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
194 cmpl %ecx,%eax /* overlapping && src < dst? */
197 shrl $2,%ecx /* copy by 32-bit words */
198 cld /* nope, copy forwards */
202 andl $3,%ecx /* any bytes left? */
212 addl %ecx,%edi /* copy backwards */
216 andl $3,%ecx /* any fractional bytes? */
220 movl 16(%ebp),%ecx /* copy remainder by 32-bit words */
234 * Note: memcpy does not support overlapping copies
243 shrl $2,%ecx /* copy by 32-bit words */
244 cld /* nope, copy forwards */
248 andl $3,%ecx /* any bytes left? */
256 /*****************************************************************************/
257 /* copyout and fubyte family */
258 /*****************************************************************************/
260 * Access user memory from inside the kernel. These routines and possibly
261 * the math- and DOS emulators should be the only places that do this.
263 * We have to access the memory with user's permissions, so use a segment
264 * selector with RPL 3. For writes to user space we have to additionally
265 * check the PTE for write permission, because the 386 does not check
266 * write permissions when we are executing with EPL 0. The 486 does check
267 * this if the WP bit is set in CR0, so we can use a simpler version here.
269 * These routines set curpcb->pcb_onfault for the time they execute. When a
270 * protection violation occurs inside the functions, the trap handler
271 * returns to *curpcb->pcb_onfault instead of the function.
275 * copyout(from_kernel, to_user, len) - MP SAFE
278 movl PCPU(CURPCB),%eax
279 movl $copyout_fault,PCB_ONFAULT(%eax)
286 testl %ebx,%ebx /* anything to do? */
290 * Check explicitly for non-user addresses. If 486 write protection
291 * is being used, this check is essential because we are in kernel
292 * mode so the h/w does not provide any protection against writing
297 * First, prevent address wrapping.
303 * XXX STOP USING VM_MAXUSER_ADDRESS.
304 * It is an end address, not a max, so every time it is used correctly it
305 * looks like there is an off by one error, and of course it caused an off
306 * by one error in several places.
308 cmpl $VM_MAXUSER_ADDRESS,%eax
311 /* bcopy(%esi, %edi, %ebx) */
328 movl PCPU(CURPCB),%edx
329 movl %eax,PCB_ONFAULT(%edx)
338 movl PCPU(CURPCB),%edx
339 movl $0,PCB_ONFAULT(%edx)
344 * copyin(from_user, to_kernel, len) - MP SAFE
347 movl PCPU(CURPCB),%eax
348 movl $copyin_fault,PCB_ONFAULT(%eax)
351 movl 12(%esp),%esi /* caddr_t from */
352 movl 16(%esp),%edi /* caddr_t to */
353 movl 20(%esp),%ecx /* size_t len */
356 * make sure address is valid
361 cmpl $VM_MAXUSER_ADDRESS,%edx
365 shrl $2,%ecx /* copy longword-wise */
370 andb $3,%cl /* copy remaining bytes */
377 movl PCPU(CURPCB),%edx
378 movl %eax,PCB_ONFAULT(%edx)
386 movl PCPU(CURPCB),%edx
387 movl $0,PCB_ONFAULT(%edx)
392 * casuword. Compare and set user word. Returns -1 or the current value.
397 movl PCPU(CURPCB),%ecx
398 movl $fusufault,PCB_ONFAULT(%ecx)
399 movl 4(%esp),%edx /* dst */
400 movl 8(%esp),%eax /* old */
401 movl 12(%esp),%ecx /* new */
403 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
409 cmpxchgl %ecx,(%edx) /* Compare and set. */
412 * The old value is in %eax. If the store succeeded it will be the
413 * value we expected (old) from before the store, otherwise it will
414 * be the current value.
417 movl PCPU(CURPCB),%ecx
418 movl $0,PCB_ONFAULT(%ecx)
424 * Fetch (load) a 32-bit word, a 16-bit word, or an 8-bit byte from user
425 * memory. All these functions are MPSAFE.
430 movl PCPU(CURPCB),%ecx
431 movl $fusufault,PCB_ONFAULT(%ecx)
432 movl 4(%esp),%edx /* from */
434 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
438 movl $0,PCB_ONFAULT(%ecx)
444 * fuswintr() and suswintr() are specialized variants of fuword16() and
445 * suword16(), respectively. They are called from the profiling code,
446 * potentially at interrupt time. If they fail, that's okay; good things
447 * will happen later. They always fail for now, until the trap code is
448 * able to deal with this.
458 movl PCPU(CURPCB),%ecx
459 movl $fusufault,PCB_ONFAULT(%ecx)
462 cmpl $VM_MAXUSER_ADDRESS-2,%edx
466 movl $0,PCB_ONFAULT(%ecx)
471 movl PCPU(CURPCB),%ecx
472 movl $fusufault,PCB_ONFAULT(%ecx)
475 cmpl $VM_MAXUSER_ADDRESS-1,%edx
479 movl $0,PCB_ONFAULT(%ecx)
485 movl PCPU(CURPCB),%ecx
487 movl %eax,PCB_ONFAULT(%ecx)
492 * Store a 32-bit word, a 16-bit word, or an 8-bit byte to user memory.
493 * All these functions are MPSAFE.
498 movl PCPU(CURPCB),%ecx
499 movl $fusufault,PCB_ONFAULT(%ecx)
502 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
508 movl PCPU(CURPCB),%ecx
509 movl %eax,PCB_ONFAULT(%ecx)
515 movl PCPU(CURPCB),%ecx
516 movl $fusufault,PCB_ONFAULT(%ecx)
519 cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
525 movl PCPU(CURPCB),%ecx /* restore trashed register */
526 movl %eax,PCB_ONFAULT(%ecx)
531 movl PCPU(CURPCB),%ecx
532 movl $fusufault,PCB_ONFAULT(%ecx)
535 cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
541 movl PCPU(CURPCB),%ecx /* restore trashed register */
542 movl %eax,PCB_ONFAULT(%ecx)
547 * copyinstr(from, to, maxlen, int *lencopied) - MP SAFE
549 * copy a string from from to to, stop when a 0 character is reached.
550 * return ENAMETOOLONG if string is longer than maxlen, and
551 * EFAULT on protection violations. If lencopied is non-zero,
552 * return the actual length in *lencopied.
557 movl PCPU(CURPCB),%ecx
558 movl $cpystrflt,PCB_ONFAULT(%ecx)
560 movl 12(%esp),%esi /* %esi = from */
561 movl 16(%esp),%edi /* %edi = to */
562 movl 20(%esp),%edx /* %edx = maxlen */
564 movl $VM_MAXUSER_ADDRESS,%eax
566 /* make sure 'from' is within bounds */
570 /* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
588 /* Success -- 0 byte reached */
593 /* edx is zero - return ENAMETOOLONG or EFAULT */
594 cmpl $VM_MAXUSER_ADDRESS,%esi
597 movl $ENAMETOOLONG,%eax
604 /* set *lencopied and return %eax */
605 movl PCPU(CURPCB),%ecx
606 movl $0,PCB_ONFAULT(%ecx)
620 * copystr(from, to, maxlen, int *lencopied) - MP SAFE
626 movl 12(%esp),%esi /* %esi = from */
627 movl 16(%esp),%edi /* %edi = to */
628 movl 20(%esp),%edx /* %edx = maxlen */
639 /* Success -- 0 byte reached */
644 /* edx is zero -- return ENAMETOOLONG */
645 movl $ENAMETOOLONG,%eax
648 /* set *lencopied and return %eax */
670 cld /* compare forwards */
688 * Handling of special 386 registers and descriptor tables etc
690 /* void lgdt(struct region_descriptor *rdp); */
693 /* reload the descriptor table */
698 /* flush the prefetch q */
702 /* reload "stale" selectors */
711 /* reload code selector by turning return into intersegmental return */
719 /* ssdtosd(*ssdp,*sdp) */
741 /* void reset_dbregs() */
744 movl %eax,%dr7 /* disable all breakpoints first */
753 /*****************************************************************************/
754 /* setjump, longjump */
755 /*****************************************************************************/
759 movl %ebx,(%eax) /* save ebx */
760 movl %esp,4(%eax) /* save esp */
761 movl %ebp,8(%eax) /* save ebp */
762 movl %esi,12(%eax) /* save esi */
763 movl %edi,16(%eax) /* save edi */
764 movl (%esp),%edx /* get rta */
765 movl %edx,20(%eax) /* save eip */
766 xorl %eax,%eax /* return(0); */
772 movl (%eax),%ebx /* restore ebx */
773 movl 4(%eax),%esp /* restore esp */
774 movl 8(%eax),%ebp /* restore ebp */
775 movl 12(%eax),%esi /* restore esi */
776 movl 16(%eax),%edi /* restore edi */
777 movl 20(%eax),%edx /* get rta */
778 movl %edx,(%esp) /* put in return frame */
779 xorl %eax,%eax /* return(1); */
785 * Support for reading MSRs in the safe manner.
788 /* int rdmsr_safe(u_int msr, uint64_t *data) */
789 movl PCPU(CURPCB),%ecx
790 movl $msr_onfault,PCB_ONFAULT(%ecx)
799 movl PCPU(CURPCB),%ecx
800 movl %eax,PCB_ONFAULT(%ecx)
805 * Support for writing MSRs in the safe manner.
808 /* int wrmsr_safe(u_int msr, uint64_t data) */
809 movl PCPU(CURPCB),%ecx
810 movl $msr_onfault,PCB_ONFAULT(%ecx)
818 movl PCPU(CURPCB),%ecx
819 movl %eax,PCB_ONFAULT(%ecx)
824 * MSR operations fault handler
828 movl PCPU(CURPCB),%ecx
829 movl $0,PCB_ONFAULT(%ecx)