Fixed bug where system would lock if a user task segfaulted (forgot to sti)

[tpg/acess2.git] / Kernel / syscalls.c

diff --git a/Kernel/syscalls.c b/Kernel/syscalls.c
index 8790be7..5774dbe 100644 (file)
--- a/Kernel/syscalls.c
+++ b/Kernel/syscalls.c
@@ -17,27 +17,35 @@ extern int  Proc_GetMessage(Uint *Err, Uint *Source, void *Buffer);
 extern int     Proc_Execve(char *File, char **ArgV, char **EnvP);
 extern Uint    Binary_Load(char *file, Uint *entryPoint);
 extern int     VFS_FInfo(int FD, void *Dest, int MaxACLs);
+extern int     VFS_GetACL(int FD, void *Dest);
+extern int     VFS_ChDir(char *Dest);
 extern int     Threads_SetName(char *NewName);
 extern int     Threads_GetPID();
 extern int     Threads_GetTID();
 extern int     Threads_GetUID();
 extern int     Threads_GetGID();
 
+// === PROTOTYPES ===
+ int   Syscall_ValidString(Uint Addr);
+ int   Syscall_Valid(int Size, Uint Addr);
+
 // === CODE ===
+// TODO: Do sanity checking on arguments, ATM the user can really fuck with the kernel
 void SyscallHandler(tSyscallRegs *Regs)
 {
        Uint64  ret = 0;
        Uint    err = 0;
        #if DEBUG
-       ENTER("iThread iNum", gCurrentThread->TID, Regs->Num);
+       ENTER("iThread iNum", Threads_GetTID(), Regs->Num);
        if(Regs->Num < NUM_SYSCALLS)
                LOG("Syscall %s", cSYSCALL_NAMES[Regs->Num]);
        LOG("Arg1: 0x%x, Arg2: 0x%x, Arg3: 0x%x", Regs->Arg1, Regs->Arg2, Regs->Arg3);
        #endif
+       
        switch(Regs->Num)
        {
        // -- Exit the current thread
-       case SYS_EXIT:  Threads_Exit(); break;
+       case SYS_EXIT:  Threads_Exit(0, Regs->Arg1);    break;
        
        // -- Put the current thread to sleep
        case SYS_SLEEP: Threads_Sleep();        break;
@@ -49,7 +57,7 @@ void SyscallHandler(tSyscallRegs *Regs)
        case SYS_CLONE:
                // Call clone system call
                ret = Proc_Clone(&err, Regs->Arg1);
-               // Change user stack if requested
+               // Change user stack if a new stack address is passed
                if(ret == 0 && Regs->Arg2)
                        Regs->StackPointer = Regs->Arg2;
                break;
@@ -87,6 +95,10 @@ void SyscallHandler(tSyscallRegs *Regs)
        case SYS_GETUID:        ret = Threads_GetUID(); break;
        case SYS_GETGID:        ret = Threads_GetGID(); break;
        
+       // -- Set User/Group IDs
+       case SYS_SETUID:        Log("Setting User ID to %i", Regs->Arg1);       break;
+       case SYS_SETGID:        Log("Setting Group ID to %i", Regs->Arg1);      break;
+       
        // -- Send Message
        case SYS_SENDMSG:
                ret = Proc_SendMessage(&err, Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
@@ -107,9 +119,20 @@ void SyscallHandler(tSyscallRegs *Regs)
        // Binary Control
        // ---
        case SYS_EXECVE:
+               if( !Syscall_ValidString(Regs->Arg1) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
                ret = Proc_Execve((char*)Regs->Arg1, (char**)Regs->Arg2, (char**)Regs->Arg3);
                break;
        case SYS_LOADBIN:
+               if( !Syscall_ValidString(Regs->Arg1)
+               ||  !Syscall_Valid(sizeof(Uint), Regs->Arg2) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
                ret = Binary_Load((char*)Regs->Arg1, (Uint*)Regs->Arg2);
                break;
        
@@ -117,6 +140,11 @@ void SyscallHandler(tSyscallRegs *Regs)
        // Virtual Filesystem
        // ---
        case SYS_OPEN:
+               if( !Syscall_ValidString(Regs->Arg1) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
                ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
                break;
        
@@ -126,28 +154,54 @@ void SyscallHandler(tSyscallRegs *Regs)
        
        case SYS_WRITE:
                #if BITS < 64
-               VFS_Write( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
+               ret = VFS_Write( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
                #else
-               VFS_Write( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
+               ret = VFS_Write( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
                #endif
                break;
        
        case SYS_READ:
                #if BITS < 64
-               VFS_Read( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
+               ret = VFS_Read( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
                #else
-               VFS_Read( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
+               ret = VFS_Read( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
                #endif
                break;
        
        case SYS_FINFO:
                ret = VFS_FInfo( Regs->Arg1, (void*)Regs->Arg2, Regs->Arg3 );
                break;
-               
+       
+       // Get ACL Value
+       case SYS_GETACL:
+               if( !Syscall_Valid(8, Regs->Arg1) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
+               ret = VFS_GetACL( Regs->Arg1, (void*)Regs->Arg2 );
+               break;
+       
+       // Read Directory
        case SYS_READDIR:
+               if( !Syscall_ValidString(Regs->Arg2) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
                ret = VFS_ReadDir( Regs->Arg1, (void*)Regs->Arg2 );
                break;
        
+       // Change Directory
+       case SYS_CHDIR:
+               if( !Syscall_ValidString(Regs->Arg1) ) {
+                       err = -EINVAL;
+                       ret = -1;
+                       break;
+               }
+               ret = VFS_ChDir( (void*)Regs->Arg1 );
+               break;
+       
        // -- Debug
        case SYS_DEBUG:
                Log((char*)Regs->Arg1,
@@ -176,3 +230,36 @@ void SyscallHandler(tSyscallRegs *Regs)
        #endif
 }
 
+/**
+ * \fn int Syscall_ValidString(Uint Addr)
+ * \brief Checks if a memory address contains a valid string
+ */
+int Syscall_ValidString(Uint Addr)
+{
+       // Check 1st page
+       if(!MM_GetPhysAddr(Addr))       return 0;
+       
+       // Traverse String
+       while(*(char*)Addr)
+       {
+               if(!MM_GetPhysAddr(Addr))       return 0;
+               // Increment string pointer
+               Addr ++;
+       }
+       
+       return 1;
+}
+
+/**
+ * \fn int Syscall_Valid(int Size, Uint Addr)
+ * \brief Checks if a memory address is valid
+ */
+int Syscall_Valid(int Size, Uint Addr)
+{
+       while(Size--)
+       {
+               if(!MM_GetPhysAddr(Addr))       return 0;
+               Addr ++;
+       }
+       return 1;
+}