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 systrace_probe_func_t systrace_probe_func; 58 extern bool systrace_enabled; 59 60 #ifdef KDTRACE_HOOKS 61 #define SYSTRACE_ENABLED() (systrace_enabled) 62 #else 63 #define SYSTRACE_ENABLED() (0) 64 #endif 65 #endif /* _KERNEL */ 66 67 struct sysent { /* system call table */ 68 int sy_narg; /* number of arguments */ 69 sy_call_t *sy_call; /* implementing function */ 70 au_event_t sy_auevent; /* audit event associated with syscall */ 71 systrace_args_func_t sy_systrace_args_func; 72 /* optional argument conversion function. */ 73 u_int32_t sy_entry; /* DTrace entry ID for systrace. */ 74 u_int32_t sy_return; /* DTrace return ID for systrace. */ 75 u_int32_t sy_flags; /* General flags for system calls. */ 76 u_int32_t sy_thrcnt; 77 }; 78 79 /* 80 * A system call is permitted in capability mode. 81 */ 82 #define SYF_CAPENABLED 0x00000001 83 84 #define SY_THR_FLAGMASK 0x7 85 #define SY_THR_STATIC 0x1 86 #define SY_THR_DRAINING 0x2 87 #define SY_THR_ABSENT 0x4 88 #define SY_THR_INCR 0x8 89 90 #ifdef KLD_MODULE 91 #define SY_THR_STATIC_KLD 0 92 #else 93 #define SY_THR_STATIC_KLD SY_THR_STATIC 94 #endif 95 96 struct image_params; 97 struct __sigset; 98 struct trapframe; 99 struct vnode; 100 101 struct sysentvec { 102 int sv_size; /* number of entries */ 103 struct sysent *sv_table; /* pointer to sysent */ 104 int sv_errsize; /* size of errno translation table */ 105 const int *sv_errtbl; /* errno translation table */ 106 int (*sv_transtrap)(int, int); 107 /* translate trap-to-signal mapping */ 108 int (*sv_fixup)(uintptr_t *, struct image_params *); 109 /* stack fixup function */ 110 void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *); 111 /* send signal */ 112 char *sv_sigcode; /* start of sigtramp code */ 113 int *sv_szsigcode; /* size of sigtramp code */ 114 char *sv_name; /* name of binary type */ 115 int (*sv_coredump)(struct thread *, struct vnode *, off_t, int); 116 /* function to dump core, or NULL */ 117 int (*sv_imgact_try)(struct image_params *); 118 void (*sv_stackgap)(struct image_params *, uintptr_t *); 119 int (*sv_copyout_auxargs)(struct image_params *, 120 uintptr_t); 121 int sv_minsigstksz; /* minimum signal stack size */ 122 vm_offset_t sv_minuser; /* VM_MIN_ADDRESS */ 123 vm_offset_t sv_maxuser; /* VM_MAXUSER_ADDRESS */ 124 vm_offset_t sv_usrstack; /* USRSTACK */ 125 vm_offset_t sv_psstrings; /* PS_STRINGS */ 126 int sv_stackprot; /* vm protection for stack */ 127 int (*sv_copyout_strings)(struct image_params *, 128 uintptr_t *); 129 void (*sv_setregs)(struct thread *, struct image_params *, 130 uintptr_t); 131 void (*sv_fixlimit)(struct rlimit *, int); 132 u_long *sv_maxssiz; 133 u_int sv_flags; 134 void (*sv_set_syscall_retval)(struct thread *, int); 135 int (*sv_fetch_syscall_args)(struct thread *); 136 const char **sv_syscallnames; 137 vm_offset_t sv_timekeep_base; 138 vm_offset_t sv_shared_page_base; 139 vm_offset_t sv_shared_page_len; 140 vm_offset_t sv_sigcode_base; 141 void *sv_shared_page_obj; 142 void (*sv_schedtail)(struct thread *); 143 void (*sv_thread_detach)(struct thread *); 144 int (*sv_trap)(struct thread *); 145 u_long *sv_hwcap; /* Value passed in AT_HWCAP. */ 146 u_long *sv_hwcap2; /* Value passed in AT_HWCAP2. */ 147 }; 148 149 #define SV_ILP32 0x000100 /* 32-bit executable. */ 150 #define SV_LP64 0x000200 /* 64-bit executable. */ 151 #define SV_IA32 0x004000 /* Intel 32-bit executable. */ 152 #define SV_AOUT 0x008000 /* a.out executable. */ 153 #define SV_SHP 0x010000 /* Shared page. */ 154 #define SV_CAPSICUM 0x020000 /* Force cap_enter() on startup. */ 155 #define SV_TIMEKEEP 0x040000 /* Shared page timehands. */ 156 #define SV_ASLR 0x080000 /* ASLR allowed. */ 157 158 #define SV_ABI_MASK 0xff 159 #define SV_ABI_ERRNO(p, e) ((p)->p_sysent->sv_errsize <= 0 ? e : \ 160 ((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e])) 161 #define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x)) 162 #define SV_PROC_ABI(p) ((p)->p_sysent->sv_flags & SV_ABI_MASK) 163 #define SV_CURPROC_FLAG(x) SV_PROC_FLAG(curproc, x) 164 #define SV_CURPROC_ABI() SV_PROC_ABI(curproc) 165 /* same as ELFOSABI_XXX, to prevent header pollution */ 166 #define SV_ABI_LINUX 3 167 #define SV_ABI_FREEBSD 9 168 #define SV_ABI_CLOUDABI 17 169 #define SV_ABI_UNDEF 255 170 171 #ifdef _KERNEL 172 extern struct sysentvec aout_sysvec; 173 extern struct sysent sysent[]; 174 extern const char *syscallnames[]; 175 176 #define NO_SYSCALL (-1) 177 178 struct module; 179 180 struct syscall_module_data { 181 int (*chainevh)(struct module *, int, void *); /* next handler */ 182 void *chainarg; /* arg for next event handler */ 183 int *offset; /* offset into sysent */ 184 struct sysent *new_sysent; /* new sysent */ 185 struct sysent old_sysent; /* old sysent */ 186 int flags; /* flags for syscall_register */ 187 }; 188 189 /* separate initialization vector so it can be used in a substructure */ 190 #define SYSENT_INIT_VALS(_syscallname) { \ 191 .sy_narg = (sizeof(struct _syscallname ## _args ) \ 192 / sizeof(register_t)), \ 193 .sy_call = (sy_call_t *)&sys_##_syscallname, \ 194 .sy_auevent = SYS_AUE_##_syscallname, \ 195 .sy_systrace_args_func = NULL, \ 196 .sy_entry = 0, \ 197 .sy_return = 0, \ 198 .sy_flags = 0, \ 199 .sy_thrcnt = 0 \ 200 } 201 202 #define MAKE_SYSENT(syscallname) \ 203 static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname); 204 205 #define MAKE_SYSENT_COMPAT(syscallname) \ 206 static struct sysent syscallname##_sysent = { \ 207 (sizeof(struct syscallname ## _args ) \ 208 / sizeof(register_t)), \ 209 (sy_call_t *)& syscallname, \ 210 SYS_AUE_##syscallname \ 211 } 212 213 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg) \ 214 static struct syscall_module_data name##_syscall_mod = { \ 215 evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL } \ 216 }; \ 217 \ 218 static moduledata_t name##_mod = { \ 219 "sys/" #name, \ 220 syscall_module_handler, \ 221 &name##_syscall_mod \ 222 }; \ 223 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE) 224 225 #define SYSCALL_MODULE_HELPER(syscallname) \ 226 static int syscallname##_syscall = SYS_##syscallname; \ 227 MAKE_SYSENT(syscallname); \ 228 SYSCALL_MODULE(syscallname, \ 229 & syscallname##_syscall, & syscallname##_sysent, \ 230 NULL, NULL) 231 232 #define SYSCALL_MODULE_PRESENT(syscallname) \ 233 (sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys && \ 234 sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys) 235 236 /* 237 * Syscall registration helpers with resource allocation handling. 238 */ 239 struct syscall_helper_data { 240 struct sysent new_sysent; 241 struct sysent old_sysent; 242 int syscall_no; 243 int registered; 244 }; 245 #define SYSCALL_INIT_HELPER_F(syscallname, flags) { \ 246 .new_sysent = { \ 247 .sy_narg = (sizeof(struct syscallname ## _args ) \ 248 / sizeof(register_t)), \ 249 .sy_call = (sy_call_t *)& sys_ ## syscallname, \ 250 .sy_auevent = SYS_AUE_##syscallname, \ 251 .sy_flags = (flags) \ 252 }, \ 253 .syscall_no = SYS_##syscallname \ 254 } 255 #define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) { \ 256 .new_sysent = { \ 257 .sy_narg = (sizeof(struct syscallname ## _args ) \ 258 / sizeof(register_t)), \ 259 .sy_call = (sy_call_t *)& syscallname, \ 260 .sy_auevent = SYS_AUE_##syscallname, \ 261 .sy_flags = (flags) \ 262 }, \ 263 .syscall_no = SYS_##syscallname \ 264 } 265 #define SYSCALL_INIT_HELPER(syscallname) \ 266 SYSCALL_INIT_HELPER_F(syscallname, 0) 267 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) \ 268 SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0) 269 #define SYSCALL_INIT_LAST { \ 270 .syscall_no = NO_SYSCALL \ 271 } 272 273 int syscall_module_handler(struct module *mod, int what, void *arg); 274 int syscall_helper_register(struct syscall_helper_data *sd, int flags); 275 int syscall_helper_unregister(struct syscall_helper_data *sd); 276 /* Implementation, exposed for COMPAT code */ 277 int kern_syscall_register(struct sysent *sysents, int *offset, 278 struct sysent *new_sysent, struct sysent *old_sysent, int flags); 279 int kern_syscall_deregister(struct sysent *sysents, int offset, 280 const struct sysent *old_sysent); 281 int kern_syscall_module_handler(struct sysent *sysents, 282 struct module *mod, int what, void *arg); 283 int kern_syscall_helper_register(struct sysent *sysents, 284 struct syscall_helper_data *sd, int flags); 285 int kern_syscall_helper_unregister(struct sysent *sysents, 286 struct syscall_helper_data *sd); 287 288 struct proc; 289 const char *syscallname(struct proc *p, u_int code); 290 291 /* Special purpose system call functions. */ 292 struct nosys_args; 293 294 int lkmnosys(struct thread *, struct nosys_args *); 295 int lkmressys(struct thread *, struct nosys_args *); 296 297 int _syscall_thread_enter(struct thread *td, struct sysent *se); 298 void _syscall_thread_exit(struct thread *td, struct sysent *se); 299 300 static inline int 301 syscall_thread_enter(struct thread *td, struct sysent *se) 302 { 303 304 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 305 return (0); 306 return (_syscall_thread_enter(td, se)); 307 } 308 309 static inline void 310 syscall_thread_exit(struct thread *td, struct sysent *se) 311 { 312 313 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 314 return; 315 _syscall_thread_exit(td, se); 316 } 317 318 int shared_page_alloc(int size, int align); 319 int shared_page_fill(int size, int align, const void *data); 320 void shared_page_write(int base, int size, const void *data); 321 void exec_sysvec_init(void *param); 322 void exec_inittk(void); 323 324 #define INIT_SYSENTVEC(name, sv) \ 325 SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \ 326 (sysinit_cfunc_t)exec_sysvec_init, sv); 327 328 #endif /* _KERNEL */ 329 330 #endif /* !_SYS_SYSENT_H_ */ 331