1 /* $NetBSD: cpu_i386.c,v 1.8 2018/11/27 14:09:54 maxv Exp $ */
2
3 /*-
4 * Copyright (c) 2011 Reinoud Zandijk <reinoud@netbsd.org>
5 * Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: cpu_i386.c,v 1.8 2018/11/27 14:09:54 maxv Exp $");
33
34 #include <sys/types.h>
35 #include <sys/systm.h>
36 #include <sys/param.h>
37 #include <sys/time.h>
38 #include <sys/exec.h>
39 #include <sys/buf.h>
40 #include <sys/boot_flag.h>
41 #include <sys/ucontext.h>
42 #include <sys/utsname.h>
43 #include <machine/pcb.h>
44 #include <machine/psl.h>
45
46 #include <uvm/uvm_extern.h>
47 #include <uvm/uvm_page.h>
48
49 #include <dev/mm.h>
50 #include <machine/machdep.h>
51 #include <machine/thunk.h>
52 #include <machine/mcontext.h>
53
54 #include "opt_exec.h"
55
56 #if 0
57 static void dump_regs(register_t *reg);
58
59 static void
60 dump_regs(register_t *reg)
61 {
62 int i;
63
64 /* register dump before call */
65 const char *name[] = {"GS", "FS", "ES", "DS", "EDI", "ESI", "EBP", "ESP",
66 "EBX", "EDX", "ECX", "EAX", "TRAPNO", "ERR", "EIP", "CS", "EFL",
67 "UESP", "SS"};
68
69 for (i =0; i < 19; i++)
70 printf("reg[%02d] (%6s) = %"PRIx32"\n", i, name[i], (uint32_t) reg[i]);
71 }
72 #endif
73
74
75 /* from sys/arch/i386/include/frame.h : KEEP IN SYNC */
76
77 /*
78 * New-style signal frame
79 */
80 struct sigframe_siginfo {
81 int sf_ra; /* return address for handler */
82 int sf_signum; /* "signum" argument for handler */
83 siginfo_t *sf_sip; /* "sip" argument for handler */
84 ucontext_t *sf_ucp; /* "ucp" argument for handler */
85 siginfo_t sf_si; /* actual saved siginfo */
86 ucontext_t sf_uc; /* actual saved ucontext */
87 };
88
89
90 /*
91 * mcontext extensions to handle signal delivery.
92 */
93
94 void
sendsig_siginfo(const ksiginfo_t * ksi,const sigset_t * mask)95 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
96 {
97 struct lwp *l = curlwp;
98 struct proc *p = l->l_proc;
99 struct pcb *pcb = lwp_getpcb(l);
100 struct sigacts *ps = p->p_sigacts;
101 struct sigframe_siginfo *fp, frame;
102 int sig = ksi->ksi_signo;
103 sig_t catcher = SIGACTION(p, sig).sa_handler;
104 ucontext_t *ucp;
105 register_t *reg;
106 int onstack, error;
107
108 KASSERT(mutex_owned(p->p_lock));
109
110 ucp = &pcb->pcb_userret_ucp;
111 reg = (register_t *) &ucp->uc_mcontext.__gregs;
112 #if 0
113 thunk_printf("%s: ", __func__);
114 thunk_printf("flags %d, ", (int) ksi->ksi_flags);
115 thunk_printf("to lwp %d, signo %d, code %d, errno %d\n",
116 (int) ksi->ksi_lid,
117 ksi->ksi_signo,
118 ksi->ksi_code,
119 ksi->ksi_errno);
120 #endif
121
122 /* do we need to jump onto the signal stack? */
123 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0
124 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
125
126 fp = (void *) reg[17]; /* ESP */
127 if (onstack)
128 fp = (void *)
129 ((char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size);
130
131 fp--;
132
133 /* set up stack frame */
134 memset(&frame, 0, sizeof(frame));
135 frame.sf_ra = (int)ps->sa_sigdesc[sig].sd_tramp;
136 frame.sf_signum = sig;
137 frame.sf_sip = &fp->sf_si;
138 frame.sf_ucp = &fp->sf_uc;
139 frame.sf_si._info = ksi->ksi_info;
140
141 /* copy our userret context into sf_uc */
142 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t));
143 frame.sf_uc.uc_sigmask = *mask;
144 frame.sf_uc.uc_link = l->l_ctxlink; /* XXX ??? */
145 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK)
146 ? _UC_SETSTACK : _UC_CLRSTACK;
147 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack));
148
149 sendsig_reset(l, sig);
150
151 /* copyout our frame to the stackframe */
152 mutex_exit(p->p_lock);
153 error = copyout(&frame, fp, sizeof(frame));
154 mutex_enter(p->p_lock);
155
156 if (error != 0) {
157 /*
158 * Process has trashed its stack; give it an illegal
159 * instruction to halt it in its tracks.
160 */
161 sigexit(l, SIGILL);
162 /* NOTREACHED */
163 }
164
165 /* set catcher and the new stack pointer */
166 reg[17] = (register_t) fp; /* ESP */
167 reg[14] = (register_t) catcher; /* EIP */
168
169 /* Remember that we're now on the signal stack. */
170 if (onstack)
171 l->l_sigstk.ss_flags |= SS_ONSTACK;
172 }
173
174 void
setregs(struct lwp * l,struct exec_package * pack,vaddr_t stack)175 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack)
176 {
177 struct pcb *pcb = lwp_getpcb(l);
178 ucontext_t *ucp;
179 uint *reg, i;
180
181 #ifdef DEBUG_EXEC
182 printf("setregs called: lwp %p, exec package %p, stack %p\n",
183 l, pack, (void *) stack);
184 printf("current stat of pcb %p\n", pcb);
185 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n",
186 pcb->pcb_ucp.uc_stack.ss_sp);
187 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n",
188 (int) pcb->pcb_ucp.uc_stack.ss_size);
189 #endif
190
191 /* set up the user context */
192 ucp = &pcb->pcb_userret_ucp;
193 reg = (int *) &ucp->uc_mcontext.__gregs;
194 for (i = 4; i < 11; i++)
195 reg[i] = 0;
196
197 /* use given stack */
198 ucp->uc_stack.ss_sp = (void *) (stack-4); /* to prevent clearing */
199 ucp->uc_stack.ss_size = 0; //pack->ep_ssize;
200 thunk_makecontext(ucp, (void *) pack->ep_entry,
201 0, NULL, NULL, NULL, NULL);
202
203 /* patch up */
204 reg[ 8] = l->l_proc->p_psstrp; /* _REG_EBX */
205 reg[17] = (stack); /* _REG_UESP */
206
207 //dump_regs(reg);
208
209 #ifdef DEBUG_EXEC
210 printf("updated pcb %p\n", pcb);
211 printf("\tpcb->pcb_ucp.uc_stack.ss_sp = %p\n",
212 pcb->pcb_ucp.uc_stack.ss_sp);
213 printf("\tpcb->pcb_ucp.uc_stack.ss_size = %d\n",
214 (int) pcb->pcb_ucp.uc_stack.ss_size);
215 printf("\tpack->ep_entry = %p\n",
216 (void *) pack->ep_entry);
217 #endif
218 }
219
220 void
md_syscall_get_syscallnumber(ucontext_t * ucp,uint32_t * code)221 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code)
222 {
223 uint *reg = (int *) &ucp->uc_mcontext.__gregs;
224 *code = reg[11]; /* EAX */
225 }
226
227 int
md_syscall_getargs(lwp_t * l,ucontext_t * ucp,int nargs,int argsize,register_t * args)228 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize,
229 register_t *args)
230 {
231 uint *reg = (int *) &ucp->uc_mcontext.__gregs;
232 register_t *sp = (register_t *) reg[17];/* ESP */
233 int ret;
234
235 //dump_regs(reg);
236 ret = copyin(sp + 1, args, argsize);
237
238 return ret;
239 }
240
241 void
md_syscall_set_returnargs(lwp_t * l,ucontext_t * ucp,int error,register_t * rval)242 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp,
243 int error, register_t *rval)
244 {
245 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
246
247 reg[16] &= ~PSL_C; /* EFL */
248 if (error > 0) {
249 rval[0] = error;
250 reg[16] |= PSL_C; /* EFL */
251 }
252
253 /* set return parameters */
254 reg[11] = rval[0]; /* EAX */
255 if (error == 0)
256 reg[ 9] = rval[1]; /* EDX */
257
258 //dump_regs(reg);
259 }
260
261 register_t
md_get_pc(ucontext_t * ucp)262 md_get_pc(ucontext_t *ucp)
263 {
264 KASSERT(ucp);
265 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
266
267 return reg[14]; /* EIP */
268 }
269
270 register_t
md_get_sp(ucontext_t * ucp)271 md_get_sp(ucontext_t *ucp)
272 {
273 KASSERT(ucp);
274 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
275
276 return reg[17]; /* ESP */
277 }
278
279 int
md_syscall_check_opcode(ucontext_t * ucp)280 md_syscall_check_opcode(ucontext_t *ucp)
281 {
282 uint32_t opcode;
283
284 md_syscall_get_opcode(ucp, &opcode);
285
286 switch (opcode) {
287 case 0xff0f: /* UD1 */
288 case 0xff0b: /* UD2 */
289 case 0x80cd: /* int $80 */
290 case 0x340f: /* sysenter */
291 case 0x050f: /* syscall */
292 return 1;
293 default:
294 return 0;
295 }
296 }
297
298 void
md_syscall_get_opcode(ucontext_t * ucp,uint32_t * opcode)299 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode)
300 {
301 KASSERT(ucp);
302 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
303 // uint8_t *p8 = (uint8_t *) (reg[14]);
304 uint16_t *p16 = (uint16_t*) (reg[14]); /* EIP */
305
306 switch (*p16) {
307 case 0xff0f: /* UD1 */
308 case 0xff0b: /* UD2 */
309 case 0x80cd: /* int $80 */
310 case 0x340f: /* sysenter */
311 case 0x050f: /* syscall */
312 *opcode = *p16;
313 break;
314 default:
315 *opcode = 0;
316 }
317 }
318
319 void
md_syscall_inc_pc(ucontext_t * ucp,uint32_t opcode)320 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode)
321 {
322 KASSERT(ucp);
323 uint *reg = (int *) &ucp->uc_mcontext.__gregs;
324
325 /* advance program counter */
326 switch (opcode) {
327 case 0xff0f: /* UD1 */
328 case 0xff0b: /* UD2 */
329 case 0x80cd: /* int $80 */
330 case 0x340f: /* sysenter */
331 case 0x050f: /* syscall */
332 reg[14] += 2; /* EIP */
333 break;
334 default:
335 panic("%s, unknown illegal instruction: opcode = %x\n",
336 __func__, (uint32_t) opcode);
337 }
338 }
339
340 void
md_syscall_dec_pc(ucontext_t * ucp,uint32_t opcode)341 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode)
342 {
343 KASSERT(ucp);
344 uint *reg = (int *) &ucp->uc_mcontext.__gregs;
345
346 switch (opcode) {
347 case 0xff0f: /* UD1 */
348 case 0xff0b: /* UD2 */
349 case 0x80cd: /* int $80 */
350 case 0x340f: /* sysenter */
351 case 0x050f: /* syscall */
352 reg[14] -= 2; /* EIP */
353 break;
354 default:
355 panic("%s, unknown illegal instruction: opcode = %x\n",
356 __func__, (uint32_t) opcode);
357 }
358 }
359
360