/* $NetBSD: copyoutstr.c,v 1.9.64.1 2020/03/09 11:52:14 martin Exp $ */ /* * Copyright 2001 Wasabi Systems, Inc. * All rights reserved. * * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: copyoutstr.c,v 1.9.64.1 2020/03/09 11:52:14 martin Exp $"); #include #include #include int copyoutstr(const void *kaddr, void *udaddr, size_t len, size_t *done) { struct pmap *pm = curproc->p_vmspace->vm_map.pmap; size_t resid; int rv, msr, pid, data, ctx; struct faultbuf env; if (__predict_false(len == 0)) { if (done) *done = 0; return 0; } if ((rv = setfault(&env))) { curpcb->pcb_onfault = NULL; if (done) *done = 0; return rv; } if (!(ctx = pm->pm_ctx)) { /* No context -- assign it one */ ctx_alloc(pm); ctx = pm->pm_ctx; } resid = len; __asm volatile( "mtctr %3;" /* Set up counter */ "mfmsr %0;" /* Save MSR */ "li %1,0x20;" "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */ "mfpid %1;" /* Save old PID */ "sync; isync;" "1:" "mtpid %1; sync;" "lbz %2,0(%6); addi %6,%6,1;" /* Store kernel byte */ "sync; isync;" "mtpid %4; sync;" /* Load user ctx */ "stb %2,0(%5); dcbst 0,%5; addi %5,%5,1;" /* Load byte */ "sync; isync;" "or. %2,%2,%2;" "bdnzf 2,1b;" /* while(ctr-- && !zero) */ "mtpid %1; mtmsr %0;" /* Restore PID, MSR */ "sync; isync;" "mfctr %3;" /* Restore resid */ : "=&r" (msr), "=&r" (pid), "=&r" (data), "+r" (resid) : "r" (ctx), "b" (udaddr), "b" (kaddr)); curpcb->pcb_onfault = NULL; if (done) *done = len - resid; if (resid == 0 && (char)data != '\0') return ENAMETOOLONG; else return 0; }