Get Command
                if(     ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'))
                {
@@ -1069,8 +1073,6 @@ void VT_int_PutChar(tVTerm *Term, Uint32 Ch)
        {
                 int    base, i;
                
-               //Debug("Scrolling entire buffer");
-               
                // Move back by one
                Term->WritePos -= Term->TextWidth;
                // Update the scren
@@ -1114,6 +1116,7 @@ void VT_int_PutChar(tVTerm *Term, Uint32 Ch)
                Term->WritePos -= Term->TextWidth;
                VT_int_UpdateScreen( Term, 0 );
                Term->WritePos += Term->TextWidth;
+               VT_int_ClearLine(Term, Term->WritePos / Term->TextWidth);
                
                // Scroll
                Term->ViewPos += Term->TextWidth;