1 /*- 2 * Copyright (c) 2010, 2012 Konstantin Belousov <kib@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_compat.h" 31 #include "opt_vm.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/rwlock.h> 38 #include <sys/sysent.h> 39 #include <sys/sysctl.h> 40 #include <sys/vdso.h> 41 42 #include <vm/vm.h> 43 #include <vm/vm_param.h> 44 #include <vm/pmap.h> 45 #include <vm/vm_extern.h> 46 #include <vm/vm_kern.h> 47 #include <vm/vm_map.h> 48 #include <vm/vm_object.h> 49 #include <vm/vm_page.h> 50 #include <vm/vm_pager.h> 51 52 static struct sx shared_page_alloc_sx; 53 static vm_object_t shared_page_obj; 54 static int shared_page_free; 55 char *shared_page_mapping; 56 57 void 58 shared_page_write(int base, int size, const void *data) 59 { 60 61 bcopy(data, shared_page_mapping + base, size); 62 } 63 64 static int 65 shared_page_alloc_locked(int size, int align) 66 { 67 int res; 68 69 res = roundup(shared_page_free, align); 70 if (res + size >= IDX_TO_OFF(shared_page_obj->size)) 71 res = -1; 72 else 73 shared_page_free = res + size; 74 return (res); 75 } 76 77 int 78 shared_page_alloc(int size, int align) 79 { 80 int res; 81 82 sx_xlock(&shared_page_alloc_sx); 83 res = shared_page_alloc_locked(size, align); 84 sx_xunlock(&shared_page_alloc_sx); 85 return (res); 86 } 87 88 int 89 shared_page_fill(int size, int align, const void *data) 90 { 91 int res; 92 93 sx_xlock(&shared_page_alloc_sx); 94 res = shared_page_alloc_locked(size, align); 95 if (res != -1) 96 shared_page_write(res, size, data); 97 sx_xunlock(&shared_page_alloc_sx); 98 return (res); 99 } 100 101 static void 102 shared_page_init(void *dummy __unused) 103 { 104 vm_page_t m; 105 vm_offset_t addr; 106 107 sx_init(&shared_page_alloc_sx, "shpsx"); 108 shared_page_obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE, 109 VM_PROT_DEFAULT, 0, NULL); 110 VM_OBJECT_WLOCK(shared_page_obj); 111 m = vm_page_grab(shared_page_obj, 0, VM_ALLOC_RETRY | VM_ALLOC_NOBUSY | 112 VM_ALLOC_ZERO); 113 m->valid = VM_PAGE_BITS_ALL; 114 VM_OBJECT_WUNLOCK(shared_page_obj); 115 addr = kmem_alloc_nofault(kernel_map, PAGE_SIZE); 116 pmap_qenter(addr, &m, 1); 117 shared_page_mapping = (char *)addr; 118 } 119 120 SYSINIT(shp, SI_SUB_EXEC, SI_ORDER_FIRST, (sysinit_cfunc_t)shared_page_init, 121 NULL); 122 123 static void 124 timehands_update(struct sysentvec *sv) 125 { 126 struct vdso_timehands th; 127 struct vdso_timekeep *tk; 128 uint32_t enabled, idx; 129 130 enabled = tc_fill_vdso_timehands(&th); 131 tk = (struct vdso_timekeep *)(shared_page_mapping + 132 sv->sv_timekeep_off); 133 idx = sv->sv_timekeep_curr; 134 atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); 135 if (++idx >= VDSO_TH_NUM) 136 idx = 0; 137 sv->sv_timekeep_curr = idx; 138 if (++sv->sv_timekeep_gen == 0) 139 sv->sv_timekeep_gen = 1; 140 th.th_gen = 0; 141 if (enabled) 142 tk->tk_th[idx] = th; 143 tk->tk_enabled = enabled; 144 atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); 145 tk->tk_current = idx; 146 } 147 148 #ifdef COMPAT_FREEBSD32 149 static void 150 timehands_update32(struct sysentvec *sv) 151 { 152 struct vdso_timekeep32 *tk; 153 struct vdso_timehands32 th; 154 uint32_t enabled, idx; 155 156 enabled = tc_fill_vdso_timehands32(&th); 157 tk = (struct vdso_timekeep32 *)(shared_page_mapping + 158 sv->sv_timekeep_off); 159 idx = sv->sv_timekeep_curr; 160 atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); 161 if (++idx >= VDSO_TH_NUM) 162 idx = 0; 163 sv->sv_timekeep_curr = idx; 164 if (++sv->sv_timekeep_gen == 0) 165 sv->sv_timekeep_gen = 1; 166 th.th_gen = 0; 167 if (enabled) 168 tk->tk_th[idx] = th; 169 tk->tk_enabled = enabled; 170 atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); 171 tk->tk_current = idx; 172 } 173 #endif 174 175 /* 176 * This is hackish, but easiest way to avoid creating list structures 177 * that needs to be iterated over from the hardclock interrupt 178 * context. 179 */ 180 static struct sysentvec *host_sysentvec; 181 #ifdef COMPAT_FREEBSD32 182 static struct sysentvec *compat32_sysentvec; 183 #endif 184 185 void 186 timekeep_push_vdso(void) 187 { 188 189 if (host_sysentvec != NULL && host_sysentvec->sv_timekeep_base != 0) 190 timehands_update(host_sysentvec); 191 #ifdef COMPAT_FREEBSD32 192 if (compat32_sysentvec != NULL && 193 compat32_sysentvec->sv_timekeep_base != 0) 194 timehands_update32(compat32_sysentvec); 195 #endif 196 } 197 198 void 199 exec_sysvec_init(void *param) 200 { 201 struct sysentvec *sv; 202 int tk_base; 203 uint32_t tk_ver; 204 205 sv = (struct sysentvec *)param; 206 207 if ((sv->sv_flags & SV_SHP) == 0) 208 return; 209 sv->sv_shared_page_obj = shared_page_obj; 210 sv->sv_sigcode_base = sv->sv_shared_page_base + 211 shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode); 212 if ((sv->sv_flags & SV_ABI_MASK) != SV_ABI_FREEBSD) 213 return; 214 tk_ver = VDSO_TK_VER_CURR; 215 #ifdef COMPAT_FREEBSD32 216 if ((sv->sv_flags & SV_ILP32) != 0) { 217 tk_base = shared_page_alloc(sizeof(struct vdso_timekeep32) + 218 sizeof(struct vdso_timehands32) * VDSO_TH_NUM, 16); 219 KASSERT(tk_base != -1, ("tk_base -1 for 32bit")); 220 shared_page_write(tk_base + offsetof(struct vdso_timekeep32, 221 tk_ver), sizeof(uint32_t), &tk_ver); 222 KASSERT(compat32_sysentvec == 0, 223 ("Native compat32 already registered")); 224 compat32_sysentvec = sv; 225 } else { 226 #endif 227 tk_base = shared_page_alloc(sizeof(struct vdso_timekeep) + 228 sizeof(struct vdso_timehands) * VDSO_TH_NUM, 16); 229 KASSERT(tk_base != -1, ("tk_base -1 for native")); 230 shared_page_write(tk_base + offsetof(struct vdso_timekeep, 231 tk_ver), sizeof(uint32_t), &tk_ver); 232 KASSERT(host_sysentvec == 0, ("Native already registered")); 233 host_sysentvec = sv; 234 #ifdef COMPAT_FREEBSD32 235 } 236 #endif 237 sv->sv_timekeep_base = sv->sv_shared_page_base + tk_base; 238 sv->sv_timekeep_off = tk_base; 239 timekeep_push_vdso(); 240 } 241