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 b940afa..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];
@@ -71,7 +72,7 @@ extern void   Debug_SetKTerminal(char *File);
 void   VT_InitOutput(void);
 void   VT_InitInput(void);
 char   *VT_ReadDir(tVFS_Node *Node, int Pos);
-tVFS_Node      *VT_FindDir(tVFS_Node *Node, char *Name);
+tVFS_Node      *VT_FindDir(tVFS_Node *Node, const char *Name);
  int   VT_Root_IOCtl(tVFS_Node *Node, int Id, void *Data);
 Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
 Uint64 VT_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
@@ -148,12 +149,10 @@ int VT_Install(char **Arguments)
                        val = arg + strpos(arg, '=');   *val++ = '\0';
                        
                        if( strcmp(opt, "Video") == 0 ) {
-                               if(gsVT_OutputDevice)   free(gsVT_OutputDevice);
-                               gsVT_OutputDevice = strdup(val);
+                               gsVT_OutputDevice = val;
                        }
                        else if( strcmp(opt, "Input") == 0 ) {
-                               if(gsVT_InputDevice)    free(gsVT_InputDevice);
-                               gsVT_InputDevice = strdup(val);
+                               gsVT_InputDevice = val;
                        }
                        else if( strcmp(opt, "Width") == 0 ) {
                                giVT_RealWidth = atoi( val );
@@ -167,9 +166,25 @@ int VT_Install(char **Arguments)
                }
        }
        
+       if(gsVT_OutputDevice)   Modules_InitialiseBuiltin( gsVT_OutputDevice );
+       if(gsVT_InputDevice)    Modules_InitialiseBuiltin( gsVT_InputDevice );
+       
        // Apply Defaults
-       if(!gsVT_OutputDevice)  gsVT_OutputDevice = "/Devices/"DEFAULT_OUTPUT;
-       if(!gsVT_InputDevice)   gsVT_InputDevice = "/Devices/"DEFAULT_INPUT;
+       if(!gsVT_OutputDevice)  gsVT_OutputDevice = DEFAULT_OUTPUT;
+       if(!gsVT_InputDevice)   gsVT_InputDevice = DEFAULT_INPUT;
+       
+       // Create paths
+       {
+               char    *tmp;
+               tmp = malloc( 9 + strlen(gsVT_OutputDevice) + 1 );
+               strcpy(tmp, "/Devices/");
+               strcpy(&tmp[9], gsVT_OutputDevice);
+               gsVT_OutputDevice = tmp;
+               tmp = malloc( 9 + strlen(gsVT_InputDevice) + 1 );
+               strcpy(tmp, "/Devices/");
+               strcpy(&tmp[9], gsVT_InputDevice);
+               gsVT_InputDevice = tmp;
+       }
        
        Log_Log("VTerm", "Using '%s' as output", gsVT_OutputDevice);
        Log_Log("VTerm", "Using '%s' as input", gsVT_InputDevice);
@@ -310,12 +325,12 @@ char *VT_ReadDir(tVFS_Node *Node, int Pos)
 }
 
 /**
- * \fn tVFS_Node *VT_FindDir(tVFS_Node *Node, char *Name)
+ * \fn tVFS_Node *VT_FindDir(tVFS_Node *Node, const char *Name)
  * \brief Find an item in the VTerm directory
  * \param Node Root node
  * \param Name Name (number) of the terminal
  */
-tVFS_Node *VT_FindDir(tVFS_Node *Node, char *Name)
+tVFS_Node *VT_FindDir(tVFS_Node *Node, const char *Name)
 {
         int    num;
        
@@ -388,6 +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)
        {
@@ -395,7 +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 ++;
@@ -409,7 +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 ++;
@@ -417,6 +436,10 @@ Uint64 VT_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
                }
                break;
        }
+       
+       term->ReadingThread = -1;
+       Mutex_Release( &term->ReadingLock );
+       
        return 0;
 }
 
@@ -600,7 +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);
@@ -634,7 +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 )
@@ -804,6 +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);
+       }
 }
 
 /**
@@ -814,7 +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--; )
        {
@@ -854,17 +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'))
                {
@@ -1055,8 +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
@@ -1100,6 +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;