xref: /freebsd/sys/sys/sysent.h (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
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  * 4. 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 
42 typedef	int	sy_call_t(struct thread *, void *);
43 
44 /* Used by the machine dependent syscall() code. */
45 typedef	void (*systrace_probe_func_t)(u_int32_t, int, struct sysent *, void *,
46     int);
47 
48 /*
49  * Used by loaded syscalls to convert arguments to a DTrace array
50  * of 64-bit arguments.
51  */
52 typedef	void (*systrace_args_func_t)(int, void *, u_int64_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 syscall_args;
88 struct trapframe;
89 struct vnode;
90 
91 struct sysentvec {
92 	int		sv_size;	/* number of entries */
93 	struct sysent	*sv_table;	/* pointer to sysent */
94 	u_int		sv_mask;	/* optional mask to index */
95 	int		sv_sigsize;	/* size of signal translation table */
96 	int		*sv_sigtbl;	/* signal translation table */
97 	int		sv_errsize;	/* size of errno translation table */
98 	int 		*sv_errtbl;	/* errno translation table */
99 	int		(*sv_transtrap)(int, int);
100 					/* translate trap-to-signal mapping */
101 	int		(*sv_fixup)(register_t **, struct image_params *);
102 					/* stack fixup function */
103 	void		(*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
104 			    		/* send signal */
105 	char 		*sv_sigcode;	/* start of sigtramp code */
106 	int 		*sv_szsigcode;	/* size of sigtramp code */
107 	void		(*sv_prepsyscall)(struct trapframe *, int *, u_int *,
108 			    caddr_t *);
109 	char		*sv_name;	/* name of binary type */
110 	int		(*sv_coredump)(struct thread *, struct vnode *, off_t, int);
111 					/* function to dump core, or NULL */
112 	int		(*sv_imgact_try)(struct image_params *);
113 	int		sv_minsigstksz;	/* minimum signal stack size */
114 	int		sv_pagesize;	/* pagesize */
115 	vm_offset_t	sv_minuser;	/* VM_MIN_ADDRESS */
116 	vm_offset_t	sv_maxuser;	/* VM_MAXUSER_ADDRESS */
117 	vm_offset_t	sv_usrstack;	/* USRSTACK */
118 	vm_offset_t	sv_psstrings;	/* PS_STRINGS */
119 	int		sv_stackprot;	/* vm protection for stack */
120 	register_t	*(*sv_copyout_strings)(struct image_params *);
121 	void		(*sv_setregs)(struct thread *, struct image_params *,
122 			    u_long);
123 	void		(*sv_fixlimit)(struct rlimit *, int);
124 	u_long		*sv_maxssiz;
125 	u_int		sv_flags;
126 	void		(*sv_set_syscall_retval)(struct thread *, int);
127 	int		(*sv_fetch_syscall_args)(struct thread *, struct
128 			    syscall_args *);
129 	const char	**sv_syscallnames;
130 	vm_offset_t	sv_shared_page_base;
131 	vm_offset_t	sv_shared_page_len;
132 	vm_offset_t	sv_sigcode_base;
133 	vm_offset_t	sv_timekeep_base;
134 	int		sv_timekeep_off;
135 	int		sv_timekeep_curr;
136 	uint32_t	sv_timekeep_gen;
137 	void		*sv_shared_page_obj;
138 	void		(*sv_schedtail)(struct thread *);
139 	void		(*sv_thread_detach)(struct thread *);
140 };
141 
142 #define	SV_ILP32	0x000100	/* 32-bit executable. */
143 #define	SV_LP64		0x000200	/* 64-bit executable. */
144 #define	SV_IA32		0x004000	/* Intel 32-bit executable. */
145 #define	SV_AOUT		0x008000	/* a.out executable. */
146 #define	SV_SHP		0x010000	/* Shared page. */
147 #define	SV_CAPSICUM	0x020000	/* Force cap_enter() on startup. */
148 
149 #define	SV_ABI_MASK	0xff
150 #define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))
151 #define	SV_PROC_ABI(p)		((p)->p_sysent->sv_flags & SV_ABI_MASK)
152 #define	SV_CURPROC_FLAG(x)	SV_PROC_FLAG(curproc, x)
153 #define	SV_CURPROC_ABI()	SV_PROC_ABI(curproc)
154 /* same as ELFOSABI_XXX, to prevent header pollution */
155 #define	SV_ABI_LINUX	3
156 #define	SV_ABI_FREEBSD 	9
157 #define	SV_ABI_CLOUDABI	17
158 #define	SV_ABI_UNDEF	255
159 
160 #ifdef _KERNEL
161 extern struct sysentvec aout_sysvec;
162 extern struct sysentvec elf_freebsd_sysvec;
163 extern struct sysentvec null_sysvec;
164 extern struct sysent sysent[];
165 extern const char *syscallnames[];
166 
167 #if defined(__amd64__)
168 extern int i386_read_exec;
169 #endif
170 
171 #define	NO_SYSCALL (-1)
172 
173 struct module;
174 
175 struct syscall_module_data {
176 	int	(*chainevh)(struct module *, int, void *); /* next handler */
177 	void	*chainarg;		/* arg for next event handler */
178 	int	*offset;		/* offset into sysent */
179 	struct sysent *new_sysent;	/* new sysent */
180 	struct sysent old_sysent;	/* old sysent */
181 	int	flags;			/* flags for syscall_register */
182 };
183 
184 #define	MAKE_SYSENT(syscallname)				\
185 static struct sysent syscallname##_sysent = {			\
186 	(sizeof(struct syscallname ## _args )			\
187 	    / sizeof(register_t)),				\
188 	(sy_call_t *)& sys_##syscallname,	       		\
189 	SYS_AUE_##syscallname					\
190 }
191 
192 #define	MAKE_SYSENT_COMPAT(syscallname)				\
193 static struct sysent syscallname##_sysent = {			\
194 	(sizeof(struct syscallname ## _args )			\
195 	    / sizeof(register_t)),				\
196 	(sy_call_t *)& syscallname,				\
197 	SYS_AUE_##syscallname					\
198 }
199 
200 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)	\
201 static struct syscall_module_data name##_syscall_mod = {	\
202 	evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }	\
203 };								\
204 								\
205 static moduledata_t name##_mod = {				\
206 	"sys/" #name,						\
207 	syscall_module_handler,					\
208 	&name##_syscall_mod					\
209 };								\
210 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
211 
212 #define	SYSCALL_MODULE_HELPER(syscallname)			\
213 static int syscallname##_syscall = SYS_##syscallname;		\
214 MAKE_SYSENT(syscallname);					\
215 SYSCALL_MODULE(syscallname,					\
216     & syscallname##_syscall, & syscallname##_sysent,		\
217     NULL, NULL)
218 
219 #define	SYSCALL_MODULE_PRESENT(syscallname)				\
220 	(sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys &&	\
221 	sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
222 
223 /*
224  * Syscall registration helpers with resource allocation handling.
225  */
226 struct syscall_helper_data {
227 	struct sysent new_sysent;
228 	struct sysent old_sysent;
229 	int syscall_no;
230 	int registered;
231 };
232 #define SYSCALL_INIT_HELPER(syscallname) {			\
233     .new_sysent = {						\
234 	.sy_narg = (sizeof(struct syscallname ## _args )	\
235 	    / sizeof(register_t)),				\
236 	.sy_call = (sy_call_t *)& sys_ ## syscallname,		\
237 	.sy_auevent = SYS_AUE_##syscallname			\
238     },								\
239     .syscall_no = SYS_##syscallname				\
240 }
241 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) {		\
242     .new_sysent = {						\
243 	.sy_narg = (sizeof(struct syscallname ## _args )	\
244 	    / sizeof(register_t)),				\
245 	.sy_call = (sy_call_t *)& syscallname,			\
246 	.sy_auevent = SYS_AUE_##syscallname			\
247     },								\
248     .syscall_no = SYS_##syscallname				\
249 }
250 #define SYSCALL_INIT_LAST {					\
251     .syscall_no = NO_SYSCALL					\
252 }
253 
254 int	syscall_register(int *offset, struct sysent *new_sysent,
255 	    struct sysent *old_sysent, int flags);
256 int	syscall_deregister(int *offset, struct sysent *old_sysent);
257 int	syscall_module_handler(struct module *mod, int what, void *arg);
258 int	syscall_helper_register(struct syscall_helper_data *sd, int flags);
259 int	syscall_helper_unregister(struct syscall_helper_data *sd);
260 
261 struct proc;
262 const char *syscallname(struct proc *p, u_int code);
263 
264 /* Special purpose system call functions. */
265 struct nosys_args;
266 
267 int	lkmnosys(struct thread *, struct nosys_args *);
268 int	lkmressys(struct thread *, struct nosys_args *);
269 
270 int	syscall_thread_enter(struct thread *td, struct sysent *se);
271 void	syscall_thread_exit(struct thread *td, struct sysent *se);
272 
273 int shared_page_alloc(int size, int align);
274 int shared_page_fill(int size, int align, const void *data);
275 void shared_page_write(int base, int size, const void *data);
276 void exec_sysvec_init(void *param);
277 
278 #define INIT_SYSENTVEC(name, sv)					\
279     SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
280 	(sysinit_cfunc_t)exec_sysvec_init, sv);
281 
282 #endif /* _KERNEL */
283 
284 #endif /* !_SYS_SYSENT_H_ */
285