KernelLand/Kernel/syscalls.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * syscalls.c
   4  */
   5 #define DEBUG   0
   6
   7 #include <acess.h>
   8 #include <syscalls.h>
   9 #include <proc.h>
  10 #include <hal_proc.h>
  11 #include <errno.h>
  12 #include <threads.h>
  13 #include <events.h>
  14
  15 #define CHECK_NUM_NULLOK(v,size)        \
  16         if((v)&&!Syscall_Valid((size),(v))){ret=-1;err=-EINVAL;break;}
  17 #define CHECK_STR_NULLOK(v)     \
  18         if((v)&&!Syscall_ValidString((v))){ret=-1;err=-EINVAL;break;}
  19 #define CHECK_NUM_NONULL(v,size)        \
  20         if(!(v)||!Syscall_Valid((size),(v))){ret=-1;err=-EINVAL;break;}
  21 #define CHECK_STR_NONULL(v)     \
  22         if(!(v)||!Syscall_ValidString((v))){ret=-1;err=-EINVAL;break;}
  23 #define CHECK_STR_ARRAY(arr)    do {\
  24          int    i;\
  25         char    **tmp = (char**)arr; \
  26         CHECK_NUM_NONULL( tmp, sizeof(char**) ); \
  27         for(i=0;tmp[i];i++) { \
  28                 CHECK_STR_NONULL( tmp[i] ); \
  29                 CHECK_NUM_NONULL( &tmp[i+1], sizeof(char*) ); \
  30         }\
  31         if(tmp[i]) break;\
  32 } while(0)
  33
  34 // === IMPORTS ===
  35 extern Uint     Binary_Load(const char *file, Uint *entryPoint);
  36
  37 // === PROTOTYPES ===
  38 void    SyscallHandler(tSyscallRegs *Regs);
  39  int    Syscall_ValidString(const char *Addr);
  40  int    Syscall_Valid(int Size, const void *Addr);
  41
  42 // === CODE ===
  43 // TODO: Do sanity checking on arguments, ATM the user can really fuck with the kernel
  44 void SyscallHandler(tSyscallRegs *Regs)
  45 {
  46         Uint64  ret = 0;
  47         Uint    err = -EOK;
  48          int    callNum = Regs->Num;
  49
  50         #if DEBUG < 2
  51         if(callNum != SYS_READ && callNum != SYS_WRITE) {
  52         #endif
  53         ENTER("iThread iNum", Threads_GetTID(), callNum);
  54         if(callNum < NUM_SYSCALLS)
  55                 LOG("Syscall %s", cSYSCALL_NAMES[callNum]);
  56         LOG("Arg1: 0x%x, Arg2: 0x%x, Arg3: 0x%x, Arg4: 0x%x", Regs->Arg1, Regs->Arg2, Regs->Arg3, Regs->Arg4);
  57         #if DEBUG < 2
  58         }
  59         #endif
  60
  61         switch(Regs->Num)
  62         {
  63         // -- Exit the current thread
  64         case SYS_EXIT:  Threads_Exit(0, Regs->Arg1);    break;
  65
  66         // -- Put the current thread to sleep
  67         case SYS_SLEEP: Threads_Sleep();        break;
  68
  69         // -- Yield current timeslice
  70         case SYS_YIELD: Threads_Yield();        break;
  71
  72         // -- Set Error Handler
  73         case SYS_SETFAULTHANDLER:
  74                 Threads_SetFaultHandler(Regs->Arg1);
  75                 break;
  76
  77         // -- Clone the current thread
  78         case SYS_CLONE:
  79                 // Call clone system call
  80                 ret = Proc_Clone(Regs->Arg1);
  81                 break;
  82
  83         // -- Send a signal
  84         case SYS_KILL:
  85                 err = -ENOSYS;
  86                 ret = -1;
  87                 break;
  88
  89         // -- Wait fr an event
  90         case SYS_WAITEVENT:
  91                 // Message mask
  92                 ret = Threads_WaitEvents(Regs->Arg1);
  93                 break;
  94
  95         // -- Wait for a thread
  96         case SYS_WAITTID:
  97                 // Sanity Check (Status can be NULL)
  98                 CHECK_NUM_NULLOK( (int*)Regs->Arg2, sizeof(int) );
  99                 // TID, *Status
 100                 ret = Threads_WaitTID(Regs->Arg1, (int*)Regs->Arg2);
 101                 break;
 102
 103         // -- Get the physical address of a page
 104         case SYS_GETPHYS:
 105                 ret = MM_GetPhysAddr( (void*)Regs->Arg1 );
 106                 break;
 107
 108         // -- Map an address
 109         case SYS_MAP:   MM_Map(Regs->Arg1, Regs->Arg2); break;
 110
 111         // -- Allocate an address
 112         case SYS_ALLOCATE:      ret = MM_Allocate(Regs->Arg1);  break;
 113
 114         // -- Unmap an address
 115         case SYS_UNMAP:         MM_Deallocate(Regs->Arg1);      break;
 116
 117         // -- Get Thread/Process IDs
 118         case SYS_GETTID:        ret = Threads_GetTID(); break;
 119         case SYS_GETPID:        ret = Threads_GetPID(); break;
 120
 121         // -- Get User/Group IDs
 122         case SYS_GETUID:        ret = Threads_GetUID(); break;
 123         case SYS_GETGID:        ret = Threads_GetGID(); break;
 124
 125         // -- Set User/Group IDs
 126         case SYS_SETUID:        ret = Threads_SetUID(Regs->Arg1);       break;
 127         case SYS_SETGID:        ret = Threads_SetGID(Regs->Arg1);       break;
 128
 129         // -- Send Message
 130         case SYS_SENDMSG:
 131                 CHECK_NUM_NONULL( (void*)Regs->Arg3, Regs->Arg2 );
 132                 // Destination, Size, *Data
 133                 ret = Proc_SendMessage(Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 134                 break;
 135         // -- Check for messages
 136         case SYS_GETMSG:
 137                 CHECK_NUM_NULLOK( (Uint*)Regs->Arg1, sizeof(Uint) );
 138                 if( Regs->Arg3 != -1 )
 139                         CHECK_NUM_NULLOK((void*)Regs->Arg3, Regs->Arg2);
 140                 // *Source, *Data
 141                 ret = Proc_GetMessage((Uint*)Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 142                 break;
 143
 144         // -- Get the current timestamp
 145         case SYS_GETTIME:
 146                 ret = now();
 147                 break;
 148
 149         // -- Set the thread's name
 150         case SYS_SETNAME:
 151                 CHECK_STR_NONULL( (char*) Regs->Arg1);
 152                 Threads_SetName( (char*)Regs->Arg1 );
 153                 break;
 154
 155         // ---
 156         // Binary Control
 157         // ---
 158         // -- Create a new process
 159         case SYS_SPAWN:
 160                 CHECK_STR_NONULL((const char*)Regs->Arg1);
 161                 CHECK_STR_ARRAY((const char**)Regs->Arg2);
 162                 CHECK_STR_ARRAY((const char**)Regs->Arg3);
 163                 CHECK_NUM_NONULL((void*)Regs->Arg5, Regs->Arg4*sizeof(int));
 164                 ret = Proc_SysSpawn(
 165                         (const char*)Regs->Arg1, (const char**)Regs->Arg2, (const char**)Regs->Arg3,
 166                         Regs->Arg4, (int*)Regs->Arg5
 167                         );
 168                 break;
 169         // -- Replace the current process with another
 170         case SYS_EXECVE:
 171                 CHECK_STR_NONULL((char*)Regs->Arg1);
 172                 CHECK_STR_ARRAY( (char**)Regs->Arg2 );
 173                 if( Regs->Arg3 )
 174                         CHECK_STR_ARRAY( (char**)Regs->Arg3 );
 175                 LEAVE('s', "Assuming 0");
 176                 // Path, **Argv, **Envp, DataSize (=0 to tell it to create a copy)
 177                 ret = Proc_Execve(
 178                         (const char*)Regs->Arg1, (const char**)Regs->Arg2, (const char**)Regs->Arg3,
 179                         0
 180                         );
 181                 break;
 182         // -- Load a binary into the current process
 183         case SYS_LOADBIN:
 184                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 185                 CHECK_NUM_NONULL( (Uint*)Regs->Arg2, sizeof(Uint) );
 186                 // Path, *Entrypoint
 187                 ret = Binary_Load((char*)Regs->Arg1, (Uint*)Regs->Arg2);
 188                 break;
 189
 190         // ---
 191         // Virtual Filesystem
 192         // ---
 193         case SYS_OPEN:
 194                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 195                 LOG("VFS_Open(\"%s\", 0x%x)", (char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 196                 ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 197                 break;
 198
 199         case SYS_CLOSE:
 200                 LOG("VFS_Close(%i)", Regs->Arg1);
 201                 VFS_Close( Regs->Arg1 );
 202                 break;
 203
 204         case SYS_SEEK:
 205                 #if BITS == 64
 206                 ret = VFS_Seek( Regs->Arg1, Regs->Arg2, Regs->Arg3 );
 207                 #else
 208                 ret = VFS_Seek( Regs->Arg1, Regs->Arg2|(((Uint64)Regs->Arg3)<<32), Regs->Arg4 );
 209                 #endif
 210                 break;
 211
 212         case SYS_TELL:
 213                 ret = VFS_Tell( Regs->Arg1 );
 214                 break;
 215
 216         case SYS_WRITE:
 217                 CHECK_NUM_NONULL( (void*)Regs->Arg2, Regs->Arg3 );
 218                 ret = VFS_Write( Regs->Arg1, Regs->Arg3, (void*)Regs->Arg2 );
 219                 break;
 220
 221         case SYS_READ:
 222                 CHECK_NUM_NONULL( (void*)Regs->Arg2, Regs->Arg3 );
 223                 ret = VFS_Read( Regs->Arg1, Regs->Arg3, (void*)Regs->Arg2 );
 224                 break;
 225
 226         case SYS_FINFO:
 227                 CHECK_NUM_NONULL( (void*)Regs->Arg2, sizeof(tFInfo) + Regs->Arg3*sizeof(tVFS_ACL) );
 228                 // FP, Dest, MaxACLs
 229                 ret = VFS_FInfo( Regs->Arg1, (void*)Regs->Arg2, Regs->Arg3 );
 230                 break;
 231
 232         // Get ACL Value
 233         case SYS_GETACL:
 234                 CHECK_NUM_NONULL( (void*)Regs->Arg2, sizeof(tVFS_ACL) );
 235                 ret = VFS_GetACL( Regs->Arg1, (void*)Regs->Arg2 );
 236                 break;
 237
 238         // Read Directory
 239         case SYS_READDIR:
 240                 // TODO: What if the filename is longer?
 241                 // Maybe force it to be a 256 byte buffer
 242                 CHECK_NUM_NONULL( (void*)Regs->Arg2, 256 );
 243                 ret = VFS_ReadDir( Regs->Arg1, (void*)Regs->Arg2 );
 244                 break;
 245
 246         // Open a file that is a entry in an open directory
 247         case SYS_OPENCHILD:
 248                 CHECK_STR_NONULL( (char*)Regs->Arg2 );
 249                 ret = VFS_OpenChild( Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
 250                 break;
 251
 252         // Change Directory
 253         case SYS_CHDIR:
 254                 CHECK_STR_NONULL( (const char*)Regs->Arg1 );
 255                 ret = VFS_ChDir( (const char*)Regs->Arg1 );
 256                 break;
 257
 258         // IO Control
 259         case SYS_IOCTL:
 260                 // All sanity checking should be done by the driver
 261                 if( Regs->Arg3 && !MM_IsUser(Regs->Arg3) ) {
 262                         err = -EINVAL;  ret = -1;       break;
 263                 }
 264                 ret = VFS_IOCtl( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 265                 break;
 266
 267         // Mount a filesystem
 268         case SYS_MOUNT:
 269                 // Only root can mount filesystems
 270                 if(Threads_GetUID() != 0) {
 271                         err = -EACCES;
 272                         ret = -1;
 273                         break;
 274                 }
 275
 276                 if( !Regs->Arg1 )
 277                 {
 278                         if( !Syscall_ValidString((char*)Regs->Arg2) ) {
 279                                 err = -EINVAL;
 280                                 ret = -1;
 281                                 break;
 282                         }
 283
 284                         ret = VFS_Unmount((char*)Regs->Arg2);
 285                 }
 286                 else
 287                 {
 288                         // Sanity check the paths
 289                         if(!Syscall_ValidString((char*)Regs->Arg1)
 290                         || !Syscall_ValidString((char*)Regs->Arg2)
 291                         || (Regs->Arg3 && !Syscall_ValidString((char*)Regs->Arg3))
 292                         || !Syscall_ValidString((char*)Regs->Arg4) ) {
 293                                 err = -EINVAL;
 294                                 ret = -1;
 295                                 break;
 296                         }
 297                         ret = VFS_Mount(
 298                                 (char*)Regs->Arg1,      // Device
 299                                 (char*)Regs->Arg2,      // Mount point
 300                                 (char*)Regs->Arg3,      // Filesystem
 301                                 (char*)Regs->Arg4       // Options
 302                                 );
 303                 }
 304                 break;
 305
 306         // Wait on a set of handles
 307         case SYS_SELECT:
 308                 // Sanity checks
 309                 if( (Regs->Arg2 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg2))
 310                  || (Regs->Arg3 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg3))
 311                  || (Regs->Arg4 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg4))
 312                  || (Regs->Arg5 && !Syscall_Valid(sizeof(tTime), (void*)Regs->Arg5)) )
 313                 {
 314                         err = -EINVAL;
 315                         ret = -1;
 316                         break;
 317                 }
 318                 // Perform the call
 319                 ret = VFS_Select(
 320                         Regs->Arg1,     // Max handle
 321                         (fd_set *)Regs->Arg2,   // Read
 322                         (fd_set *)Regs->Arg3,   // Write
 323                         (fd_set *)Regs->Arg4,   // Errors
 324                         (tTime *)Regs->Arg5,    // Timeout
 325                         (Uint32)Regs->Arg6,     // Extra wakeup events
 326                         0       // User handles
 327                         );
 328                 break;
 329
 330         // -- Debug
 331         //#if DEBUG_BUILD
 332         case SYS_DEBUG:
 333                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 334                 LogF("Log: %08lli [%i] ", now(), Threads_GetTID());
 335                 LogF((const char*)Regs->Arg1,
 336                         Regs->Arg2, Regs->Arg3, Regs->Arg4, Regs->Arg5, Regs->Arg6);
 337                 LogF("\r\n");
 338                 break;
 339         //#endif
 340
 341         // -- Default (Return Error)
 342         default:
 343                 Log_Warning("Syscalls", "Unknown System Call %i", Regs->Num);
 344                 if(Regs->Num < NUM_SYSCALLS)
 345                         Log_Warning("Syscall", " named '%s'", cSYSCALL_NAMES[Regs->Num]);
 346                 err = -ENOSYS;
 347                 ret = -1;
 348                 break;
 349         }
 350
 351         if(err == 0)    err = errno;
 352
 353         if(err != 0) {
 354                 LOG("ID: %i, Return errno = %i", Regs->Num, err);
 355         }
 356
 357         #if BITS < 64
 358         Regs->Return = ret&0xFFFFFFFF;
 359         Regs->RetHi = ret >> 32;
 360         #else
 361         Regs->Return = ret;
 362         #endif
 363         Regs->Error = err;
 364         #if DEBUG
 365         # if DEBUG < 2
 366         if( callNum != SYS_READ && callNum != SYS_WRITE ) {
 367         # endif
 368         LOG("err = %i", err);
 369         if( callNum == SYS_EXECVE )
 370                 LOG("Actual %i", ret);
 371         else
 372                 LEAVE('x', ret);
 373         # if DEBUG < 2
 374         }
 375         # endif
 376         #endif
 377 }
 378
 379 /**
 380  * \fn int Syscall_ValidString(const char *Addr)
 381  * \brief Checks if a memory address contains a valid string
 382  */
 383 int Syscall_ValidString(const char *Addr)
 384 {
 385         // Check if the memory is user memory
 386         if(!MM_IsUser( (tVAddr) Addr))  return 0;
 387
 388         return CheckString( Addr );
 389 }
 390
 391 /**
 392  * \fn int Syscall_Valid(int Size, const void *Addr)
 393  * \brief Checks if a memory address is valid
 394  */
 395 int Syscall_Valid(int Size, const void *Addr)
 396 {
 397         if(!MM_IsUser( (tVAddr)Addr ))  return 0;
 398
 399         return CheckMem( Addr, Size );
 400 }