2 * Copyright (c) 2003 Peter Wemm.
3 * Copyright (c) 1993 The Regents of the University of California.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #include <machine/asmacros.h>
36 #include <machine/specialreg.h>
37 #include <machine/pmap.h>
45 * void bzero(void *buf, u_int len)
67 movq $PAGE_SIZE/8,%rcx
83 * The loop takes 29 bytes. Ensure that it doesn't cross a 32-byte
88 movnti %rax,(%rdi,%rdx)
89 movnti %rax,8(%rdi,%rdx)
90 movnti %rax,16(%rdi,%rdx)
91 movnti %rax,24(%rdi,%rdx)
119 * bcopy(src, dst, cnt)
121 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
130 cmpq %rcx,%rax /* overlapping && src < dst? */
133 shrq $3,%rcx /* copy by 64-bit words */
137 andq $7,%rcx /* any bytes left? */
145 addq %rcx,%rdi /* copy backwards */
149 andq $7,%rcx /* any fractional bytes? */
153 movq %rdx,%rcx /* copy remainder by 32-bit words */
165 * memmove(dst, src, cnt)
167 * Adapted from bcopy written by:
168 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
177 cmpq %rcx,%rax /* overlapping && src < dst? */
180 shrq $3,%rcx /* copy by 64-bit words */
184 andq $7,%rcx /* any bytes left? */
193 addq %rcx,%rdi /* copy backwards */
197 andq $7,%rcx /* any fractional bytes? */
201 movq %rdx,%rcx /* copy remainder by 32-bit words */
214 * memcpy(dst, src, len)
217 * Note: memcpy does not support overlapping copies
223 shrq $3,%rcx /* copy by 64-bit words */
227 andq $7,%rcx /* any bytes left? */
235 * memset(dst, c, len)
242 movabs $0x0101010101010101,%rax
257 * pagecopy(%rdi=from, %rsi=to)
261 movq $-PAGE_SIZE,%rax
266 prefetchnta (%rdi,%rax)
270 movq (%rdi,%rdx),%rax
271 movnti %rax,(%rsi,%rdx)
272 movq 8(%rdi,%rdx),%rax
273 movnti %rax,8(%rsi,%rdx)
274 movq 16(%rdi,%rdx),%rax
275 movnti %rax,16(%rsi,%rdx)
276 movq 24(%rdi,%rdx),%rax
277 movnti %rax,24(%rsi,%rdx)
285 /* fillw(pat, base, cnt) */
286 /* %rdi,%rsi, %rdx */
298 /*****************************************************************************/
299 /* copyout and fubyte family */
300 /*****************************************************************************/
302 * Access user memory from inside the kernel. These routines should be
303 * the only places that do this.
305 * These routines set curpcb->pcb_onfault for the time they execute. When a
306 * protection violation occurs inside the functions, the trap handler
307 * returns to *curpcb->pcb_onfault instead of the function.
311 * copyout(from_kernel, to_user, len)
316 movq PCPU(CURPCB),%rax
317 movq $copyout_fault,PCB_ONFAULT(%rax)
318 testq %rdx,%rdx /* anything to do? */
322 * Check explicitly for non-user addresses. This check is essential
323 * because it prevents usermode from writing into the kernel. We do
324 * not verify anywhere else that the user did not specify a rogue
328 * First, prevent address wrapping.
334 * XXX STOP USING VM_MAXUSER_ADDRESS.
335 * It is an end address, not a max, so every time it is used correctly it
336 * looks like there is an off by one error, and of course it caused an off
337 * by one error in several places.
339 movq $VM_MAXUSER_ADDRESS,%rcx
344 /* bcopy(%rsi, %rdi, %rdx) */
357 movq PCPU(CURPCB),%rdx
358 movq %rax,PCB_ONFAULT(%rdx)
364 movq PCPU(CURPCB),%rdx
365 movq $0,PCB_ONFAULT(%rdx)
372 * copyin(from_user, to_kernel, len)
377 movq PCPU(CURPCB),%rax
378 movq $copyin_fault,PCB_ONFAULT(%rax)
379 testq %rdx,%rdx /* anything to do? */
383 * make sure address is valid
388 movq $VM_MAXUSER_ADDRESS,%rcx
395 shrq $3,%rcx /* copy longword-wise */
399 andb $7,%cl /* copy remaining bytes */
405 movq PCPU(CURPCB),%rdx
406 movq %rax,PCB_ONFAULT(%rdx)
412 movq PCPU(CURPCB),%rdx
413 movq $0,PCB_ONFAULT(%rdx)
420 * casueword32. Compare and set user integer. Returns -1 on fault,
421 * 0 if access was successful. Old value is written to *oldp.
422 * dst = %rdi, old = %esi, oldp = %rdx, new = %ecx
426 movq PCPU(CURPCB),%r8
427 movq $fusufault,PCB_ONFAULT(%r8)
429 movq $VM_MAXUSER_ADDRESS-4,%rax
430 cmpq %rax,%rdi /* verify address is valid */
433 movl %esi,%eax /* old */
437 cmpxchgl %ecx,(%rdi) /* new = %ecx */
440 * The old value is in %eax. If the store succeeded it will be the
441 * value we expected (old) from before the store, otherwise it will
442 * be the current value. Save %eax into %esi to prepare the return
447 movq %rax,PCB_ONFAULT(%r8)
450 * Access the oldp after the pcb_onfault is cleared, to correctly
451 * catch corrupted pointer.
453 movl %esi,(%rdx) /* oldp = %rdx */
459 * casueword. Compare and set user long. Returns -1 on fault,
460 * 0 if access was successful. Old value is written to *oldp.
461 * dst = %rdi, old = %rsi, oldp = %rdx, new = %rcx
465 movq PCPU(CURPCB),%r8
466 movq $fusufault,PCB_ONFAULT(%r8)
468 movq $VM_MAXUSER_ADDRESS-4,%rax
469 cmpq %rax,%rdi /* verify address is valid */
472 movq %rsi,%rax /* old */
476 cmpxchgq %rcx,(%rdi) /* new = %rcx */
479 * The old value is in %rax. If the store succeeded it will be the
480 * value we expected (old) from before the store, otherwise it will
481 * be the current value.
485 movq %rax,PCB_ONFAULT(%r8)
492 * Fetch (load) a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit
493 * byte from user memory.
494 * addr = %rdi, valp = %rsi
500 movq PCPU(CURPCB),%rcx
501 movq $fusufault,PCB_ONFAULT(%rcx)
503 movq $VM_MAXUSER_ADDRESS-8,%rax
504 cmpq %rax,%rdi /* verify address is valid */
509 movq %rax,PCB_ONFAULT(%rcx)
518 movq PCPU(CURPCB),%rcx
519 movq $fusufault,PCB_ONFAULT(%rcx)
521 movq $VM_MAXUSER_ADDRESS-4,%rax
522 cmpq %rax,%rdi /* verify address is valid */
527 movq %rax,PCB_ONFAULT(%rcx)
535 movq PCPU(CURPCB),%rcx
536 movq $fusufault,PCB_ONFAULT(%rcx)
538 movq $VM_MAXUSER_ADDRESS-2,%rax
543 movq $0,PCB_ONFAULT(%rcx)
550 movq PCPU(CURPCB),%rcx
551 movq $fusufault,PCB_ONFAULT(%rcx)
553 movq $VM_MAXUSER_ADDRESS-1,%rax
558 movq $0,PCB_ONFAULT(%rcx)
565 movq PCPU(CURPCB),%rcx
567 movq %rax,PCB_ONFAULT(%rcx)
573 * Store a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit byte to
575 * addr = %rdi, value = %rsi
580 movq PCPU(CURPCB),%rcx
581 movq $fusufault,PCB_ONFAULT(%rcx)
583 movq $VM_MAXUSER_ADDRESS-8,%rax
584 cmpq %rax,%rdi /* verify address validity */
589 movq PCPU(CURPCB),%rcx
590 movq %rax,PCB_ONFAULT(%rcx)
598 movq PCPU(CURPCB),%rcx
599 movq $fusufault,PCB_ONFAULT(%rcx)
601 movq $VM_MAXUSER_ADDRESS-4,%rax
602 cmpq %rax,%rdi /* verify address validity */
607 movq PCPU(CURPCB),%rcx
608 movq %rax,PCB_ONFAULT(%rcx)
615 movq PCPU(CURPCB),%rcx
616 movq $fusufault,PCB_ONFAULT(%rcx)
618 movq $VM_MAXUSER_ADDRESS-2,%rax
619 cmpq %rax,%rdi /* verify address validity */
624 movq PCPU(CURPCB),%rcx /* restore trashed register */
625 movq %rax,PCB_ONFAULT(%rcx)
632 movq PCPU(CURPCB),%rcx
633 movq $fusufault,PCB_ONFAULT(%rcx)
635 movq $VM_MAXUSER_ADDRESS-1,%rax
636 cmpq %rax,%rdi /* verify address validity */
642 movq PCPU(CURPCB),%rcx /* restore trashed register */
643 movq %rax,PCB_ONFAULT(%rcx)
649 * copyinstr(from, to, maxlen, int *lencopied)
650 * %rdi, %rsi, %rdx, %rcx
652 * copy a string from 'from' to 'to', stop when a 0 character is reached.
653 * return ENAMETOOLONG if string is longer than maxlen, and
654 * EFAULT on protection violations. If lencopied is non-zero,
655 * return the actual length in *lencopied.
659 movq %rdx,%r8 /* %r8 = maxlen */
660 movq %rcx,%r9 /* %r9 = *len */
661 xchgq %rdi,%rsi /* %rdi = from, %rsi = to */
662 movq PCPU(CURPCB),%rcx
663 movq $cpystrflt,PCB_ONFAULT(%rcx)
665 movq $VM_MAXUSER_ADDRESS,%rax
667 /* make sure 'from' is within bounds */
671 /* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
688 /* Success -- 0 byte reached */
693 /* rdx is zero - return ENAMETOOLONG or EFAULT */
694 movq $VM_MAXUSER_ADDRESS,%rax
698 movq $ENAMETOOLONG,%rax
705 /* set *lencopied and return %eax */
706 movq PCPU(CURPCB),%rcx
707 movq $0,PCB_ONFAULT(%rcx)
719 * copystr(from, to, maxlen, int *lencopied)
720 * %rdi, %rsi, %rdx, %rcx
724 movq %rdx,%r8 /* %r8 = maxlen */
736 /* Success -- 0 byte reached */
741 /* rdx is zero -- return ENAMETOOLONG */
742 movq $ENAMETOOLONG,%rax
748 /* set *lencopied and return %rax */
757 * Handling of special amd64 registers and descriptor tables etc
759 /* void lgdt(struct region_descriptor *rdp); */
761 /* reload the descriptor table */
764 /* flush the prefetch q */
771 movl %eax,%fs /* Beware, use wrmsr to set 64 bit base */
775 /* reload code selector by turning return into intersegmental return */
783 /*****************************************************************************/
784 /* setjump, longjump */
785 /*****************************************************************************/
788 movq %rbx,0(%rdi) /* save rbx */
789 movq %rsp,8(%rdi) /* save rsp */
790 movq %rbp,16(%rdi) /* save rbp */
791 movq %r12,24(%rdi) /* save r12 */
792 movq %r13,32(%rdi) /* save r13 */
793 movq %r14,40(%rdi) /* save r14 */
794 movq %r15,48(%rdi) /* save r15 */
795 movq 0(%rsp),%rdx /* get rta */
796 movq %rdx,56(%rdi) /* save rip */
797 xorl %eax,%eax /* return(0); */
802 movq 0(%rdi),%rbx /* restore rbx */
803 movq 8(%rdi),%rsp /* restore rsp */
804 movq 16(%rdi),%rbp /* restore rbp */
805 movq 24(%rdi),%r12 /* restore r12 */
806 movq 32(%rdi),%r13 /* restore r13 */
807 movq 40(%rdi),%r14 /* restore r14 */
808 movq 48(%rdi),%r15 /* restore r15 */
809 movq 56(%rdi),%rdx /* get rta */
810 movq %rdx,0(%rsp) /* put in return frame */
811 xorl %eax,%eax /* return(1); */
817 * Support for reading MSRs in the safe manner. (Instead of panic on #gp,
821 /* int rdmsr_safe(u_int msr, uint64_t *data) */
823 movq PCPU(CURPCB),%r8
824 movq $msr_onfault,PCB_ONFAULT(%r8)
826 rdmsr /* Read MSR pointed by %ecx. Returns
827 hi byte in edx, lo in %eax */
828 salq $32,%rdx /* sign-shift %rdx left */
829 movl %eax,%eax /* zero-extend %eax -> %rax */
833 movq %rax,PCB_ONFAULT(%r8)
838 * Support for writing MSRs in the safe manner. (Instead of panic on #gp,
842 /* int wrmsr_safe(u_int msr, uint64_t data) */
844 movq PCPU(CURPCB),%r8
845 movq $msr_onfault,PCB_ONFAULT(%r8)
850 wrmsr /* Write MSR pointed by %ecx. Accepts
851 hi byte in edx, lo in %eax. */
853 movq %rax,PCB_ONFAULT(%r8)
858 * MSR operations fault handler
862 movq $0,PCB_ONFAULT(%r8)
868 * void pmap_pti_pcid_invalidate(uint64_t ucr3, uint64_t kcr3);
869 * Invalidates address space addressed by ucr3, then returns to kcr3.
870 * Done in assembler to ensure no other memory accesses happen while
874 ENTRY(pmap_pti_pcid_invalidate)
877 movq %rdi,%cr3 /* to user page table */
878 movq %rsi,%cr3 /* back to kernel */
883 * void pmap_pti_pcid_invlpg(uint64_t ucr3, uint64_t kcr3, vm_offset_t va);
884 * Invalidates virtual address va in address space ucr3, then returns to kcr3.
887 ENTRY(pmap_pti_pcid_invlpg)
890 movq %rdi,%cr3 /* to user page table */
892 movq %rsi,%cr3 /* back to kernel */
897 * void pmap_pti_pcid_invlrng(uint64_t ucr3, uint64_t kcr3, vm_offset_t sva,
899 * Invalidates virtual addresses between sva and eva in address space ucr3,
900 * then returns to kcr3.
903 ENTRY(pmap_pti_pcid_invlrng)
906 movq %rdi,%cr3 /* to user page table */
911 movq %rsi,%cr3 /* back to kernel */
916 .macro ibrs_seq_label l
919 .macro ibrs_call_label l
922 .macro ibrs_seq count
925 ibrs_call_label %(ll)
933 /* all callers already saved %rax, %rdx, and %rcx */
934 ENTRY(handle_ibrs_entry)
935 cmpb $0,hw_ibrs_active(%rip)
937 movl $MSR_IA32_SPEC_CTRL,%ecx
938 movl $(IA32_SPEC_CTRL_IBRS|IA32_SPEC_CTRL_STIBP),%eax
939 movl $(IA32_SPEC_CTRL_IBRS|IA32_SPEC_CTRL_STIBP)>>32,%edx
941 movb $1,PCPU(IBPB_SET)
942 testl $CPUID_STDEXT_SMEP,cpu_stdext_feature(%rip)
946 END(handle_ibrs_entry)
948 ENTRY(handle_ibrs_exit)
949 cmpb $0,PCPU(IBPB_SET)
951 movl $MSR_IA32_SPEC_CTRL,%ecx
955 movb $0,PCPU(IBPB_SET)
957 END(handle_ibrs_exit)
959 /* registers-neutral version, but needs stack */
960 ENTRY(handle_ibrs_exit_rs)
961 cmpb $0,PCPU(IBPB_SET)
966 movl $MSR_IA32_SPEC_CTRL,%ecx
973 movb $0,PCPU(IBPB_SET)
975 END(handle_ibrs_exit_rs)