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(); 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                 Log("ret = %i", ret);
  61                 __asm__ __volatile__("xchg %bx, %bx");
  62                 // Change user stack if requested
  63                 if(ret == 0 && !(Regs->Arg1 & CLONE_VM))
  64                         Regs->StackPointer = Regs->Arg2;
  65                 break;
  66
  67         // -- Send a signal
  68         case SYS_KILL:
  69                 err = -ENOSYS;
  70                 ret = -1;
  71                 break;
  72
  73         // -- Wait for a thread
  74         case SYS_WAITTID:
  75                 ret = Threads_WaitTID(Regs->Arg1, (void*)Regs->Arg2);
  76                 break;
  77
  78         // -- Get the physical address of a page
  79         case SYS_GETPHYS:
  80                 ret = MM_GetPhysAddr(Regs->Arg1);
  81                 break;
  82
  83         // -- Map an address
  84         case SYS_MAP:   MM_Map(Regs->Arg1, Regs->Arg2); break;
  85
  86         // -- Allocate an address
  87         case SYS_ALLOCATE:      ret = MM_Allocate(Regs->Arg1);  break;
  88
  89         // -- Unmap an address
  90         case SYS_UNMAP:         MM_Deallocate(Regs->Arg1);      break;
  91
  92         // -- Get Thread/Process IDs
  93         case SYS_GETTID:        ret = Threads_GetTID(); break;
  94         case SYS_GETPID:        ret = Threads_GetPID(); break;
  95
  96         // -- Get User/Group IDs
  97         case SYS_GETUID:        ret = Threads_GetUID(); break;
  98         case SYS_GETGID:        ret = Threads_GetGID(); break;
  99
 100         // -- Send Message
 101         case SYS_SENDMSG:
 102                 ret = Proc_SendMessage(&err, Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3);
 103                 break;
 104         // -- Check for messages
 105         case SYS_GETMSG:
 106                 ret = Proc_GetMessage(&err, (Uint*)Regs->Arg1, (void*)Regs->Arg2);
 107                 break;
 108
 109         // -- Set the thread's name
 110         case SYS_SETNAME:
 111                 // Sanity Check
 112                 if(!Regs->Arg1) {       ret = -1;       err = -EINVAL;  break;  }
 113                 Threads_SetName( (void*)Regs->Arg1 );
 114                 break;
 115
 116         // ---
 117         // Binary Control
 118         // ---
 119         case SYS_EXECVE:
 120                 ret = Proc_Execve((char*)Regs->Arg1, (char**)Regs->Arg2, (char**)Regs->Arg3);
 121                 break;
 122         case SYS_LOADBIN:
 123                 ret = Binary_Load((char*)Regs->Arg1, (Uint*)Regs->Arg2);
 124                 break;
 125
 126         // ---
 127         // Virtual Filesystem
 128         // ---
 129         case SYS_OPEN:
 130                 ret = VFS_Open((char*)Regs->Arg1, Regs->Arg2 | VFS_OPENFLAG_USER);
 131                 break;
 132
 133         case SYS_CLOSE:
 134                 VFS_Close( Regs->Arg1 );
 135                 break;
 136
 137         case SYS_WRITE:
 138                 #if BITS < 64
 139                 VFS_Write( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
 140                 #else
 141                 VFS_Write( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 142                 #endif
 143                 break;
 144
 145         case SYS_READ:
 146                 #if BITS < 64
 147                 VFS_Read( Regs->Arg1, Regs->Arg2|((Uint64)Regs->Arg3<<32), (void*)Regs->Arg4 );
 148                 #else
 149                 VFS_Read( Regs->Arg1, Regs->Arg2, (void*)Regs->Arg3 );
 150                 #endif
 151                 break;
 152
 153         case SYS_FINFO:
 154                 ret = VFS_FInfo( Regs->Arg1, (void*)Regs->Arg2, Regs->Arg3 );
 155                 break;
 156
 157         // Get ACL Value
 158         case SYS_GETACL:
 159                 if( !Syscall_Valid(8, Regs->Arg1) ) {
 160                         err = -EINVAL;
 161                         ret = -1;
 162                         break;
 163                 }
 164                 ret = VFS_GetACL( Regs->Arg1, (void*)Regs->Arg2 );
 165                 break;
 166
 167         // Read Directory
 168         case SYS_READDIR:
 169                 if( !Syscall_ValidString(Regs->Arg2) ) {
 170                         err = -EINVAL;
 171                         ret = -1;
 172                         break;
 173                 }
 174                 ret = VFS_ReadDir( Regs->Arg1, (void*)Regs->Arg2 );
 175                 break;
 176
 177         // Change Directory
 178         case SYS_CHDIR:
 179                 if( !Syscall_ValidString(Regs->Arg1) ) {
 180                         err = -EINVAL;
 181                         ret = -1;
 182                         break;
 183                 }
 184                 ret = VFS_ChDir( (void*)Regs->Arg1 );
 185                 break;
 186
 187         // -- Debug
 188         case SYS_DEBUG:
 189                 Log((char*)Regs->Arg1,
 190                         Regs->Arg2, Regs->Arg3, Regs->Arg4, Regs->Arg5, Regs->Arg6);
 191                 break;
 192
 193         // -- Default (Return Error)
 194         default:
 195                 Warning("SyscallHandler: Unknown System Call %i", Regs->Num);
 196                 if(Regs->Num < NUM_SYSCALLS)
 197                         Warning(" Syscall '%s'", cSYSCALL_NAMES[Regs->Num]);
 198                 err = -ENOSYS;
 199                 ret = -1;
 200                 break;
 201         }
 202         #if BITS < 64
 203         Regs->Return = ret&0xFFFFFFFF;
 204         Regs->RetHi = ret >> 32;
 205         #else
 206         Regs->Return = ret;
 207         #endif
 208         Regs->Error = err;
 209         #if DEBUG
 210         LOG("SyscallHandler: err = %i", err);
 211         LEAVE('x', ret);
 212         #endif
 213 }
 214
 215 /**
 216  * \fn int Syscall_ValidString(Uint Addr)
 217  * \brief Checks if a memory address contains a valid string
 218  */
 219 int Syscall_ValidString(Uint Addr)
 220 {
 221         // Check 1st page
 222         if(!MM_GetPhysAddr(Addr))       return 0;
 223
 224         // Traverse String
 225         while(*(char*)Addr)
 226         {
 227                 if(!MM_GetPhysAddr(Addr))       return 0;
 228                 // Increment string pointer
 229                 Addr ++;
 230         }
 231
 232         return 1;
 233 }
 234
 235 /**
 236  * \fn int Syscall_Valid(int Size, Uint Addr)
 237  * \brief Checks if a memory address is valid
 238  */
 239 int Syscall_Valid(int Size, Uint Addr)
 240 {
 241         while(Size--)
 242         {
 243                 if(!MM_GetPhysAddr(Addr))       return 0;
 244                 Addr ++;
 245         }
 246         return 1;
 247 }