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
32#ifndef _SYS_SYSENT_H_
33#define _SYS_SYSENT_H_
34
35#include <bsm/audit.h>
36
37struct rlimit;
38struct sysent;
39struct thread;
40struct ksiginfo;
41struct syscall_args;
42
43enum systrace_probe_t {
44 SYSTRACE_ENTRY,
45 SYSTRACE_RETURN,
46};
47
48typedef int sy_call_t(struct thread *, void *);
49
50typedef void (*systrace_probe_func_t)(struct syscall_args *,
51 enum systrace_probe_t, int);
52typedef void (*systrace_args_func_t)(int, void *, uint64_t *, int *);
53
54#ifdef _KERNEL
55extern systrace_probe_func_t systrace_probe_func;
56extern bool systrace_enabled;
57
58#ifdef KDTRACE_HOOKS
59#define SYSTRACE_ENABLED() (systrace_enabled)
60#else
61#define SYSTRACE_ENABLED() (0)
62#endif
63#endif /* _KERNEL */
64
65struct sysent { /* system call table */
66 sy_call_t *sy_call; /* implementing function */
67 systrace_args_func_t sy_systrace_args_func;
68 /* optional argument conversion function. */
69 u_int8_t sy_narg; /* number of arguments */
70 u_int8_t sy_flags; /* General flags for system calls. */
71 au_event_t sy_auevent; /* audit event associated with syscall */
72 u_int32_t sy_entry; /* DTrace entry ID for systrace. */
73 u_int32_t sy_return; /* DTrace return ID for systrace. */
74 u_int32_t sy_thrcnt;
75};
76
77/*
78 * A system call is permitted in capability mode.
79 */
80#define SYF_CAPENABLED 0x00000001
81
82#define SY_THR_STATIC 0x01
83#define SY_THR_DRAINING 0x02
84#define SY_THR_ABSENT 0x04
85#define SY_THR_INCR 0x08
86
87#ifdef KLD_MODULE
88#define SY_THR_STATIC_KLD 0
89#else
90#define SY_THR_STATIC_KLD SY_THR_STATIC
91#endif
92
93struct coredump_writer;
94struct image_params;
95struct proc;
96struct __sigset;
97struct trapframe;
98struct vnode;
99struct note_info_list;
100
101struct sysentvec {
102 int sv_size; /* number of entries */
103 struct sysent *sv_table; /* pointer to sysent */
104 int (*sv_fixup)(uintptr_t *, struct image_params *);
105 /* stack fixup function */
106 void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
107 /* send signal */
108 const char *sv_sigcode; /* start of sigtramp code */
109 int *sv_szsigcode; /* size of sigtramp code */
110 int sv_sigcodeoff;
111 char *sv_name; /* name of binary type */
112 int (*sv_coredump)(struct thread *, struct coredump_writer *,
113 off_t, int);
114 /* function to dump core, or NULL */
115 int sv_elf_core_osabi;
116 const char *sv_elf_core_abi_vendor;
117 void (*sv_elf_core_prepare_notes)(struct thread *,
118 struct note_info_list *, size_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 size_t sv_psstringssz; /* PS_STRINGS size */
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_offset;
139 vm_offset_t sv_shared_page_base;
140 vm_offset_t sv_shared_page_len;
141 vm_offset_t sv_sigcode_offset;
142 void *sv_shared_page_obj;
143 vm_offset_t sv_vdso_offset;
144 void (*sv_schedtail)(struct thread *);
145 void (*sv_thread_detach)(struct thread *);
146 int (*sv_trap)(struct thread *);
147 u_long *sv_hwcap; /* Value passed in AT_HWCAP. */
148 u_long *sv_hwcap2; /* Value passed in AT_HWCAP2. */
149 u_long *sv_hwcap3; /* Value passed in AT_HWCAP3. */
150 u_long *sv_hwcap4; /* Value passed in AT_HWCAP4. */
151 const char *(*sv_machine_arch)(struct proc *);
152 vm_offset_t sv_fxrng_gen_offset;
153 void (*sv_onexec_old)(struct thread *td);
154 int (*sv_onexec)(struct proc *, struct image_params *);
155 void (*sv_protect)(struct image_params *, int);
156 void (*sv_onexit)(struct proc *);
157 void (*sv_ontdexit)(struct thread *td);
158 int (*sv_setid_allowed)(struct thread *td,
159 struct image_params *imgp);
160 void (*sv_set_fork_retval)(struct thread *);
161 /* Only used on x86 */
162 struct regset **sv_regset_begin;
163 struct regset **sv_regset_end;
164};
165
166#define SV_ILP32 0x000100 /* 32-bit executable. */
167#define SV_LP64 0x000200 /* 64-bit executable. */
168#define SV_RESERVED0 0x004000 /* Formerly SV_IA32 */
169#define SV_AOUT 0x008000 /* a.out executable. */
170#define SV_SHP 0x010000 /* Shared page. */
171#define SV_SIGSYS 0x020000 /* SIGSYS for non-existing syscall */
172#define SV_TIMEKEEP 0x040000 /* Shared page timehands. */
173#define SV_ASLR 0x080000 /* ASLR allowed. */
174#define SV_RNG_SEED_VER 0x100000 /* random(4) reseed generation. */
175#define SV_SIG_DISCIGN 0x200000 /* Do not discard ignored signals */
176#define SV_SIG_WAITNDQ 0x400000 /* Wait does not dequeue SIGCHLD */
177#define SV_DSO_SIG 0x800000 /* Signal trampoline packed in dso */
178
179#define SV_ABI_MASK 0xff
180#define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x))
181#define SV_PROC_ABI(p) ((p)->p_sysent->sv_flags & SV_ABI_MASK)
182#define SV_CURPROC_FLAG(x) SV_PROC_FLAG(curproc, x)
183#define SV_CURPROC_ABI() SV_PROC_ABI(curproc)
184/* same as ELFOSABI_XXX, to prevent header pollution */
185#define SV_ABI_LINUX 3
186#define SV_ABI_FREEBSD 9
187#define SV_ABI_UNDEF 255
188
189/* sv_coredump flags */
190#define SVC_PT_COREDUMP 0x00000001 /* dump requested by ptrace(2) */
191#define SVC_NOCOMPRESS 0x00000002 /* disable compression. */
192#define SVC_ALL 0x00000004 /* dump everything */
193
194/* sv_protect flags */
195#define SVP_IMAGE 0x00000001
196#define SVP_INTERP 0x00000002
197
198#ifdef _KERNEL
199extern struct sysentvec aout_sysvec;
200extern struct sysent sysent[];
201extern const char *syscallnames[];
202extern struct sysent nosys_sysent;
203
204struct nosys_args {
205 register_t dummy;
206};
207
208int nosys(struct thread *, struct nosys_args *);
209
210#define NO_SYSCALL (-1)
211
212struct module;
213
214struct syscall_module_data {
215 int (*chainevh)(struct module *, int, void *); /* next handler */
216 void *chainarg; /* arg for next event handler */
217 int *offset; /* offset into sysent */
218 struct sysent *new_sysent; /* new sysent */
219 struct sysent old_sysent; /* old sysent */
220 int flags; /* flags for syscall_register */
221};
222
223/* separate initialization vector so it can be used in a substructure */
224#define SYSENT_INIT_VALS(_syscallname) { \
225 .sy_narg = (sizeof(struct _syscallname ## _args ) \
226 / sizeof(register_t)), \
227 .sy_call = (sy_call_t *)&sys_##_syscallname, \
228 .sy_auevent = SYS_AUE_##_syscallname, \
229 .sy_systrace_args_func = NULL, \
230 .sy_entry = 0, \
231 .sy_return = 0, \
232 .sy_flags = 0, \
233 .sy_thrcnt = 0 \
234}
235
236#define MAKE_SYSENT(syscallname) \
237static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname);
238
239#define MAKE_SYSENT_COMPAT(syscallname) \
240static struct sysent syscallname##_sysent = { \
241 (sizeof(struct syscallname ## _args ) \
242 / sizeof(register_t)), \
243 (sy_call_t *)& syscallname, \
244 SYS_AUE_##syscallname \
245}
246
247#define SYSCALL_MODULE(name, offset, new_sysent, evh, arg) \
248static struct syscall_module_data name##_syscall_mod = { \
249 evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL } \
250}; \
251 \
252static moduledata_t name##_mod = { \
253 "sys/" #name, \
254 syscall_module_handler, \
255 &name##_syscall_mod \
256}; \
257DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
258
259#define SYSCALL_MODULE_HELPER(syscallname) \
260static int syscallname##_syscall = SYS_##syscallname; \
261MAKE_SYSENT(syscallname); \
262SYSCALL_MODULE(syscallname, \
263 & syscallname##_syscall, & syscallname##_sysent, \
264 NULL, NULL)
265
266#define SYSCALL_MODULE_PRESENT(syscallname) \
267 (sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys && \
268 sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
269
270/*
271 * Syscall registration helpers with resource allocation handling.
272 */
273struct syscall_helper_data {
274 struct sysent new_sysent;
275 struct sysent old_sysent;
276 int syscall_no;
277 int registered;
278};
279#define SYSCALL_INIT_HELPER_F(syscallname, flags) { \
280 .new_sysent = { \
281 .sy_narg = (sizeof(struct syscallname ## _args ) \
282 / sizeof(register_t)), \
283 .sy_call = (sy_call_t *)& sys_ ## syscallname, \
284 .sy_auevent = SYS_AUE_##syscallname, \
285 .sy_flags = (flags) \
286 }, \
287 .syscall_no = SYS_##syscallname \
288}
289#define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) { \
290 .new_sysent = { \
291 .sy_narg = (sizeof(struct syscallname ## _args ) \
292 / sizeof(register_t)), \
293 .sy_call = (sy_call_t *)& syscallname, \
294 .sy_auevent = SYS_AUE_##syscallname, \
295 .sy_flags = (flags) \
296 }, \
297 .syscall_no = SYS_##syscallname \
298}
299#define SYSCALL_INIT_HELPER(syscallname) \
300 SYSCALL_INIT_HELPER_F(syscallname, 0)
301#define SYSCALL_INIT_HELPER_COMPAT(syscallname) \
302 SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0)
303#define SYSCALL_INIT_LAST { \
304 .syscall_no = NO_SYSCALL \
305}
306
307int syscall_module_handler(struct module *mod, int what, void *arg);
308int syscall_helper_register(struct syscall_helper_data *sd, int flags);
309int syscall_helper_unregister(struct syscall_helper_data *sd);
310/* Implementation, exposed for COMPAT code */
311int kern_syscall_register(struct sysent *sysents, int *offset,
312 struct sysent *new_sysent, struct sysent *old_sysent, int flags);
313int kern_syscall_deregister(struct sysent *sysents, int offset,
314 const struct sysent *old_sysent);
315int kern_syscall_module_handler(struct sysent *sysents,
316 struct module *mod, int what, void *arg);
317int kern_syscall_helper_register(struct sysent *sysents,
318 struct syscall_helper_data *sd, int flags);
319int kern_syscall_helper_unregister(struct sysent *sysents,
320 struct syscall_helper_data *sd);
321
322struct proc;
323const char *syscallname(struct proc *p, u_int code);
324
325/* Special purpose system call functions. */
326struct nosys_args;
327
328int lkmnosys(struct thread *, struct nosys_args *);
329int lkmressys(struct thread *, struct nosys_args *);
330
331int syscall_thread_enter(struct thread *td, struct sysent **se);
332void syscall_thread_exit(struct thread *td, struct sysent *se);
333
334int shared_page_alloc(int size, int align);
335int shared_page_fill(int size, int align, const void *data);
336void shared_page_write(int base, int size, const void *data);
337void exec_sysvec_init(void *param);
338void exec_sysvec_init_secondary(struct sysentvec *sv, struct sysentvec *sv2);
339void exec_inittk(void);
340
341void exit_onexit(struct proc *p);
342void exec_free_abi_mappings(struct proc *p);
343void exec_onexec_old(struct thread *td);
344
345#define INIT_SYSENTVEC(name, sv) \
346 SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \
347 (sysinit_cfunc_t)exec_sysvec_init, sv);
348
349#endif /* _KERNEL */
350
351#endif /* !_SYS_SYSENT_H_ */