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 proc; 98 struct __sigset; 99 struct trapframe; 100 struct vnode; 101 102 struct sysentvec { 103 int sv_size; /* number of entries */ 104 struct sysent *sv_table; /* pointer to sysent */ 105 int sv_errsize; /* size of errno translation table */ 106 const int *sv_errtbl; /* errno translation table */ 107 int (*sv_transtrap)(int, int); 108 /* translate trap-to-signal mapping */ 109 int (*sv_fixup)(uintptr_t *, struct image_params *); 110 /* stack fixup function */ 111 void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *); 112 /* send signal */ 113 char *sv_sigcode; /* start of sigtramp code */ 114 int *sv_szsigcode; /* size of sigtramp code */ 115 char *sv_name; /* name of binary type */ 116 int (*sv_coredump)(struct thread *, struct vnode *, off_t, int); 117 /* function to dump core, or NULL */ 118 int (*sv_imgact_try)(struct image_params *); 119 void (*sv_stackgap)(struct image_params *, uintptr_t *); 120 int (*sv_copyout_auxargs)(struct image_params *, 121 uintptr_t); 122 int sv_minsigstksz; /* minimum signal stack size */ 123 vm_offset_t sv_minuser; /* VM_MIN_ADDRESS */ 124 vm_offset_t sv_maxuser; /* VM_MAXUSER_ADDRESS */ 125 vm_offset_t sv_usrstack; /* USRSTACK */ 126 vm_offset_t sv_psstrings; /* PS_STRINGS */ 127 int sv_stackprot; /* vm protection for stack */ 128 int (*sv_copyout_strings)(struct image_params *, 129 uintptr_t *); 130 void (*sv_setregs)(struct thread *, struct image_params *, 131 uintptr_t); 132 void (*sv_fixlimit)(struct rlimit *, int); 133 u_long *sv_maxssiz; 134 u_int sv_flags; 135 void (*sv_set_syscall_retval)(struct thread *, int); 136 int (*sv_fetch_syscall_args)(struct thread *); 137 const char **sv_syscallnames; 138 vm_offset_t sv_timekeep_base; 139 vm_offset_t sv_shared_page_base; 140 vm_offset_t sv_shared_page_len; 141 vm_offset_t sv_sigcode_base; 142 void *sv_shared_page_obj; 143 void (*sv_schedtail)(struct thread *); 144 void (*sv_thread_detach)(struct thread *); 145 int (*sv_trap)(struct thread *); 146 u_long *sv_hwcap; /* Value passed in AT_HWCAP. */ 147 u_long *sv_hwcap2; /* Value passed in AT_HWCAP2. */ 148 const char *(*sv_machine_arch)(struct proc *); 149 }; 150 151 #define SV_ILP32 0x000100 /* 32-bit executable. */ 152 #define SV_LP64 0x000200 /* 64-bit executable. */ 153 #define SV_IA32 0x004000 /* Intel 32-bit executable. */ 154 #define SV_AOUT 0x008000 /* a.out executable. */ 155 #define SV_SHP 0x010000 /* Shared page. */ 156 #define SV_CAPSICUM 0x020000 /* Force cap_enter() on startup. */ 157 #define SV_TIMEKEEP 0x040000 /* Shared page timehands. */ 158 #define SV_ASLR 0x080000 /* ASLR allowed. */ 159 160 #define SV_ABI_MASK 0xff 161 #define SV_ABI_ERRNO(p, e) ((p)->p_sysent->sv_errsize <= 0 ? e : \ 162 ((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e])) 163 #define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x)) 164 #define SV_PROC_ABI(p) ((p)->p_sysent->sv_flags & SV_ABI_MASK) 165 #define SV_CURPROC_FLAG(x) SV_PROC_FLAG(curproc, x) 166 #define SV_CURPROC_ABI() SV_PROC_ABI(curproc) 167 /* same as ELFOSABI_XXX, to prevent header pollution */ 168 #define SV_ABI_LINUX 3 169 #define SV_ABI_FREEBSD 9 170 #define SV_ABI_CLOUDABI 17 171 #define SV_ABI_UNDEF 255 172 173 #ifdef _KERNEL 174 extern struct sysentvec aout_sysvec; 175 extern struct sysent sysent[]; 176 extern const char *syscallnames[]; 177 178 #define NO_SYSCALL (-1) 179 180 struct module; 181 182 struct syscall_module_data { 183 int (*chainevh)(struct module *, int, void *); /* next handler */ 184 void *chainarg; /* arg for next event handler */ 185 int *offset; /* offset into sysent */ 186 struct sysent *new_sysent; /* new sysent */ 187 struct sysent old_sysent; /* old sysent */ 188 int flags; /* flags for syscall_register */ 189 }; 190 191 /* separate initialization vector so it can be used in a substructure */ 192 #define SYSENT_INIT_VALS(_syscallname) { \ 193 .sy_narg = (sizeof(struct _syscallname ## _args ) \ 194 / sizeof(register_t)), \ 195 .sy_call = (sy_call_t *)&sys_##_syscallname, \ 196 .sy_auevent = SYS_AUE_##_syscallname, \ 197 .sy_systrace_args_func = NULL, \ 198 .sy_entry = 0, \ 199 .sy_return = 0, \ 200 .sy_flags = 0, \ 201 .sy_thrcnt = 0 \ 202 } 203 204 #define MAKE_SYSENT(syscallname) \ 205 static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname); 206 207 #define MAKE_SYSENT_COMPAT(syscallname) \ 208 static struct sysent syscallname##_sysent = { \ 209 (sizeof(struct syscallname ## _args ) \ 210 / sizeof(register_t)), \ 211 (sy_call_t *)& syscallname, \ 212 SYS_AUE_##syscallname \ 213 } 214 215 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg) \ 216 static struct syscall_module_data name##_syscall_mod = { \ 217 evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL } \ 218 }; \ 219 \ 220 static moduledata_t name##_mod = { \ 221 "sys/" #name, \ 222 syscall_module_handler, \ 223 &name##_syscall_mod \ 224 }; \ 225 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE) 226 227 #define SYSCALL_MODULE_HELPER(syscallname) \ 228 static int syscallname##_syscall = SYS_##syscallname; \ 229 MAKE_SYSENT(syscallname); \ 230 SYSCALL_MODULE(syscallname, \ 231 & syscallname##_syscall, & syscallname##_sysent, \ 232 NULL, NULL) 233 234 #define SYSCALL_MODULE_PRESENT(syscallname) \ 235 (sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys && \ 236 sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys) 237 238 /* 239 * Syscall registration helpers with resource allocation handling. 240 */ 241 struct syscall_helper_data { 242 struct sysent new_sysent; 243 struct sysent old_sysent; 244 int syscall_no; 245 int registered; 246 }; 247 #define SYSCALL_INIT_HELPER_F(syscallname, flags) { \ 248 .new_sysent = { \ 249 .sy_narg = (sizeof(struct syscallname ## _args ) \ 250 / sizeof(register_t)), \ 251 .sy_call = (sy_call_t *)& sys_ ## syscallname, \ 252 .sy_auevent = SYS_AUE_##syscallname, \ 253 .sy_flags = (flags) \ 254 }, \ 255 .syscall_no = SYS_##syscallname \ 256 } 257 #define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) { \ 258 .new_sysent = { \ 259 .sy_narg = (sizeof(struct syscallname ## _args ) \ 260 / sizeof(register_t)), \ 261 .sy_call = (sy_call_t *)& syscallname, \ 262 .sy_auevent = SYS_AUE_##syscallname, \ 263 .sy_flags = (flags) \ 264 }, \ 265 .syscall_no = SYS_##syscallname \ 266 } 267 #define SYSCALL_INIT_HELPER(syscallname) \ 268 SYSCALL_INIT_HELPER_F(syscallname, 0) 269 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) \ 270 SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0) 271 #define SYSCALL_INIT_LAST { \ 272 .syscall_no = NO_SYSCALL \ 273 } 274 275 int syscall_module_handler(struct module *mod, int what, void *arg); 276 int syscall_helper_register(struct syscall_helper_data *sd, int flags); 277 int syscall_helper_unregister(struct syscall_helper_data *sd); 278 /* Implementation, exposed for COMPAT code */ 279 int kern_syscall_register(struct sysent *sysents, int *offset, 280 struct sysent *new_sysent, struct sysent *old_sysent, int flags); 281 int kern_syscall_deregister(struct sysent *sysents, int offset, 282 const struct sysent *old_sysent); 283 int kern_syscall_module_handler(struct sysent *sysents, 284 struct module *mod, int what, void *arg); 285 int kern_syscall_helper_register(struct sysent *sysents, 286 struct syscall_helper_data *sd, int flags); 287 int kern_syscall_helper_unregister(struct sysent *sysents, 288 struct syscall_helper_data *sd); 289 290 struct proc; 291 const char *syscallname(struct proc *p, u_int code); 292 293 /* Special purpose system call functions. */ 294 struct nosys_args; 295 296 int lkmnosys(struct thread *, struct nosys_args *); 297 int lkmressys(struct thread *, struct nosys_args *); 298 299 int _syscall_thread_enter(struct thread *td, struct sysent *se); 300 void _syscall_thread_exit(struct thread *td, struct sysent *se); 301 302 static inline int 303 syscall_thread_enter(struct thread *td, struct sysent *se) 304 { 305 306 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 307 return (0); 308 return (_syscall_thread_enter(td, se)); 309 } 310 311 static inline void 312 syscall_thread_exit(struct thread *td, struct sysent *se) 313 { 314 315 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 316 return; 317 _syscall_thread_exit(td, se); 318 } 319 320 int shared_page_alloc(int size, int align); 321 int shared_page_fill(int size, int align, const void *data); 322 void shared_page_write(int base, int size, const void *data); 323 void exec_sysvec_init(void *param); 324 void exec_inittk(void); 325 326 #define INIT_SYSENTVEC(name, sv) \ 327 SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \ 328 (sysinit_cfunc_t)exec_sysvec_init, sv); 329 330 #endif /* _KERNEL */ 331 332 #endif /* !_SYS_SYSENT_H_ */ 333