2 * Copyright (c) 1993 The Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <machine/asmacros.h>
35 #include <machine/cputypes.h>
36 #include <machine/intr_machdep.h>
37 #include <machine/pmap.h>
38 #include <machine/specialreg.h>
48 * void bzero(void *buf, u_int len)
134 /* fillw(pat, base, cnt) */
155 cmpl %ecx,%eax /* overlapping && src < dst? */
157 cld /* nope, copy forwards */
166 addl %ecx,%edi /* copy backwards. */
180 * bcopy(src, dst, cnt)
181 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
192 cmpl %ecx,%eax /* overlapping && src < dst? */
195 shrl $2,%ecx /* copy by 32-bit words */
196 cld /* nope, copy forwards */
200 andl $3,%ecx /* any bytes left? */
209 addl %ecx,%edi /* copy backwards */
213 andl $3,%ecx /* any fractional bytes? */
217 movl 20(%esp),%ecx /* copy remainder by 32-bit words */
230 * Note: memcpy does not support overlapping copies
239 shrl $2,%ecx /* copy by 32-bit words */
240 cld /* nope, copy forwards */
244 andl $3,%ecx /* any bytes left? */
252 /*****************************************************************************/
253 /* copyout and fubyte family */
254 /*****************************************************************************/
256 * Access user memory from inside the kernel. These routines and possibly
257 * the math- and DOS emulators should be the only places that do this.
259 * We have to access the memory with user's permissions, so use a segment
260 * selector with RPL 3. For writes to user space we have to additionally
261 * check the PTE for write permission, because the 386 does not check
262 * write permissions when we are executing with EPL 0. The 486 does check
263 * this if the WP bit is set in CR0, so we can use a simpler version here.
265 * These routines set curpcb->onfault for the time they execute. When a
266 * protection violation occurs inside the functions, the trap handler
267 * returns to *curpcb->onfault instead of the function.
271 * copyout(from_kernel, to_user, len) - MP SAFE
274 movl PCPU(CURPCB),%eax
275 movl $copyout_fault,PCB_ONFAULT(%eax)
282 testl %ebx,%ebx /* anything to do? */
286 * Check explicitly for non-user addresses. If 486 write protection
287 * is being used, this check is essential because we are in kernel
288 * mode so the h/w does not provide any protection against writing
293 * First, prevent address wrapping.
299 * XXX STOP USING VM_MAXUSER_ADDRESS.
300 * It is an end address, not a max, so every time it is used correctly it
301 * looks like there is an off by one error, and of course it caused an off
302 * by one error in several places.
304 cmpl $VM_MAXUSER_ADDRESS,%eax
307 /* bcopy(%esi, %edi, %ebx) */
324 movl PCPU(CURPCB),%edx
325 movl %eax,PCB_ONFAULT(%edx)
334 movl PCPU(CURPCB),%edx
335 movl $0,PCB_ONFAULT(%edx)
340 * copyin(from_user, to_kernel, len) - MP SAFE
343 movl PCPU(CURPCB),%eax
344 movl $copyin_fault,PCB_ONFAULT(%eax)
347 movl 12(%esp),%esi /* caddr_t from */
348 movl 16(%esp),%edi /* caddr_t to */
349 movl 20(%esp),%ecx /* size_t len */
352 * make sure address is valid
357 cmpl $VM_MAXUSER_ADDRESS,%edx
361 shrl $2,%ecx /* copy longword-wise */
366 andb $3,%cl /* copy remaining bytes */
373 movl PCPU(CURPCB),%edx
374 movl %eax,PCB_ONFAULT(%edx)
382 movl PCPU(CURPCB),%edx
383 movl $0,PCB_ONFAULT(%edx)
388 * casuword. Compare and set user word. Returns -1 or the current value.
393 movl PCPU(CURPCB),%ecx
394 movl $fusufault,PCB_ONFAULT(%ecx)
395 movl 4(%esp),%edx /* dst */
396 movl 8(%esp),%eax /* old */
397 movl 12(%esp),%ecx /* new */
399 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
405 cmpxchgl %ecx,(%edx) /* Compare and set. */
408 * The old value is in %eax. If the store succeeded it will be the
409 * value we expected (old) from before the store, otherwise it will
410 * be the current value.
413 movl PCPU(CURPCB),%ecx
414 movl $0,PCB_ONFAULT(%ecx)
420 * Fetch (load) a 32-bit word, a 16-bit word, or an 8-bit byte from user
421 * memory. All these functions are MPSAFE.
426 movl PCPU(CURPCB),%ecx
427 movl $fusufault,PCB_ONFAULT(%ecx)
428 movl 4(%esp),%edx /* from */
430 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
434 movl $0,PCB_ONFAULT(%ecx)
440 * fuswintr() and suswintr() are specialized variants of fuword16() and
441 * suword16(), respectively. They are called from the profiling code,
442 * potentially at interrupt time. If they fail, that's okay; good things
443 * will happen later. They always fail for now, until the trap code is
444 * able to deal with this.
454 movl PCPU(CURPCB),%ecx
455 movl $fusufault,PCB_ONFAULT(%ecx)
458 cmpl $VM_MAXUSER_ADDRESS-2,%edx
462 movl $0,PCB_ONFAULT(%ecx)
467 movl PCPU(CURPCB),%ecx
468 movl $fusufault,PCB_ONFAULT(%ecx)
471 cmpl $VM_MAXUSER_ADDRESS-1,%edx
475 movl $0,PCB_ONFAULT(%ecx)
481 movl PCPU(CURPCB),%ecx
483 movl %eax,PCB_ONFAULT(%ecx)
488 * Store a 32-bit word, a 16-bit word, or an 8-bit byte to user memory.
489 * All these functions are MPSAFE.
494 movl PCPU(CURPCB),%ecx
495 movl $fusufault,PCB_ONFAULT(%ecx)
498 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
504 movl PCPU(CURPCB),%ecx
505 movl %eax,PCB_ONFAULT(%ecx)
511 movl PCPU(CURPCB),%ecx
512 movl $fusufault,PCB_ONFAULT(%ecx)
515 cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
521 movl PCPU(CURPCB),%ecx /* restore trashed register */
522 movl %eax,PCB_ONFAULT(%ecx)
527 movl PCPU(CURPCB),%ecx
528 movl $fusufault,PCB_ONFAULT(%ecx)
531 cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
537 movl PCPU(CURPCB),%ecx /* restore trashed register */
538 movl %eax,PCB_ONFAULT(%ecx)
543 * copyinstr(from, to, maxlen, int *lencopied) - MP SAFE
545 * copy a string from from to to, stop when a 0 character is reached.
546 * return ENAMETOOLONG if string is longer than maxlen, and
547 * EFAULT on protection violations. If lencopied is non-zero,
548 * return the actual length in *lencopied.
553 movl PCPU(CURPCB),%ecx
554 movl $cpystrflt,PCB_ONFAULT(%ecx)
556 movl 12(%esp),%esi /* %esi = from */
557 movl 16(%esp),%edi /* %edi = to */
558 movl 20(%esp),%edx /* %edx = maxlen */
560 movl $VM_MAXUSER_ADDRESS,%eax
562 /* make sure 'from' is within bounds */
566 /* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
584 /* Success -- 0 byte reached */
589 /* edx is zero - return ENAMETOOLONG or EFAULT */
590 cmpl $VM_MAXUSER_ADDRESS,%esi
593 movl $ENAMETOOLONG,%eax
600 /* set *lencopied and return %eax */
601 movl PCPU(CURPCB),%ecx
602 movl $0,PCB_ONFAULT(%ecx)
616 * copystr(from, to, maxlen, int *lencopied) - MP SAFE
622 movl 12(%esp),%esi /* %esi = from */
623 movl 16(%esp),%edi /* %edi = to */
624 movl 20(%esp),%edx /* %edx = maxlen */
635 /* Success -- 0 byte reached */
640 /* edx is zero -- return ENAMETOOLONG */
641 movl $ENAMETOOLONG,%eax
644 /* set *lencopied and return %eax */
666 cld /* compare forwards */
684 * Handling of special 386 registers and descriptor tables etc
686 /* void lgdt(struct region_descriptor *rdp); */
689 /* reload the descriptor table */
694 /* flush the prefetch q */
698 /* reload "stale" selectors */
707 /* reload code selector by turning return into intersegmental return */
715 /* ssdtosd(*ssdp,*sdp) */
737 /* void reset_dbregs() */
740 movl %eax,%dr7 /* disable all breapoints first */
749 /*****************************************************************************/
750 /* setjump, longjump */
751 /*****************************************************************************/
755 movl %ebx,(%eax) /* save ebx */
756 movl %esp,4(%eax) /* save esp */
757 movl %ebp,8(%eax) /* save ebp */
758 movl %esi,12(%eax) /* save esi */
759 movl %edi,16(%eax) /* save edi */
760 movl (%esp),%edx /* get rta */
761 movl %edx,20(%eax) /* save eip */
762 xorl %eax,%eax /* return(0); */
768 movl (%eax),%ebx /* restore ebx */
769 movl 4(%eax),%esp /* restore esp */
770 movl 8(%eax),%ebp /* restore ebp */
771 movl 12(%eax),%esi /* restore esi */
772 movl 16(%eax),%edi /* restore edi */
773 movl 20(%eax),%edx /* get rta */
774 movl %edx,(%esp) /* put in return frame */
775 xorl %eax,%eax /* return(1); */
781 * Support for reading MSRs in the safe manner.
784 /* int rdmsr_safe(u_int msr, uint64_t *data) */
785 movl PCPU(CURPCB),%ecx
786 movl $msr_onfault,PCB_ONFAULT(%ecx)
795 movl PCPU(CURPCB),%ecx
796 movl %eax,PCB_ONFAULT(%ecx)
801 * Support for writing MSRs in the safe manner.
804 /* int wrmsr_safe(u_int msr, uint64_t data) */
805 movl PCPU(CURPCB),%ecx
806 movl $msr_onfault,PCB_ONFAULT(%ecx)
814 movl PCPU(CURPCB),%ecx
815 movl %eax,PCB_ONFAULT(%ecx)
820 * MSR operations fault handler
824 movl PCPU(CURPCB),%ecx
825 movl $0,PCB_ONFAULT(%ecx)