1 /* $NetBSD: cpu_x86_64.c,v 1.7 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_x86_64.c,v 1.7 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 #if 0
55 static void dump_regs(register_t *reg);
56
57 static void
58 dump_regs(register_t *reg)
59 {
60 int i;
61
62 /* register dump before call */
63 const char *name[] = {"RDI", "RSI", "RDX", "RCX", "R8", "R9", "R10",
64 "R11", "R12", "R13", "R14", "R15", "RBP", "RAX",
65 "GS", "FS", "ES", "DS", "TRAPNO", "ERR", "RIP", "CS",
66 "RFLAGS", "RSP", "SS"};
67
68 for (i =0; i < 26; i++)
69 printf("reg[%02d] (%6s) = %"PRIx32"\n",
70 i, name[i], (uint32_t) reg[i]);
71 }
72 #endif
73
74
75 /* from sys/arch/amd64/include/frame.h : KEEP IN SYNC */
76
77 /*
78 * Signal frame
79 */
80 struct sigframe_siginfo {
81 uint64_t sf_ra; /* return address for handler */
82 siginfo_t sf_si; /* actual saved siginfo */
83 ucontext_t sf_uc; /* actual saved ucontext */
84 };
85
86
87 /*
88 * mcontext extensions to handle signal delivery.
89 */
90 void
sendsig_siginfo(const ksiginfo_t * ksi,const sigset_t * mask)91 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
92 {
93 struct lwp *l = curlwp;
94 struct proc *p = l->l_proc;
95 struct pcb *pcb = lwp_getpcb(l);
96 struct sigacts *ps = p->p_sigacts;
97 struct sigframe_siginfo *fp, frame;
98 int sig = ksi->ksi_signo;
99 sig_t catcher = SIGACTION(p, sig).sa_handler;
100 ucontext_t *ucp;
101 register_t *reg;
102 int onstack, error;
103 char *sp;
104
105 KASSERT(mutex_owned(p->p_lock));
106
107 ucp = &pcb->pcb_userret_ucp;
108 reg = (register_t *) &ucp->uc_mcontext.__gregs;
109 #if 0
110 thunk_printf("%s: ", __func__);
111 thunk_printf("flags %d, ", (int) ksi->ksi_flags);
112 thunk_printf("to lwp %d, signo %d, code %d, errno %d\n",
113 (int) ksi->ksi_lid,
114 ksi->ksi_signo,
115 ksi->ksi_code,
116 ksi->ksi_errno);
117 #endif
118
119 /* do we need to jump onto the signal stack? */
120 onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0
121 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
122
123 sp = ((char *) reg[24] - 128);/* why -128?*//* RSP */
124 if (onstack)
125 sp = (char *) l->l_sigstk.ss_sp + l->l_sigstk.ss_size;
126
127 sp -= sizeof(struct sigframe_siginfo);
128 /*
129 * Round down the stackpointer to a multiple of 16 for
130 * fxsave and the ABI
131 */
132 fp = (struct sigframe_siginfo *) (((unsigned long)sp & ~15) - 8);
133
134 /* set up stack frame */
135 memset(&frame, 0, sizeof(frame));
136 frame.sf_ra = (uint64_t) ps->sa_sigdesc[sig].sd_tramp;
137 frame.sf_si._info = ksi->ksi_info;
138
139 /* copy our userret context into sf_uc */
140 memcpy(&frame.sf_uc, ucp, sizeof(ucontext_t));
141 frame.sf_uc.uc_sigmask = *mask;
142 frame.sf_uc.uc_link = l->l_ctxlink;
143 frame.sf_uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK)
144 ? _UC_SETSTACK : _UC_CLRSTACK;
145 memset(&frame.sf_uc.uc_stack, 0, sizeof(frame.sf_uc.uc_stack));
146 sendsig_reset(l, sig);
147
148 /* copyout our frame to the stackframe */
149 mutex_exit(p->p_lock);
150 error = copyout(&frame, fp, sizeof(frame));
151 mutex_enter(p->p_lock);
152
153 if (error != 0) {
154 /*
155 * Process has trashed its stack; give it an illegal
156 * instruction to halt it in its tracks.
157 */
158 sigexit(l, SIGILL);
159 /* NOTREACHED */
160 }
161
162 /* set catcher and the new stack pointer */
163 reg[24] = (register_t) fp; /* RSP */
164 reg[21] = (register_t) catcher; /* RIP */
165
166 reg[ 0] = sig; /* RDI */
167 reg[ 1] = (uint64_t) &fp->sf_si; /* RSI */
168 reg[ 2] = (uint64_t) &fp->sf_uc; /* RDX */
169 reg[11] = reg[ 2]; /* R15 = RDX */
170
171 /* Remember that we're now on the signal stack. */
172 if (onstack)
173 l->l_sigstk.ss_flags |= SS_ONSTACK;
174 }
175
176 void
setregs(struct lwp * l,struct exec_package * pack,vaddr_t stack)177 setregs(struct lwp *l, struct exec_package *pack, vaddr_t stack)
178 {
179 struct pcb *pcb = lwp_getpcb(l);
180 ucontext_t *ucp;
181 register_t *reg;
182 int i;
183
184 /* set up the user context */
185 ucp = &pcb->pcb_userret_ucp;
186 reg = (register_t *) &ucp->uc_mcontext.__gregs;
187 for (i = 0; i < 15; i++)
188 reg[i] = 0;
189
190 reg[13] = l->l_proc->p_psstrp; /* RBX */
191 reg[21] = pack->ep_entry; /* RIP */
192 reg[24] = (register_t) stack; /* RSP */
193
194 /* use given stack */
195 ucp->uc_stack.ss_sp = (void *) stack;
196 ucp->uc_stack.ss_size = pack->ep_ssize;
197
198 //dump_regs(reg);
199 }
200
201 void
md_syscall_get_syscallnumber(ucontext_t * ucp,uint32_t * code)202 md_syscall_get_syscallnumber(ucontext_t *ucp, uint32_t *code)
203 {
204 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
205 *code = reg[14]; /* RAX */
206 }
207
208 int
md_syscall_getargs(lwp_t * l,ucontext_t * ucp,int nargs,int argsize,register_t * args)209 md_syscall_getargs(lwp_t *l, ucontext_t *ucp, int nargs, int argsize,
210 register_t *args)
211 {
212 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
213 register_t *sp = (register_t *) reg[24];/* RSP */
214 int ret;
215
216 //dump_regs(reg);
217
218 /*
219 * 1st 6 syscall args are passed in
220 * rdi, rsi, rdx, r10, r8 and r9
221 */
222 args[0] = reg[ 0]; /* RDI */
223 args[1] = reg[ 1]; /* RSI */
224 args[2] = reg[ 2]; /* RDX */
225 args[3] = reg[ 6]; /* R10 (RCX got clobbered) */
226 args[4] = reg[ 4]; /* R8 */
227 args[5] = reg[ 5]; /* R9 */
228
229 ret = 0;
230 if (argsize > 6 * 8) {
231 ret = copyin(sp + 1,
232 args + 6, argsize - 6 * 8);
233 }
234
235 return ret;
236 }
237
238 void
md_syscall_set_returnargs(lwp_t * l,ucontext_t * ucp,int error,register_t * rval)239 md_syscall_set_returnargs(lwp_t *l, ucontext_t *ucp,
240 int error, register_t *rval)
241 {
242 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
243
244 reg[23] &= ~PSL_C; /* RFLAGS */
245 if (error > 0) {
246 rval[0] = error;
247 reg[23] |= PSL_C; /* RFLAGS */
248 }
249
250 /* set return parameters */
251 reg[14] = rval[0]; /* RAX */
252 if (error == 0)
253 reg[ 2] = rval[1]; /* RDX */
254
255 //dump_regs(reg);
256 }
257
258 register_t
md_get_pc(ucontext_t * ucp)259 md_get_pc(ucontext_t *ucp)
260 {
261 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
262
263 return reg[21]; /* RIP */
264 }
265
266 register_t
md_get_sp(ucontext_t * ucp)267 md_get_sp(ucontext_t *ucp)
268 {
269 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
270
271 return reg[24]; /* RSP */
272 }
273
274 int
md_syscall_check_opcode(ucontext_t * ucp)275 md_syscall_check_opcode(ucontext_t *ucp)
276 {
277 uint32_t opcode;
278
279 md_syscall_get_opcode(ucp, &opcode);
280
281 switch (opcode) {
282 case 0xff0f: /* UD1 */
283 case 0xff0b: /* UD2 */
284 case 0x80cd: /* int $80 */
285 case 0x340f: /* sysenter */
286 case 0x050f: /* syscall */
287 return 1;
288 default:
289 return 0;
290 }
291 }
292
293
294 void
md_syscall_get_opcode(ucontext_t * ucp,uint32_t * opcode)295 md_syscall_get_opcode(ucontext_t *ucp, uint32_t *opcode)
296 {
297 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
298 // uint8_t *p8 = (uint8_t *) (reg[21]);
299 uint16_t *p16 = (uint16_t*) (reg[21]); /* RIP */
300
301 switch (*p16) {
302 case 0xff0f: /* UD1 */
303 case 0xff0b: /* UD2 */
304 case 0x80cd: /* int $80 */
305 case 0x340f: /* sysenter */
306 case 0x050f: /* syscall */
307 *opcode = *p16;
308 break;
309 default:
310 *opcode = 0;
311 }
312 }
313
314 void
md_syscall_inc_pc(ucontext_t * ucp,uint32_t opcode)315 md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode)
316 {
317 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
318
319 /* advance program counter */
320 switch (opcode) {
321 case 0xff0f: /* UD1 */
322 case 0xff0b: /* UD2 */
323 case 0x80cd: /* int $80 */
324 case 0x340f: /* sysenter */
325 case 0x050f: /* syscall */
326 reg[21] += 2; /* RIP */
327 break;
328 default:
329 panic("%s, unknown illegal instruction: opcode = %x\n",
330 __func__, (uint32_t) opcode);
331 }
332 }
333
334 void
md_syscall_dec_pc(ucontext_t * ucp,uint32_t opcode)335 md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode)
336 {
337 register_t *reg = (register_t *) &ucp->uc_mcontext.__gregs;
338
339 switch (opcode) {
340 case 0xff0f: /* UD1 */
341 case 0xff0b: /* UD2 */
342 case 0x80cd: /* int $80 */
343 case 0x340f: /* sysenter */
344 case 0x050f: /* syscall */
345 reg[21] -= 2; /* RIP */
346 break;
347 default:
348 panic("%s, unknown illegal instruction: opcode = %x\n",
349 __func__, (uint32_t) opcode);
350 }
351 }
352
353