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 #if 1
  16 # define MERR(f,v...) Log_Debug("Syscalls", "0x%x "f, callNum ,## v)
  17 #else
  18 # define MERR(v...) do{}while(0)
  19 #endif
  20
  21 #define CHECK_NUM_NULLOK(v,size)        \
  22         if((v)&&!Syscall_Valid((size),(v))){MERR("CHECK_NUM_NULLOK: %p(%x) FAIL",v,size);ret=-1;err=-EINVAL;break;}
  23 #define CHECK_STR_NULLOK(v)     \
  24         if((v)&&!Syscall_ValidString((v))){MERR("CHECK_STR_NULLOK: %p FAIL",v);ret=-1;err=-EINVAL;break;}
  25 #define CHECK_NUM_NONULL(v,size)        \
  26         if(!(v)||!Syscall_Valid((size),(v))){MERR("CHECK_NUM_NONULL: %p(%x) FAIL",v,size);ret=-1;err=-EINVAL;break;}
  27 #define CHECK_STR_NONULL(v)     \
  28         if(!(v)||!Syscall_ValidString((v))){MERR("CHECK_STR_NONULL: %p FAIL",v);ret=-1;err=-EINVAL;break;}
  29 #define CHECK_STR_ARRAY(arr)    do {\
  30          int    i;\
  31         char    **tmp = (char**)arr; \
  32         CHECK_NUM_NULLOK( tmp, sizeof(char**) ); \
  33         for(i=0;tmp&&tmp[i];i++) { \
  34                 CHECK_STR_NONULL( tmp[i] ); \
  35                 CHECK_NUM_NONULL( &tmp[i+1], sizeof(char*) ); \
  36         }\
  37         if(tmp[i]) break;\
  38 } while(0)
  39
  40 // === IMPORTS ===
  41 extern Uint     Binary_Load(const char *file, Uint *entryPoint);
  42
  43 // === PROTOTYPES ===
  44 void    SyscallHandler(tSyscallRegs *Regs);
  45  int    Syscall_ValidString(const char *Addr);
  46  int    Syscall_Valid(int Size, const void *Addr);
  47  int    Syscall_MM_SetFlags(void *Addr, Uint Flags, Uint Mask);
  48
  49 // === CODE ===
  50 // TODO: Do sanity checking on arguments, ATM the user can really fuck with the kernel
  51 void SyscallHandler(tSyscallRegs *Regs)
  52 {
  53         Uint64  ret = 0;
  54         Uint    err = -EOK;
  55          int    callNum = Regs->Num;
  56
  57         #if DEBUG < 2
  58         if(callNum != SYS_READ && callNum != SYS_WRITE) {
  59         #endif
  60         ENTER("iThread iNum", Threads_GetTID(), callNum);
  61         if(callNum < NUM_SYSCALLS)
  62                 LOG("Syscall %s", cSYSCALL_NAMES[callNum]);
  63         LOG("Arg1: 0x%x, Arg2: 0x%x, Arg3: 0x%x, Arg4: 0x%x", Regs->Arg1, Regs->Arg2, Regs->Arg3, Regs->Arg4);
  64         #if DEBUG < 2
  65         }
  66         #endif
  67
  68         switch(Regs->Num)
  69         {
  70         // -- Exit the current thread
  71         case SYS_EXIT:  Threads_Exit(0, Regs->Arg1);    break;
  72
  73         // -- Put the current thread to sleep
  74         case SYS_SLEEP: Threads_Sleep();        break;
  75
  76         case SYS_TIMEDSLEEP:
  77                 Time_Delay(Regs->Arg1);
  78                 break;
  79
  80         // -- Yield current timeslice
  81         case SYS_YIELD: Threads_Yield();        break;
  82
  83         // -- Set Error Handler
  84         case SYS_SETFAULTHANDLER:
  85                 Threads_SetFaultHandler(Regs->Arg1);
  86                 break;
  87
  88         // -- Clone the current thread
  89         case SYS_CLONE:
  90                 // Call clone system call
  91                 ret = Proc_Clone(Regs->Arg1);
  92                 break;
  93
  94         // -- Send a signal
  95         case SYS_KILL:
  96                 err = -ENOSYS;
  97                 ret = -1;
  98                 break;
  99
 100         // -- Wait fr an event
 101         case SYS_WAITEVENT:
 102                 // Message mask
 103                 ret = Threads_WaitEvents(Regs->Arg1);
 104                 break;
 105
 106         // -- Wait for a thread
 107         case SYS_WAITTID:
 108                 // Sanity Check (Status can be NULL)
 109                 CHECK_NUM_NULLOK( (int*)Regs->Arg2, sizeof(int) );
 110                 // TID, *Status
 111                 ret = Threads_WaitTID(Regs->Arg1, (int*)Regs->Arg2);
 112                 break;
 113
 114         // -- Get the physical address of a page
 115         case SYS_GETPHYS:
 116                 ret = MM_GetPhysAddr( (void*)Regs->Arg1 );
 117                 break;
 118
 119         // -- Map an address
 120         case SYS_MAP:   MM_Map((void*)Regs->Arg1, Regs->Arg2);  break;
 121
 122         // -- Allocate an address
 123         case SYS_ALLOCATE:      ret = MM_Allocate((void*)Regs->Arg1);   break;
 124
 125         // -- Unmap an address
 126         case SYS_UNMAP:         MM_Deallocate((void*)Regs->Arg1);       break;
 127
 128         // -- Change the protection on an address
 129         case SYS_SETFLAGS:
 130                 ret = Syscall_MM_SetFlags((void*)Regs->Arg1, Regs->Arg2, Regs->Arg3);
 131                 break;
 132
 133         // -- Get Thread/Process IDs
 134         case SYS_GETTID:        ret = Threads_GetTID(); break;
 135         case SYS_GETPID:        ret = Threads_GetPID(); break;
 136
 137         // -- Get User/Group IDs
 138         case SYS_GETUID:        ret = Threads_GetUID(); break;
 139         case SYS_GETGID:        ret = Threads_GetGID(); break;
 140
 141         // -- Set User/Group IDs
 142         case SYS_SETUID:        ret = Threads_SetUID(Regs->Arg1);       break;
 143         case SYS_SETGID:        ret = Threads_SetGID(Regs->Arg1);       break;
 144
 145         // -- Send Message
 146         case SYS_SENDMSG:
 147                 CHECK_NUM_NONULL( (void*)Regs->Arg3, Regs->Arg2 );
 148                 // Destination, Size, *Data
 149                 ret = Proc_SendMessage(Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 150                 break;
 151         // -- Check for messages
 152         case SYS_GETMSG:
 153                 CHECK_NUM_NULLOK( (Uint*)Regs->Arg1, sizeof(Uint) );
 154                 if( Regs->Arg3 != -1 )
 155                         CHECK_NUM_NULLOK((void*)Regs->Arg3, Regs->Arg2);
 156                 // *Source, *Data
 157                 ret = Proc_GetMessage((Uint*)Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 158                 break;
 159
 160         // -- Get the current timestamp
 161         case SYS_GETTIME:
 162                 ret = now();
 163                 break;
 164
 165         // -- Set the thread's name
 166         case SYS_SETNAME:
 167                 CHECK_STR_NONULL( (char*) Regs->Arg1);
 168                 Threads_SetName( (char*)Regs->Arg1 );
 169                 break;
 170
 171         // ---
 172         // Binary Control
 173         // ---
 174         // -- Create a new process
 175         case SYS_SPAWN:
 176                 CHECK_STR_NONULL((const char*)Regs->Arg1);
 177                 CHECK_STR_ARRAY((const char**)Regs->Arg2);
 178                 CHECK_STR_ARRAY((const char**)Regs->Arg3);
 179                 if( Regs->Arg4 > 0 )
 180                         CHECK_NUM_NONULL((void*)Regs->Arg5, Regs->Arg4*sizeof(int));
 181                 ret = Proc_SysSpawn(
 182                         (const char*)Regs->Arg1, (const char**)Regs->Arg2, (const char**)Regs->Arg3,
 183                         Regs->Arg4, (int*)Regs->Arg5
 184                         );
 185                 break;
 186         // -- Replace the current process with another
 187         case SYS_EXECVE:
 188                 CHECK_STR_NONULL((char*)Regs->Arg1);
 189                 CHECK_STR_ARRAY( (char**)Regs->Arg2 );
 190                 if( Regs->Arg3 )
 191                         CHECK_STR_ARRAY( (char**)Regs->Arg3 );
 192                 LEAVE('s', "Assuming 0");
 193                 // Path, **Argv, **Envp, DataSize (=0 to tell it to create a copy)
 194                 ret = Proc_Execve(
 195                         (const char*)Regs->Arg1, (const char**)Regs->Arg2, (const char**)Regs->Arg3,
 196                         0
 197                         );
 198                 break;
 199         // -- Load a binary into the current process
 200         case SYS_LOADBIN:
 201                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 202                 CHECK_NUM_NONULL( (Uint*)Regs->Arg2, sizeof(Uint) );
 203                 // Path, *Entrypoint
 204                 ret = Binary_Load((char*)Regs->Arg1, (Uint*)Regs->Arg2);
 205                 break;
 206
 207         // -- Load a kernel module
 208         case SYS_LOADMOD:
 209                 CHECK_STR_NONULL( (const char *)Regs->Arg1 );
 210                 if( Threads_GetUID() != 0 ) {
 211                         MERR("Not root");
 212                         ret = EACCES;
 213                 }
 214                 else {
 215                         LOG("Module_LoadFile(\"%s\", NULL)", (const char *)Regs->Arg1);
 216                         ret = Module_LoadFile( (const char *)Regs->Arg1, NULL );
 217                 }
 218                 break;
 219
 220         // ---
 221         // Virtual Filesystem
 222         // ---
 223         case SYS_OPEN:
 224                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 225                 LOG("VFS_Open(\"%s\", 0x%x)", (char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 226                 ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 227                 break;
 228         case SYS_REOPEN:
 229                 CHECK_STR_NONULL( (char*)Regs->Arg2 );
 230                 LOG("VFS_Reopen(%i, \"%s\", 0x%x)", Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
 231                 ret = VFS_Reopen(Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
 232                 break;
 233
 234         case SYS_CLOSE:
 235                 LOG("VFS_Close(%i)", Regs->Arg1);
 236                 VFS_Close( Regs->Arg1 );
 237                 break;
 238
 239         case SYS_COPYFD:
 240                 LOG("VFS_DuplicateFD(%i,%i)", Regs->Arg1, Regs->Arg2);
 241                 ret = VFS_DuplicateFD(Regs->Arg1, Regs->Arg2);
 242                 break;
 243
 244         case SYS_FDCTL:
 245                 LOG("VFS_SetFDFlags(%i,0%o,0%o)", Regs->Arg1, Regs->Arg2, Regs->Arg3);
 246                 ret = VFS_SetFDFlags(Regs->Arg1, Regs->Arg2, Regs->Arg3);
 247                 break;
 248
 249         case SYS_SEEK:
 250                 #if BITS == 64
 251                 ret = VFS_Seek( Regs->Arg1, Regs->Arg2, Regs->Arg3 );
 252                 #else
 253                 ret = VFS_Seek( Regs->Arg1, Regs->Arg2|(((Uint64)Regs->Arg3)<<32), Regs->Arg4 );
 254                 #endif
 255                 break;
 256
 257         case SYS_TELL:
 258                 ret = VFS_Tell( Regs->Arg1 );
 259                 break;
 260
 261         case SYS_WRITE:
 262                 CHECK_NUM_NONULL( (void*)Regs->Arg2, Regs->Arg3 );
 263                 ret = VFS_Write( Regs->Arg1, Regs->Arg3, (void*)Regs->Arg2 );
 264                 break;
 265
 266         case SYS_READ:
 267                 CHECK_NUM_NONULL( (void*)Regs->Arg2, Regs->Arg3 );
 268                 ret = VFS_Read( Regs->Arg1, Regs->Arg3, (void*)Regs->Arg2 );
 269                 break;
 270
 271         case SYS_FINFO:
 272                 CHECK_NUM_NONULL( (void*)Regs->Arg2, sizeof(tFInfo) + Regs->Arg3*sizeof(tVFS_ACL) );
 273                 // FP, Dest, MaxACLs
 274                 ret = VFS_FInfo( Regs->Arg1, (void*)Regs->Arg2, Regs->Arg3 );
 275                 break;
 276
 277         // Get ACL Value
 278         case SYS_GETACL:
 279                 CHECK_NUM_NONULL( (void*)Regs->Arg2, sizeof(tVFS_ACL) );
 280                 ret = VFS_GetACL( Regs->Arg1, (void*)Regs->Arg2 );
 281                 break;
 282
 283         // Read Directory
 284         case SYS_READDIR:
 285                 // TODO: What if the filename is longer?
 286                 // Maybe force it to be a 256 byte buffer
 287                 CHECK_NUM_NONULL( (void*)Regs->Arg2, 256 );
 288                 ret = VFS_ReadDir( Regs->Arg1, (void*)Regs->Arg2 );
 289                 break;
 290
 291         // Open a file that is a entry in an open directory
 292         case SYS_OPENCHILD:
 293                 CHECK_STR_NONULL( (char*)Regs->Arg2 );
 294                 ret = VFS_OpenChild( Regs->Arg1, (char*)Regs->Arg2, Regs->Arg3 | VFS_OPENFLAG_USER);
 295                 break;
 296
 297         // Change Directory
 298         case SYS_CHDIR:
 299                 CHECK_STR_NONULL( (const char*)Regs->Arg1 );
 300                 ret = VFS_ChDir( (const char*)Regs->Arg1 );
 301                 break;
 302
 303         // IO Control
 304         case SYS_IOCTL:
 305                 // All sanity checking should be done by the driver
 306                 if( Regs->Arg3 && !MM_IsUser(Regs->Arg3) ) {
 307                         MERR("IOCtl Invalid arg %p", Regs->Arg3);
 308                         err = -EINVAL;  ret = -1;       break;
 309                 }
 310                 ret = VFS_IOCtl( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 311                 break;
 312
 313         // Mount a filesystem
 314         case SYS_MOUNT:
 315                 // Only root can mount filesystems
 316                 if(Threads_GetUID() != 0) {
 317                         err = -EACCES;
 318                         ret = -1;
 319                         break;
 320                 }
 321
 322                 if( !Regs->Arg1 )
 323                 {
 324                         if( !Syscall_ValidString((char*)Regs->Arg2) ) {
 325                                 err = -EINVAL;
 326                                 ret = -1;
 327                                 break;
 328                         }
 329
 330                         ret = VFS_Unmount((char*)Regs->Arg2);
 331                 }
 332                 else
 333                 {
 334                         // Sanity check the paths
 335                         CHECK_STR_NONULL((char*)Regs->Arg1);
 336                         CHECK_STR_NONULL((char*)Regs->Arg2);
 337                         CHECK_STR_NULLOK((char*)Regs->Arg3);
 338                         CHECK_STR_NONULL((char*)Regs->Arg4);
 339                         ret = VFS_Mount(
 340                                 (char*)Regs->Arg1,      // Device
 341                                 (char*)Regs->Arg2,      // Mount point
 342                                 (char*)Regs->Arg3,      // Filesystem
 343                                 (char*)Regs->Arg4       // Options
 344                                 );
 345                 }
 346                 break;
 347
 348         // Wait on a set of handles
 349         case SYS_SELECT:
 350                 // Sanity checks
 351                 if( (Regs->Arg2 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg2))
 352                  || (Regs->Arg3 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg3))
 353                  || (Regs->Arg4 && !Syscall_Valid(sizeof(fd_set), (void*)Regs->Arg4))
 354                  || (Regs->Arg5 && !Syscall_Valid(sizeof(tTime), (void*)Regs->Arg5)) )
 355                 {
 356                         err = -EINVAL;
 357                         ret = -1;
 358                         break;
 359                 }
 360                 // Perform the call
 361                 ret = VFS_Select(
 362                         Regs->Arg1,     // Max handle
 363                         (fd_set *)Regs->Arg2,   // Read
 364                         (fd_set *)Regs->Arg3,   // Write
 365                         (fd_set *)Regs->Arg4,   // Errors
 366                         (tTime *)Regs->Arg5,    // Timeout
 367                         (Uint32)Regs->Arg6,     // Extra wakeup events
 368                         0       // User handles
 369                         );
 370                 break;
 371
 372
 373         // Create a directory
 374         case SYS_MKDIR:
 375                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 376                 ret = VFS_MkDir( (char*)Regs->Arg1 );
 377                 break;
 378
 379         case SYS_UNLINK:
 380                 Log_Error("Syscalls", "TODO: Impliment SYS_UNLINK");
 381                 // Fall
 382         // -- Debug
 383         //#if DEBUG_BUILD
 384         case SYS_DEBUG:
 385                 CHECK_STR_NONULL( (char*)Regs->Arg1 );
 386                 LogF("Log: %08lli [%i] ", now(), Threads_GetTID());
 387                 LogF((const char*)Regs->Arg1,
 388                         Regs->Arg2, Regs->Arg3, Regs->Arg4, Regs->Arg5, Regs->Arg6);
 389                 LogF("\r\n");
 390                 break;
 391         //#endif
 392
 393         // -- Default (Return Error)
 394         default:
 395                 Log_Warning("Syscalls", "Unknown System Call %i", Regs->Num);
 396                 if(Regs->Num < NUM_SYSCALLS)
 397                         Log_Warning("Syscall", " named '%s'", cSYSCALL_NAMES[Regs->Num]);
 398                 err = -ENOSYS;
 399                 ret = -1;
 400                 break;
 401         }
 402
 403         if(err == 0)    err = errno;
 404
 405         if(err != 0) {
 406                 LOG("ID: %i, Return errno = %i", Regs->Num, err);
 407         }
 408
 409         #if BITS < 64
 410         Regs->Return = ret&0xFFFFFFFF;
 411         Regs->RetHi = ret >> 32;
 412         #else
 413         Regs->Return = ret;
 414         #endif
 415         Regs->Error = err;
 416         #if DEBUG
 417         # if DEBUG < 2
 418         if( callNum != SYS_READ && callNum != SYS_WRITE ) {
 419         # endif
 420         LOG("err = %i", err);
 421         if( callNum == SYS_EXECVE )
 422                 LOG("Actual %i", ret);
 423         else
 424                 LEAVE('x', ret);
 425         # if DEBUG < 2
 426         }
 427         # endif
 428         #endif
 429 }
 430
 431 /**
 432  * \fn int Syscall_ValidString(const char *Addr)
 433  * \brief Checks if a memory address contains a valid string
 434  */
 435 int Syscall_ValidString(const char *Addr)
 436 {
 437         // Check if the memory is user memory
 438         if(!MM_IsUser( (tVAddr) Addr))  return 0;
 439
 440         return CheckString( Addr );
 441 }
 442
 443 /**
 444  * \fn int Syscall_Valid(int Size, const void *Addr)
 445  * \brief Checks if a memory address is valid
 446  */
 447 int Syscall_Valid(int Size, const void *Addr)
 448 {
 449         if(!MM_IsUser( (tVAddr)Addr )) {
 450                 Log_Debug("Syscalls", "Syscall_Valid - %p not user", Addr);
 451                 return 0;
 452         }
 453
 454         return CheckMem( Addr, Size );
 455 }
 456
 457 int Syscall_MM_SetFlags(void *Addr, Uint Flags, Uint Mask)
 458 {
 459         tPAddr  paddr = MM_GetPhysAddr(Addr);
 460         Flags &= MM_PFLAG_RO|MM_PFLAG_EXEC;
 461         Mask &= MM_PFLAG_RO|MM_PFLAG_EXEC;
 462
 463         //Log_Debug("Syscalls", "SYS_SETFLAGS: %p %x %x", Addr, Flags, Mask);
 464
 465         // Enable write?
 466         if( (Mask & MM_PFLAG_RO) && !(Flags & MM_PFLAG_RO) ) {
 467                 void    *node;
 468                 // HACK - Assume that RO mmap'd files are immutable
 469                 if( MM_GetPageNode(paddr, &node) == 0 && node ) {
 470                         Flags |= MM_PFLAG_COW;
 471                         Mask |= MM_PFLAG_COW;
 472                 }
 473         }
 474         MM_SetFlags(Addr, Flags, Mask);
 475         return 0;
 476 }