xref: /freebsd/sys/sys/sysent.h (revision a2aef24aa3c8458e4036735dd6928b4ef77294e5)
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 	u_long		*sv_hwcap;	/* Value passed in AT_HWCAP. */
133 	u_long		*sv_hwcap2;	/* Value passed in AT_HWCAP2. */
134 };
135 
136 #define	SV_ILP32	0x000100	/* 32-bit executable. */
137 #define	SV_LP64		0x000200	/* 64-bit executable. */
138 #define	SV_IA32		0x004000	/* Intel 32-bit executable. */
139 #define	SV_AOUT		0x008000	/* a.out executable. */
140 #define	SV_SHP		0x010000	/* Shared page. */
141 #define	SV_CAPSICUM	0x020000	/* Force cap_enter() on startup. */
142 #define	SV_TIMEKEEP	0x040000	/* Shared page timehands. */
143 
144 #define	SV_ABI_MASK	0xff
145 #define	SV_ABI_ERRNO(p, e)	((p)->p_sysent->sv_errsize <= 0 ? e :	\
146 	((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e]))
147 #define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))
148 #define	SV_PROC_ABI(p)		((p)->p_sysent->sv_flags & SV_ABI_MASK)
149 #define	SV_CURPROC_FLAG(x)	SV_PROC_FLAG(curproc, x)
150 #define	SV_CURPROC_ABI()	SV_PROC_ABI(curproc)
151 /* same as ELFOSABI_XXX, to prevent header pollution */
152 #define	SV_ABI_LINUX	3
153 #define	SV_ABI_FREEBSD 	9
154 #define	SV_ABI_CLOUDABI	17
155 #define	SV_ABI_UNDEF	255
156 
157 #ifdef _KERNEL
158 extern struct sysentvec aout_sysvec;
159 extern struct sysent sysent[];
160 extern const char *syscallnames[];
161 
162 #if defined(__amd64__)
163 extern int i386_read_exec;
164 #endif
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_register(int *offset, struct sysent *new_sysent,
264 	    struct sysent *old_sysent, int flags);
265 int	syscall_deregister(int *offset, struct sysent *old_sysent);
266 int	syscall_module_handler(struct module *mod, int what, void *arg);
267 int	syscall_helper_register(struct syscall_helper_data *sd, int flags);
268 int	syscall_helper_unregister(struct syscall_helper_data *sd);
269 
270 struct proc;
271 const char *syscallname(struct proc *p, u_int code);
272 
273 /* Special purpose system call functions. */
274 struct nosys_args;
275 
276 int	lkmnosys(struct thread *, struct nosys_args *);
277 int	lkmressys(struct thread *, struct nosys_args *);
278 
279 int	syscall_thread_enter(struct thread *td, struct sysent *se);
280 void	syscall_thread_exit(struct thread *td, struct sysent *se);
281 
282 int shared_page_alloc(int size, int align);
283 int shared_page_fill(int size, int align, const void *data);
284 void shared_page_write(int base, int size, const void *data);
285 void exec_sysvec_init(void *param);
286 void exec_inittk(void);
287 
288 #define INIT_SYSENTVEC(name, sv)					\
289     SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
290 	(sysinit_cfunc_t)exec_sysvec_init, sv);
291 
292 #endif /* _KERNEL */
293 
294 #endif /* !_SYS_SYSENT_H_ */
295