Kernel/syscalls.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * syscalls.c
   4  */
   5 #define DEBUG   0
   6
   7 #include <common.h>
   8 #include <syscalls.h>
   9 #include <proc.h>
  10 #include <errno.h>
  11
  12 // === IMPORTS ===
  13 extern int      Proc_Clone(Uint *Err, Uint Flags);
  14 extern int      Threads_WaitTID(int TID, int *status);
  15 extern Uint     Proc_SendMessage(Uint *Err, Uint Dest, Uint Length, void *Data);
  16 extern int      Proc_GetMessage(Uint *Err, Uint *Source, void *Buffer);
  17 extern int      Proc_Execve(char *File, char **ArgV, char **EnvP);
  18 extern Uint     Binary_Load(char *file, Uint *entryPoint);
  19 extern int      VFS_FInfo(int FD, void *Dest, int MaxACLs);
  20 extern int      VFS_GetACL(int FD, void *Dest);
  21 extern int      VFS_ChDir(char *Dest);
  22 extern int      Threads_SetName(char *NewName);
  23 extern int      Threads_GetPID();
  24 extern int      Threads_GetTID();
  25 extern int      Threads_GetUID();
  26 extern int      Threads_GetGID();
  27
  28 // === PROTOTYPES ===
  29  int    Syscall_ValidString(Uint Addr);
  30  int    Syscall_Valid(int Size, Uint Addr);
  31
  32 // === CODE ===
  33 // TODO: Do sanity checking on arguments, ATM the user can really fuck with the kernel
  34 void SyscallHandler(tSyscallRegs *Regs)
  35 {
  36         Uint64  ret = 0;
  37         Uint    err = 0;
  38         #if DEBUG
  39         ENTER("iThread iNum", Threads_GetTID(), Regs->Num);
  40         if(Regs->Num < NUM_SYSCALLS)
  41                 LOG("Syscall %s", cSYSCALL_NAMES[Regs->Num]);
  42         LOG("Arg1: 0x%x, Arg2: 0x%x, Arg3: 0x%x", Regs->Arg1, Regs->Arg2, Regs->Arg3);
  43         #endif
  44
  45         switch(Regs->Num)
  46         {
  47         // -- Exit the current thread
  48         case SYS_EXIT:  Threads_Exit(0, Regs->Arg1);    break;
  49
  50         // -- Put the current thread to sleep
  51         case SYS_SLEEP: Threads_Sleep();        break;
  52
  53         // -- Yield current timeslice
  54         case SYS_YIELD: Threads_Yield();        break;
  55
  56         // -- Clone the current thread
  57         case SYS_CLONE:
  58                 // Call clone system call
  59                 ret = Proc_Clone(&err, Regs->Arg1);
  60                 // Change user stack if a new stack address is passed
  61                 if(ret == 0 && Regs->Arg2)
  62                         Regs->StackPointer = Regs->Arg2;
  63                 break;
  64
  65         // -- Send a signal
  66         case SYS_KILL:
  67                 err = -ENOSYS;
  68                 ret = -1;
  69                 break;
  70
  71         // -- Wait for a thread
  72         case SYS_WAITTID:
  73                 ret = Threads_WaitTID(Regs->Arg1, (void*)Regs->Arg2);
  74                 break;
  75
  76         // -- Get the physical address of a page
  77         case SYS_GETPHYS:
  78                 ret = MM_GetPhysAddr(Regs->Arg1);
  79                 break;
  80
  81         // -- Map an address
  82         case SYS_MAP:   MM_Map(Regs->Arg1, Regs->Arg2); break;
  83
  84         // -- Allocate an address
  85         case SYS_ALLOCATE:      ret = MM_Allocate(Regs->Arg1);  break;
  86
  87         // -- Unmap an address
  88         case SYS_UNMAP:         MM_Deallocate(Regs->Arg1);      break;
  89
  90         // -- Get Thread/Process IDs
  91         case SYS_GETTID:        ret = Threads_GetTID(); break;
  92         case SYS_GETPID:        ret = Threads_GetPID(); break;
  93
  94         // -- Get User/Group IDs
  95         case SYS_GETUID:        ret = Threads_GetUID(); break;
  96         case SYS_GETGID:        ret = Threads_GetGID(); break;
  97
  98         // -- Send Message
  99         case SYS_SENDMSG:
 100                 ret = Proc_SendMessage(&err, Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 101                 break;
 102         // -- Check for messages
 103         case SYS_GETMSG:
 104                 ret = Proc_GetMessage(&err, (Uint*)Regs->Arg1, (void*)Regs->Arg2);
 105                 break;
 106
 107         // -- Set the thread's name
 108         case SYS_SETNAME:
 109                 // Sanity Check
 110                 if(!Regs->Arg1) {       ret = -1;       err = -EINVAL;  break;  }
 111                 Threads_SetName( (void*)Regs->Arg1 );
 112                 break;
 113
 114         // ---
 115         // Binary Control
 116         // ---
 117         case SYS_EXECVE:
 118                 ret = Proc_Execve((char*)Regs->Arg1, (char**)Regs->Arg2, (char**)Regs->Arg3);
 119                 break;
 120         case SYS_LOADBIN:
 121                 ret = Binary_Load((char*)Regs->Arg1, (Uint*)Regs->Arg2);
 122                 break;
 123
 124         // ---
 125         // Virtual Filesystem
 126         // ---
 127         case SYS_OPEN:
 128                 ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 129                 break;
 130
 131         case SYS_CLOSE:
 132                 VFS_Close( Regs->Arg1 );
 133                 break;
 134
 135         case SYS_WRITE:
 136                 #if BITS < 64
 137                 ret = VFS_Write( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
 138                 #else
 139                 ret = VFS_Write( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 140                 #endif
 141                 break;
 142
 143         case SYS_READ:
 144                 #if BITS < 64
 145                 ret = VFS_Read( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
 146                 #else
 147                 ret = VFS_Read( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 148                 #endif
 149                 break;
 150
 151         case SYS_FINFO:
 152                 ret = VFS_FInfo( Regs->Arg1, (void*)Regs->Arg2, Regs->Arg3 );
 153                 break;
 154
 155         // Get ACL Value
 156         case SYS_GETACL:
 157                 if( !Syscall_Valid(8, Regs->Arg1) ) {
 158                         err = -EINVAL;
 159                         ret = -1;
 160                         break;
 161                 }
 162                 ret = VFS_GetACL( Regs->Arg1, (void*)Regs->Arg2 );
 163                 break;
 164
 165         // Read Directory
 166         case SYS_READDIR:
 167                 if( !Syscall_ValidString(Regs->Arg2) ) {
 168                         err = -EINVAL;
 169                         ret = -1;
 170                         break;
 171                 }
 172                 ret = VFS_ReadDir( Regs->Arg1, (void*)Regs->Arg2 );
 173                 break;
 174
 175         // Change Directory
 176         case SYS_CHDIR:
 177                 if( !Syscall_ValidString(Regs->Arg1) ) {
 178                         err = -EINVAL;
 179                         ret = -1;
 180                         break;
 181                 }
 182                 ret = VFS_ChDir( (void*)Regs->Arg1 );
 183                 break;
 184
 185         // -- Debug
 186         case SYS_DEBUG:
 187                 Log((char*)Regs->Arg1,
 188                         Regs->Arg2, Regs->Arg3, Regs->Arg4, Regs->Arg5, Regs->Arg6);
 189                 break;
 190
 191         // -- Default (Return Error)
 192         default:
 193                 Warning("SyscallHandler: Unknown System Call %i", Regs->Num);
 194                 if(Regs->Num < NUM_SYSCALLS)
 195                         Warning(" Syscall '%s'", cSYSCALL_NAMES[Regs->Num]);
 196                 err = -ENOSYS;
 197                 ret = -1;
 198                 break;
 199         }
 200         #if BITS < 64
 201         Regs->Return = ret&0xFFFFFFFF;
 202         Regs->RetHi = ret >> 32;
 203         #else
 204         Regs->Return = ret;
 205         #endif
 206         Regs->Error = err;
 207         #if DEBUG
 208         LOG("SyscallHandler: err = %i", err);
 209         LEAVE('x', ret);
 210         #endif
 211 }
 212
 213 /**
 214  * \fn int Syscall_ValidString(Uint Addr)
 215  * \brief Checks if a memory address contains a valid string
 216  */
 217 int Syscall_ValidString(Uint Addr)
 218 {
 219         // Check 1st page
 220         if(!MM_GetPhysAddr(Addr))       return 0;
 221
 222         // Traverse String
 223         while(*(char*)Addr)
 224         {
 225                 if(!MM_GetPhysAddr(Addr))       return 0;
 226                 // Increment string pointer
 227                 Addr ++;
 228         }
 229
 230         return 1;
 231 }
 232
 233 /**
 234  * \fn int Syscall_Valid(int Size, Uint Addr)
 235  * \brief Checks if a memory address is valid
 236  */
 237 int Syscall_Valid(int Size, Uint Addr)
 238 {
 239         while(Size--)
 240         {
 241                 if(!MM_GetPhysAddr(Addr))       return 0;
 242                 Addr ++;
 243         }
 244         return 1;
 245 }