ia32_syscall.c revision 329462
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: stable/11/sys/amd64/ia32/ia32_syscall.c 329462 2018-02-17 18:00:01Z kib $");
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
96extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti),
97    IDTVEC(rsvd), IDTVEC(rsvd_pti);
98
99void ia32_syscall(struct trapframe *frame);	/* Called from asm code */
100
101void
102ia32_set_syscall_retval(struct thread *td, int error)
103{
104
105	cpu_set_syscall_retval(td, error);
106}
107
108int
109ia32_fetch_syscall_args(struct thread *td)
110{
111	struct proc *p;
112	struct trapframe *frame;
113	struct syscall_args *sa;
114	caddr_t params;
115	u_int32_t args[8], tmp;
116	int error, i;
117
118	p = td->td_proc;
119	frame = td->td_frame;
120	sa = &td->td_sa;
121
122	params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t);
123	sa->code = frame->tf_rax;
124
125	/*
126	 * Need to check if this is a 32 bit or 64 bit syscall.
127	 */
128	if (sa->code == SYS_syscall) {
129		/*
130		 * Code is first argument, followed by actual args.
131		 */
132		error = fueword32(params, &tmp);
133		if (error == -1)
134			return (EFAULT);
135		sa->code = tmp;
136		params += sizeof(int);
137	} else if (sa->code == SYS___syscall) {
138		/*
139		 * Like syscall, but code is a quad, so as to maintain
140		 * quad alignment for the rest of the arguments.
141		 * We use a 32-bit fetch in case params is not
142		 * aligned.
143		 */
144		error = fueword32(params, &tmp);
145		if (error == -1)
146			return (EFAULT);
147		sa->code = tmp;
148		params += sizeof(quad_t);
149	}
150 	if (p->p_sysent->sv_mask)
151 		sa->code &= p->p_sysent->sv_mask;
152 	if (sa->code >= p->p_sysent->sv_size)
153 		sa->callp = &p->p_sysent->sv_table[0];
154  	else
155 		sa->callp = &p->p_sysent->sv_table[sa->code];
156	sa->narg = sa->callp->sy_narg;
157
158	if (params != NULL && sa->narg != 0)
159		error = copyin(params, (caddr_t)args,
160		    (u_int)(sa->narg * sizeof(int)));
161	else
162		error = 0;
163
164	for (i = 0; i < sa->narg; i++)
165		sa->args[i] = args[i];
166
167	if (error == 0) {
168		td->td_retval[0] = 0;
169		td->td_retval[1] = frame->tf_rdx;
170	}
171
172	return (error);
173}
174
175#include "../../kern/subr_syscall.c"
176
177void
178ia32_syscall(struct trapframe *frame)
179{
180	struct thread *td;
181	register_t orig_tf_rflags;
182	int error;
183	ksiginfo_t ksi;
184
185	orig_tf_rflags = frame->tf_rflags;
186	td = curthread;
187	td->td_frame = frame;
188
189	error = syscallenter(td);
190
191	/*
192	 * Traced syscall.
193	 */
194	if (orig_tf_rflags & PSL_T) {
195		frame->tf_rflags &= ~PSL_T;
196		ksiginfo_init_trap(&ksi);
197		ksi.ksi_signo = SIGTRAP;
198		ksi.ksi_code = TRAP_TRACE;
199		ksi.ksi_addr = (void *)frame->tf_rip;
200		trapsignal(td, &ksi);
201	}
202
203	syscallret(td, error);
204}
205
206static void
207ia32_syscall_enable(void *dummy)
208{
209
210 	setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) :
211	    &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0);
212}
213
214static void
215ia32_syscall_disable(void *dummy)
216{
217
218 	setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd),
219	    SDT_SYSIGT, SEL_KPL, 0);
220}
221
222SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
223SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
224
225#ifdef COMPAT_43
226int
227setup_lcall_gate(void)
228{
229	struct i386_ldt_args uap;
230	struct user_segment_descriptor desc;
231	uint32_t lcall_addr;
232	int error;
233
234	bzero(&uap, sizeof(uap));
235	uap.start = 0;
236	uap.num = 1;
237	lcall_addr = curproc->p_sysent->sv_psstrings - sz_lcall_tramp;
238	bzero(&desc, sizeof(desc));
239	desc.sd_type = SDT_MEMERA;
240	desc.sd_dpl = SEL_UPL;
241	desc.sd_p = 1;
242	desc.sd_def32 = 1;
243	desc.sd_gran = 1;
244	desc.sd_lolimit = 0xffff;
245	desc.sd_hilimit = 0xf;
246	desc.sd_lobase = lcall_addr;
247	desc.sd_hibase = lcall_addr >> 24;
248	error = amd64_set_ldt(curthread, &uap, &desc);
249	if (error != 0)
250		return (error);
251
252	return (0);
253}
254#endif
255