1 /* $NetBSD: kern_ras.c,v 1.14 2006/10/12 01:32:17 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Gregory McGarry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: kern_ras.c,v 1.14 2006/10/12 01:32:17 christos Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/lock.h> 44 #include <sys/systm.h> 45 #include <sys/pool.h> 46 #include <sys/proc.h> 47 #include <sys/ras.h> 48 #include <sys/sa.h> 49 #include <sys/savar.h> 50 51 #include <sys/mount.h> 52 #include <sys/syscallargs.h> 53 54 #include <uvm/uvm_extern.h> 55 56 POOL_INIT(ras_pool, sizeof(struct ras), 0, 0, 0, "raspl", 57 &pool_allocator_nointr); 58 59 #define MAX_RAS_PER_PROC 16 60 61 u_int ras_per_proc = MAX_RAS_PER_PROC; 62 63 #ifdef DEBUG 64 int ras_debug = 0; 65 #define DPRINTF(x) if (ras_debug) printf x 66 #else 67 #define DPRINTF(x) /* nothing */ 68 #endif 69 70 /* 71 * Check the specified address to see if it is within the 72 * sequence. If it is found, we return the restart address, 73 * otherwise we return -1. If we do perform a restart, we 74 * mark the sequence as hit. 75 */ 76 caddr_t 77 ras_lookup(struct proc *p, caddr_t addr) 78 { 79 struct ras *rp; 80 81 #ifdef DIAGNOSTIC 82 if (addr < (caddr_t)VM_MIN_ADDRESS || 83 addr > (caddr_t)VM_MAXUSER_ADDRESS) 84 return ((caddr_t)-1); 85 #endif 86 87 simple_lock(&p->p_lock); 88 LIST_FOREACH(rp, &p->p_raslist, ras_list) { 89 if (addr > rp->ras_startaddr && addr < rp->ras_endaddr) { 90 rp->ras_hits++; 91 simple_unlock(&p->p_lock); 92 #ifdef DIAGNOSTIC 93 DPRINTF(("RAS hit: p=%p %p\n", p, addr)); 94 #endif 95 return (rp->ras_startaddr); 96 } 97 } 98 simple_unlock(&p->p_lock); 99 100 return ((caddr_t)-1); 101 } 102 103 /* 104 * During a fork, we copy all of the sequences from parent p1 to 105 * the child p2. 106 */ 107 int 108 ras_fork(struct proc *p1, struct proc *p2) 109 { 110 struct ras *rp, *nrp; 111 int nras; 112 113 again: 114 /* 115 * first, try to shortcut. 116 */ 117 118 if (LIST_EMPTY(&p1->p_raslist)) 119 return (0); 120 121 /* 122 * count entries. 123 */ 124 125 nras = 0; 126 simple_lock(&p1->p_lock); 127 LIST_FOREACH(rp, &p1->p_raslist, ras_list) 128 nras++; 129 simple_unlock(&p1->p_lock); 130 131 /* 132 * allocate entries. 133 */ 134 135 for ( ; nras > 0; nras--) { 136 nrp = pool_get(&ras_pool, PR_WAITOK); 137 nrp->ras_hits = 0; 138 LIST_INSERT_HEAD(&p2->p_raslist, nrp, ras_list); 139 } 140 141 /* 142 * copy entries. 143 */ 144 145 simple_lock(&p1->p_lock); 146 nrp = LIST_FIRST(&p2->p_raslist); 147 LIST_FOREACH(rp, &p1->p_raslist, ras_list) { 148 if (nrp == NULL) 149 break; 150 nrp->ras_startaddr = rp->ras_startaddr; 151 nrp->ras_endaddr = rp->ras_endaddr; 152 nrp = LIST_NEXT(nrp, ras_list); 153 } 154 simple_unlock(&p1->p_lock); 155 156 /* 157 * if we lose a race, retry. 158 */ 159 160 if (rp != NULL || nrp != NULL) { 161 ras_purgeall(p2); 162 goto again; 163 } 164 165 DPRINTF(("ras_fork: p1=%p, p2=%p, nras=%d\n", p1, p2, nras)); 166 167 return (0); 168 } 169 170 /* 171 * Nuke all sequences for this process. 172 */ 173 int 174 ras_purgeall(struct proc *p) 175 { 176 struct ras *rp; 177 178 simple_lock(&p->p_lock); 179 while (!LIST_EMPTY(&p->p_raslist)) { 180 rp = LIST_FIRST(&p->p_raslist); 181 DPRINTF(("RAS %p-%p, hits %d\n", rp->ras_startaddr, 182 rp->ras_endaddr, rp->ras_hits)); 183 LIST_REMOVE(rp, ras_list); 184 pool_put(&ras_pool, rp); 185 } 186 simple_unlock(&p->p_lock); 187 188 return (0); 189 } 190 191 #if defined(__HAVE_RAS) 192 193 /* 194 * Install the new sequence. If it already exists, return 195 * an error. 196 */ 197 static int 198 ras_install(struct proc *p, caddr_t addr, size_t len) 199 { 200 struct ras *rp; 201 struct ras *newrp; 202 caddr_t endaddr = addr + len; 203 int nras = 0; 204 205 if (addr < (caddr_t)VM_MIN_ADDRESS || 206 endaddr > (caddr_t)VM_MAXUSER_ADDRESS) 207 return (EINVAL); 208 209 if (len <= 0) 210 return (EINVAL); 211 212 newrp = NULL; 213 again: 214 simple_lock(&p->p_lock); 215 LIST_FOREACH(rp, &p->p_raslist, ras_list) { 216 if (++nras >= ras_per_proc || 217 (addr < rp->ras_endaddr && endaddr > rp->ras_startaddr)) { 218 simple_unlock(&p->p_lock); 219 return (EINVAL); 220 } 221 } 222 if (newrp == NULL) { 223 simple_unlock(&p->p_lock); 224 newrp = pool_get(&ras_pool, PR_WAITOK); 225 goto again; 226 } 227 newrp->ras_startaddr = addr; 228 newrp->ras_endaddr = endaddr; 229 newrp->ras_hits = 0; 230 LIST_INSERT_HEAD(&p->p_raslist, newrp, ras_list); 231 simple_unlock(&p->p_lock); 232 233 return (0); 234 } 235 236 /* 237 * Nuke the specified sequence. Both address and len must 238 * match, otherwise we return an error. 239 */ 240 static int 241 ras_purge(struct proc *p, caddr_t addr, size_t len) 242 { 243 struct ras *rp; 244 caddr_t endaddr = addr + len; 245 int error = ESRCH; 246 247 simple_lock(&p->p_lock); 248 LIST_FOREACH(rp, &p->p_raslist, ras_list) { 249 if (addr == rp->ras_startaddr && endaddr == rp->ras_endaddr) { 250 LIST_REMOVE(rp, ras_list); 251 pool_put(&ras_pool, rp); 252 error = 0; 253 break; 254 } 255 } 256 simple_unlock(&p->p_lock); 257 258 return (error); 259 } 260 261 #endif /* defined(__HAVE_RAS) */ 262 263 /*ARGSUSED*/ 264 int 265 sys_rasctl(struct lwp *l, void *v, register_t *retval __unused) 266 { 267 268 #if defined(__HAVE_RAS) 269 270 struct sys_rasctl_args /* { 271 syscallarg(caddr_t) addr; 272 syscallarg(size_t) len; 273 syscallarg(int) op; 274 } */ *uap = v; 275 struct proc *p = l->l_proc; 276 caddr_t addr; 277 size_t len; 278 int op; 279 int error; 280 281 /* 282 * first, extract syscall args from the uap. 283 */ 284 285 addr = (caddr_t)SCARG(uap, addr); 286 len = (size_t)SCARG(uap, len); 287 op = SCARG(uap, op); 288 289 DPRINTF(("sys_rasctl: p=%p addr=%p, len=%ld, op=0x%x\n", 290 p, addr, (long)len, op)); 291 292 switch (op) { 293 case RAS_INSTALL: 294 error = ras_install(p, addr, len); 295 break; 296 case RAS_PURGE: 297 error = ras_purge(p, addr, len); 298 break; 299 case RAS_PURGE_ALL: 300 error = ras_purgeall(p); 301 break; 302 default: 303 error = EINVAL; 304 break; 305 } 306 307 return (error); 308 309 #else 310 311 return (EOPNOTSUPP); 312 313 #endif 314 315 } 316