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_transtrap)(int, int); 106 /* translate trap-to-signal mapping */ 107 int (*sv_fixup)(uintptr_t *, struct image_params *); 108 /* stack fixup function */ 109 void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *); 110 /* send signal */ 111 char *sv_sigcode; /* start of sigtramp code */ 112 int *sv_szsigcode; /* size of sigtramp code */ 113 char *sv_name; /* name of binary type */ 114 int (*sv_coredump)(struct thread *, struct vnode *, off_t, int); 115 /* function to dump core, or NULL */ 116 int (*sv_imgact_try)(struct image_params *); 117 void (*sv_stackgap)(struct image_params *, uintptr_t *); 118 int (*sv_copyout_auxargs)(struct image_params *, 119 uintptr_t); 120 int sv_minsigstksz; /* minimum signal stack size */ 121 vm_offset_t sv_minuser; /* VM_MIN_ADDRESS */ 122 vm_offset_t sv_maxuser; /* VM_MAXUSER_ADDRESS */ 123 vm_offset_t sv_usrstack; /* USRSTACK */ 124 vm_offset_t sv_psstrings; /* PS_STRINGS */ 125 int sv_stackprot; /* vm protection for stack */ 126 int (*sv_copyout_strings)(struct image_params *, 127 uintptr_t *); 128 void (*sv_setregs)(struct thread *, struct image_params *, 129 uintptr_t); 130 void (*sv_fixlimit)(struct rlimit *, int); 131 u_long *sv_maxssiz; 132 u_int sv_flags; 133 void (*sv_set_syscall_retval)(struct thread *, int); 134 int (*sv_fetch_syscall_args)(struct thread *); 135 const char **sv_syscallnames; 136 vm_offset_t sv_timekeep_base; 137 vm_offset_t sv_shared_page_base; 138 vm_offset_t sv_shared_page_len; 139 vm_offset_t sv_sigcode_base; 140 void *sv_shared_page_obj; 141 void (*sv_schedtail)(struct thread *); 142 void (*sv_thread_detach)(struct thread *); 143 int (*sv_trap)(struct thread *); 144 u_long *sv_hwcap; /* Value passed in AT_HWCAP. */ 145 u_long *sv_hwcap2; /* Value passed in AT_HWCAP2. */ 146 const char *(*sv_machine_arch)(struct proc *); 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_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x)) 160 #define SV_PROC_ABI(p) ((p)->p_sysent->sv_flags & SV_ABI_MASK) 161 #define SV_CURPROC_FLAG(x) SV_PROC_FLAG(curproc, x) 162 #define SV_CURPROC_ABI() SV_PROC_ABI(curproc) 163 /* same as ELFOSABI_XXX, to prevent header pollution */ 164 #define SV_ABI_LINUX 3 165 #define SV_ABI_FREEBSD 9 166 #define SV_ABI_CLOUDABI 17 167 #define SV_ABI_UNDEF 255 168 169 #ifdef _KERNEL 170 extern struct sysentvec aout_sysvec; 171 extern struct sysent sysent[]; 172 extern const char *syscallnames[]; 173 174 #define NO_SYSCALL (-1) 175 176 struct module; 177 178 struct syscall_module_data { 179 int (*chainevh)(struct module *, int, void *); /* next handler */ 180 void *chainarg; /* arg for next event handler */ 181 int *offset; /* offset into sysent */ 182 struct sysent *new_sysent; /* new sysent */ 183 struct sysent old_sysent; /* old sysent */ 184 int flags; /* flags for syscall_register */ 185 }; 186 187 /* separate initialization vector so it can be used in a substructure */ 188 #define SYSENT_INIT_VALS(_syscallname) { \ 189 .sy_narg = (sizeof(struct _syscallname ## _args ) \ 190 / sizeof(register_t)), \ 191 .sy_call = (sy_call_t *)&sys_##_syscallname, \ 192 .sy_auevent = SYS_AUE_##_syscallname, \ 193 .sy_systrace_args_func = NULL, \ 194 .sy_entry = 0, \ 195 .sy_return = 0, \ 196 .sy_flags = 0, \ 197 .sy_thrcnt = 0 \ 198 } 199 200 #define MAKE_SYSENT(syscallname) \ 201 static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname); 202 203 #define MAKE_SYSENT_COMPAT(syscallname) \ 204 static struct sysent syscallname##_sysent = { \ 205 (sizeof(struct syscallname ## _args ) \ 206 / sizeof(register_t)), \ 207 (sy_call_t *)& syscallname, \ 208 SYS_AUE_##syscallname \ 209 } 210 211 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg) \ 212 static struct syscall_module_data name##_syscall_mod = { \ 213 evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL } \ 214 }; \ 215 \ 216 static moduledata_t name##_mod = { \ 217 "sys/" #name, \ 218 syscall_module_handler, \ 219 &name##_syscall_mod \ 220 }; \ 221 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE) 222 223 #define SYSCALL_MODULE_HELPER(syscallname) \ 224 static int syscallname##_syscall = SYS_##syscallname; \ 225 MAKE_SYSENT(syscallname); \ 226 SYSCALL_MODULE(syscallname, \ 227 & syscallname##_syscall, & syscallname##_sysent, \ 228 NULL, NULL) 229 230 #define SYSCALL_MODULE_PRESENT(syscallname) \ 231 (sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys && \ 232 sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys) 233 234 /* 235 * Syscall registration helpers with resource allocation handling. 236 */ 237 struct syscall_helper_data { 238 struct sysent new_sysent; 239 struct sysent old_sysent; 240 int syscall_no; 241 int registered; 242 }; 243 #define SYSCALL_INIT_HELPER_F(syscallname, flags) { \ 244 .new_sysent = { \ 245 .sy_narg = (sizeof(struct syscallname ## _args ) \ 246 / sizeof(register_t)), \ 247 .sy_call = (sy_call_t *)& sys_ ## syscallname, \ 248 .sy_auevent = SYS_AUE_##syscallname, \ 249 .sy_flags = (flags) \ 250 }, \ 251 .syscall_no = SYS_##syscallname \ 252 } 253 #define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) { \ 254 .new_sysent = { \ 255 .sy_narg = (sizeof(struct syscallname ## _args ) \ 256 / sizeof(register_t)), \ 257 .sy_call = (sy_call_t *)& syscallname, \ 258 .sy_auevent = SYS_AUE_##syscallname, \ 259 .sy_flags = (flags) \ 260 }, \ 261 .syscall_no = SYS_##syscallname \ 262 } 263 #define SYSCALL_INIT_HELPER(syscallname) \ 264 SYSCALL_INIT_HELPER_F(syscallname, 0) 265 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) \ 266 SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0) 267 #define SYSCALL_INIT_LAST { \ 268 .syscall_no = NO_SYSCALL \ 269 } 270 271 int syscall_module_handler(struct module *mod, int what, void *arg); 272 int syscall_helper_register(struct syscall_helper_data *sd, int flags); 273 int syscall_helper_unregister(struct syscall_helper_data *sd); 274 /* Implementation, exposed for COMPAT code */ 275 int kern_syscall_register(struct sysent *sysents, int *offset, 276 struct sysent *new_sysent, struct sysent *old_sysent, int flags); 277 int kern_syscall_deregister(struct sysent *sysents, int offset, 278 const struct sysent *old_sysent); 279 int kern_syscall_module_handler(struct sysent *sysents, 280 struct module *mod, int what, void *arg); 281 int kern_syscall_helper_register(struct sysent *sysents, 282 struct syscall_helper_data *sd, int flags); 283 int kern_syscall_helper_unregister(struct sysent *sysents, 284 struct syscall_helper_data *sd); 285 286 struct proc; 287 const char *syscallname(struct proc *p, u_int code); 288 289 /* Special purpose system call functions. */ 290 struct nosys_args; 291 292 int lkmnosys(struct thread *, struct nosys_args *); 293 int lkmressys(struct thread *, struct nosys_args *); 294 295 int _syscall_thread_enter(struct thread *td, struct sysent *se); 296 void _syscall_thread_exit(struct thread *td, struct sysent *se); 297 298 static inline int 299 syscall_thread_enter(struct thread *td, struct sysent *se) 300 { 301 302 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 303 return (0); 304 return (_syscall_thread_enter(td, se)); 305 } 306 307 static inline void 308 syscall_thread_exit(struct thread *td, struct sysent *se) 309 { 310 311 if (__predict_true((se->sy_thrcnt & SY_THR_STATIC) != 0)) 312 return; 313 _syscall_thread_exit(td, se); 314 } 315 316 int shared_page_alloc(int size, int align); 317 int shared_page_fill(int size, int align, const void *data); 318 void shared_page_write(int base, int size, const void *data); 319 void exec_sysvec_init(void *param); 320 void exec_sysvec_init_secondary(struct sysentvec *sv, struct sysentvec *sv2); 321 void exec_inittk(void); 322 323 #define INIT_SYSENTVEC(name, sv) \ 324 SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \ 325 (sysinit_cfunc_t)exec_sysvec_init, sv); 326 327 #endif /* _KERNEL */ 328 329 #endif /* !_SYS_SYSENT_H_ */ 330