osfmk/ppc/PseudoKernel.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26         File:           PseudoKernel.c
  27
  28         Contains:       BlueBox PseudoKernel calls
  29         Written by:     Mark Gorlinsky
  30                                 Bill Angell
  31
  32         Copyright:      1997 by Apple Computer, Inc., all rights reserved
  33
  34 */
  35
  36 #include <mach/mach_types.h>
  37 #include <mach/kern_return.h>
  38 #include <kern/host.h>
  39 #include <kern/task.h>
  40 #include <kern/thread.h>
  41 #include <ppc/PseudoKernel.h>
  42 #include <ppc/exception.h>
  43 #include <ppc/misc_protos.h>
  44 #include <ppc/proc_reg.h>
  45 #include <vm/vm_kern.h>
  46
  47 void bbSetRupt(ReturnHandler *rh, thread_act_t ct);
  48
  49 /*
  50 ** Function:    NotifyInterruption
  51 **
  52 ** Inputs:
  53 **              ppcInterrupHandler      - interrupt handler to execute
  54 **              interruptStatePtr       - current interrupt state
  55 **
  56 ** Outputs:
  57 **
  58 ** Notes:
  59 **
  60 */
  61 kern_return_t syscall_notify_interrupt ( void ) {
  62
  63     UInt32                      interruptState;
  64     task_t                      task;
  65         thread_act_t    act, fact;
  66         thread_t                thread;
  67         bbRupt                  *bbr;
  68         BTTD_t                  *bttd;
  69         int                             i;
  70
  71         task = current_task();                                                  /* Figure out who our task is */
  72
  73         task_lock(task);                                                /* Lock our task */
  74
  75         fact = (thread_act_t)task->thr_acts.next;               /* Get the first activation on task */
  76         act = 0;                                                                                /* Pretend we didn't find it yet */
  77
  78         for(i = 0; i < task->thr_act_count; i++) {              /* Scan the whole list */
  79                 if(fact->mact.bbDescAddr) {                                     /* Is this a Blue thread? */
  80                         bttd = (BTTD_t *)(fact->mact.bbDescAddr & -PAGE_SIZE);
  81                         if(bttd->InterruptVector) {                             /* Is this the Blue interrupt thread? */
  82                                 act = fact;                                                     /* Yeah... */
  83                                 break;                                                          /* Found it, Bail the loop... */
  84                         }
  85                 }
  86                 fact = (thread_act_t)fact->thr_acts.next;       /* Go to the next one */
  87         }
  88
  89         if(!act) {                                                              /* Couldn't find a bluebox */
  90                 task_unlock(task);                                      /* Release task lock */
  91                 return KERN_FAILURE;                            /* No tickie, no shirtee... */
  92         }
  93
  94         act_lock_thread(act);                                                   /* Make sure this stays 'round */
  95         task_unlock(task);                                                              /* Safe to release now */
  96
  97         /* if the calling thread is the BlueBox thread that handles interrupts
  98          * we know that we are in the PsuedoKernel and we can short circuit
  99          * setting up the asynchronous task by setting a pending interrupt.
 100          */
 101
 102         if ( (unsigned int)act == (unsigned int)current_act() ) {
 103                 bttd->InterruptControlWord = bttd->InterruptControlWord |
 104                         ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 105
 106                 act_unlock_thread(act);                                         /* Unlock the activation */
 107                 return KERN_SUCCESS;
 108         }
 109
 110         if(act->mact.emPendRupts >= 16) {                               /* Have we hit the arbitrary maximum? */
 111                 act_unlock_thread(act);                                         /* Unlock the activation */
 112                 return KERN_RESOURCE_SHORTAGE;                          /* Too many pending right now */
 113         }
 114
 115         if(!(bbr = (bbRupt *)kalloc(sizeof(bbRupt)))) { /* Get a return handler control block */
 116                 act_unlock_thread(act);                                         /* Unlock the activation */
 117                 return KERN_RESOURCE_SHORTAGE;                          /* No storage... */
 118         }
 119
 120         (void)hw_atomic_add(&act->mact.emPendRupts, 1); /* Count this 'rupt */
 121         bbr->rh.handler = bbSetRupt;                                    /* Set interruption routine */
 122
 123         bbr->rh.next = act->handlers;                                   /* Put our interrupt at the start of the list */
 124         act->handlers = &bbr->rh;
 125
 126         act_set_apc(act);                                                               /* Set an APC AST */
 127
 128         act_unlock_thread(act);                                                 /* Unlock the activation */
 129         return KERN_SUCCESS;                                                    /* We're done... */
 130 }
 131
 132 /*
 133  *      This guy is fired off asynchronously to actually do the 'rupt.
 134  *      We will find the user state savearea and modify it.  If we can't,
 135  *      we just leave after releasing our work area
 136  */
 137
 138 void bbSetRupt(ReturnHandler *rh, thread_act_t act) {
 139
 140         savearea        *sv;
 141         BTTD_t          *bttd;
 142         bbRupt          *bbr;
 143         UInt32          interruptState;
 144
 145         bbr = (bbRupt *)rh;                                                             /* Make our area convenient */
 146
 147         if(!(act->mact.bbDescAddr)) {                                   /* Is BlueBox still enabled? */
 148                 kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* No, release the control block */
 149                 return;
 150         }
 151
 152         (void)hw_atomic_sub(&act->mact.emPendRupts, 1); /* Uncount this 'rupt */
 153
 154         if(!(sv = find_user_regs(act))) {                               /* Find the user state registers */
 155                 kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* Couldn't find 'em, release the control block */
 156                 return;
 157         }
 158
 159         bttd = (BTTD_t *)(act->mact.bbDescAddr & -PAGE_SIZE);
 160
 161     interruptState = (bttd->InterruptControlWord & kInterruptStateMask) >> kInterruptStateShift;
 162
 163     switch (interruptState) {
 164
 165                 case kInSystemContext:
 166                         sv->save_cr |= bttd->postIntMask;               /* post int in CR2 */
 167                         break;
 168
 169                 case kInAlternateContext:
 170                         bttd->InterruptControlWord = (bttd->InterruptControlWord & ~kInterruptStateMask) |
 171                                 (kInPseudoKernel << kInterruptStateShift);
 172
 173                         bttd->exceptionInfo.srr0 = (unsigned int)sv->save_srr0;         /* Save the current PC */
 174                         sv->save_srr0 = (uint64_t)bttd->InterruptVector;        /* Set the new PC */
 175                         bttd->exceptionInfo.sprg1 = (unsigned int)sv->save_r1;          /* Save the original R1 */
 176                         sv->save_r1 = (uint64_t)bttd->exceptionInfo.sprg0;      /* Set the new R1 */
 177                         bttd->exceptionInfo.srr1 = (unsigned int)sv->save_srr1;         /* Save the original MSR */
 178                         sv->save_srr1 &= ~(MASK(MSR_BE)|MASK(MSR_SE));  /* Clear SE|BE bits in MSR */
 179                         act->mact.specFlags &= ~bbNoMachSC;                             /* reactivate Mach SCs */
 180                         disable_preemption();                                                   /* Don't move us around */
 181                         per_proc_info[cpu_number()].spcFlags = act->mact.specFlags;     /* Copy the flags */
 182                         enable_preemption();                                                    /* Ok to move us around */
 183                         /* drop through to post int in backup CR2 in ICW */
 184
 185                 case kInExceptionHandler:
 186                 case kInPseudoKernel:
 187                 case kOutsideBlue:
 188                         bttd->InterruptControlWord = bttd->InterruptControlWord |
 189                                 ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
 190                         break;
 191
 192                 default:
 193                         break;
 194         }
 195
 196         kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* Release the control block */
 197         return;
 198
 199 }
 200
 201 /*
 202  * This function is used to enable the firmware assist code for bluebox traps, system calls
 203  * and interrupts.
 204  *
 205  * The assist code can be called from two types of threads.  The blue thread, which handles
 206  * traps, system calls and interrupts and preemptive threads that only issue system calls.
 207  *
 208  */
 209
 210 kern_return_t enable_bluebox(
 211       host_t host,
 212           void *taskID,                                                         /* opaque task ID */
 213           void *TWI_TableStart,                                         /* Start of TWI table */
 214           char *Desc_TableStart                                         /* Start of descriptor table */
 215          ) {
 216
 217         thread_t                th;
 218         vm_offset_t             kerndescaddr, origdescoffset;
 219         kern_return_t   ret;
 220         ppnum_t                 physdescpage;
 221
 222         th = current_thread();                                                                  /* Get our thread */
 223
 224         if ( host == HOST_NULL ) return KERN_INVALID_HOST;
 225         if ( ! is_suser() ) return KERN_FAILURE;                                                /* We will only do this for the superuser */
 226         if ( th->top_act->mact.bbDescAddr ) return KERN_FAILURE;                /* Bail if already authorized... */
 227         if ( ! (unsigned int) Desc_TableStart ) return KERN_FAILURE;    /* There has to be a descriptor page */
 228         if ( ! TWI_TableStart ) return KERN_FAILURE;                                    /* There has to be a TWI table */
 229
 230         /* Get the page offset of the descriptor */
 231         origdescoffset = (vm_offset_t)Desc_TableStart & (PAGE_SIZE - 1);
 232
 233         /* Align the descriptor to a page */
 234         Desc_TableStart = (char *)((vm_offset_t)Desc_TableStart & -PAGE_SIZE);
 235
 236         ret = vm_map_wire(th->top_act->map,                                     /* Kernel wire the descriptor in the user's map */
 237                 (vm_offset_t)Desc_TableStart,
 238                 (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 239                 VM_PROT_READ | VM_PROT_WRITE,
 240                 FALSE);
 241
 242         if(ret != KERN_SUCCESS) {                                                               /* Couldn't wire it, spit on 'em... */
 243                 return KERN_FAILURE;
 244         }
 245
 246         physdescpage =                                                                                  /* Get the physical page number of the page */
 247                 pmap_find_phys(th->top_act->map->pmap, (addr64_t)Desc_TableStart);
 248
 249         ret =  kmem_alloc_pageable(kernel_map, &kerndescaddr, PAGE_SIZE);       /* Find a virtual address to use */
 250         if(ret != KERN_SUCCESS) {                                                               /* Could we get an address? */
 251                 (void) vm_map_unwire(th->top_act->map,                          /* No, unwire the descriptor */
 252                         (vm_offset_t)Desc_TableStart,
 253                         (vm_offset_t)Desc_TableStart + PAGE_SIZE,
 254                         TRUE);
 255                 return KERN_FAILURE;                                                            /* Split... */
 256         }
 257
 258         (void) pmap_enter(kernel_pmap,                                                  /* Map this into the kernel */
 259                 kerndescaddr, physdescpage, VM_PROT_READ|VM_PROT_WRITE,
 260                 VM_WIMG_USE_DEFAULT, TRUE);
 261
 262         th->top_act->mact.bbDescAddr = (unsigned int)kerndescaddr+origdescoffset;       /* Set kernel address of the table */
 263         th->top_act->mact.bbUserDA = (unsigned int)Desc_TableStart;     /* Set user address of the table */
 264         th->top_act->mact.bbTableStart = (unsigned int)TWI_TableStart;  /* Set address of the trap table */
 265         th->top_act->mact.bbTaskID = (unsigned int)taskID;              /* Assign opaque task ID */
 266         th->top_act->mact.bbTaskEnv = 0;                                                /* Clean task environment data */
 267         th->top_act->mact.emPendRupts = 0;                                              /* Clean pending 'rupt count */
 268         th->top_act->mact.specFlags &= ~(bbNoMachSC | bbPreemptive);    /* Make sure mach SCs are enabled and we are not marked preemptive */
 269         th->top_act->mact.specFlags |= bbThread;                                /* Set that we are Classic thread */
 270
 271         if(!(((BTTD_t *)kerndescaddr)->InterruptVector)) {              /* See if this is a preemptive (MP) BlueBox thread */
 272                 th->top_act->mact.specFlags |= bbPreemptive;            /* Yes, remember it */
 273         }
 274
 275         disable_preemption();                                                                   /* Don't move us around */
 276         per_proc_info[cpu_number()].spcFlags = th->top_act->mact.specFlags;     /* Copy the flags */
 277         enable_preemption();                                                                    /* Ok to move us around */
 278
 279         {
 280                 /* mark the proc to indicate that this is a TBE proc */
 281                 extern void tbeproc(void *proc);
 282
 283                 tbeproc(th->top_act->task->bsd_info);
 284         }
 285
 286         return KERN_SUCCESS;
 287 }
 288
 289 kern_return_t disable_bluebox( host_t host ) {                          /* User call to terminate bluebox */
 290
 291         thread_act_t    act;
 292
 293         act = current_act();                                                                    /* Get our thread */
 294
 295         if (host == HOST_NULL) return KERN_INVALID_HOST;
 296
 297         if(!is_suser()) return KERN_FAILURE;                                    /* We will only do this for the superuser */
 298         if(!act->mact.bbDescAddr) return KERN_FAILURE;                  /* Bail if not authorized... */
 299
 300         disable_bluebox_internal(act);                                                  /* Clean it all up */
 301         return KERN_SUCCESS;                                                                    /* Leave */
 302 }
 303
 304 void disable_bluebox_internal(thread_act_t act) {                       /* Terminate bluebox */
 305
 306         (void) vm_map_unwire(act->map,                                                  /* Unwire the descriptor in user's address space */
 307                 (vm_offset_t)act->mact.bbUserDA,
 308                 (vm_offset_t)act->mact.bbUserDA + PAGE_SIZE,
 309                 FALSE);
 310
 311         kmem_free(kernel_map, (vm_offset_t)act->mact.bbDescAddr & -PAGE_SIZE, PAGE_SIZE);       /* Release the page */
 312
 313         act->mact.bbDescAddr = 0;                                                               /* Clear kernel pointer to it */
 314         act->mact.bbUserDA = 0;                                                                 /* Clear user pointer to it */
 315         act->mact.bbTableStart = 0;                                                             /* Clear user pointer to TWI table */
 316         act->mact.bbTaskID = 0;                                                                 /* Clear opaque task ID */
 317         act->mact.bbTaskEnv = 0;                                                                /* Clean task environment data */
 318         act->mact.emPendRupts = 0;                                                              /* Clean pending 'rupt count */
 319         act->mact.specFlags &= ~(bbNoMachSC | bbPreemptive | bbThread); /* Clean up Blue Box enables */
 320         disable_preemption();                                                           /* Don't move us around */
 321         per_proc_info[cpu_number()].spcFlags = act->mact.specFlags;     /* Copy the flags */
 322         enable_preemption();                                                            /* Ok to move us around */
 323         return;
 324 }
 325
 326 /*
 327  * Use the new PPCcall method to enable blue box threads
 328  *
 329  *      save->r3 = taskID
 330  *      save->r4 = TWI_TableStart
 331  *      save->r5 = Desc_TableStart
 332  *
 333  */
 334 int bb_enable_bluebox( struct savearea *save )
 335 {
 336         kern_return_t rc;
 337
 338         rc = enable_bluebox( (host_t)0xFFFFFFFF, (void *)save->save_r3, (void *)save->save_r4, (char *)save->save_r5 );
 339         save->save_r3 = rc;
 340         return 1;                                                                               /* Return with normal AST checking */
 341 }
 342
 343 /*
 344  * Use the new PPCcall method to disable blue box threads
 345  *
 346  */
 347 int bb_disable_bluebox( struct savearea *save )
 348 {
 349         kern_return_t rc;
 350
 351         rc = disable_bluebox( (host_t)0xFFFFFFFF );
 352         save->save_r3 = rc;
 353         return 1;                                                                               /* Return with normal AST checking */
 354 }
 355
 356 /*
 357  * Search through the list of threads to find the matching taskIDs, then
 358  * set the task environment pointer.  A task in this case is a preemptive thread
 359  * in MacOS 9.
 360  *
 361  *      save->r3 = taskID
 362  *      save->r4 = taskEnv
 363  */
 364
 365 int bb_settaskenv( struct savearea *save )
 366 {
 367         int                             i;
 368     task_t                      task;
 369         thread_act_t    act, fact;
 370
 371
 372         task = current_task();                                                  /* Figure out who our task is */
 373
 374         task_lock(task);                                                                /* Lock our task */
 375         fact = (thread_act_t)task->thr_acts.next;               /* Get the first activation on task */
 376         act = 0;                                                                                /* Pretend we didn't find it yet */
 377
 378         for(i = 0; i < task->thr_act_count; i++) {              /* Scan the whole list */
 379                 if(fact->mact.bbDescAddr) {                                     /* Is this a Blue thread? */
 380                         if ( fact->mact.bbTaskID == save->save_r3 ) {   /* Is this the task we are looking for? */
 381                                 act = fact;                                                     /* Yeah... */
 382                                 break;                                                          /* Found it, Bail the loop... */
 383                         }
 384                 }
 385                 fact = (thread_act_t)fact->thr_acts.next;       /* Go to the next one */
 386         }
 387
 388         if ( !act || !act->active) {
 389                 task_unlock(task);                                                      /* Release task lock */
 390                 goto failure;
 391         }
 392
 393         act_lock_thread(act);                                                   /* Make sure this stays 'round */
 394         task_unlock(task);                                                              /* Safe to release now */
 395
 396         act->mact.bbTaskEnv = save->save_r4;
 397         if(act == current_act()) {                                              /* Are we setting our own? */
 398                 disable_preemption();                                           /* Don't move us around */
 399                 per_proc_info[cpu_number()].ppbbTaskEnv = act->mact.bbTaskEnv;  /* Remember the environment */
 400                 enable_preemption();                                            /* Ok to move us around */
 401         }
 402
 403         act_unlock_thread(act);                                                 /* Unlock the activation */
 404         save->save_r3 = 0;
 405         return 1;
 406
 407 failure:
 408         save->save_r3 = -1;                                                             /* we failed to find the taskID */
 409         return 1;
 410 }