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 /*
42 * 386 Trap and System call handling
43 */
44
45 #include "opt_clock.h"
46 #include "opt_cpu.h"
47 #include "opt_isa.h"
48
49 #include <sys/param.h>
50 #include <sys/bus.h>
51 #include <sys/systm.h>
52 #include <sys/proc.h>
53 #include <sys/kernel.h>
54 #include <sys/ktr.h>
55 #include <sys/lock.h>
56 #include <sys/msan.h>
57 #include <sys/mutex.h>
58 #include <sys/proc.h>
59 #include <sys/ptrace.h>
60 #include <sys/resourcevar.h>
61 #include <sys/signalvar.h>
62 #include <sys/syscall.h>
63 #include <sys/sysctl.h>
64 #include <sys/sysent.h>
65 #include <sys/uio.h>
66 #include <sys/vmmeter.h>
67 #include <security/audit/audit.h>
68
69 #include <vm/vm.h>
70 #include <vm/vm_param.h>
71 #include <vm/pmap.h>
72 #include <vm/vm_kern.h>
73 #include <vm/vm_map.h>
74 #include <vm/vm_page.h>
75 #include <vm/vm_extern.h>
76
77 #include <machine/cpu.h>
78 #include <machine/intr_machdep.h>
79 #include <machine/md_var.h>
80
81 #include <compat/freebsd32/freebsd32_signal.h>
82 #include <compat/freebsd32/freebsd32_util.h>
83 #include <compat/ia32/ia32_signal.h>
84 #include <machine/psl.h>
85 #include <machine/segments.h>
86 #include <machine/specialreg.h>
87 #include <machine/sysarch.h>
88 #include <machine/frame.h>
89 #include <machine/md_var.h>
90 #include <machine/pcb.h>
91 #include <machine/cpufunc.h>
92
93 #include "vdso_ia32_offsets.h"
94
95 extern const char _binary_elf_vdso32_so_1_start[];
96 extern const char _binary_elf_vdso32_so_1_end[];
97 extern char _binary_elf_vdso32_so_1_size;
98
99 #define IDTVEC(name) __CONCAT(X,name)
100
101 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti),
102 IDTVEC(rsvd), IDTVEC(rsvd_pti);
103
104 void ia32_syscall(struct trapframe *frame); /* Called from asm code */
105
106 void
ia32_set_syscall_retval(struct thread * td,int error)107 ia32_set_syscall_retval(struct thread *td, int error)
108 {
109
110 cpu_set_syscall_retval(td, error);
111 }
112
113 int
ia32_fetch_syscall_args(struct thread * td)114 ia32_fetch_syscall_args(struct thread *td)
115 {
116 struct proc *p;
117 struct trapframe *frame;
118 struct syscall_args *sa;
119 caddr_t params;
120 u_int32_t args[8], tmp;
121 int error, i;
122 #ifdef COMPAT_43
123 u_int32_t eip;
124 int cs;
125 #endif
126
127 p = td->td_proc;
128 frame = td->td_frame;
129 sa = &td->td_sa;
130
131 #ifdef COMPAT_43
132 if (__predict_false(frame->tf_cs == 7 && frame->tf_rip == 2)) {
133 /*
134 * In lcall $7,$0 after int $0x80. Convert the user
135 * frame to what it would be for a direct int 0x80 instead
136 * of lcall $7,$0, by popping the lcall return address.
137 */
138 error = fueword32((void *)frame->tf_rsp, &eip);
139 if (error == -1)
140 return (EFAULT);
141 cs = fuword16((void *)(frame->tf_rsp + sizeof(u_int32_t)));
142 if (cs == -1)
143 return (EFAULT);
144
145 /*
146 * Unwind in-kernel frame after all stack frame pieces
147 * were successfully read.
148 */
149 frame->tf_rip = eip;
150 frame->tf_cs = cs;
151 frame->tf_rsp += 2 * sizeof(u_int32_t);
152 frame->tf_err = 7; /* size of lcall $7,$0 */
153 }
154 #endif
155
156 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t);
157 sa->code = frame->tf_rax;
158 sa->original_code = sa->code;
159
160 /*
161 * Need to check if this is a 32 bit or 64 bit syscall.
162 */
163 if (sa->code == SYS_syscall) {
164 /*
165 * Code is first argument, followed by actual args.
166 */
167 error = fueword32(params, &tmp);
168 if (error == -1)
169 return (EFAULT);
170 sa->code = tmp;
171 params += sizeof(int);
172 } else if (sa->code == SYS___syscall) {
173 /*
174 * Like syscall, but code is a quad, so as to maintain
175 * quad alignment for the rest of the arguments.
176 * We use a 32-bit fetch in case params is not
177 * aligned.
178 */
179 error = fueword32(params, &tmp);
180 if (error == -1)
181 return (EFAULT);
182 sa->code = tmp;
183 params += sizeof(quad_t);
184 }
185 if (sa->code >= p->p_sysent->sv_size)
186 sa->callp = &nosys_sysent;
187 else
188 sa->callp = &p->p_sysent->sv_table[sa->code];
189
190 if (params != NULL && sa->callp->sy_narg != 0)
191 error = copyin(params, (caddr_t)args,
192 (u_int)(sa->callp->sy_narg * sizeof(int)));
193 else
194 error = 0;
195
196 for (i = 0; i < sa->callp->sy_narg; i++)
197 sa->args[i] = args[i];
198
199 if (error == 0) {
200 td->td_retval[0] = 0;
201 td->td_retval[1] = frame->tf_rdx;
202 }
203
204 return (error);
205 }
206
207 #include "../../kern/subr_syscall.c"
208
209 void
ia32_syscall(struct trapframe * frame)210 ia32_syscall(struct trapframe *frame)
211 {
212 struct thread *td;
213 register_t orig_tf_rflags;
214 ksiginfo_t ksi;
215
216 kmsan_mark(frame, sizeof(*frame), KMSAN_STATE_INITED);
217
218 orig_tf_rflags = frame->tf_rflags;
219 td = curthread;
220 td->td_frame = frame;
221
222 syscallenter(td);
223
224 /*
225 * Traced syscall.
226 */
227 if (orig_tf_rflags & PSL_T) {
228 frame->tf_rflags &= ~PSL_T;
229 ksiginfo_init_trap(&ksi);
230 ksi.ksi_signo = SIGTRAP;
231 ksi.ksi_code = TRAP_TRACE;
232 ksi.ksi_addr = (void *)frame->tf_rip;
233 trapsignal(td, &ksi);
234 }
235
236 syscallret(td);
237 amd64_syscall_ret_flush_l1d(td->td_errno);
238 }
239
240 static void
ia32_syscall_enable(void * dummy)241 ia32_syscall_enable(void *dummy)
242 {
243
244 setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) :
245 &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0);
246 }
247
248 static void
ia32_syscall_disable(void * dummy)249 ia32_syscall_disable(void *dummy)
250 {
251
252 setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd),
253 SDT_SYSIGT, SEL_KPL, 0);
254 }
255
256 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
257 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
258
259 #ifdef COMPAT_43
260 int
setup_lcall_gate(void)261 setup_lcall_gate(void)
262 {
263 struct i386_ldt_args uap;
264 struct user_segment_descriptor desc;
265 uint32_t lcall_addr;
266 int error;
267
268 bzero(&uap, sizeof(uap));
269 uap.start = 0;
270 uap.num = 1;
271 lcall_addr = PROC_PS_STRINGS(curproc) -
272 (_binary_elf_vdso32_so_1_end - _binary_elf_vdso32_so_1_start) +
273 VDSO_LCALL_TRAMP_OFFSET;
274 bzero(&desc, sizeof(desc));
275 desc.sd_type = SDT_MEMERA;
276 desc.sd_dpl = SEL_UPL;
277 desc.sd_p = 1;
278 desc.sd_def32 = 1;
279 desc.sd_gran = 1;
280 desc.sd_lolimit = 0xffff;
281 desc.sd_hilimit = 0xf;
282 desc.sd_lobase = lcall_addr;
283 desc.sd_hibase = lcall_addr >> 24;
284 error = amd64_set_ldt(curthread, &uap, &desc);
285 if (error != 0)
286 return (error);
287
288 return (0);
289 }
290 #endif
291