1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1988, 1991 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD$ 32 */ 33 34 #ifndef _SYS_SYSENT_H_ 35 #define _SYS_SYSENT_H_ 36 37 #include <bsm/audit.h> 38 39 struct rlimit; 40 struct sysent; 41 struct thread; 42 struct ksiginfo; 43 struct syscall_args; 44 45 enum systrace_probe_t { 46 SYSTRACE_ENTRY, 47 SYSTRACE_RETURN, 48 }; 49 50 typedef int sy_call_t(struct thread *, void *); 51 52 typedef void (*systrace_probe_func_t)(struct syscall_args *, 53 enum systrace_probe_t, int); 54 typedef void (*systrace_args_func_t)(int, void *, uint64_t *, int *); 55 56 #ifdef _KERNEL 57 extern bool systrace_enabled; 58 #endif 59 extern systrace_probe_func_t systrace_probe_func; 60 61 struct sysent { /* system call table */ 62 int sy_narg; /* number of arguments */ 63 sy_call_t *sy_call; /* implementing function */ 64 au_event_t sy_auevent; /* audit event associated with syscall */ 65 systrace_args_func_t sy_systrace_args_func; 66 /* optional argument conversion function. */ 67 u_int32_t sy_entry; /* DTrace entry ID for systrace. */ 68 u_int32_t sy_return; /* DTrace return ID for systrace. */ 69 u_int32_t sy_flags; /* General flags for system calls. */ 70 u_int32_t sy_thrcnt; 71 }; 72 73 /* 74 * A system call is permitted in capability mode. 75 */ 76 #define SYF_CAPENABLED 0x00000001 77 78 #define SY_THR_FLAGMASK 0x7 79 #define SY_THR_STATIC 0x1 80 #define SY_THR_DRAINING 0x2 81 #define SY_THR_ABSENT 0x4 82 #define SY_THR_INCR 0x8 83 84 #ifdef KLD_MODULE 85 #define SY_THR_STATIC_KLD 0 86 #else 87 #define SY_THR_STATIC_KLD SY_THR_STATIC 88 #endif 89 90 struct image_params; 91 struct __sigset; 92 struct trapframe; 93 struct vnode; 94 95 struct sysentvec { 96 int sv_size; /* number of entries */ 97 struct sysent *sv_table; /* pointer to sysent */ 98 u_int sv_mask; /* optional mask to index */ 99 int sv_errsize; /* size of errno translation table */ 100 const int *sv_errtbl; /* errno translation table */ 101 int (*sv_transtrap)(int, int); 102 /* translate trap-to-signal mapping */ 103 int (*sv_fixup)(register_t **, struct image_params *); 104 /* stack fixup function */ 105 void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *); 106 /* send signal */ 107 char *sv_sigcode; /* start of sigtramp code */ 108 int *sv_szsigcode; /* size of sigtramp code */ 109 char *sv_name; /* name of binary type */ 110 int (*sv_coredump)(struct thread *, struct vnode *, off_t, int); 111 /* function to dump core, or NULL */ 112 int (*sv_imgact_try)(struct image_params *); 113 int sv_minsigstksz; /* minimum signal stack size */ 114 int sv_pagesize; /* pagesize */ 115 vm_offset_t sv_minuser; /* VM_MIN_ADDRESS */ 116 vm_offset_t sv_maxuser; /* VM_MAXUSER_ADDRESS */ 117 vm_offset_t sv_usrstack; /* USRSTACK */ 118 vm_offset_t sv_psstrings; /* PS_STRINGS */ 119 int sv_stackprot; /* vm protection for stack */ 120 register_t *(*sv_copyout_strings)(struct image_params *); 121 void (*sv_setregs)(struct thread *, struct image_params *, 122 u_long); 123 void (*sv_fixlimit)(struct rlimit *, int); 124 u_long *sv_maxssiz; 125 u_int sv_flags; 126 void (*sv_set_syscall_retval)(struct thread *, int); 127 int (*sv_fetch_syscall_args)(struct thread *); 128 const char **sv_syscallnames; 129 vm_offset_t sv_timekeep_base; 130 vm_offset_t sv_shared_page_base; 131 vm_offset_t sv_shared_page_len; 132 vm_offset_t sv_sigcode_base; 133 void *sv_shared_page_obj; 134 void (*sv_schedtail)(struct thread *); 135 void (*sv_thread_detach)(struct thread *); 136 int (*sv_trap)(struct thread *); 137 u_long *sv_hwcap; /* Value passed in AT_HWCAP. */ 138 u_long *sv_hwcap2; /* Value passed in AT_HWCAP2. */ 139 }; 140 141 #define SV_ILP32 0x000100 /* 32-bit executable. */ 142 #define SV_LP64 0x000200 /* 64-bit executable. */ 143 #define SV_IA32 0x004000 /* Intel 32-bit executable. */ 144 #define SV_AOUT 0x008000 /* a.out executable. */ 145 #define SV_SHP 0x010000 /* Shared page. */ 146 #define SV_CAPSICUM 0x020000 /* Force cap_enter() on startup. */ 147 #define SV_TIMEKEEP 0x040000 /* Shared page timehands. */ 148 149 #define SV_ABI_MASK 0xff 150 #define SV_ABI_ERRNO(p, e) ((p)->p_sysent->sv_errsize <= 0 ? e : \ 151 ((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e])) 152 #define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x)) 153 #define SV_PROC_ABI(p) ((p)->p_sysent->sv_flags & SV_ABI_MASK) 154 #define SV_CURPROC_FLAG(x) SV_PROC_FLAG(curproc, x) 155 #define SV_CURPROC_ABI() SV_PROC_ABI(curproc) 156 /* same as ELFOSABI_XXX, to prevent header pollution */ 157 #define SV_ABI_LINUX 3 158 #define SV_ABI_FREEBSD 9 159 #define SV_ABI_CLOUDABI 17 160 #define SV_ABI_UNDEF 255 161 162 #ifdef _KERNEL 163 extern struct sysentvec aout_sysvec; 164 extern struct sysent sysent[]; 165 extern const char *syscallnames[]; 166 167 #if defined(__amd64__) 168 extern int i386_read_exec; 169 #endif 170 171 #define NO_SYSCALL (-1) 172 173 struct module; 174 175 struct syscall_module_data { 176 int (*chainevh)(struct module *, int, void *); /* next handler */ 177 void *chainarg; /* arg for next event handler */ 178 int *offset; /* offset into sysent */ 179 struct sysent *new_sysent; /* new sysent */ 180 struct sysent old_sysent; /* old sysent */ 181 int flags; /* flags for syscall_register */ 182 }; 183 184 /* separate initialization vector so it can be used in a substructure */ 185 #define SYSENT_INIT_VALS(_syscallname) { \ 186 .sy_narg = (sizeof(struct _syscallname ## _args ) \ 187 / sizeof(register_t)), \ 188 .sy_call = (sy_call_t *)&sys_##_syscallname, \ 189 .sy_auevent = SYS_AUE_##_syscallname, \ 190 .sy_systrace_args_func = NULL, \ 191 .sy_entry = 0, \ 192 .sy_return = 0, \ 193 .sy_flags = 0, \ 194 .sy_thrcnt = 0 \ 195 } 196 197 #define MAKE_SYSENT(syscallname) \ 198 static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname); 199 200 #define MAKE_SYSENT_COMPAT(syscallname) \ 201 static struct sysent syscallname##_sysent = { \ 202 (sizeof(struct syscallname ## _args ) \ 203 / sizeof(register_t)), \ 204 (sy_call_t *)& syscallname, \ 205 SYS_AUE_##syscallname \ 206 } 207 208 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg) \ 209 static struct syscall_module_data name##_syscall_mod = { \ 210 evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL } \ 211 }; \ 212 \ 213 static moduledata_t name##_mod = { \ 214 "sys/" #name, \ 215 syscall_module_handler, \ 216 &name##_syscall_mod \ 217 }; \ 218 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE) 219 220 #define SYSCALL_MODULE_HELPER(syscallname) \ 221 static int syscallname##_syscall = SYS_##syscallname; \ 222 MAKE_SYSENT(syscallname); \ 223 SYSCALL_MODULE(syscallname, \ 224 & syscallname##_syscall, & syscallname##_sysent, \ 225 NULL, NULL) 226 227 #define SYSCALL_MODULE_PRESENT(syscallname) \ 228 (sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys && \ 229 sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys) 230 231 /* 232 * Syscall registration helpers with resource allocation handling. 233 */ 234 struct syscall_helper_data { 235 struct sysent new_sysent; 236 struct sysent old_sysent; 237 int syscall_no; 238 int registered; 239 }; 240 #define SYSCALL_INIT_HELPER_F(syscallname, flags) { \ 241 .new_sysent = { \ 242 .sy_narg = (sizeof(struct syscallname ## _args ) \ 243 / sizeof(register_t)), \ 244 .sy_call = (sy_call_t *)& sys_ ## syscallname, \ 245 .sy_auevent = SYS_AUE_##syscallname, \ 246 .sy_flags = (flags) \ 247 }, \ 248 .syscall_no = SYS_##syscallname \ 249 } 250 #define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) { \ 251 .new_sysent = { \ 252 .sy_narg = (sizeof(struct syscallname ## _args ) \ 253 / sizeof(register_t)), \ 254 .sy_call = (sy_call_t *)& syscallname, \ 255 .sy_auevent = SYS_AUE_##syscallname, \ 256 .sy_flags = (flags) \ 257 }, \ 258 .syscall_no = SYS_##syscallname \ 259 } 260 #define SYSCALL_INIT_HELPER(syscallname) \ 261 SYSCALL_INIT_HELPER_F(syscallname, 0) 262 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) \ 263 SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0) 264 #define SYSCALL_INIT_LAST { \ 265 .syscall_no = NO_SYSCALL \ 266 } 267 268 int syscall_module_handler(struct module *mod, int what, void *arg); 269 int syscall_helper_register(struct syscall_helper_data *sd, int flags); 270 int syscall_helper_unregister(struct syscall_helper_data *sd); 271 /* Implementation, exposed for COMPAT code */ 272 int kern_syscall_register(struct sysent *sysents, int *offset, 273 struct sysent *new_sysent, struct sysent *old_sysent, int flags); 274 int kern_syscall_deregister(struct sysent *sysents, int offset, 275 const struct sysent *old_sysent); 276 int kern_syscall_module_handler(struct sysent *sysents, 277 struct module *mod, int what, void *arg); 278 int kern_syscall_helper_register(struct sysent *sysents, 279 struct syscall_helper_data *sd, int flags); 280 int kern_syscall_helper_unregister(struct sysent *sysents, 281 struct syscall_helper_data *sd); 282 283 struct proc; 284 const char *syscallname(struct proc *p, u_int code); 285 286 /* Special purpose system call functions. */ 287 struct nosys_args; 288 289 int lkmnosys(struct thread *, struct nosys_args *); 290 int lkmressys(struct thread *, struct nosys_args *); 291 292 int _syscall_thread_enter(struct thread *td, struct sysent *se); 293 void _syscall_thread_exit(struct thread *td, struct sysent *se); 294 295 static inline int 296 syscall_thread_enter(struct thread *td, struct sysent *se) 297 { 298 299 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 300 return (0); 301 return (_syscall_thread_enter(td, se)); 302 } 303 304 static inline void 305 syscall_thread_exit(struct thread *td, struct sysent *se) 306 { 307 308 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 309 return; 310 _syscall_thread_exit(td, se); 311 } 312 313 int shared_page_alloc(int size, int align); 314 int shared_page_fill(int size, int align, const void *data); 315 void shared_page_write(int base, int size, const void *data); 316 void exec_sysvec_init(void *param); 317 void exec_inittk(void); 318 319 #define INIT_SYSENTVEC(name, sv) \ 320 SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \ 321 (sysinit_cfunc_t)exec_sysvec_init, sv); 322 323 #endif /* _KERNEL */ 324 325 #endif /* !_SYS_SYSENT_H_ */ 326