osfmk/ppc/PseudoKernel.c

   1 /*
   2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  23  * Please see the License for the specific language governing rights and
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  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29         File:           PseudoKernel.c
  30
  31         Contains:       BlueBox PseudoKernel calls
  32         Written by:     Mark Gorlinsky
  33                                 Bill Angell
  34
  35         Copyright:      1997 by Apple Computer, Inc., all rights reserved
  36
  37 */
  38
  39 #include <mach/mach_types.h>
  40 #include <mach/mach_host.h>
  41 #include <mach/kern_return.h>
  42
  43 #include <kern/kalloc.h>
  44 #include <kern/kern_types.h>
  45 #include <kern/host.h>
  46 #include <kern/task.h>
  47 #include <kern/thread.h>
  48 #include <ppc/PseudoKernel.h>
  49 #include <ppc/exception.h>
  50 #include <ppc/misc_protos.h>
  51 #include <ppc/proc_reg.h>
  52
  53 #include <vm/pmap.h>
  54 #include <vm/vm_map.h>
  55 #include <vm/vm_kern.h>
  56
  57 extern int is_suser(void);
  58 extern void tbeproc(void *proc);
  59
  60 void bbSetRupt(ReturnHandler *rh, thread_t ct);
  61
  62 /*
  63 ** Function:    NotifyInterruption
  64 **
  65 ** Inputs:
  66 **              ppcInterrupHandler      - interrupt handler to execute
  67 **              interruptStatePtr       - current interrupt state
  68 **
  69 ** Outputs:
  70 **
  71 ** Notes:
  72 **
  73 */
  74 kern_return_t
  75 syscall_notify_interrupt(void)
  76 {
  77         task_t                  task;
  78         thread_t                act, fact;
  79         bbRupt                  *bbr;
  80         BTTD_t                  *bttd;
  81         int                             i;
  82
  83         task = current_task();                                                  /* Figure out who our task is */
  84
  85         task_lock(task);                                                /* Lock our task */
  86
  87         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
  88         act = NULL;                                                                             /* Pretend we didn't find it yet */
  89
  90         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
  91                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
  92                         bttd = (BTTD_t *)(fact->machine.bbDescAddr & -PAGE_SIZE);
  93                         if(bttd->InterruptVector) {                             /* Is this the Blue interrupt thread? */
  94                                 act = fact;                                                     /* Yeah... */
  95                                 break;                                                          /* Found it, Bail the loop... */
  96                         }
  97                 }
  98                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
  99         }
 100
 101         if(!act) {                                                              /* Couldn't find a bluebox */
 102                 task_unlock(task);                                      /* Release task lock */
 103                 return KERN_FAILURE;                            /* No tickie, no shirtee... */
 104         }
 105
 106         thread_reference(act);
 107
 108         task_unlock(task);                                                              /* Safe to release now */
 109
 110         thread_mtx_lock(act);
 111
 112         /* if the calling thread is the BlueBox thread that handles interrupts
 113          * we know that we are in the PsuedoKernel and we can short circuit
 114          * setting up the asynchronous task by setting a pending interrupt.
 115          */
 116
 117         if (act == current_thread()) {
 118                 bttd->InterruptControlWord = bttd->InterruptControlWord |
 119                         ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 120
 121                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 122                 thread_deallocate(act);
 123                 return KERN_SUCCESS;
 124         }
 125
 126         if(act->machine.emPendRupts >= 16) {                            /* Have we hit the arbitrary maximum? */
 127                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 128                 thread_deallocate(act);
 129                 return KERN_RESOURCE_SHORTAGE;                          /* Too many pending right now */
 130         }
 131
 132         if(!(bbr = (bbRupt *)kalloc(sizeof(bbRupt)))) { /* Get a return handler control block */
 133                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 134                 thread_deallocate(act);
 135                 return KERN_RESOURCE_SHORTAGE;                          /* No storage... */
 136         }
 137
 138         (void)hw_atomic_add(&act->machine.emPendRupts, 1);      /* Count this 'rupt */
 139         bbr->rh.handler = bbSetRupt;                                    /* Set interruption routine */
 140
 141         bbr->rh.next = act->handlers;                                   /* Put our interrupt at the start of the list */
 142         act->handlers = &bbr->rh;
 143
 144         act_set_apc(act);                                                               /* Set an APC AST */
 145
 146         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 147         thread_deallocate(act);
 148         return KERN_SUCCESS;                                                    /* We're done... */
 149 }
 150
 151 /*
 152  *      This guy is fired off asynchronously to actually do the 'rupt.
 153  *      We will find the user state savearea and modify it.  If we can't,
 154  *      we just leave after releasing our work area
 155  */
 156
 157 void bbSetRupt(ReturnHandler *rh, thread_t act) {
 158
 159         struct savearea *sv;
 160         BTTD_t          *bttd;
 161         bbRupt          *bbr;
 162         UInt32          interruptState;
 163
 164         bbr = (bbRupt *)rh;                                                             /* Make our area convenient */
 165
 166         if(!(act->machine.bbDescAddr)) {                                        /* Is BlueBox still enabled? */
 167                 kfree(bbr, sizeof(bbRupt));     /* No, release the control block */
 168                 return;
 169         }
 170
 171         (void)hw_atomic_sub(&act->machine.emPendRupts, 1);      /* Uncount this 'rupt */
 172
 173         if(!(sv = find_user_regs(act))) {                               /* Find the user state registers */
 174                 kfree(bbr, sizeof(bbRupt));     /* Couldn't find 'em, release the control block */
 175                 return;
 176         }
 177
 178         bttd = (BTTD_t *)(act->machine.bbDescAddr & -PAGE_SIZE);
 179
 180     interruptState = (bttd->InterruptControlWord & kInterruptStateMask) >> kInterruptStateShift;
 181
 182     switch (interruptState) {
 183
 184                 case kInSystemContext:
 185                         sv->save_cr |= bttd->postIntMask;               /* post int in CR2 */
 186                         break;
 187
 188                 case kInAlternateContext:
 189                         bttd->InterruptControlWord = (bttd->InterruptControlWord & ~kInterruptStateMask) |
 190                                 (kInPseudoKernel << kInterruptStateShift);
 191
 192                         bttd->exceptionInfo.srr0 = (unsigned int)sv->save_srr0;         /* Save the current PC */
 193                         sv->save_srr0 = (uint64_t)act->machine.bbInterrupt;     /* Set the new PC */
 194                         bttd->exceptionInfo.sprg1 = (unsigned int)sv->save_r1;          /* Save the original R1 */
 195                         sv->save_r1 = (uint64_t)bttd->exceptionInfo.sprg0;      /* Set the new R1 */
 196                         bttd->exceptionInfo.srr1 = (unsigned int)sv->save_srr1;         /* Save the original MSR */
 197                         sv->save_srr1 &= ~(MASK(MSR_BE)|MASK(MSR_SE));  /* Clear SE|BE bits in MSR */
 198                         act->machine.specFlags &= ~bbNoMachSC;                          /* reactivate Mach SCs */
 199                         disable_preemption();                                                   /* Don't move us around */
 200                         getPerProc()->spcFlags = act->machine.specFlags;        /* Copy the flags */
 201                         enable_preemption();                                                    /* Ok to move us around */
 202                         /* drop through to post int in backup CR2 in ICW */
 203
 204                 case kInExceptionHandler:
 205                 case kInPseudoKernel:
 206                 case kOutsideBlue:
 207                         bttd->InterruptControlWord = bttd->InterruptControlWord |
 208                                 ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 209                         break;
 210
 211                 default:
 212                         break;
 213         }
 214
 215         kfree(bbr, sizeof(bbRupt));     /* Release the control block */
 216         return;
 217
 218 }
 219
 220 /*
 221  * This function is used to enable the firmware assist code for bluebox traps, system calls
 222  * and interrupts.
 223  *
 224  * The assist code can be called from two types of threads.  The blue thread, which handles
 225  * traps, system calls and interrupts and preemptive threads that only issue system calls.
 226  *
 227  * Parameters:  host                    .
 228  *              _taskID                 opaque task ID
 229  *              _TWI_TableStart         Start of TWI table
 230  *              _Desc_TableStart        Start of descriptor table
 231  */
 232
 233 kern_return_t
 234 enable_bluebox(host_t host, unsigned _taskID, unsigned _TWI_TableStart,
 235                unsigned _Desc_TableStart)
 236 {
 237         /* XXX mig funness */
 238         void *taskID = (void *)_taskID;
 239         void *TWI_TableStart = (void *)_TWI_TableStart;
 240         char *Desc_TableStart = (char *)_Desc_TableStart;
 241
 242         thread_t                th;
 243         vm_offset_t             kerndescaddr, origdescoffset;
 244         kern_return_t   ret;
 245         ppnum_t                 physdescpage;
 246         BTTD_t                  *bttd;
 247
 248         th = current_thread();                                                                  /* Get our thread */
 249
 250         if ( host == HOST_NULL ) return KERN_INVALID_HOST;
 251         if ( ! is_suser() ) return KERN_FAILURE;                                                /* We will only do this for the superuser */
 252         if ( th->machine.bbDescAddr ) return KERN_FAILURE;              /* Bail if already authorized... */
 253         if ( ! (unsigned int) Desc_TableStart ) return KERN_FAILURE;    /* There has to be a descriptor page */
 254         if ( ! TWI_TableStart ) return KERN_FAILURE;                                    /* There has to be a TWI table */
 255
 256         /* Get the page offset of the descriptor */
 257         origdescoffset = (vm_offset_t)Desc_TableStart & (PAGE_SIZE - 1);
 258
 259         /* Align the descriptor to a page */
 260         Desc_TableStart = (char *)((vm_offset_t)Desc_TableStart & -PAGE_SIZE);
 261
 262         ret = vm_map_wire(th->map,                                      /* Kernel wire the descriptor in the user's map */
 263                 (vm_offset_t)Desc_TableStart,
 264                 (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 265                 VM_PROT_READ | VM_PROT_WRITE,
 266                 FALSE);
 267
 268         if(ret != KERN_SUCCESS) {                                                               /* Couldn't wire it, spit on 'em... */
 269                 return KERN_FAILURE;
 270         }
 271
 272         physdescpage =                                                                                  /* Get the physical page number of the page */
 273                 pmap_find_phys(th->map->pmap, CAST_USER_ADDR_T(Desc_TableStart));
 274
 275         ret =  kmem_alloc_pageable(kernel_map, &kerndescaddr, PAGE_SIZE);       /* Find a virtual address to use */
 276         if(ret != KERN_SUCCESS) {                                                               /* Could we get an address? */
 277                 (void) vm_map_unwire(th->map,                           /* No, unwire the descriptor */
 278                         (vm_offset_t)Desc_TableStart,
 279                         (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 280                         TRUE);
 281                 return KERN_FAILURE;                                                            /* Split... */
 282         }
 283
 284         (void) pmap_enter(kernel_pmap,                                                  /* Map this into the kernel */
 285                 kerndescaddr, physdescpage, VM_PROT_READ|VM_PROT_WRITE,
 286                 VM_WIMG_USE_DEFAULT, TRUE);
 287
 288         bttd = (BTTD_t *)kerndescaddr;                                                  /* Get the address in a convienient spot */
 289
 290         th->machine.bbDescAddr = (unsigned int)kerndescaddr+origdescoffset;     /* Set kernel address of the table */
 291         th->machine.bbUserDA = (unsigned int)Desc_TableStart;   /* Set user address of the table */
 292         th->machine.bbTableStart = (unsigned int)TWI_TableStart;        /* Set address of the trap table */
 293         th->machine.bbTaskID = (unsigned int)taskID;            /* Assign opaque task ID */
 294         th->machine.bbTaskEnv = 0;                                              /* Clean task environment data */
 295         th->machine.emPendRupts = 0;                                            /* Clean pending 'rupt count */
 296         th->machine.bbTrap = bttd->TrapVector;                  /* Remember trap vector */
 297         th->machine.bbSysCall = bttd->SysCallVector;            /* Remember syscall vector */
 298         th->machine.bbInterrupt = bttd->InterruptVector;        /* Remember interrupt vector */
 299         th->machine.bbPending = bttd->PendingIntVector; /* Remember pending vector */
 300         th->machine.specFlags &= ~(bbNoMachSC | bbPreemptive);  /* Make sure mach SCs are enabled and we are not marked preemptive */
 301         th->machine.specFlags |= bbThread;                              /* Set that we are Classic thread */
 302
 303         if(!(bttd->InterruptVector)) {                                                  /* See if this is a preemptive (MP) BlueBox thread */
 304                 th->machine.specFlags |= bbPreemptive;          /* Yes, remember it */
 305         }
 306
 307         disable_preemption();                                                                   /* Don't move us around */
 308         getPerProc()->spcFlags = th->machine.specFlags; /* Copy the flags */
 309         enable_preemption();                                                                    /* Ok to move us around */
 310
 311         {
 312                 /* mark the proc to indicate that this is a TBE proc */
 313
 314                 tbeproc(th->task->bsd_info);
 315         }
 316
 317         return KERN_SUCCESS;
 318 }
 319
 320 kern_return_t disable_bluebox( host_t host ) {                          /* User call to terminate bluebox */
 321
 322         thread_t        act;
 323
 324         act = current_thread();                                                                 /* Get our thread */
 325
 326         if (host == HOST_NULL) return KERN_INVALID_HOST;
 327
 328         if(!is_suser()) return KERN_FAILURE;                                    /* We will only do this for the superuser */
 329         if(!act->machine.bbDescAddr) return KERN_FAILURE;                       /* Bail if not authorized... */
 330
 331         disable_bluebox_internal(act);                                                  /* Clean it all up */
 332         return KERN_SUCCESS;                                                                    /* Leave */
 333 }
 334
 335 void disable_bluebox_internal(thread_t act) {                   /* Terminate bluebox */
 336
 337         (void) vm_map_unwire(act->map,                                                  /* Unwire the descriptor in user's address space */
 338                 (vm_offset_t)act->machine.bbUserDA,
 339                 (vm_offset_t)act->machine.bbUserDA + PAGE_SIZE,
 340                 FALSE);
 341
 342         kmem_free(kernel_map, (vm_offset_t)act->machine.bbDescAddr & -PAGE_SIZE, PAGE_SIZE);    /* Release the page */
 343
 344         act->machine.bbDescAddr = 0;                                                            /* Clear kernel pointer to it */
 345         act->machine.bbUserDA = 0;                                                                      /* Clear user pointer to it */
 346         act->machine.bbTableStart = 0;                                                          /* Clear user pointer to TWI table */
 347         act->machine.bbTaskID = 0;                                                                      /* Clear opaque task ID */
 348         act->machine.bbTaskEnv = 0;                                                             /* Clean task environment data */
 349         act->machine.emPendRupts = 0;                                                           /* Clean pending 'rupt count */
 350         act->machine.specFlags &= ~(bbNoMachSC | bbPreemptive | bbThread);      /* Clean up Blue Box enables */
 351         disable_preemption();                                                           /* Don't move us around */
 352         getPerProc()->spcFlags = act->machine.specFlags;                /* Copy the flags */
 353         enable_preemption();                                                            /* Ok to move us around */
 354         return;
 355 }
 356
 357 /*
 358  * Use the new PPCcall method to enable blue box threads
 359  *
 360  *      save->r3 = taskID
 361  *      save->r4 = TWI_TableStart
 362  *      save->r5 = Desc_TableStart
 363  *
 364  */
 365 int bb_enable_bluebox( struct savearea *save )
 366 {
 367         kern_return_t rc;
 368
 369         rc = enable_bluebox((host_t)0xFFFFFFFF,
 370                             CAST_DOWN(unsigned, save->save_r3),
 371                             CAST_DOWN(unsigned, save->save_r4),
 372                             CAST_DOWN(unsigned, save->save_r5));
 373         save->save_r3 = rc;
 374         return 1;                                                                               /* Return with normal AST checking */
 375 }
 376
 377 /*
 378  * Use the new PPCcall method to disable blue box threads
 379  *
 380  */
 381 int bb_disable_bluebox( struct savearea *save )
 382 {
 383         kern_return_t rc;
 384
 385         rc = disable_bluebox( (host_t)0xFFFFFFFF );
 386         save->save_r3 = rc;
 387         return 1;                                                                               /* Return with normal AST checking */
 388 }
 389
 390 /*
 391  * Search through the list of threads to find the matching taskIDs, then
 392  * set the task environment pointer.  A task in this case is a preemptive thread
 393  * in MacOS 9.
 394  *
 395  *      save->r3 = taskID
 396  *      save->r4 = taskEnv
 397  */
 398
 399 int bb_settaskenv( struct savearea *save )
 400 {
 401         int                             i;
 402     task_t                      task;
 403         thread_t        act, fact;
 404
 405
 406         task = current_task();                                                  /* Figure out who our task is */
 407
 408         task_lock(task);                                                                /* Lock our task */
 409         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
 410         act = NULL;                                                                             /* Pretend we didn't find it yet */
 411
 412         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
 413                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
 414                         if ( fact->machine.bbTaskID == save->save_r3 ) {        /* Is this the task we are looking for? */
 415                                 act = fact;                                                     /* Yeah... */
 416                                 break;                                                          /* Found it, Bail the loop... */
 417                         }
 418                 }
 419                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
 420         }
 421
 422         if ( !act || !act->active) {
 423                 task_unlock(task);                                                      /* Release task lock */
 424                 save->save_r3 = -1;                                                     /* we failed to find the taskID */
 425                 return 1;
 426         }
 427
 428         thread_reference(act);
 429
 430         task_unlock(task);                                                              /* Safe to release now */
 431
 432         thread_mtx_lock(act);                                                   /* Make sure this stays 'round */
 433
 434         act->machine.bbTaskEnv = save->save_r4;
 435         if(act == current_thread()) {                                           /* Are we setting our own? */
 436                 disable_preemption();                                           /* Don't move us around */
 437                 getPerProc()->ppbbTaskEnv = act->machine.bbTaskEnv;     /* Remember the environment */
 438                 enable_preemption();                                            /* Ok to move us around */
 439         }
 440
 441         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 442         thread_deallocate(act);
 443         save->save_r3 = 0;
 444         return 1;
 445 }