osfmk/ppc/PseudoKernel.c

   1 /*
   2  * Copyright (c) 2000-2004 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/kern_return.h>
  41
  42 #include <kern/kalloc.h>
  43 #include <kern/kern_types.h>
  44 #include <kern/host.h>
  45 #include <kern/task.h>
  46 #include <kern/thread.h>
  47 #include <ppc/PseudoKernel.h>
  48 #include <ppc/exception.h>
  49 #include <ppc/misc_protos.h>
  50 #include <ppc/proc_reg.h>
  51
  52 #include <vm/pmap.h>
  53 #include <vm/vm_map.h>
  54 #include <vm/vm_kern.h>
  55
  56 void bbSetRupt(ReturnHandler *rh, thread_t ct);
  57
  58 /*
  59 ** Function:    NotifyInterruption
  60 **
  61 ** Inputs:
  62 **              ppcInterrupHandler      - interrupt handler to execute
  63 **              interruptStatePtr       - current interrupt state
  64 **
  65 ** Outputs:
  66 **
  67 ** Notes:
  68 **
  69 */
  70 kern_return_t syscall_notify_interrupt ( void ) {
  71
  72     UInt32                      interruptState;
  73     task_t                      task;
  74         thread_t                act, fact;
  75         bbRupt                  *bbr;
  76         BTTD_t                  *bttd;
  77         int                             i;
  78
  79         task = current_task();                                                  /* Figure out who our task is */
  80
  81         task_lock(task);                                                /* Lock our task */
  82
  83         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
  84         act = 0;                                                                                /* Pretend we didn't find it yet */
  85
  86         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
  87                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
  88                         bttd = (BTTD_t *)(fact->machine.bbDescAddr & -PAGE_SIZE);
  89                         if(bttd->InterruptVector) {                             /* Is this the Blue interrupt thread? */
  90                                 act = fact;                                                     /* Yeah... */
  91                                 break;                                                          /* Found it, Bail the loop... */
  92                         }
  93                 }
  94                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
  95         }
  96
  97         if(!act) {                                                              /* Couldn't find a bluebox */
  98                 task_unlock(task);                                      /* Release task lock */
  99                 return KERN_FAILURE;                            /* No tickie, no shirtee... */
 100         }
 101
 102         thread_reference(act);
 103
 104         task_unlock(task);                                                              /* Safe to release now */
 105
 106         thread_mtx_lock(act);
 107
 108         /* if the calling thread is the BlueBox thread that handles interrupts
 109          * we know that we are in the PsuedoKernel and we can short circuit
 110          * setting up the asynchronous task by setting a pending interrupt.
 111          */
 112
 113         if ( (unsigned int)act == (unsigned int)current_thread() ) {
 114                 bttd->InterruptControlWord = bttd->InterruptControlWord |
 115                         ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 116
 117                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 118                 thread_deallocate(act);
 119                 return KERN_SUCCESS;
 120         }
 121
 122         if(act->machine.emPendRupts >= 16) {                            /* Have we hit the arbitrary maximum? */
 123                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 124                 thread_deallocate(act);
 125                 return KERN_RESOURCE_SHORTAGE;                          /* Too many pending right now */
 126         }
 127
 128         if(!(bbr = (bbRupt *)kalloc(sizeof(bbRupt)))) { /* Get a return handler control block */
 129                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 130                 thread_deallocate(act);
 131                 return KERN_RESOURCE_SHORTAGE;                          /* No storage... */
 132         }
 133
 134         (void)hw_atomic_add(&act->machine.emPendRupts, 1);      /* Count this 'rupt */
 135         bbr->rh.handler = bbSetRupt;                                    /* Set interruption routine */
 136
 137         bbr->rh.next = act->handlers;                                   /* Put our interrupt at the start of the list */
 138         act->handlers = &bbr->rh;
 139
 140         act_set_apc(act);                                                               /* Set an APC AST */
 141
 142         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 143         thread_deallocate(act);
 144         return KERN_SUCCESS;                                                    /* We're done... */
 145 }
 146
 147 /*
 148  *      This guy is fired off asynchronously to actually do the 'rupt.
 149  *      We will find the user state savearea and modify it.  If we can't,
 150  *      we just leave after releasing our work area
 151  */
 152
 153 void bbSetRupt(ReturnHandler *rh, thread_t act) {
 154
 155         savearea        *sv;
 156         BTTD_t          *bttd;
 157         bbRupt          *bbr;
 158         UInt32          interruptState;
 159
 160         bbr = (bbRupt *)rh;                                                             /* Make our area convenient */
 161
 162         if(!(act->machine.bbDescAddr)) {                                        /* Is BlueBox still enabled? */
 163                 kfree(bbr, sizeof(bbRupt));     /* No, release the control block */
 164                 return;
 165         }
 166
 167         (void)hw_atomic_sub(&act->machine.emPendRupts, 1);      /* Uncount this 'rupt */
 168
 169         if(!(sv = find_user_regs(act))) {                               /* Find the user state registers */
 170                 kfree(bbr, sizeof(bbRupt));     /* Couldn't find 'em, release the control block */
 171                 return;
 172         }
 173
 174         bttd = (BTTD_t *)(act->machine.bbDescAddr & -PAGE_SIZE);
 175
 176     interruptState = (bttd->InterruptControlWord & kInterruptStateMask) >> kInterruptStateShift;
 177
 178     switch (interruptState) {
 179
 180                 case kInSystemContext:
 181                         sv->save_cr |= bttd->postIntMask;               /* post int in CR2 */
 182                         break;
 183
 184                 case kInAlternateContext:
 185                         bttd->InterruptControlWord = (bttd->InterruptControlWord & ~kInterruptStateMask) |
 186                                 (kInPseudoKernel << kInterruptStateShift);
 187
 188                         bttd->exceptionInfo.srr0 = (unsigned int)sv->save_srr0;         /* Save the current PC */
 189                         sv->save_srr0 = (uint64_t)act->machine.bbInterrupt;     /* Set the new PC */
 190                         bttd->exceptionInfo.sprg1 = (unsigned int)sv->save_r1;          /* Save the original R1 */
 191                         sv->save_r1 = (uint64_t)bttd->exceptionInfo.sprg0;      /* Set the new R1 */
 192                         bttd->exceptionInfo.srr1 = (unsigned int)sv->save_srr1;         /* Save the original MSR */
 193                         sv->save_srr1 &= ~(MASK(MSR_BE)|MASK(MSR_SE));  /* Clear SE|BE bits in MSR */
 194                         act->machine.specFlags &= ~bbNoMachSC;                          /* reactivate Mach SCs */
 195                         disable_preemption();                                                   /* Don't move us around */
 196                         getPerProc()->spcFlags = act->machine.specFlags;        /* Copy the flags */
 197                         enable_preemption();                                                    /* Ok to move us around */
 198                         /* drop through to post int in backup CR2 in ICW */
 199
 200                 case kInExceptionHandler:
 201                 case kInPseudoKernel:
 202                 case kOutsideBlue:
 203                         bttd->InterruptControlWord = bttd->InterruptControlWord |
 204                                 ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 205                         break;
 206
 207                 default:
 208                         break;
 209         }
 210
 211         kfree(bbr, sizeof(bbRupt));     /* Release the control block */
 212         return;
 213
 214 }
 215
 216 /*
 217  * This function is used to enable the firmware assist code for bluebox traps, system calls
 218  * and interrupts.
 219  *
 220  * The assist code can be called from two types of threads.  The blue thread, which handles
 221  * traps, system calls and interrupts and preemptive threads that only issue system calls.
 222  *
 223  */
 224
 225 kern_return_t enable_bluebox(
 226       host_t host,
 227           void *taskID,                                                         /* opaque task ID */
 228           void *TWI_TableStart,                                         /* Start of TWI table */
 229           char *Desc_TableStart                                         /* Start of descriptor table */
 230          ) {
 231
 232         thread_t                th;
 233         vm_offset_t             kerndescaddr, origdescoffset;
 234         kern_return_t   ret;
 235         ppnum_t                 physdescpage;
 236         BTTD_t                  *bttd;
 237
 238         th = current_thread();                                                                  /* Get our thread */
 239
 240         if ( host == HOST_NULL ) return KERN_INVALID_HOST;
 241         if ( ! is_suser() ) return KERN_FAILURE;                                                /* We will only do this for the superuser */
 242         if ( th->machine.bbDescAddr ) return KERN_FAILURE;              /* Bail if already authorized... */
 243         if ( ! (unsigned int) Desc_TableStart ) return KERN_FAILURE;    /* There has to be a descriptor page */
 244         if ( ! TWI_TableStart ) return KERN_FAILURE;                                    /* There has to be a TWI table */
 245
 246         /* Get the page offset of the descriptor */
 247         origdescoffset = (vm_offset_t)Desc_TableStart & (PAGE_SIZE - 1);
 248
 249         /* Align the descriptor to a page */
 250         Desc_TableStart = (char *)((vm_offset_t)Desc_TableStart & -PAGE_SIZE);
 251
 252         ret = vm_map_wire(th->map,                                      /* Kernel wire the descriptor in the user's map */
 253                 (vm_offset_t)Desc_TableStart,
 254                 (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 255                 VM_PROT_READ | VM_PROT_WRITE,
 256                 FALSE);
 257
 258         if(ret != KERN_SUCCESS) {                                                               /* Couldn't wire it, spit on 'em... */
 259                 return KERN_FAILURE;
 260         }
 261
 262         physdescpage =                                                                                  /* Get the physical page number of the page */
 263                 pmap_find_phys(th->map->pmap, (addr64_t)Desc_TableStart);
 264
 265         ret =  kmem_alloc_pageable(kernel_map, &kerndescaddr, PAGE_SIZE);       /* Find a virtual address to use */
 266         if(ret != KERN_SUCCESS) {                                                               /* Could we get an address? */
 267                 (void) vm_map_unwire(th->map,                           /* No, unwire the descriptor */
 268                         (vm_offset_t)Desc_TableStart,
 269                         (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 270                         TRUE);
 271                 return KERN_FAILURE;                                                            /* Split... */
 272         }
 273
 274         (void) pmap_enter(kernel_pmap,                                                  /* Map this into the kernel */
 275                 kerndescaddr, physdescpage, VM_PROT_READ|VM_PROT_WRITE,
 276                 VM_WIMG_USE_DEFAULT, TRUE);
 277
 278         bttd = (BTTD_t *)kerndescaddr;                                                  /* Get the address in a convienient spot */
 279
 280         th->machine.bbDescAddr = (unsigned int)kerndescaddr+origdescoffset;     /* Set kernel address of the table */
 281         th->machine.bbUserDA = (unsigned int)Desc_TableStart;   /* Set user address of the table */
 282         th->machine.bbTableStart = (unsigned int)TWI_TableStart;        /* Set address of the trap table */
 283         th->machine.bbTaskID = (unsigned int)taskID;            /* Assign opaque task ID */
 284         th->machine.bbTaskEnv = 0;                                              /* Clean task environment data */
 285         th->machine.emPendRupts = 0;                                            /* Clean pending 'rupt count */
 286         th->machine.bbTrap = bttd->TrapVector;                  /* Remember trap vector */
 287         th->machine.bbSysCall = bttd->SysCallVector;            /* Remember syscall vector */
 288         th->machine.bbInterrupt = bttd->InterruptVector;        /* Remember interrupt vector */
 289         th->machine.bbPending = bttd->PendingIntVector; /* Remember pending vector */
 290         th->machine.specFlags &= ~(bbNoMachSC | bbPreemptive);  /* Make sure mach SCs are enabled and we are not marked preemptive */
 291         th->machine.specFlags |= bbThread;                              /* Set that we are Classic thread */
 292
 293         if(!(bttd->InterruptVector)) {                                                  /* See if this is a preemptive (MP) BlueBox thread */
 294                 th->machine.specFlags |= bbPreemptive;          /* Yes, remember it */
 295         }
 296
 297         disable_preemption();                                                                   /* Don't move us around */
 298         getPerProc()->spcFlags = th->machine.specFlags; /* Copy the flags */
 299         enable_preemption();                                                                    /* Ok to move us around */
 300
 301         {
 302                 /* mark the proc to indicate that this is a TBE proc */
 303                 extern void tbeproc(void *proc);
 304
 305                 tbeproc(th->task->bsd_info);
 306         }
 307
 308         return KERN_SUCCESS;
 309 }
 310
 311 kern_return_t disable_bluebox( host_t host ) {                          /* User call to terminate bluebox */
 312
 313         thread_t        act;
 314
 315         act = current_thread();                                                                 /* Get our thread */
 316
 317         if (host == HOST_NULL) return KERN_INVALID_HOST;
 318
 319         if(!is_suser()) return KERN_FAILURE;                                    /* We will only do this for the superuser */
 320         if(!act->machine.bbDescAddr) return KERN_FAILURE;                       /* Bail if not authorized... */
 321
 322         disable_bluebox_internal(act);                                                  /* Clean it all up */
 323         return KERN_SUCCESS;                                                                    /* Leave */
 324 }
 325
 326 void disable_bluebox_internal(thread_t act) {                   /* Terminate bluebox */
 327
 328         (void) vm_map_unwire(act->map,                                                  /* Unwire the descriptor in user's address space */
 329                 (vm_offset_t)act->machine.bbUserDA,
 330                 (vm_offset_t)act->machine.bbUserDA + PAGE_SIZE,
 331                 FALSE);
 332
 333         kmem_free(kernel_map, (vm_offset_t)act->machine.bbDescAddr & -PAGE_SIZE, PAGE_SIZE);    /* Release the page */
 334
 335         act->machine.bbDescAddr = 0;                                                            /* Clear kernel pointer to it */
 336         act->machine.bbUserDA = 0;                                                                      /* Clear user pointer to it */
 337         act->machine.bbTableStart = 0;                                                          /* Clear user pointer to TWI table */
 338         act->machine.bbTaskID = 0;                                                                      /* Clear opaque task ID */
 339         act->machine.bbTaskEnv = 0;                                                             /* Clean task environment data */
 340         act->machine.emPendRupts = 0;                                                           /* Clean pending 'rupt count */
 341         act->machine.specFlags &= ~(bbNoMachSC | bbPreemptive | bbThread);      /* Clean up Blue Box enables */
 342         disable_preemption();                                                           /* Don't move us around */
 343         getPerProc()->spcFlags = act->machine.specFlags;                /* Copy the flags */
 344         enable_preemption();                                                            /* Ok to move us around */
 345         return;
 346 }
 347
 348 /*
 349  * Use the new PPCcall method to enable blue box threads
 350  *
 351  *      save->r3 = taskID
 352  *      save->r4 = TWI_TableStart
 353  *      save->r5 = Desc_TableStart
 354  *
 355  */
 356 int bb_enable_bluebox( struct savearea *save )
 357 {
 358         kern_return_t rc;
 359
 360         rc = enable_bluebox( (host_t)0xFFFFFFFF, (void *)save->save_r3, (void *)save->save_r4, (char *)save->save_r5 );
 361         save->save_r3 = rc;
 362         return 1;                                                                               /* Return with normal AST checking */
 363 }
 364
 365 /*
 366  * Use the new PPCcall method to disable blue box threads
 367  *
 368  */
 369 int bb_disable_bluebox( struct savearea *save )
 370 {
 371         kern_return_t rc;
 372
 373         rc = disable_bluebox( (host_t)0xFFFFFFFF );
 374         save->save_r3 = rc;
 375         return 1;                                                                               /* Return with normal AST checking */
 376 }
 377
 378 /*
 379  * Search through the list of threads to find the matching taskIDs, then
 380  * set the task environment pointer.  A task in this case is a preemptive thread
 381  * in MacOS 9.
 382  *
 383  *      save->r3 = taskID
 384  *      save->r4 = taskEnv
 385  */
 386
 387 int bb_settaskenv( struct savearea *save )
 388 {
 389         int                             i;
 390     task_t                      task;
 391         thread_t        act, fact;
 392
 393
 394         task = current_task();                                                  /* Figure out who our task is */
 395
 396         task_lock(task);                                                                /* Lock our task */
 397         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
 398         act = 0;                                                                                /* Pretend we didn't find it yet */
 399
 400         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
 401                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
 402                         if ( fact->machine.bbTaskID == save->save_r3 ) {        /* Is this the task we are looking for? */
 403                                 act = fact;                                                     /* Yeah... */
 404                                 break;                                                          /* Found it, Bail the loop... */
 405                         }
 406                 }
 407                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
 408         }
 409
 410         if ( !act || !act->active) {
 411                 task_unlock(task);                                                      /* Release task lock */
 412                 save->save_r3 = -1;                                                     /* we failed to find the taskID */
 413                 return 1;
 414         }
 415
 416         thread_reference(act);
 417
 418         task_unlock(task);                                                              /* Safe to release now */
 419
 420         thread_mtx_lock(act);                                                   /* Make sure this stays 'round */
 421
 422         act->machine.bbTaskEnv = save->save_r4;
 423         if(act == current_thread()) {                                           /* Are we setting our own? */
 424                 disable_preemption();                                           /* Don't move us around */
 425                 getPerProc()->ppbbTaskEnv = act->machine.bbTaskEnv;     /* Remember the environment */
 426                 enable_preemption();                                            /* Ok to move us around */
 427         }
 428
 429         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 430         thread_deallocate(act);
 431         save->save_r3 = 0;
 432         return 1;
 433 }