xref: /freebsd/sys/sys/sysent.h (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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 struct image_params;
80 struct __sigset;
81 struct syscall_args;
82 struct trapframe;
83 struct vnode;
84 
85 struct sysentvec {
86 	int		sv_size;	/* number of entries */
87 	struct sysent	*sv_table;	/* pointer to sysent */
88 	u_int		sv_mask;	/* optional mask to index */
89 	int		sv_sigsize;	/* size of signal translation table */
90 	int		*sv_sigtbl;	/* signal translation table */
91 	int		sv_errsize;	/* size of errno translation table */
92 	int 		*sv_errtbl;	/* errno translation table */
93 	int		(*sv_transtrap)(int, int);
94 					/* translate trap-to-signal mapping */
95 	int		(*sv_fixup)(register_t **, struct image_params *);
96 					/* stack fixup function */
97 	void		(*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
98 			    		/* send signal */
99 	char 		*sv_sigcode;	/* start of sigtramp code */
100 	int 		*sv_szsigcode;	/* size of sigtramp code */
101 	void		(*sv_prepsyscall)(struct trapframe *, int *, u_int *,
102 			    caddr_t *);
103 	char		*sv_name;	/* name of binary type */
104 	int		(*sv_coredump)(struct thread *, struct vnode *, off_t, int);
105 					/* function to dump core, or NULL */
106 	int		(*sv_imgact_try)(struct image_params *);
107 	int		sv_minsigstksz;	/* minimum signal stack size */
108 	int		sv_pagesize;	/* pagesize */
109 	vm_offset_t	sv_minuser;	/* VM_MIN_ADDRESS */
110 	vm_offset_t	sv_maxuser;	/* VM_MAXUSER_ADDRESS */
111 	vm_offset_t	sv_usrstack;	/* USRSTACK */
112 	vm_offset_t	sv_psstrings;	/* PS_STRINGS */
113 	int		sv_stackprot;	/* vm protection for stack */
114 	register_t	*(*sv_copyout_strings)(struct image_params *);
115 	void		(*sv_setregs)(struct thread *, struct image_params *,
116 			    u_long);
117 	void		(*sv_fixlimit)(struct rlimit *, int);
118 	u_long		*sv_maxssiz;
119 	u_int		sv_flags;
120 	void		(*sv_set_syscall_retval)(struct thread *, int);
121 	int		(*sv_fetch_syscall_args)(struct thread *, struct
122 			    syscall_args *);
123 	const char	**sv_syscallnames;
124 	vm_offset_t	sv_shared_page_base;
125 	vm_offset_t	sv_shared_page_len;
126 	vm_offset_t	sv_sigcode_base;
127 	vm_offset_t	sv_timekeep_base;
128 	int		sv_timekeep_off;
129 	int		sv_timekeep_curr;
130 	uint32_t	sv_timekeep_gen;
131 	void		*sv_shared_page_obj;
132 	void		(*sv_schedtail)(struct thread *);
133 };
134 
135 #define	SV_ILP32	0x000100
136 #define	SV_LP64		0x000200
137 #define	SV_IA32		0x004000
138 #define	SV_AOUT		0x008000
139 #define	SV_SHP		0x010000
140 
141 #define	SV_ABI_MASK	0xff
142 #define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))
143 #define	SV_PROC_ABI(p)		((p)->p_sysent->sv_flags & SV_ABI_MASK)
144 #define	SV_CURPROC_FLAG(x)	SV_PROC_FLAG(curproc, x)
145 #define	SV_CURPROC_ABI()	SV_PROC_ABI(curproc)
146 /* same as ELFOSABI_XXX, to prevent header pollution */
147 #define	SV_ABI_LINUX	3
148 #define	SV_ABI_FREEBSD 	9
149 #define	SV_ABI_UNDEF	255
150 
151 #ifdef _KERNEL
152 extern struct sysentvec aout_sysvec;
153 extern struct sysentvec elf_freebsd_sysvec;
154 extern struct sysentvec null_sysvec;
155 extern struct sysent sysent[];
156 extern const char *syscallnames[];
157 
158 #if defined(__amd64__) || defined(__ia64__)
159 extern int i386_read_exec;
160 #endif
161 
162 #define	NO_SYSCALL (-1)
163 
164 struct module;
165 
166 struct syscall_module_data {
167 	int	(*chainevh)(struct module *, int, void *); /* next handler */
168 	void	*chainarg;		/* arg for next event handler */
169 	int	*offset;		/* offset into sysent */
170 	struct sysent *new_sysent;	/* new sysent */
171 	struct sysent old_sysent;	/* old sysent */
172 };
173 
174 #define	MAKE_SYSENT(syscallname)				\
175 static struct sysent syscallname##_sysent = {			\
176 	(sizeof(struct syscallname ## _args )			\
177 	    / sizeof(register_t)),				\
178 	(sy_call_t *)& sys_##syscallname,	       		\
179 	SYS_AUE_##syscallname					\
180 }
181 
182 #define	MAKE_SYSENT_COMPAT(syscallname)				\
183 static struct sysent syscallname##_sysent = {			\
184 	(sizeof(struct syscallname ## _args )			\
185 	    / sizeof(register_t)),				\
186 	(sy_call_t *)& syscallname,				\
187 	SYS_AUE_##syscallname					\
188 }
189 
190 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)	\
191 static struct syscall_module_data name##_syscall_mod = {	\
192 	evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }	\
193 };								\
194 								\
195 static moduledata_t name##_mod = {				\
196 	"sys/" #name,						\
197 	syscall_module_handler,					\
198 	&name##_syscall_mod					\
199 };								\
200 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
201 
202 #define	SYSCALL_MODULE_HELPER(syscallname)			\
203 static int syscallname##_syscall = SYS_##syscallname;		\
204 MAKE_SYSENT(syscallname);					\
205 SYSCALL_MODULE(syscallname,					\
206     & syscallname##_syscall, & syscallname##_sysent,		\
207     NULL, NULL)
208 
209 #define	SYSCALL_MODULE_PRESENT(syscallname)				\
210 	(sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys &&	\
211 	sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
212 
213 /*
214  * Syscall registration helpers with resource allocation handling.
215  */
216 struct syscall_helper_data {
217 	struct sysent new_sysent;
218 	struct sysent old_sysent;
219 	int syscall_no;
220 	int registered;
221 };
222 #define SYSCALL_INIT_HELPER(syscallname) {			\
223     .new_sysent = {						\
224 	.sy_narg = (sizeof(struct syscallname ## _args )	\
225 	    / sizeof(register_t)),				\
226 	.sy_call = (sy_call_t *)& sys_ ## syscallname,		\
227 	.sy_auevent = SYS_AUE_##syscallname			\
228     },								\
229     .syscall_no = SYS_##syscallname				\
230 }
231 #define SYSCALL_INIT_HELPER_COMPAT(syscallname) {		\
232     .new_sysent = {						\
233 	.sy_narg = (sizeof(struct syscallname ## _args )	\
234 	    / sizeof(register_t)),				\
235 	.sy_call = (sy_call_t *)& syscallname,			\
236 	.sy_auevent = SYS_AUE_##syscallname			\
237     },								\
238     .syscall_no = SYS_##syscallname				\
239 }
240 #define SYSCALL_INIT_LAST {					\
241     .syscall_no = NO_SYSCALL					\
242 }
243 
244 int	syscall_register(int *offset, struct sysent *new_sysent,
245 	    struct sysent *old_sysent);
246 int	syscall_deregister(int *offset, struct sysent *old_sysent);
247 int	syscall_module_handler(struct module *mod, int what, void *arg);
248 int	syscall_helper_register(struct syscall_helper_data *sd);
249 int	syscall_helper_unregister(struct syscall_helper_data *sd);
250 
251 struct proc;
252 const char *syscallname(struct proc *p, u_int code);
253 
254 /* Special purpose system call functions. */
255 struct nosys_args;
256 
257 int	lkmnosys(struct thread *, struct nosys_args *);
258 int	lkmressys(struct thread *, struct nosys_args *);
259 
260 int	syscall_thread_enter(struct thread *td, struct sysent *se);
261 void	syscall_thread_exit(struct thread *td, struct sysent *se);
262 
263 int shared_page_alloc(int size, int align);
264 int shared_page_fill(int size, int align, const void *data);
265 void shared_page_write(int base, int size, const void *data);
266 void exec_sysvec_init(void *param);
267 
268 #define INIT_SYSENTVEC(name, sv)					\
269     SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
270 	(sysinit_cfunc_t)exec_sysvec_init, sv);
271 
272 #endif /* _KERNEL */
273 
274 #endif /* !_SYS_SYSENT_H_ */
275