xref: /freebsd/sys/sys/sysent.h (revision 0e1497aefd602cea581d2380d22e67dfdcac6b4e)
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 #define	SY_THR_FLAGMASK	0x7
69 #define	SY_THR_STATIC	0x1
70 #define	SY_THR_DRAINING	0x2
71 #define	SY_THR_ABSENT	0x4
72 #define	SY_THR_INCR	0x8
73 
74 struct image_params;
75 struct __sigset;
76 struct syscall_args;
77 struct trapframe;
78 struct vnode;
79 
80 struct sysentvec {
81 	int		sv_size;	/* number of entries */
82 	struct sysent	*sv_table;	/* pointer to sysent */
83 	u_int		sv_mask;	/* optional mask to index */
84 	int		sv_sigsize;	/* size of signal translation table */
85 	int		*sv_sigtbl;	/* signal translation table */
86 	int		sv_errsize;	/* size of errno translation table */
87 	int 		*sv_errtbl;	/* errno translation table */
88 	int		(*sv_transtrap)(int, int);
89 					/* translate trap-to-signal mapping */
90 	int		(*sv_fixup)(register_t **, struct image_params *);
91 					/* stack fixup function */
92 	void		(*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
93 			    		/* send signal */
94 	char 		*sv_sigcode;	/* start of sigtramp code */
95 	int 		*sv_szsigcode;	/* size of sigtramp code */
96 	void		(*sv_prepsyscall)(struct trapframe *, int *, u_int *,
97 			    caddr_t *);
98 	char		*sv_name;	/* name of binary type */
99 	int		(*sv_coredump)(struct thread *, struct vnode *, off_t, int);
100 					/* function to dump core, or NULL */
101 	int		(*sv_imgact_try)(struct image_params *);
102 	int		sv_minsigstksz;	/* minimum signal stack size */
103 	int		sv_pagesize;	/* pagesize */
104 	vm_offset_t	sv_minuser;	/* VM_MIN_ADDRESS */
105 	vm_offset_t	sv_maxuser;	/* VM_MAXUSER_ADDRESS */
106 	vm_offset_t	sv_usrstack;	/* USRSTACK */
107 	vm_offset_t	sv_psstrings;	/* PS_STRINGS */
108 	int		sv_stackprot;	/* vm protection for stack */
109 	register_t	*(*sv_copyout_strings)(struct image_params *);
110 	void		(*sv_setregs)(struct thread *, struct image_params *,
111 			    u_long);
112 	void		(*sv_fixlimit)(struct rlimit *, int);
113 	u_long		*sv_maxssiz;
114 	u_int		sv_flags;
115 	void		(*sv_set_syscall_retval)(struct thread *, int);
116 	int		(*sv_fetch_syscall_args)(struct thread *, struct
117 			    syscall_args *);
118 	const char	**sv_syscallnames;
119 };
120 
121 #define	SV_ILP32	0x000100
122 #define	SV_LP64		0x000200
123 #define	SV_IA32		0x004000
124 #define	SV_AOUT		0x008000
125 
126 #define	SV_ABI_MASK	0xff
127 #define	SV_CURPROC_FLAG(x) (curproc->p_sysent->sv_flags & (x))
128 #define	SV_CURPROC_ABI() (curproc->p_sysent->sv_flags & SV_ABI_MASK)
129 /* same as ELFOSABI_XXX, to prevent header pollution */
130 #define	SV_ABI_LINUX	3
131 #define	SV_ABI_FREEBSD 	9
132 #define	SV_ABI_UNDEF	255
133 
134 #ifdef _KERNEL
135 extern struct sysentvec aout_sysvec;
136 extern struct sysentvec elf_freebsd_sysvec;
137 extern struct sysentvec null_sysvec;
138 extern struct sysent sysent[];
139 extern const char *syscallnames[];
140 
141 #define	NO_SYSCALL (-1)
142 
143 struct module;
144 
145 struct syscall_module_data {
146 	int	(*chainevh)(struct module *, int, void *); /* next handler */
147 	void	*chainarg;		/* arg for next event handler */
148 	int	*offset;		/* offset into sysent */
149 	struct sysent *new_sysent;	/* new sysent */
150 	struct sysent old_sysent;	/* old sysent */
151 };
152 
153 #define	MAKE_SYSENT(syscallname)				\
154 static struct sysent syscallname##_sysent = {			\
155 	(sizeof(struct syscallname ## _args )			\
156 	    / sizeof(register_t)),				\
157 	(sy_call_t *)& syscallname,				\
158 	SYS_AUE_##syscallname					\
159 }
160 
161 #define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)	\
162 static struct syscall_module_data name##_syscall_mod = {	\
163 	evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }	\
164 };								\
165 								\
166 static moduledata_t name##_mod = {				\
167 	"sys/" #name,						\
168 	syscall_module_handler,					\
169 	&name##_syscall_mod					\
170 };								\
171 DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
172 
173 #define	SYSCALL_MODULE_HELPER(syscallname)			\
174 static int syscallname##_syscall = SYS_##syscallname;		\
175 MAKE_SYSENT(syscallname);					\
176 SYSCALL_MODULE(syscallname,					\
177     & syscallname##_syscall, & syscallname##_sysent,		\
178     NULL, NULL)
179 
180 #define	SYSCALL_MODULE_PRESENT(syscallname)				\
181 	(sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys &&	\
182 	sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
183 
184 /*
185  * Syscall registration helpers with resource allocation handling.
186  */
187 struct syscall_helper_data {
188 	struct sysent new_sysent;
189 	struct sysent old_sysent;
190 	int syscall_no;
191 	int registered;
192 };
193 #define SYSCALL_INIT_HELPER(syscallname) {			\
194     .new_sysent = {						\
195 	.sy_narg = (sizeof(struct syscallname ## _args )	\
196 	    / sizeof(register_t)),				\
197 	.sy_call = (sy_call_t *)& syscallname,			\
198 	.sy_auevent = SYS_AUE_##syscallname			\
199     },								\
200     .syscall_no = SYS_##syscallname				\
201 }
202 #define SYSCALL_INIT_LAST {					\
203     .syscall_no = NO_SYSCALL					\
204 }
205 
206 int	syscall_register(int *offset, struct sysent *new_sysent,
207 	    struct sysent *old_sysent);
208 int	syscall_deregister(int *offset, struct sysent *old_sysent);
209 int	syscall_module_handler(struct module *mod, int what, void *arg);
210 int	syscall_helper_register(struct syscall_helper_data *sd);
211 int	syscall_helper_unregister(struct syscall_helper_data *sd);
212 
213 struct proc;
214 const char *syscallname(struct proc *p, u_int code);
215 
216 /* Special purpose system call functions. */
217 struct nosys_args;
218 
219 int	lkmnosys(struct thread *, struct nosys_args *);
220 int	lkmressys(struct thread *, struct nosys_args *);
221 
222 int	syscall_thread_enter(struct thread *td, struct sysent *se);
223 void	syscall_thread_exit(struct thread *td, struct sysent *se);
224 
225 #endif /* _KERNEL */
226 
227 #endif /* !_SYS_SYSENT_H_ */
228