sysent.h revision 331722
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: stable/11/sys/sys/sysent.h 331722 2018-03-29 02:50:57Z eadler $
30 */
31
32#ifndef _SYS_SYSENT_H_
33#define	_SYS_SYSENT_H_
34
35#include <bsm/audit.h>
36
37struct rlimit;
38struct sysent;
39struct thread;
40struct ksiginfo;
41struct syscall_args;
42
43enum systrace_probe_t {
44	SYSTRACE_ENTRY,
45	SYSTRACE_RETURN,
46};
47
48typedef	int	sy_call_t(struct thread *, void *);
49
50typedef	void	(*systrace_probe_func_t)(struct syscall_args *,
51		    enum systrace_probe_t, int);
52typedef	void	(*systrace_args_func_t)(int, void *, uint64_t *, int *);
53
54extern systrace_probe_func_t	systrace_probe_func;
55
56struct 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
85struct image_params;
86struct __sigset;
87struct trapframe;
88struct vnode;
89
90struct 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#define	SV_HWCAP	0x080000	/* sv_hwcap field is valid. */
144
145#define	SV_ABI_MASK	0xff
146#define	SV_ABI_ERRNO(p, e)	((p)->p_sysent->sv_errsize <= 0 ? e :	\
147	((e) >= (p)->p_sysent->sv_errsize ? -1 : (p)->p_sysent->sv_errtbl[e]))
148#define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))
149#define	SV_PROC_ABI(p)		((p)->p_sysent->sv_flags & SV_ABI_MASK)
150#define	SV_CURPROC_FLAG(x)	SV_PROC_FLAG(curproc, x)
151#define	SV_CURPROC_ABI()	SV_PROC_ABI(curproc)
152/* same as ELFOSABI_XXX, to prevent header pollution */
153#define	SV_ABI_LINUX	3
154#define	SV_ABI_FREEBSD 	9
155#define	SV_ABI_CLOUDABI	17
156#define	SV_ABI_UNDEF	255
157
158#ifdef _KERNEL
159extern struct sysentvec aout_sysvec;
160extern struct sysent sysent[];
161extern const char *syscallnames[];
162
163#if defined(__amd64__)
164extern int i386_read_exec;
165#endif
166
167#define	NO_SYSCALL (-1)
168
169struct module;
170
171struct syscall_module_data {
172	int	(*chainevh)(struct module *, int, void *); /* next handler */
173	void	*chainarg;		/* arg for next event handler */
174	int	*offset;		/* offset into sysent */
175	struct sysent *new_sysent;	/* new sysent */
176	struct sysent old_sysent;	/* old sysent */
177	int	flags;			/* flags for syscall_register */
178};
179
180/* separate initialization vector so it can be used in a substructure */
181#define SYSENT_INIT_VALS(_syscallname) {			\
182	.sy_narg = (sizeof(struct _syscallname ## _args )	\
183	    / sizeof(register_t)),				\
184	.sy_call = (sy_call_t *)&sys_##_syscallname,		\
185	.sy_auevent = SYS_AUE_##_syscallname,			\
186	.sy_systrace_args_func = NULL,				\
187	.sy_entry = 0,						\
188	.sy_return = 0,						\
189	.sy_flags = 0,						\
190	.sy_thrcnt = 0						\
191}
192
193#define	MAKE_SYSENT(syscallname)				\
194static struct sysent syscallname##_sysent = SYSENT_INIT_VALS(syscallname);
195
196#define	MAKE_SYSENT_COMPAT(syscallname)				\
197static struct sysent syscallname##_sysent = {			\
198	(sizeof(struct syscallname ## _args )			\
199	    / sizeof(register_t)),				\
200	(sy_call_t *)& syscallname,				\
201	SYS_AUE_##syscallname					\
202}
203
204#define SYSCALL_MODULE(name, offset, new_sysent, evh, arg)	\
205static struct syscall_module_data name##_syscall_mod = {	\
206	evh, arg, offset, new_sysent, { 0, NULL, AUE_NULL }	\
207};								\
208								\
209static moduledata_t name##_mod = {				\
210	"sys/" #name,						\
211	syscall_module_handler,					\
212	&name##_syscall_mod					\
213};								\
214DECLARE_MODULE(name, name##_mod, SI_SUB_SYSCALLS, SI_ORDER_MIDDLE)
215
216#define	SYSCALL_MODULE_HELPER(syscallname)			\
217static int syscallname##_syscall = SYS_##syscallname;		\
218MAKE_SYSENT(syscallname);					\
219SYSCALL_MODULE(syscallname,					\
220    & syscallname##_syscall, & syscallname##_sysent,		\
221    NULL, NULL)
222
223#define	SYSCALL_MODULE_PRESENT(syscallname)				\
224	(sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmnosys &&	\
225	sysent[SYS_##syscallname].sy_call != (sy_call_t *)lkmressys)
226
227/*
228 * Syscall registration helpers with resource allocation handling.
229 */
230struct syscall_helper_data {
231	struct sysent new_sysent;
232	struct sysent old_sysent;
233	int syscall_no;
234	int registered;
235};
236#define SYSCALL_INIT_HELPER_F(syscallname, flags) {		\
237    .new_sysent = {						\
238	.sy_narg = (sizeof(struct syscallname ## _args )	\
239	    / sizeof(register_t)),				\
240	.sy_call = (sy_call_t *)& sys_ ## syscallname,		\
241	.sy_auevent = SYS_AUE_##syscallname,			\
242	.sy_flags = (flags)					\
243    },								\
244    .syscall_no = SYS_##syscallname				\
245}
246#define SYSCALL_INIT_HELPER_COMPAT_F(syscallname, flags) {	\
247    .new_sysent = {						\
248	.sy_narg = (sizeof(struct syscallname ## _args )	\
249	    / sizeof(register_t)),				\
250	.sy_call = (sy_call_t *)& syscallname,			\
251	.sy_auevent = SYS_AUE_##syscallname,			\
252	.sy_flags = (flags)					\
253    },								\
254    .syscall_no = SYS_##syscallname				\
255}
256#define SYSCALL_INIT_HELPER(syscallname)			\
257    SYSCALL_INIT_HELPER_F(syscallname, 0)
258#define SYSCALL_INIT_HELPER_COMPAT(syscallname)			\
259    SYSCALL_INIT_HELPER_COMPAT_F(syscallname, 0)
260#define SYSCALL_INIT_LAST {					\
261    .syscall_no = NO_SYSCALL					\
262}
263
264int	syscall_register(int *offset, struct sysent *new_sysent,
265	    struct sysent *old_sysent, int flags);
266int	syscall_deregister(int *offset, struct sysent *old_sysent);
267int	syscall_module_handler(struct module *mod, int what, void *arg);
268int	syscall_helper_register(struct syscall_helper_data *sd, int flags);
269int	syscall_helper_unregister(struct syscall_helper_data *sd);
270
271struct proc;
272const char *syscallname(struct proc *p, u_int code);
273
274/* Special purpose system call functions. */
275struct nosys_args;
276
277int	lkmnosys(struct thread *, struct nosys_args *);
278int	lkmressys(struct thread *, struct nosys_args *);
279
280int	syscall_thread_enter(struct thread *td, struct sysent *se);
281void	syscall_thread_exit(struct thread *td, struct sysent *se);
282
283int shared_page_alloc(int size, int align);
284int shared_page_fill(int size, int align, const void *data);
285void shared_page_write(int base, int size, const void *data);
286void exec_sysvec_init(void *param);
287void exec_inittk(void);
288
289#define INIT_SYSENTVEC(name, sv)					\
290    SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
291	(sysinit_cfunc_t)exec_sysvec_init, sv);
292
293#endif /* _KERNEL */
294
295#endif /* !_SYS_SYSENT_H_ */
296