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