osfmk/ppc/PseudoKernel.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31         File:           PseudoKernel.c
  32
  33         Contains:       BlueBox PseudoKernel calls
  34         Written by:     Mark Gorlinsky
  35                                 Bill Angell
  36
  37         Copyright:      1997 by Apple Computer, Inc., all rights reserved
  38
  39 */
  40
  41 #include <mach/mach_types.h>
  42 #include <mach/kern_return.h>
  43
  44 #include <kern/kalloc.h>
  45 #include <kern/kern_types.h>
  46 #include <kern/host.h>
  47 #include <kern/task.h>
  48 #include <kern/thread.h>
  49 #include <ppc/PseudoKernel.h>
  50 #include <ppc/exception.h>
  51 #include <ppc/misc_protos.h>
  52 #include <ppc/proc_reg.h>
  53
  54 #include <vm/pmap.h>
  55 #include <vm/vm_map.h>
  56 #include <vm/vm_kern.h>
  57
  58 void bbSetRupt(ReturnHandler *rh, thread_t ct);
  59
  60 /*
  61 ** Function:    NotifyInterruption
  62 **
  63 ** Inputs:
  64 **              ppcInterrupHandler      - interrupt handler to execute
  65 **              interruptStatePtr       - current interrupt state
  66 **
  67 ** Outputs:
  68 **
  69 ** Notes:
  70 **
  71 */
  72 kern_return_t syscall_notify_interrupt ( void ) {
  73
  74     UInt32                      interruptState;
  75     task_t                      task;
  76         thread_t                act, fact;
  77         bbRupt                  *bbr;
  78         BTTD_t                  *bttd;
  79         int                             i;
  80
  81         task = current_task();                                                  /* Figure out who our task is */
  82
  83         task_lock(task);                                                /* Lock our task */
  84
  85         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
  86         act = 0;                                                                                /* Pretend we didn't find it yet */
  87
  88         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
  89                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
  90                         bttd = (BTTD_t *)(fact->machine.bbDescAddr & -PAGE_SIZE);
  91                         if(bttd->InterruptVector) {                             /* Is this the Blue interrupt thread? */
  92                                 act = fact;                                                     /* Yeah... */
  93                                 break;                                                          /* Found it, Bail the loop... */
  94                         }
  95                 }
  96                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
  97         }
  98
  99         if(!act) {                                                              /* Couldn't find a bluebox */
 100                 task_unlock(task);                                      /* Release task lock */
 101                 return KERN_FAILURE;                            /* No tickie, no shirtee... */
 102         }
 103
 104         thread_reference(act);
 105
 106         task_unlock(task);                                                              /* Safe to release now */
 107
 108         thread_mtx_lock(act);
 109
 110         /* if the calling thread is the BlueBox thread that handles interrupts
 111          * we know that we are in the PsuedoKernel and we can short circuit
 112          * setting up the asynchronous task by setting a pending interrupt.
 113          */
 114
 115         if ( (unsigned int)act == (unsigned int)current_thread() ) {
 116                 bttd->InterruptControlWord = bttd->InterruptControlWord |
 117                         ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 118
 119                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 120                 thread_deallocate(act);
 121                 return KERN_SUCCESS;
 122         }
 123
 124         if(act->machine.emPendRupts >= 16) {                            /* Have we hit the arbitrary maximum? */
 125                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 126                 thread_deallocate(act);
 127                 return KERN_RESOURCE_SHORTAGE;                          /* Too many pending right now */
 128         }
 129
 130         if(!(bbr = (bbRupt *)kalloc(sizeof(bbRupt)))) { /* Get a return handler control block */
 131                 thread_mtx_unlock(act);                                         /* Unlock the activation */
 132                 thread_deallocate(act);
 133                 return KERN_RESOURCE_SHORTAGE;                          /* No storage... */
 134         }
 135
 136         (void)hw_atomic_add(&act->machine.emPendRupts, 1);      /* Count this 'rupt */
 137         bbr->rh.handler = bbSetRupt;                                    /* Set interruption routine */
 138
 139         bbr->rh.next = act->handlers;                                   /* Put our interrupt at the start of the list */
 140         act->handlers = &bbr->rh;
 141
 142         act_set_apc(act);                                                               /* Set an APC AST */
 143
 144         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 145         thread_deallocate(act);
 146         return KERN_SUCCESS;                                                    /* We're done... */
 147 }
 148
 149 /*
 150  *      This guy is fired off asynchronously to actually do the 'rupt.
 151  *      We will find the user state savearea and modify it.  If we can't,
 152  *      we just leave after releasing our work area
 153  */
 154
 155 void bbSetRupt(ReturnHandler *rh, thread_t act) {
 156
 157         savearea        *sv;
 158         BTTD_t          *bttd;
 159         bbRupt          *bbr;
 160         UInt32          interruptState;
 161
 162         bbr = (bbRupt *)rh;                                                             /* Make our area convenient */
 163
 164         if(!(act->machine.bbDescAddr)) {                                        /* Is BlueBox still enabled? */
 165                 kfree(bbr, sizeof(bbRupt));     /* No, release the control block */
 166                 return;
 167         }
 168
 169         (void)hw_atomic_sub(&act->machine.emPendRupts, 1);      /* Uncount this 'rupt */
 170
 171         if(!(sv = find_user_regs(act))) {                               /* Find the user state registers */
 172                 kfree(bbr, sizeof(bbRupt));     /* Couldn't find 'em, release the control block */
 173                 return;
 174         }
 175
 176         bttd = (BTTD_t *)(act->machine.bbDescAddr & -PAGE_SIZE);
 177
 178     interruptState = (bttd->InterruptControlWord & kInterruptStateMask) >> kInterruptStateShift;
 179
 180     switch (interruptState) {
 181
 182                 case kInSystemContext:
 183                         sv->save_cr |= bttd->postIntMask;               /* post int in CR2 */
 184                         break;
 185
 186                 case kInAlternateContext:
 187                         bttd->InterruptControlWord = (bttd->InterruptControlWord & ~kInterruptStateMask) |
 188                                 (kInPseudoKernel << kInterruptStateShift);
 189
 190                         bttd->exceptionInfo.srr0 = (unsigned int)sv->save_srr0;         /* Save the current PC */
 191                         sv->save_srr0 = (uint64_t)act->machine.bbInterrupt;     /* Set the new PC */
 192                         bttd->exceptionInfo.sprg1 = (unsigned int)sv->save_r1;          /* Save the original R1 */
 193                         sv->save_r1 = (uint64_t)bttd->exceptionInfo.sprg0;      /* Set the new R1 */
 194                         bttd->exceptionInfo.srr1 = (unsigned int)sv->save_srr1;         /* Save the original MSR */
 195                         sv->save_srr1 &= ~(MASK(MSR_BE)|MASK(MSR_SE));  /* Clear SE|BE bits in MSR */
 196                         act->machine.specFlags &= ~bbNoMachSC;                          /* reactivate Mach SCs */
 197                         disable_preemption();                                                   /* Don't move us around */
 198                         getPerProc()->spcFlags = act->machine.specFlags;        /* Copy the flags */
 199                         enable_preemption();                                                    /* Ok to move us around */
 200                         /* drop through to post int in backup CR2 in ICW */
 201
 202                 case kInExceptionHandler:
 203                 case kInPseudoKernel:
 204                 case kOutsideBlue:
 205                         bttd->InterruptControlWord = bttd->InterruptControlWord |
 206                                 ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 207                         break;
 208
 209                 default:
 210                         break;
 211         }
 212
 213         kfree(bbr, sizeof(bbRupt));     /* Release the control block */
 214         return;
 215
 216 }
 217
 218 /*
 219  * This function is used to enable the firmware assist code for bluebox traps, system calls
 220  * and interrupts.
 221  *
 222  * The assist code can be called from two types of threads.  The blue thread, which handles
 223  * traps, system calls and interrupts and preemptive threads that only issue system calls.
 224  *
 225  */
 226
 227 kern_return_t enable_bluebox(
 228       host_t host,
 229           void *taskID,                                                         /* opaque task ID */
 230           void *TWI_TableStart,                                         /* Start of TWI table */
 231           char *Desc_TableStart                                         /* Start of descriptor table */
 232          ) {
 233
 234         thread_t                th;
 235         vm_offset_t             kerndescaddr, origdescoffset;
 236         kern_return_t   ret;
 237         ppnum_t                 physdescpage;
 238         BTTD_t                  *bttd;
 239
 240         th = current_thread();                                                                  /* Get our thread */
 241
 242         if ( host == HOST_NULL ) return KERN_INVALID_HOST;
 243         if ( ! is_suser() ) return KERN_FAILURE;                                                /* We will only do this for the superuser */
 244         if ( th->machine.bbDescAddr ) return KERN_FAILURE;              /* Bail if already authorized... */
 245         if ( ! (unsigned int) Desc_TableStart ) return KERN_FAILURE;    /* There has to be a descriptor page */
 246         if ( ! TWI_TableStart ) return KERN_FAILURE;                                    /* There has to be a TWI table */
 247
 248         /* Get the page offset of the descriptor */
 249         origdescoffset = (vm_offset_t)Desc_TableStart & (PAGE_SIZE - 1);
 250
 251         /* Align the descriptor to a page */
 252         Desc_TableStart = (char *)((vm_offset_t)Desc_TableStart & -PAGE_SIZE);
 253
 254         ret = vm_map_wire(th->map,                                      /* Kernel wire the descriptor in the user's map */
 255                 (vm_offset_t)Desc_TableStart,
 256                 (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 257                 VM_PROT_READ | VM_PROT_WRITE,
 258                 FALSE);
 259
 260         if(ret != KERN_SUCCESS) {                                                               /* Couldn't wire it, spit on 'em... */
 261                 return KERN_FAILURE;
 262         }
 263
 264         physdescpage =                                                                                  /* Get the physical page number of the page */
 265                 pmap_find_phys(th->map->pmap, (addr64_t)Desc_TableStart);
 266
 267         ret =  kmem_alloc_pageable(kernel_map, &kerndescaddr, PAGE_SIZE);       /* Find a virtual address to use */
 268         if(ret != KERN_SUCCESS) {                                                               /* Could we get an address? */
 269                 (void) vm_map_unwire(th->map,                           /* No, unwire the descriptor */
 270                         (vm_offset_t)Desc_TableStart,
 271                         (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 272                         TRUE);
 273                 return KERN_FAILURE;                                                            /* Split... */
 274         }
 275
 276         (void) pmap_enter(kernel_pmap,                                                  /* Map this into the kernel */
 277                 kerndescaddr, physdescpage, VM_PROT_READ|VM_PROT_WRITE,
 278                 VM_WIMG_USE_DEFAULT, TRUE);
 279
 280         bttd = (BTTD_t *)kerndescaddr;                                                  /* Get the address in a convienient spot */
 281
 282         th->machine.bbDescAddr = (unsigned int)kerndescaddr+origdescoffset;     /* Set kernel address of the table */
 283         th->machine.bbUserDA = (unsigned int)Desc_TableStart;   /* Set user address of the table */
 284         th->machine.bbTableStart = (unsigned int)TWI_TableStart;        /* Set address of the trap table */
 285         th->machine.bbTaskID = (unsigned int)taskID;            /* Assign opaque task ID */
 286         th->machine.bbTaskEnv = 0;                                              /* Clean task environment data */
 287         th->machine.emPendRupts = 0;                                            /* Clean pending 'rupt count */
 288         th->machine.bbTrap = bttd->TrapVector;                  /* Remember trap vector */
 289         th->machine.bbSysCall = bttd->SysCallVector;            /* Remember syscall vector */
 290         th->machine.bbInterrupt = bttd->InterruptVector;        /* Remember interrupt vector */
 291         th->machine.bbPending = bttd->PendingIntVector; /* Remember pending vector */
 292         th->machine.specFlags &= ~(bbNoMachSC | bbPreemptive);  /* Make sure mach SCs are enabled and we are not marked preemptive */
 293         th->machine.specFlags |= bbThread;                              /* Set that we are Classic thread */
 294
 295         if(!(bttd->InterruptVector)) {                                                  /* See if this is a preemptive (MP) BlueBox thread */
 296                 th->machine.specFlags |= bbPreemptive;          /* Yes, remember it */
 297         }
 298
 299         disable_preemption();                                                                   /* Don't move us around */
 300         getPerProc()->spcFlags = th->machine.specFlags; /* Copy the flags */
 301         enable_preemption();                                                                    /* Ok to move us around */
 302
 303         {
 304                 /* mark the proc to indicate that this is a TBE proc */
 305                 extern void tbeproc(void *proc);
 306
 307                 tbeproc(th->task->bsd_info);
 308         }
 309
 310         return KERN_SUCCESS;
 311 }
 312
 313 kern_return_t disable_bluebox( host_t host ) {                          /* User call to terminate bluebox */
 314
 315         thread_t        act;
 316
 317         act = current_thread();                                                                 /* Get our thread */
 318
 319         if (host == HOST_NULL) return KERN_INVALID_HOST;
 320
 321         if(!is_suser()) return KERN_FAILURE;                                    /* We will only do this for the superuser */
 322         if(!act->machine.bbDescAddr) return KERN_FAILURE;                       /* Bail if not authorized... */
 323
 324         disable_bluebox_internal(act);                                                  /* Clean it all up */
 325         return KERN_SUCCESS;                                                                    /* Leave */
 326 }
 327
 328 void disable_bluebox_internal(thread_t act) {                   /* Terminate bluebox */
 329
 330         (void) vm_map_unwire(act->map,                                                  /* Unwire the descriptor in user's address space */
 331                 (vm_offset_t)act->machine.bbUserDA,
 332                 (vm_offset_t)act->machine.bbUserDA + PAGE_SIZE,
 333                 FALSE);
 334
 335         kmem_free(kernel_map, (vm_offset_t)act->machine.bbDescAddr & -PAGE_SIZE, PAGE_SIZE);    /* Release the page */
 336
 337         act->machine.bbDescAddr = 0;                                                            /* Clear kernel pointer to it */
 338         act->machine.bbUserDA = 0;                                                                      /* Clear user pointer to it */
 339         act->machine.bbTableStart = 0;                                                          /* Clear user pointer to TWI table */
 340         act->machine.bbTaskID = 0;                                                                      /* Clear opaque task ID */
 341         act->machine.bbTaskEnv = 0;                                                             /* Clean task environment data */
 342         act->machine.emPendRupts = 0;                                                           /* Clean pending 'rupt count */
 343         act->machine.specFlags &= ~(bbNoMachSC | bbPreemptive | bbThread);      /* Clean up Blue Box enables */
 344         disable_preemption();                                                           /* Don't move us around */
 345         getPerProc()->spcFlags = act->machine.specFlags;                /* Copy the flags */
 346         enable_preemption();                                                            /* Ok to move us around */
 347         return;
 348 }
 349
 350 /*
 351  * Use the new PPCcall method to enable blue box threads
 352  *
 353  *      save->r3 = taskID
 354  *      save->r4 = TWI_TableStart
 355  *      save->r5 = Desc_TableStart
 356  *
 357  */
 358 int bb_enable_bluebox( struct savearea *save )
 359 {
 360         kern_return_t rc;
 361
 362         rc = enable_bluebox( (host_t)0xFFFFFFFF, (void *)save->save_r3, (void *)save->save_r4, (char *)save->save_r5 );
 363         save->save_r3 = rc;
 364         return 1;                                                                               /* Return with normal AST checking */
 365 }
 366
 367 /*
 368  * Use the new PPCcall method to disable blue box threads
 369  *
 370  */
 371 int bb_disable_bluebox( struct savearea *save )
 372 {
 373         kern_return_t rc;
 374
 375         rc = disable_bluebox( (host_t)0xFFFFFFFF );
 376         save->save_r3 = rc;
 377         return 1;                                                                               /* Return with normal AST checking */
 378 }
 379
 380 /*
 381  * Search through the list of threads to find the matching taskIDs, then
 382  * set the task environment pointer.  A task in this case is a preemptive thread
 383  * in MacOS 9.
 384  *
 385  *      save->r3 = taskID
 386  *      save->r4 = taskEnv
 387  */
 388
 389 int bb_settaskenv( struct savearea *save )
 390 {
 391         int                             i;
 392     task_t                      task;
 393         thread_t        act, fact;
 394
 395
 396         task = current_task();                                                  /* Figure out who our task is */
 397
 398         task_lock(task);                                                                /* Lock our task */
 399         fact = (thread_t)task->threads.next;            /* Get the first activation on task */
 400         act = 0;                                                                                /* Pretend we didn't find it yet */
 401
 402         for(i = 0; i < task->thread_count; i++) {               /* Scan the whole list */
 403                 if(fact->machine.bbDescAddr) {                                  /* Is this a Blue thread? */
 404                         if ( fact->machine.bbTaskID == save->save_r3 ) {        /* Is this the task we are looking for? */
 405                                 act = fact;                                                     /* Yeah... */
 406                                 break;                                                          /* Found it, Bail the loop... */
 407                         }
 408                 }
 409                 fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
 410         }
 411
 412         if ( !act || !act->active) {
 413                 task_unlock(task);                                                      /* Release task lock */
 414                 save->save_r3 = -1;                                                     /* we failed to find the taskID */
 415                 return 1;
 416         }
 417
 418         thread_reference(act);
 419
 420         task_unlock(task);                                                              /* Safe to release now */
 421
 422         thread_mtx_lock(act);                                                   /* Make sure this stays 'round */
 423
 424         act->machine.bbTaskEnv = save->save_r4;
 425         if(act == current_thread()) {                                           /* Are we setting our own? */
 426                 disable_preemption();                                           /* Don't move us around */
 427                 getPerProc()->ppbbTaskEnv = act->machine.bbTaskEnv;     /* Remember the environment */
 428                 enable_preemption();                                            /* Ok to move us around */
 429         }
 430
 431         thread_mtx_unlock(act);                                                 /* Unlock the activation */
 432         thread_deallocate(act);
 433         save->save_r3 = 0;
 434         return 1;
 435 }