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
32 #include <machine/asmacros.h>
33 #include <machine/cputypes.h>
34 #include <machine/pmap.h>
35 #include <machine/specialreg.h>
45 * void bzero(void *buf, u_int len)
131 /* fillw(pat, base, cnt) */
152 cmpl %ecx,%eax /* overlapping && src < dst? */
154 cld /* nope, copy forwards */
163 addl %ecx,%edi /* copy backwards. */
177 * bcopy(src, dst, cnt)
178 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
191 cmpl %ecx,%eax /* overlapping && src < dst? */
194 shrl $2,%ecx /* copy by 32-bit words */
195 cld /* nope, copy forwards */
199 andl $3,%ecx /* any bytes left? */
209 addl %ecx,%edi /* copy backwards */
213 andl $3,%ecx /* any fractional bytes? */
217 movl 16(%ebp),%ecx /* copy remainder by 32-bit words */
231 * Note: memcpy does not support overlapping copies
240 shrl $2,%ecx /* copy by 32-bit words */
241 cld /* nope, copy forwards */
245 andl $3,%ecx /* any bytes left? */
253 /*****************************************************************************/
254 /* copyout and fubyte family */
255 /*****************************************************************************/
257 * Access user memory from inside the kernel. These routines and possibly
258 * the math- and DOS emulators should be the only places that do this.
260 * We have to access the memory with user's permissions, so use a segment
261 * selector with RPL 3. For writes to user space we have to additionally
262 * check the PTE for write permission, because the 386 does not check
263 * write permissions when we are executing with EPL 0. The 486 does check
264 * this if the WP bit is set in CR0, so we can use a simpler version here.
266 * These routines set curpcb->pcb_onfault for the time they execute. When a
267 * protection violation occurs inside the functions, the trap handler
268 * returns to *curpcb->pcb_onfault instead of the function.
272 * copyout(from_kernel, to_user, len) - MP SAFE
275 movl PCPU(CURPCB),%eax
276 movl $copyout_fault,PCB_ONFAULT(%eax)
283 testl %ebx,%ebx /* anything to do? */
287 * Check explicitly for non-user addresses. This check is essential
288 * because it prevents usermode from writing into the kernel. We do
289 * not verify anywhere else that the user did not specify a rogue
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 * casueword. Compare and set user word. Returns -1 on fault,
389 * 0 on non-faulting access. The current value is in *oldp.
391 ALTENTRY(casueword32)
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 16(%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)
415 movl 12(%esp),%edx /* oldp */
423 * Fetch (load) a 32-bit word, a 16-bit word, or an 8-bit byte from user
429 movl PCPU(CURPCB),%ecx
430 movl $fusufault,PCB_ONFAULT(%ecx)
431 movl 4(%esp),%edx /* from */
433 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
437 movl $0,PCB_ONFAULT(%ecx)
446 * fuswintr() and suswintr() are specialized variants of fuword16() and
447 * suword16(), respectively. They are called from the profiling code,
448 * potentially at interrupt time. If they fail, that's okay; good things
449 * will happen later. They always fail for now, until the trap code is
450 * able to deal with this.
460 movl PCPU(CURPCB),%ecx
461 movl $fusufault,PCB_ONFAULT(%ecx)
464 cmpl $VM_MAXUSER_ADDRESS-2,%edx
468 movl $0,PCB_ONFAULT(%ecx)
473 movl PCPU(CURPCB),%ecx
474 movl $fusufault,PCB_ONFAULT(%ecx)
477 cmpl $VM_MAXUSER_ADDRESS-1,%edx
481 movl $0,PCB_ONFAULT(%ecx)
487 movl PCPU(CURPCB),%ecx
489 movl %eax,PCB_ONFAULT(%ecx)
494 * Store a 32-bit word, a 16-bit word, or an 8-bit byte to user memory.
495 * All these functions are MPSAFE.
500 movl PCPU(CURPCB),%ecx
501 movl $fusufault,PCB_ONFAULT(%ecx)
504 cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
510 movl PCPU(CURPCB),%ecx
511 movl %eax,PCB_ONFAULT(%ecx)
517 movl PCPU(CURPCB),%ecx
518 movl $fusufault,PCB_ONFAULT(%ecx)
521 cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
527 movl PCPU(CURPCB),%ecx /* restore trashed register */
528 movl %eax,PCB_ONFAULT(%ecx)
533 movl PCPU(CURPCB),%ecx
534 movl $fusufault,PCB_ONFAULT(%ecx)
537 cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
543 movl PCPU(CURPCB),%ecx /* restore trashed register */
544 movl %eax,PCB_ONFAULT(%ecx)
549 * copyinstr(from, to, maxlen, int *lencopied) - MP SAFE
551 * copy a string from from to to, stop when a 0 character is reached.
552 * return ENAMETOOLONG if string is longer than maxlen, and
553 * EFAULT on protection violations. If lencopied is non-zero,
554 * return the actual length in *lencopied.
559 movl PCPU(CURPCB),%ecx
560 movl $cpystrflt,PCB_ONFAULT(%ecx)
562 movl 12(%esp),%esi /* %esi = from */
563 movl 16(%esp),%edi /* %edi = to */
564 movl 20(%esp),%edx /* %edx = maxlen */
566 movl $VM_MAXUSER_ADDRESS,%eax
568 /* make sure 'from' is within bounds */
572 /* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
590 /* Success -- 0 byte reached */
595 /* edx is zero - return ENAMETOOLONG or EFAULT */
596 cmpl $VM_MAXUSER_ADDRESS,%esi
599 movl $ENAMETOOLONG,%eax
606 /* set *lencopied and return %eax */
607 movl PCPU(CURPCB),%ecx
608 movl $0,PCB_ONFAULT(%ecx)
622 * copystr(from, to, maxlen, int *lencopied) - MP SAFE
628 movl 12(%esp),%esi /* %esi = from */
629 movl 16(%esp),%edi /* %edi = to */
630 movl 20(%esp),%edx /* %edx = maxlen */
641 /* Success -- 0 byte reached */
646 /* edx is zero -- return ENAMETOOLONG */
647 movl $ENAMETOOLONG,%eax
650 /* set *lencopied and return %eax */
672 cld /* compare forwards */
690 * Handling of special 386 registers and descriptor tables etc
692 /* void lgdt(struct region_descriptor *rdp); */
694 /* 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)