xref: /freebsd/sys/amd64/ia32/ia32_syscall.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
1 /*-
2  * Copyright (C) 1994, David Greenman
3  * Copyright (c) 1990, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * the University of Utah, and William Jolitz.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /*
42  * 386 Trap and System call handling
43  */
44 
45 #include "opt_clock.h"
46 #include "opt_compat.h"
47 #include "opt_cpu.h"
48 #include "opt_isa.h"
49 
50 #include <sys/param.h>
51 #include <sys/bus.h>
52 #include <sys/systm.h>
53 #include <sys/proc.h>
54 #include <sys/pioctl.h>
55 #include <sys/kernel.h>
56 #include <sys/ktr.h>
57 #include <sys/lock.h>
58 #include <sys/mutex.h>
59 #include <sys/proc.h>
60 #include <sys/ptrace.h>
61 #include <sys/resourcevar.h>
62 #include <sys/signalvar.h>
63 #include <sys/syscall.h>
64 #include <sys/sysctl.h>
65 #include <sys/sysent.h>
66 #include <sys/uio.h>
67 #include <sys/vmmeter.h>
68 #include <security/audit/audit.h>
69 
70 #include <vm/vm.h>
71 #include <vm/vm_param.h>
72 #include <vm/pmap.h>
73 #include <vm/vm_kern.h>
74 #include <vm/vm_map.h>
75 #include <vm/vm_page.h>
76 #include <vm/vm_extern.h>
77 
78 #include <machine/cpu.h>
79 #include <machine/intr_machdep.h>
80 #include <machine/md_var.h>
81 
82 #include <compat/freebsd32/freebsd32_signal.h>
83 #include <compat/freebsd32/freebsd32_util.h>
84 #include <compat/ia32/ia32_signal.h>
85 #include <machine/psl.h>
86 #include <machine/segments.h>
87 #include <machine/specialreg.h>
88 #include <machine/sysarch.h>
89 #include <machine/frame.h>
90 #include <machine/md_var.h>
91 #include <machine/pcb.h>
92 #include <machine/cpufunc.h>
93 
94 #define	IDTVEC(name)	__CONCAT(X,name)
95 
96 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd);
97 
98 void ia32_syscall(struct trapframe *frame);	/* Called from asm code */
99 
100 void
101 ia32_set_syscall_retval(struct thread *td, int error)
102 {
103 
104 	cpu_set_syscall_retval(td, error);
105 }
106 
107 int
108 ia32_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
109 {
110 	struct proc *p;
111 	struct trapframe *frame;
112 	caddr_t params;
113 	u_int32_t args[8], tmp;
114 	int error, i;
115 
116 	p = td->td_proc;
117 	frame = td->td_frame;
118 
119 	params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t);
120 	sa->code = frame->tf_rax;
121 
122 	/*
123 	 * Need to check if this is a 32 bit or 64 bit syscall.
124 	 */
125 	if (sa->code == SYS_syscall) {
126 		/*
127 		 * Code is first argument, followed by actual args.
128 		 */
129 		error = fueword32(params, &tmp);
130 		if (error == -1)
131 			return (EFAULT);
132 		sa->code = tmp;
133 		params += sizeof(int);
134 	} else if (sa->code == SYS___syscall) {
135 		/*
136 		 * Like syscall, but code is a quad, so as to maintain
137 		 * quad alignment for the rest of the arguments.
138 		 * We use a 32-bit fetch in case params is not
139 		 * aligned.
140 		 */
141 		error = fueword32(params, &tmp);
142 		if (error == -1)
143 			return (EFAULT);
144 		sa->code = tmp;
145 		params += sizeof(quad_t);
146 	}
147  	if (p->p_sysent->sv_mask)
148  		sa->code &= p->p_sysent->sv_mask;
149  	if (sa->code >= p->p_sysent->sv_size)
150  		sa->callp = &p->p_sysent->sv_table[0];
151   	else
152  		sa->callp = &p->p_sysent->sv_table[sa->code];
153 	sa->narg = sa->callp->sy_narg;
154 
155 	if (params != NULL && sa->narg != 0)
156 		error = copyin(params, (caddr_t)args,
157 		    (u_int)(sa->narg * sizeof(int)));
158 	else
159 		error = 0;
160 
161 	for (i = 0; i < sa->narg; i++)
162 		sa->args[i] = args[i];
163 
164 	if (error == 0) {
165 		td->td_retval[0] = 0;
166 		td->td_retval[1] = frame->tf_rdx;
167 	}
168 
169 	return (error);
170 }
171 
172 #include "../../kern/subr_syscall.c"
173 
174 void
175 ia32_syscall(struct trapframe *frame)
176 {
177 	struct thread *td;
178 	struct syscall_args sa;
179 	register_t orig_tf_rflags;
180 	int error;
181 	ksiginfo_t ksi;
182 
183 	orig_tf_rflags = frame->tf_rflags;
184 	td = curthread;
185 	td->td_frame = frame;
186 
187 	error = syscallenter(td, &sa);
188 
189 	/*
190 	 * Traced syscall.
191 	 */
192 	if (orig_tf_rflags & PSL_T) {
193 		frame->tf_rflags &= ~PSL_T;
194 		ksiginfo_init_trap(&ksi);
195 		ksi.ksi_signo = SIGTRAP;
196 		ksi.ksi_code = TRAP_TRACE;
197 		ksi.ksi_addr = (void *)frame->tf_rip;
198 		trapsignal(td, &ksi);
199 	}
200 
201 	syscallret(td, error, &sa);
202 }
203 
204 static void
205 ia32_syscall_enable(void *dummy)
206 {
207 
208  	setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0);
209 }
210 
211 static void
212 ia32_syscall_disable(void *dummy)
213 {
214 
215  	setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0);
216 }
217 
218 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
219 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
220 
221 #ifdef COMPAT_43
222 int
223 setup_lcall_gate(void)
224 {
225 	struct i386_ldt_args uap;
226 	struct user_segment_descriptor desc;
227 	uint32_t lcall_addr;
228 	int error;
229 
230 	bzero(&uap, sizeof(uap));
231 	uap.start = 0;
232 	uap.num = 1;
233 	lcall_addr = curproc->p_sysent->sv_psstrings - sz_lcall_tramp;
234 	bzero(&desc, sizeof(desc));
235 	desc.sd_type = SDT_MEMERA;
236 	desc.sd_dpl = SEL_UPL;
237 	desc.sd_p = 1;
238 	desc.sd_def32 = 1;
239 	desc.sd_gran = 1;
240 	desc.sd_lolimit = 0xffff;
241 	desc.sd_hilimit = 0xf;
242 	desc.sd_lobase = lcall_addr;
243 	desc.sd_hibase = lcall_addr >> 24;
244 	error = amd64_set_ldt(curthread, &uap, &desc);
245 	if (error != 0)
246 		return (error);
247 
248 	return (0);
249 }
250 #endif
251