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 #include "bsd-proc.h" 45 46 /* I/O */ 47 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes); 48 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t, 49 offset); 50 safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt); 51 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt, 52 off_t, offset); 53 54 safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes); 55 safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t, 56 offset); 57 safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt); 58 safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt, 59 off_t, offset); 60 61 void target_set_brk(abi_ulong new_brk) 62 { 63 } 64 65 /* 66 * errno conversion. 67 */ 68 abi_long get_errno(abi_long ret) 69 { 70 if (ret == -1) { 71 return -host_to_target_errno(errno); 72 } else { 73 return ret; 74 } 75 } 76 77 int host_to_target_errno(int err) 78 { 79 /* 80 * All the BSDs have the property that the error numbers are uniform across 81 * all architectures for a given BSD, though they may vary between different 82 * BSDs. 83 */ 84 return err; 85 } 86 87 bool is_error(abi_long ret) 88 { 89 return (abi_ulong)ret >= (abi_ulong)(-4096); 90 } 91 92 /* 93 * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is 94 * already locked from target_addr. It will be unlocked as well as all the iovec 95 * elements. 96 */ 97 static void helper_unlock_iovec(struct target_iovec *target_vec, 98 abi_ulong target_addr, struct iovec *vec, 99 int count, int copy) 100 { 101 for (int i = 0; i < count; i++) { 102 abi_ulong base = tswapal(target_vec[i].iov_base); 103 104 if (vec[i].iov_base) { 105 unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0); 106 } 107 } 108 unlock_user(target_vec, target_addr, 0); 109 } 110 111 struct iovec *lock_iovec(int type, abi_ulong target_addr, 112 int count, int copy) 113 { 114 struct target_iovec *target_vec; 115 struct iovec *vec; 116 abi_ulong total_len, max_len; 117 int i; 118 int err = 0; 119 120 if (count == 0) { 121 errno = 0; 122 return NULL; 123 } 124 if (count < 0 || count > IOV_MAX) { 125 errno = EINVAL; 126 return NULL; 127 } 128 129 vec = g_try_new0(struct iovec, count); 130 if (vec == NULL) { 131 errno = ENOMEM; 132 return NULL; 133 } 134 135 target_vec = lock_user(VERIFY_READ, target_addr, 136 count * sizeof(struct target_iovec), 1); 137 if (target_vec == NULL) { 138 err = EFAULT; 139 goto fail2; 140 } 141 142 max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK); 143 total_len = 0; 144 145 for (i = 0; i < count; i++) { 146 abi_ulong base = tswapal(target_vec[i].iov_base); 147 abi_long len = tswapal(target_vec[i].iov_len); 148 149 if (len < 0) { 150 err = EINVAL; 151 goto fail; 152 } else if (len == 0) { 153 /* Zero length pointer is ignored. */ 154 vec[i].iov_base = 0; 155 } else { 156 vec[i].iov_base = lock_user(type, base, len, copy); 157 /* 158 * If the first buffer pointer is bad, this is a fault. But 159 * subsequent bad buffers will result in a partial write; this is 160 * realized by filling the vector with null pointers and zero 161 * lengths. 162 */ 163 if (!vec[i].iov_base) { 164 if (i == 0) { 165 err = EFAULT; 166 goto fail; 167 } else { 168 /* 169 * Fail all the subsequent addresses, they are already 170 * zero'd. 171 */ 172 goto out; 173 } 174 } 175 if (len > max_len - total_len) { 176 len = max_len - total_len; 177 } 178 } 179 vec[i].iov_len = len; 180 total_len += len; 181 } 182 out: 183 unlock_user(target_vec, target_addr, 0); 184 return vec; 185 186 fail: 187 helper_unlock_iovec(target_vec, target_addr, vec, i, copy); 188 fail2: 189 g_free(vec); 190 errno = err; 191 return NULL; 192 } 193 194 void unlock_iovec(struct iovec *vec, abi_ulong target_addr, 195 int count, int copy) 196 { 197 struct target_iovec *target_vec; 198 199 target_vec = lock_user(VERIFY_READ, target_addr, 200 count * sizeof(struct target_iovec), 1); 201 if (target_vec) { 202 helper_unlock_iovec(target_vec, target_addr, vec, count, copy); 203 } 204 205 g_free(vec); 206 } 207 208 /* 209 * All errnos that freebsd_syscall() returns must be -TARGET_<errcode>. 210 */ 211 static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, 212 abi_long arg2, abi_long arg3, abi_long arg4, 213 abi_long arg5, abi_long arg6, abi_long arg7, 214 abi_long arg8) 215 { 216 abi_long ret; 217 218 switch (num) { 219 /* 220 * process system calls 221 */ 222 case TARGET_FREEBSD_NR_exit: /* exit(2) */ 223 ret = do_bsd_exit(cpu_env, arg1); 224 break; 225 226 /* 227 * File system calls. 228 */ 229 case TARGET_FREEBSD_NR_read: /* read(2) */ 230 ret = do_bsd_read(arg1, arg2, arg3); 231 break; 232 233 case TARGET_FREEBSD_NR_pread: /* pread(2) */ 234 ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 235 break; 236 237 case TARGET_FREEBSD_NR_readv: /* readv(2) */ 238 ret = do_bsd_readv(arg1, arg2, arg3); 239 break; 240 241 case TARGET_FREEBSD_NR_preadv: /* preadv(2) */ 242 ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 243 244 case TARGET_FREEBSD_NR_write: /* write(2) */ 245 ret = do_bsd_write(arg1, arg2, arg3); 246 break; 247 248 case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */ 249 ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 250 break; 251 252 case TARGET_FREEBSD_NR_writev: /* writev(2) */ 253 ret = do_bsd_writev(arg1, arg2, arg3); 254 break; 255 256 case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */ 257 ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); 258 break; 259 260 default: 261 qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); 262 ret = -TARGET_ENOSYS; 263 break; 264 } 265 266 return ret; 267 } 268 269 /* 270 * do_freebsd_syscall() should always have a single exit point at the end so 271 * that actions, such as logging of syscall results, can be performed. This 272 * as a wrapper around freebsd_syscall() so that actually happens. Since 273 * that is a singleton, modern compilers will inline it anyway... 274 */ 275 abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1, 276 abi_long arg2, abi_long arg3, abi_long arg4, 277 abi_long arg5, abi_long arg6, abi_long arg7, 278 abi_long arg8) 279 { 280 CPUState *cpu = env_cpu(cpu_env); 281 int ret; 282 283 trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); 284 if (do_strace) { 285 print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6); 286 } 287 288 ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6, 289 arg7, arg8); 290 if (do_strace) { 291 print_freebsd_syscall_ret(num, ret); 292 } 293 trace_guest_user_syscall_ret(cpu, num, ret); 294 295 return ret; 296 } 297 298 void syscall_init(void) 299 { 300 } 301