1 /* 2 * BSD syscalls 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2013-2014 Stacey D. Son 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 /* 22 * We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system 23 * calls since it doesn't use libc at all, so we have to emulate that despite 24 * FreeBSD 11 being EOL'd. 25 */ 26 #define _WANT_FREEBSD11_STAT 27 #define _WANT_FREEBSD11_STATFS 28 #define _WANT_FREEBSD11_DIRENT 29 #define _WANT_KERNEL_ERRNO 30 #define _WANT_SEMUN 31 #include "qemu/osdep.h" 32 #include "qemu/cutils.h" 33 #include "qemu/path.h" 34 #include <sys/syscall.h> 35 #include <sys/param.h> 36 #include <sys/sysctl.h> 37 #include <utime.h> 38 39 #include "qemu.h" 40 #include "signal-common.h" 41 #include "user/syscall-trace.h" 42 43 #include "bsd-file.h" 44 45 /* I/O */ 46 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes); 47 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t, 48 offset); 49 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt); 50 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt, 51 off_t, offset); 52 53 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes); 54 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t, 55 offset); 56 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt); 57 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt, 58 off_t, offset); 59 60 void target_set_brk(abi_ulong new_brk) 61 { 62 } 63 64 /* 65 * errno conversion. 66 */ 67 abi_long get_errno(abi_long ret) 68 { 69 if (ret == -1) { 70 return -host_to_target_errno(errno); 71 } else { 72 return ret; 73 } 74 } 75 76 int host_to_target_errno(int err) 77 { 78 /* 79 * All the BSDs have the property that the error numbers are uniform across 80 * all architectures for a given BSD, though they may vary between different 81 * BSDs. 82 */ 83 return err; 84 } 85 86 bool is_error(abi_long ret) 87 { 88 return (abi_ulong)ret >= (abi_ulong)(-4096); 89 } 90 91 /* 92 * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is 93 * already locked from target_addr. It will be unlocked as well as all the iovec 94 * elements. 95 */ 96 static void helper_unlock_iovec(struct target_iovec *target_vec, 97 abi_ulong target_addr, struct iovec *vec, 98 int count, int copy) 99 { 100 for (int i = 0; i < count; i++) { 101 abi_ulong base = tswapal(target_vec[i].iov_base); 102 103 if (vec[i].iov_base) { 104 unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0); 105 } 106 } 107 unlock_user(target_vec, target_addr, 0); 108 } 109 110 struct iovec *lock_iovec(int type, abi_ulong target_addr, 111 int count, int copy) 112 { 113 struct target_iovec *target_vec; 114 struct iovec *vec; 115 abi_ulong total_len, max_len; 116 int i; 117 int err = 0; 118 119 if (count == 0) { 120 errno = 0; 121 return NULL; 122 } 123 if (count < 0 || count > IOV_MAX) { 124 errno = EINVAL; 125 return NULL; 126 } 127 128 vec = g_try_new0(struct iovec, count); 129 if (vec == NULL) { 130 errno = ENOMEM; 131 return NULL; 132 } 133 134 target_vec = lock_user(VERIFY_READ, target_addr, 135 count * sizeof(struct target_iovec), 1); 136 if (target_vec == NULL) { 137 err = EFAULT; 138 goto fail2; 139 } 140 141 max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK); 142 total_len = 0; 143 144 for (i = 0; i < count; i++) { 145 abi_ulong base = tswapal(target_vec[i].iov_base); 146 abi_long len = tswapal(target_vec[i].iov_len); 147 148 if (len < 0) { 149 err = EINVAL; 150 goto fail; 151 } else if (len == 0) { 152 /* Zero length pointer is ignored. */ 153 vec[i].iov_base = 0; 154 } else { 155 vec[i].iov_base = lock_user(type, base, len, copy); 156 /* 157 * If the first buffer pointer is bad, this is a fault. But 158 * subsequent bad buffers will result in a partial write; this is 159 * realized by filling the vector with null pointers and zero 160 * lengths. 161 */ 162 if (!vec[i].iov_base) { 163 if (i == 0) { 164 err = EFAULT; 165 goto fail; 166 } else { 167 /* 168 * Fail all the subsequent addresses, they are already 169 * zero'd. 170 */ 171 goto out; 172 } 173 } 174 if (len > max_len - total_len) { 175 len = max_len - total_len; 176 } 177 } 178 vec[i].iov_len = len; 179 total_len += len; 180 } 181 out: 182 unlock_user(target_vec, target_addr, 0); 183 return vec; 184 185 fail: 186 helper_unlock_iovec(target_vec, target_addr, vec, i, copy); 187 fail2: 188 g_free(vec); 189 errno = err; 190 return NULL; 191 } 192 193 void unlock_iovec(struct iovec *vec, abi_ulong target_addr, 194 int count, int copy) 195 { 196 struct target_iovec *target_vec; 197 198 target_vec = lock_user(VERIFY_READ, target_addr, 199 count * sizeof(struct target_iovec), 1); 200 if (target_vec) { 201 helper_unlock_iovec(target_vec, target_addr, vec, count, copy); 202 } 203 204 g_free(vec); 205 } 206 207 /* 208 * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>. 209 */ 210 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, 211 abi_long arg2, abi_long arg3, abi_long arg4, 212 abi_long arg5, abi_long arg6, abi_long arg7, 213 abi_long arg8) 214 { 215 abi_long ret; 216 217 switch (num) { 218 219 /* 220 * File system calls. 221 */ 222 case TARGET_FREEBSD_NR_read: /* read(2) */ 223 ret = do_bsd_read(arg1, arg2, arg3); 224 break; 225 226 case TARGET_FREEBSD_NR_pread: /* pread(2) */ 227 ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 228 break; 229 230 case TARGET_FREEBSD_NR_readv: /* readv(2) */ 231 ret = do_bsd_readv(arg1, arg2, arg3); 232 break; 233 234 case TARGET_FREEBSD_NR_preadv: /* preadv(2) */ 235 ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 236 237 case TARGET_FREEBSD_NR_write: /* write(2) */ 238 ret = do_bsd_write(arg1, arg2, arg3); 239 break; 240 241 case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */ 242 ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 243 break; 244 245 case TARGET_FREEBSD_NR_writev: /* writev(2) */ 246 ret = do_bsd_writev(arg1, arg2, arg3); 247 break; 248 249 case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */ 250 ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 251 break; 252 253 default: 254 qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); 255 ret = -TARGET_ENOSYS; 256 break; 257 } 258 259 return ret; 260 } 261 262 /* 263 * do_freebsd_syscall() should always have a single exit point at the end so 264 * that actions, such as logging of syscall results, can be performed. This 265 * as a wrapper around freebsd_syscall() so that actually happens. Since 266 * that is a singleton, modern compilers will inline it anyway... 267 */ 268 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1, 269 abi_long arg2, abi_long arg3, abi_long arg4, 270 abi_long arg5, abi_long arg6, abi_long arg7, 271 abi_long arg8) 272 { 273 CPUState *cpu = env_cpu(cpu_env); 274 int ret; 275 276 trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); 277 if (do_strace) { 278 print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6); 279 } 280 281 ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6, 282 arg7, arg8); 283 if (do_strace) { 284 print_freebsd_syscall_ret(num, ret); 285 } 286 trace_guest_user_syscall_ret(cpu, num, ret); 287 288 return ret; 289 } 290 291 void syscall_init(void) 292 { 293 } 294