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