1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (C) 1994, David Greenman
5 * Copyright (c) 1990, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the University of Utah, and William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD$");
42
43/*
44 * 386 Trap and System call handling
45 */
46
47#include "opt_clock.h"
48#include "opt_cpu.h"
49#include "opt_isa.h"
50
51#include <sys/param.h>
52#include <sys/bus.h>
53#include <sys/systm.h>
54#include <sys/proc.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#ifdef COMPAT_43
118	u_int32_t eip;
119	int cs;
120#endif
121
122	p = td->td_proc;
123	frame = td->td_frame;
124	sa = &td->td_sa;
125
126#ifdef COMPAT_43
127	if (__predict_false(frame->tf_cs == 7 && frame->tf_rip == 2)) {
128		/*
129		 * In lcall $7,$0 after int $0x80.  Convert the user
130		 * frame to what it would be for a direct int 0x80 instead
131		 * of lcall $7,$0, by popping the lcall return address.
132		 */
133		error = fueword32((void *)frame->tf_rsp, &eip);
134		if (error == -1)
135			return (EFAULT);
136		cs = fuword16((void *)(frame->tf_rsp + sizeof(u_int32_t)));
137		if (cs == -1)
138			return (EFAULT);
139
140		/*
141		 * Unwind in-kernel frame after all stack frame pieces
142		 * were successfully read.
143		 */
144		frame->tf_rip = eip;
145		frame->tf_cs = cs;
146		frame->tf_rsp += 2 * sizeof(u_int32_t);
147		frame->tf_err = 7;		/* size of lcall $7,$0 */
148	}
149#endif
150
151	params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t);
152	sa->code = frame->tf_rax;
153
154	/*
155	 * Need to check if this is a 32 bit or 64 bit syscall.
156	 */
157	if (sa->code == SYS_syscall) {
158		/*
159		 * Code is first argument, followed by actual args.
160		 */
161		error = fueword32(params, &tmp);
162		if (error == -1)
163			return (EFAULT);
164		sa->code = tmp;
165		params += sizeof(int);
166	} else if (sa->code == SYS___syscall) {
167		/*
168		 * Like syscall, but code is a quad, so as to maintain
169		 * quad alignment for the rest of the arguments.
170		 * We use a 32-bit fetch in case params is not
171		 * aligned.
172		 */
173		error = fueword32(params, &tmp);
174		if (error == -1)
175			return (EFAULT);
176		sa->code = tmp;
177		params += sizeof(quad_t);
178	}
179 	if (sa->code >= p->p_sysent->sv_size)
180 		sa->callp = &p->p_sysent->sv_table[0];
181  	else
182 		sa->callp = &p->p_sysent->sv_table[sa->code];
183
184	if (params != NULL && sa->callp->sy_narg != 0)
185		error = copyin(params, (caddr_t)args,
186		    (u_int)(sa->callp->sy_narg * sizeof(int)));
187	else
188		error = 0;
189
190	for (i = 0; i < sa->callp->sy_narg; i++)
191		sa->args[i] = args[i];
192
193	if (error == 0) {
194		td->td_retval[0] = 0;
195		td->td_retval[1] = frame->tf_rdx;
196	}
197
198	return (error);
199}
200
201#include "../../kern/subr_syscall.c"
202
203void
204ia32_syscall(struct trapframe *frame)
205{
206	struct thread *td;
207	register_t orig_tf_rflags;
208	ksiginfo_t ksi;
209
210	orig_tf_rflags = frame->tf_rflags;
211	td = curthread;
212	td->td_frame = frame;
213
214	syscallenter(td);
215
216	/*
217	 * Traced syscall.
218	 */
219	if (orig_tf_rflags & PSL_T) {
220		frame->tf_rflags &= ~PSL_T;
221		ksiginfo_init_trap(&ksi);
222		ksi.ksi_signo = SIGTRAP;
223		ksi.ksi_code = TRAP_TRACE;
224		ksi.ksi_addr = (void *)frame->tf_rip;
225		trapsignal(td, &ksi);
226	}
227
228	syscallret(td);
229	amd64_syscall_ret_flush_l1d(td->td_errno);
230}
231
232static void
233ia32_syscall_enable(void *dummy)
234{
235
236 	setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) :
237	    &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0);
238}
239
240static void
241ia32_syscall_disable(void *dummy)
242{
243
244 	setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd),
245	    SDT_SYSIGT, SEL_KPL, 0);
246}
247
248SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
249SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
250
251#ifdef COMPAT_43
252int
253setup_lcall_gate(void)
254{
255	struct i386_ldt_args uap;
256	struct user_segment_descriptor desc;
257	uint32_t lcall_addr;
258	int error;
259
260	bzero(&uap, sizeof(uap));
261	uap.start = 0;
262	uap.num = 1;
263	lcall_addr = curproc->p_sysent->sv_psstrings - sz_lcall_tramp;
264	bzero(&desc, sizeof(desc));
265	desc.sd_type = SDT_MEMERA;
266	desc.sd_dpl = SEL_UPL;
267	desc.sd_p = 1;
268	desc.sd_def32 = 1;
269	desc.sd_gran = 1;
270	desc.sd_lolimit = 0xffff;
271	desc.sd_hilimit = 0xf;
272	desc.sd_lobase = lcall_addr;
273	desc.sd_hibase = lcall_addr >> 24;
274	error = amd64_set_ldt(curthread, &uap, &desc);
275	if (error != 0)
276		return (error);
277
278	return (0);
279}
280#endif
281