xref: /freebsd/sys/sys/sysent.h (revision aa24f48b361effe51163877d84f1b70d32b77e04)
1 /*-
2  * Copyright (c) 1982, 1988, 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _SYS_SYSENT_H_
33 #define	_SYS_SYSENT_H_
34 
35 #include <bsm/audit.h>
36 
37 struct rlimit;
38 struct sysent;
39 struct thread;
40 struct ksiginfo;
41 struct syscall_args;
42 
43 enum systrace_probe_t {
44 	SYSTRACE_ENTRY,
45 	SYSTRACE_RETURN,
46 };
47 
48 typedef	int	sy_call_t(struct thread *, void *);
49 
50 typedef	void	(*systrace_probe_func_t)(struct syscall_args *,
51 		    enum systrace_probe_t, int);
52 typedef	void	(*systrace_args_func_t)(int, void *, uint64_t *, int *);
53 
54 extern systrace_probe_func_t	systrace_probe_func;
55 
56 struct sysent {			/* system call table */
57 	int	sy_narg;	/* number of arguments */
58 	sy_call_t *sy_call;	/* implementing function */
59 	au_event_t sy_auevent;	/* audit event associated with syscall */
60 	systrace_args_func_t sy_systrace_args_func;
61 				/* optional argument conversion function. */
62 	u_int32_t sy_entry;	/* DTrace entry ID for systrace. */
63 	u_int32_t sy_return;	/* DTrace return ID for systrace. */
64 	u_int32_t sy_flags;	/* General flags for system calls. */
65 	u_int32_t sy_thrcnt;
66 };
67 
68 /*
69  * A system call is permitted in capability mode.
70  */
71 #define	SYF_CAPENABLED	0x00000001
72 
73 #define	SY_THR_FLAGMASK	0x7
74 #define	SY_THR_STATIC	0x1
75 #define	SY_THR_DRAINING	0x2
76 #define	SY_THR_ABSENT	0x4
77 #define	SY_THR_INCR	0x8
78 
79 #ifdef KLD_MODULE
80 #define	SY_THR_STATIC_KLD	0
81 #else
82 #define	SY_THR_STATIC_KLD	SY_THR_STATIC
83 #endif
84 
85 struct image_params;
86 struct __sigset;
87 struct trapframe;
88 struct vnode;
89 
90 struct sysentvec {
91 	int		sv_size;	/* number of entries */
92 	struct sysent	*sv_table;	/* pointer to sysent */
93 	u_int		sv_mask;	/* optional mask to index */
94 	int		sv_errsize;	/* size of errno translation table */
95 	int 		*sv_errtbl;	/* errno translation table */
96 	int		(*sv_transtrap)(int, int);
97 					/* translate trap-to-signal mapping */
98 	int		(*sv_fixup)(register_t **, struct image_params *);
99 					/* stack fixup function */
100 	void		(*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
101 			    		/* send signal */
102 	char 		*sv_sigcode;	/* start of sigtramp code */
103 	int 		*sv_szsigcode;	/* size of sigtramp code */
104 	char		*sv_name;	/* name of binary type */
105 	int		(*sv_coredump)(struct thread *, struct vnode *, off_t, int);
106 					/* function to dump core, or NULL */
107 	int		(*sv_imgact_try)(struct image_params *);
108 	int		sv_minsigstksz;	/* minimum signal stack size */
109 	int		sv_pagesize;	/* pagesize */
110 	vm_offset_t	sv_minuser;	/* VM_MIN_ADDRESS */
111 	vm_offset_t	sv_maxuser;	/* VM_MAXUSER_ADDRESS */
112 	vm_offset_t	sv_usrstack;	/* USRSTACK */
113 	vm_offset_t	sv_psstrings;	/* PS_STRINGS */
114 	int		sv_stackprot;	/* vm protection for stack */
115 	register_t	*(*sv_copyout_strings)(struct image_params *);
116 	void		(*sv_setregs)(struct thread *, struct image_params *,
117 			    u_long);
118 	void		(*sv_fixlimit)(struct rlimit *, int);
119 	u_long		*sv_maxssiz;
120 	u_int		sv_flags;
121 	void		(*sv_set_syscall_retval)(struct thread *, int);
122 	int		(*sv_fetch_syscall_args)(struct thread *);
123 	const char	**sv_syscallnames;
124 	vm_offset_t	sv_timekeep_base;
125 	vm_offset_t	sv_shared_page_base;
126 	vm_offset_t	sv_shared_page_len;
127 	vm_offset_t	sv_sigcode_base;
128 	void		*sv_shared_page_obj;
129 	void		(*sv_schedtail)(struct thread *);
130 	void		(*sv_thread_detach)(struct thread *);
131 	int		(*sv_trap)(struct thread *);
132 };
133 
134 #define	SV_ILP32	0x000100	/* 32-bit executable. */
135 #define	SV_LP64		0x000200	/* 64-bit executable. */
136 #define	SV_IA32		0x004000	/* Intel 32-bit executable. */
137 #define	SV_AOUT		0x008000	/* a.out executable. */
138 #define	SV_SHP		0x010000	/* Shared page. */
139 #define	SV_CAPSICUM	0x020000	/* Force cap_enter() on startup. */
140 #define	SV_TIMEKEEP	0x040000	/* Shared page timehands. */
141 
142 #define	SV_ABI_MASK	0xff
143 #define	SV_ABI_ERRNO(p, e)	((p)->p_sysent->sv_errsize <= 0 ? e :	\
144 	((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e]))
145 #define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))
146 #define	SV_PROC_ABI(p)		((p)->p_sysent->sv_flags & SV_ABI_MASK)
147 #define	SV_CURPROC_FLAG(x)	SV_PROC_FLAG(curproc, x)
148 #define	SV_CURPROC_ABI()	SV_PROC_ABI(curproc)
149 /* same as ELFOSABI_XXX, to prevent header pollution */
150 #define	SV_ABI_LINUX	3
151 #define	SV_ABI_FREEBSD 	9
152 #define	SV_ABI_CLOUDABI	17
153 #define	SV_ABI_UNDEF	255
154 
155 #ifdef _KERNEL
156 extern struct sysentvec aout_sysvec;
157 extern struct sysent sysent[];
158 extern const char *syscallnames[];
159 
160 #if defined(__amd64__)
161 extern int i386_read_exec;
162 #endif
163 
164 #define	NO_SYSCALL (-1)
165 
166 struct module;
167 
168 struct syscall_module_data {
169 	int	(*chainevh)(struct module *, int, void *); /* next handler */
170 	void	*chainarg;		/* arg for next event handler */
171 	int	*offset;		/* offset into sysent */
172 	struct sysent *new_sysent;	/* new sysent */
173 	struct sysent old_sysent;	/* old sysent */
174 	int	flags;			/* flags for syscall_register */
175 };
176 
177 /* separate initialization vector so it can be used in a substructure */
178 #define SYSENT_INIT_VALS(_syscallname) {			\
179 	.sy_narg = (sizeof(struct _syscallname ## _args )	\
180 	    / sizeof(register_t)),				\
181 	.sy_call = (sy_call_t *)&sys_##_syscallname,		\
182 	.sy_auevent = SYS_AUE_##_syscallname,			\
183 	.sy_systrace_args_func = NULL,				\
184 	.sy_entry = 0,						\
185 	.sy_return = 0,						\
186 	.sy_flags = 0,						\
187 	.sy_thrcnt = 0						\
188 }
189 
190 #define	MAKE_SYSENT(syscallname)				\
191 static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname);
192 
193 #define	MAKE_SYSENT_COMPAT(syscallname)				\
194 static struct sysent syscallname##_sysent = {			\
195 	(sizeof(struct syscallname ## _args )			\
196 	    / sizeof(register_t)),				\
197 	(sy_call_t *)& syscallname,				\
198 	SYS_AUE_##syscallname					\
199 }
200 
201 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)	\
202 static struct syscall_module_data name##_syscall_mod = {	\
203 	evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }	\
204 };								\
205 								\
206 static moduledata_t name##_mod = {				\
207 	"sys/" #name,						\
208 	syscall_module_handler,					\
209 	&name##_syscall_mod					\
210 };								\
211 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
212 
213 #define	SYSCALL_MODULE_HELPER(syscallname)			\
214 static int syscallname##_syscall = SYS_##syscallname;		\
215 MAKE_SYSENT(syscallname);					\
216 SYSCALL_MODULE(syscallname,					\
217     & syscallname##_syscall, & syscallname##_sysent,		\
218     NULL, NULL)
219 
220 #define	SYSCALL_MODULE_PRESENT(syscallname)				\
221 	(sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys &&	\
222 	sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
223 
224 /*
225  * Syscall registration helpers with resource allocation handling.
226  */
227 struct syscall_helper_data {
228 	struct sysent new_sysent;
229 	struct sysent old_sysent;
230 	int syscall_no;
231 	int registered;
232 };
233 #define SYSCALL_INIT_HELPER(syscallname) {			\
234     .new_sysent = {						\
235 	.sy_narg = (sizeof(struct syscallname ## _args )	\
236 	    / sizeof(register_t)),				\
237 	.sy_call = (sy_call_t *)& sys_ ## syscallname,		\
238 	.sy_auevent = SYS_AUE_##syscallname			\
239     },								\
240     .syscall_no = SYS_##syscallname				\
241 }
242 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) {		\
243     .new_sysent = {						\
244 	.sy_narg = (sizeof(struct syscallname ## _args )	\
245 	    / sizeof(register_t)),				\
246 	.sy_call = (sy_call_t *)& syscallname,			\
247 	.sy_auevent = SYS_AUE_##syscallname			\
248     },								\
249     .syscall_no = SYS_##syscallname				\
250 }
251 #define SYSCALL_INIT_LAST {					\
252     .syscall_no = NO_SYSCALL					\
253 }
254 
255 int	syscall_register(int *offset, struct sysent *new_sysent,
256 	    struct sysent *old_sysent, int flags);
257 int	syscall_deregister(int *offset, struct sysent *old_sysent);
258 int	syscall_module_handler(struct module *mod, int what, void *arg);
259 int	syscall_helper_register(struct syscall_helper_data *sd, int flags);
260 int	syscall_helper_unregister(struct syscall_helper_data *sd);
261 
262 struct proc;
263 const char *syscallname(struct proc *p, u_int code);
264 
265 /* Special purpose system call functions. */
266 struct nosys_args;
267 
268 int	lkmnosys(struct thread *, struct nosys_args *);
269 int	lkmressys(struct thread *, struct nosys_args *);
270 
271 int	syscall_thread_enter(struct thread *td, struct sysent *se);
272 void	syscall_thread_exit(struct thread *td, struct sysent *se);
273 
274 int shared_page_alloc(int size, int align);
275 int shared_page_fill(int size, int align, const void *data);
276 void shared_page_write(int base, int size, const void *data);
277 void exec_sysvec_init(void *param);
278 void exec_inittk(void);
279 
280 #define INIT_SYSENTVEC(name, sv)					\
281     SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
282 	(sysinit_cfunc_t)exec_sysvec_init, sv);
283 
284 #endif /* _KERNEL */
285 
286 #endif /* !_SYS_SYSENT_H_ */
287