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
96 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti),
97 IDTVEC(rsvd), IDTVEC(rsvd_pti);
98
99 void ia32_syscall(struct trapframe *frame); /* Called from asm code */
100
101 void
ia32_set_syscall_retval(struct thread * td,int error)102 ia32_set_syscall_retval(struct thread *td, int error)
103 {
104
105 cpu_set_syscall_retval(td, error);
106 }
107
108 int
ia32_fetch_syscall_args(struct thread * td)109 ia32_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
203 void
ia32_syscall(struct trapframe * frame)204 ia32_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
232 static void
ia32_syscall_enable(void * dummy)233 ia32_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
240 static void
ia32_syscall_disable(void * dummy)241 ia32_syscall_disable(void *dummy)
242 {
243
244 setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd),
245 SDT_SYSIGT, SEL_KPL, 0);
246 }
247
248 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
249 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
250
251 #ifdef COMPAT_43
252 int
setup_lcall_gate(void)253 setup_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