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