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: src/sys/amd64/ia32/ia32_syscall.c,v 1.19 2007/06/10 21:59:12 attilio Exp $");
40
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 #include "opt_ktrace.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/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 #ifdef KTRACE
68 #include <sys/ktrace.h>
69 #endif
70 #include <security/audit/audit.h>
71
72 #include <vm/vm.h>
73 #include <vm/vm_param.h>
74 #include <vm/pmap.h>
75 #include <vm/vm_kern.h>
76 #include <vm/vm_map.h>
77 #include <vm/vm_page.h>
78 #include <vm/vm_extern.h>
79
80 #include <machine/cpu.h>
81 #include <machine/intr_machdep.h>
82 #include <machine/md_var.h>
83
84 #define IDTVEC(name) __CONCAT(X,name)
85
86 extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd);
87 extern const char *freebsd32_syscallnames[];
88
89 void ia32_syscall(struct trapframe *frame); /* Called from asm code */
90
91 void
92 ia32_syscall(struct trapframe *frame)
93 {
94 caddr_t params;
95 int i;
96 struct sysent *callp;
97 struct thread *td = curthread;
98 struct proc *p = td->td_proc;
99 register_t orig_tf_rflags;
100 int error;
101 int narg;
102 u_int32_t args[8];
103 u_int64_t args64[8];
104 u_int code;
105 ksiginfo_t ksi;
106
107 PCPU_INC(cnt.v_syscall);
108 td->td_pticks = 0;
109 td->td_frame = frame;
110 if (td->td_ucred != p->p_ucred)
111 cred_update_thread(td);
112 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t);
113 code = frame->tf_rax;
114 orig_tf_rflags = frame->tf_rflags;
115
116 if (p->p_sysent->sv_prepsyscall) {
117 /*
118 * The prep code is MP aware.
119 */
120 (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms);
121 } else {
122 /*
123 * Need to check if this is a 32 bit or 64 bit syscall.
124 * fuword is MP aware.
125 */
126 if (code == SYS_syscall) {
127 /*
128 * Code is first argument, followed by actual args.
129 */
130 code = fuword32(params);
131 params += sizeof(int);
132 } else if (code == SYS___syscall) {
133 /*
134 * Like syscall, but code is a quad, so as to maintain
135 * quad alignment for the rest of the arguments.
136 * We use a 32-bit fetch in case params is not
137 * aligned.
138 */
139 code = fuword32(params);
140 params += sizeof(quad_t);
141 }
142 }
143
144 if (p->p_sysent->sv_mask)
145 code &= p->p_sysent->sv_mask;
146
147 if (code >= p->p_sysent->sv_size)
148 callp = &p->p_sysent->sv_table[0];
149 else
150 callp = &p->p_sysent->sv_table[code];
151
152 narg = callp->sy_narg;
153
154 /*
155 * copyin and the ktrsyscall()/ktrsysret() code is MP-aware
156 */
157 if (params != NULL && narg != 0)
158 error = copyin(params, (caddr_t)args,
159 (u_int)(narg * sizeof(int)));
160 else
161 error = 0;
162
163 for (i = 0; i < narg; i++)
164 args64[i] = args[i];
165
166 #ifdef KTRACE
167 if (KTRPOINT(td, KTR_SYSCALL))
168 ktrsyscall(code, narg, args64);
169 #endif
170 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td,
171 td->td_proc->p_pid, td->td_proc->p_comm, code);
172
173 if (error == 0) {
174 td->td_retval[0] = 0;
175 td->td_retval[1] = frame->tf_rdx;
176
177 STOPEVENT(p, S_SCE, narg);
178
179 PTRACESTOP_SC(p, td, S_PT_SCE);
180
181 AUDIT_SYSCALL_ENTER(code, td);
182 error = (*callp->sy_call)(td, args64);
183 AUDIT_SYSCALL_EXIT(error, td);
184 }
185
186 switch (error) {
187 case 0:
188 frame->tf_rax = td->td_retval[0];
189 frame->tf_rdx = td->td_retval[1];
190 frame->tf_rflags &= ~PSL_C;
191 break;
192
193 case ERESTART:
194 /*
195 * Reconstruct pc, assuming lcall $X,y is 7 bytes,
196 * int 0x80 is 2 bytes. We saved this in tf_err.
197 */
198 frame->tf_rip -= frame->tf_err;
199 break;
200
201 case EJUSTRETURN:
202 break;
203
204 default:
205 if (p->p_sysent->sv_errsize) {
206 if (error >= p->p_sysent->sv_errsize)
207 error = -1; /* XXX */
208 else
209 error = p->p_sysent->sv_errtbl[error];
210 }
211 frame->tf_rax = error;
212 frame->tf_rflags |= PSL_C;
213 break;
214 }
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 /*
229 * Check for misbehavior.
230 */
231 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
232 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???");
233 KASSERT(td->td_critnest == 0,
234 ("System call %s returning in a critical section",
235 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"));
236 KASSERT(td->td_locks == 0,
237 ("System call %s returning with %d locks held",
238 (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???",
239 td->td_locks));
240
241 /*
242 * Handle reschedule and other end-of-syscall issues
243 */
244 userret(td, frame);
245
246 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td,
247 td->td_proc->p_pid, td->td_proc->p_comm, code);
248 #ifdef KTRACE
249 if (KTRPOINT(td, KTR_SYSRET))
250 ktrsysret(code, error, td->td_retval[0]);
251 #endif
252
253 /*
254 * This works because errno is findable through the
255 * register set. If we ever support an emulation where this
256 * is not the case, this code will need to be revisited.
257 */
258 STOPEVENT(p, S_SCX, code);
259
260 PTRACESTOP_SC(p, td, S_PT_SCX);
261 }
262
263
264 static void
265 ia32_syscall_enable(void *dummy)
266 {
267
268 setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0);
269 }
270
271 static void
272 ia32_syscall_disable(void *dummy)
273 {
274
275 setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0);
276 }
277
278 SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL);
279 SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);
280 Cache object: 1216381a61760c25675b9f1686322d95
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