1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26 /*
27 * Copyright (c) 2018, Joyent, Inc. All rights reserved.
28 * Copyright 2014 Nexenta Systems, Inc. All rights reserved.
29 * Copyright (c) 2013 by Delphix. All rights reserved.
30 */
31
32 #include <sys/types.h>
33 #include <sys/reg.h>
34 #include <sys/privregs.h>
35 #include <sys/stack.h>
36 #include <sys/frame.h>
37
38 #include <mdb/mdb_target_impl.h>
39 #include <mdb/mdb_kreg_impl.h>
40 #include <mdb/mdb_debug.h>
41 #include <mdb/mdb_modapi.h>
42 #include <mdb/mdb_isautil.h>
43 #include <mdb/mdb_amd64util.h>
44 #include <mdb/mdb_ctf.h>
45 #include <mdb/mdb_err.h>
46 #include <mdb/mdb.h>
47
48 #include <saveargs.h>
49
50 /*
51 * This array is used by the getareg and putareg entry points, and also by our
52 * register variable discipline.
53 */
54
55 const mdb_tgt_regdesc_t mdb_amd64_kregs[] = {
56 { "savfp", KREG_SAVFP, MDB_TGT_R_EXPORT },
57 { "savpc", KREG_SAVPC, MDB_TGT_R_EXPORT },
58 { "rdi", KREG_RDI, MDB_TGT_R_EXPORT },
59 { "edi", KREG_RDI, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
60 { "di", KREG_RDI, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
61 { "dil", KREG_RDI, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
62 { "rsi", KREG_RSI, MDB_TGT_R_EXPORT },
63 { "esi", KREG_RSI, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
64 { "si", KREG_RSI, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
65 { "sil", KREG_RSI, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
66 { "rdx", KREG_RDX, MDB_TGT_R_EXPORT },
67 { "edx", KREG_RDX, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
68 { "dx", KREG_RDX, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
69 { "dh", KREG_RDX, MDB_TGT_R_EXPORT | MDB_TGT_R_8H },
70 { "dl", KREG_RDX, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
71 { "rcx", KREG_RCX, MDB_TGT_R_EXPORT },
72 { "ecx", KREG_RCX, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
73 { "cx", KREG_RCX, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
74 { "ch", KREG_RCX, MDB_TGT_R_EXPORT | MDB_TGT_R_8H },
75 { "cl", KREG_RCX, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
76 { "r8", KREG_R8, MDB_TGT_R_EXPORT },
77 { "r8d", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
78 { "r8w", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
79 { "r8l", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
80 { "r9", KREG_R9, MDB_TGT_R_EXPORT },
81 { "r9d", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
82 { "r9w", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
83 { "r9l", KREG_R8, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
84 { "rax", KREG_RAX, MDB_TGT_R_EXPORT },
85 { "eax", KREG_RAX, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
86 { "ax", KREG_RAX, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
87 { "ah", KREG_RAX, MDB_TGT_R_EXPORT | MDB_TGT_R_8H },
88 { "al", KREG_RAX, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
89 { "rbx", KREG_RBX, MDB_TGT_R_EXPORT },
90 { "ebx", KREG_RBX, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
91 { "bx", KREG_RBX, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
92 { "bh", KREG_RBX, MDB_TGT_R_EXPORT | MDB_TGT_R_8H },
93 { "bl", KREG_RBX, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
94 { "rbp", KREG_RBP, MDB_TGT_R_EXPORT },
95 { "ebp", KREG_RBP, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
96 { "bp", KREG_RBP, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
97 { "bpl", KREG_RBP, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
98 { "r10", KREG_R10, MDB_TGT_R_EXPORT },
99 { "r10d", KREG_R10, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
100 { "r10w", KREG_R10, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
101 { "r10l", KREG_R10, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
102 { "r11", KREG_R11, MDB_TGT_R_EXPORT },
103 { "r11d", KREG_R11, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
104 { "r11w", KREG_R11, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
105 { "r11l", KREG_R11, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
106 { "r12", KREG_R12, MDB_TGT_R_EXPORT },
107 { "r12d", KREG_R12, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
108 { "r12w", KREG_R12, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
109 { "r12l", KREG_R12, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
110 { "r13", KREG_R13, MDB_TGT_R_EXPORT },
111 { "r13d", KREG_R13, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
112 { "r13w", KREG_R13, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
113 { "r13l", KREG_R13, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
114 { "r14", KREG_R14, MDB_TGT_R_EXPORT },
115 { "r14d", KREG_R14, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
116 { "r14w", KREG_R14, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
117 { "r14l", KREG_R14, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
118 { "r15", KREG_R15, MDB_TGT_R_EXPORT },
119 { "r15d", KREG_R15, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
120 { "r15w", KREG_R15, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
121 { "r15l", KREG_R15, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
122 { "ds", KREG_DS, MDB_TGT_R_EXPORT },
123 { "es", KREG_ES, MDB_TGT_R_EXPORT },
124 { "fs", KREG_FS, MDB_TGT_R_EXPORT },
125 { "gs", KREG_GS, MDB_TGT_R_EXPORT },
126 { "trapno", KREG_TRAPNO, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
127 { "err", KREG_ERR, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
128 { "rip", KREG_RIP, MDB_TGT_R_EXPORT },
129 { "cs", KREG_CS, MDB_TGT_R_EXPORT },
130 { "rflags", KREG_RFLAGS, MDB_TGT_R_EXPORT },
131 { "eflags", KREG_RFLAGS, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
132 { "rsp", KREG_RSP, MDB_TGT_R_EXPORT },
133 { "esp", KREG_RSP, MDB_TGT_R_EXPORT | MDB_TGT_R_32 },
134 { "sp", KREG_RSP, MDB_TGT_R_EXPORT | MDB_TGT_R_16 },
135 { "spl", KREG_RSP, MDB_TGT_R_EXPORT | MDB_TGT_R_8L },
136 { "ss", KREG_SS, MDB_TGT_R_EXPORT },
137 { "gsbase", KREG_GSBASE, MDB_TGT_R_EXPORT },
138 { "kgsbase", KREG_KGSBASE, MDB_TGT_R_EXPORT },
139 { "cr2", KREG_CR2, MDB_TGT_R_EXPORT },
140 { "cr3", KREG_CR3, MDB_TGT_R_EXPORT },
141 { NULL, 0, 0 }
142 };
143
144 void
mdb_amd64_printregs(const mdb_tgt_gregset_t * gregs)145 mdb_amd64_printregs(const mdb_tgt_gregset_t *gregs)
146 {
147 const kreg_t *kregs = &gregs->kregs[0];
148 kreg_t rflags = kregs[KREG_RFLAGS];
149
150 #define GETREG2(x) ((uintptr_t)kregs[(x)]), ((uintptr_t)kregs[(x)])
151
152 mdb_printf("%%rax = 0x%0?p %15A %%r9 = 0x%0?p %A\n",
153 GETREG2(KREG_RAX), GETREG2(KREG_R9));
154 mdb_printf("%%rbx = 0x%0?p %15A %%r10 = 0x%0?p %A\n",
155 GETREG2(KREG_RBX), GETREG2(KREG_R10));
156 mdb_printf("%%rcx = 0x%0?p %15A %%r11 = 0x%0?p %A\n",
157 GETREG2(KREG_RCX), GETREG2(KREG_R11));
158 mdb_printf("%%rdx = 0x%0?p %15A %%r12 = 0x%0?p %A\n",
159 GETREG2(KREG_RDX), GETREG2(KREG_R12));
160 mdb_printf("%%rsi = 0x%0?p %15A %%r13 = 0x%0?p %A\n",
161 GETREG2(KREG_RSI), GETREG2(KREG_R13));
162 mdb_printf("%%rdi = 0x%0?p %15A %%r14 = 0x%0?p %A\n",
163 GETREG2(KREG_RDI), GETREG2(KREG_R14));
164 mdb_printf("%%r8 = 0x%0?p %15A %%r15 = 0x%0?p %A\n\n",
165 GETREG2(KREG_R8), GETREG2(KREG_R15));
166
167 mdb_printf("%%rip = 0x%0?p %A\n", GETREG2(KREG_RIP));
168 mdb_printf("%%rbp = 0x%0?p\n", kregs[KREG_RBP]);
169 mdb_printf("%%rsp = 0x%0?p\n", kregs[KREG_RSP]);
170
171 mdb_printf("%%rflags = 0x%08x\n", rflags);
172
173 mdb_printf(" id=%u vip=%u vif=%u ac=%u vm=%u rf=%u nt=%u iopl=0x%x\n",
174 (rflags & KREG_EFLAGS_ID_MASK) >> KREG_EFLAGS_ID_SHIFT,
175 (rflags & KREG_EFLAGS_VIP_MASK) >> KREG_EFLAGS_VIP_SHIFT,
176 (rflags & KREG_EFLAGS_VIF_MASK) >> KREG_EFLAGS_VIF_SHIFT,
177 (rflags & KREG_EFLAGS_AC_MASK) >> KREG_EFLAGS_AC_SHIFT,
178 (rflags & KREG_EFLAGS_VM_MASK) >> KREG_EFLAGS_VM_SHIFT,
179 (rflags & KREG_EFLAGS_RF_MASK) >> KREG_EFLAGS_RF_SHIFT,
180 (rflags & KREG_EFLAGS_NT_MASK) >> KREG_EFLAGS_NT_SHIFT,
181 (rflags & KREG_EFLAGS_IOPL_MASK) >> KREG_EFLAGS_IOPL_SHIFT);
182
183 mdb_printf(" status=<%s,%s,%s,%s,%s,%s,%s,%s,%s>\n\n",
184 (rflags & KREG_EFLAGS_OF_MASK) ? "OF" : "of",
185 (rflags & KREG_EFLAGS_DF_MASK) ? "DF" : "df",
186 (rflags & KREG_EFLAGS_IF_MASK) ? "IF" : "if",
187 (rflags & KREG_EFLAGS_TF_MASK) ? "TF" : "tf",
188 (rflags & KREG_EFLAGS_SF_MASK) ? "SF" : "sf",
189 (rflags & KREG_EFLAGS_ZF_MASK) ? "ZF" : "zf",
190 (rflags & KREG_EFLAGS_AF_MASK) ? "AF" : "af",
191 (rflags & KREG_EFLAGS_PF_MASK) ? "PF" : "pf",
192 (rflags & KREG_EFLAGS_CF_MASK) ? "CF" : "cf");
193
194 mdb_printf("%%cs = 0x%04x\t%%ds = 0x%04x\t"
195 "%%es = 0x%04x\t%%fs = 0x%04x\n", kregs[KREG_CS], kregs[KREG_DS],
196 kregs[KREG_ES], kregs[KREG_FS] & 0xffff);
197 mdb_printf("%%gs = 0x%04x\t%%gsbase = 0x%lx\t%%kgsbase = 0x%lx\n",
198 kregs[KREG_GS] & 0xffff, kregs[KREG_GSBASE], kregs[KREG_KGSBASE]);
199 mdb_printf("%%trapno = 0x%x\t%%err = 0x%x\t%%cr2 = 0x%lx\t"
200 "%%cr3 = 0x%lx\n", kregs[KREG_TRAPNO], kregs[KREG_ERR],
201 kregs[KREG_CR2], kregs[KREG_CR3]);
202 }
203
204 int
mdb_amd64_kvm_stack_iter(mdb_tgt_t * t,const mdb_tgt_gregset_t * gsp,mdb_tgt_stack_f * func,void * arg)205 mdb_amd64_kvm_stack_iter(mdb_tgt_t *t, const mdb_tgt_gregset_t *gsp,
206 mdb_tgt_stack_f *func, void *arg)
207 {
208 mdb_tgt_gregset_t gregs;
209 kreg_t *kregs = &gregs.kregs[0];
210 int got_pc = (gsp->kregs[KREG_RIP] != 0);
211 uint_t argc, reg_argc;
212 long fr_argv[32];
213 int start_index; /* index to save_instr where to start comparison */
214 int err;
215 int i;
216
217 struct fr {
218 uintptr_t fr_savfp;
219 uintptr_t fr_savpc;
220 } fr;
221
222 uintptr_t fp = gsp->kregs[KREG_RBP];
223 uintptr_t pc = gsp->kregs[KREG_RIP];
224 uintptr_t lastfp = 0;
225
226 ssize_t size;
227 ssize_t insnsize;
228 uint8_t ins[SAVEARGS_INSN_SEQ_LEN];
229
230 GElf_Sym s;
231 mdb_syminfo_t sip;
232 mdb_ctf_funcinfo_t mfp;
233 int xpv_panic = 0;
234 int advance_tortoise = 1;
235 uintptr_t tortoise_fp = 0;
236 #ifndef _KMDB
237 int xp;
238
239 if ((mdb_readsym(&xp, sizeof (xp), "xpv_panicking") != -1) && (xp > 0))
240 xpv_panic = 1;
241 #endif
242
243 bcopy(gsp, &gregs, sizeof (gregs));
244
245 while (fp != 0) {
246 int args_style = 0;
247
248 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_S, &fr, sizeof (fr), fp) !=
249 sizeof (fr)) {
250 err = EMDB_NOMAP;
251 goto badfp;
252 }
253
254 if (tortoise_fp == 0) {
255 tortoise_fp = fp;
256 } else {
257 /*
258 * Advance tortoise_fp every other frame, so we detect
259 * cycles with Floyd's tortoise/hare.
260 */
261 if (advance_tortoise != 0) {
262 struct fr tfr;
263
264 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_S, &tfr,
265 sizeof (tfr), tortoise_fp) !=
266 sizeof (tfr)) {
267 err = EMDB_NOMAP;
268 goto badfp;
269 }
270
271 tortoise_fp = tfr.fr_savfp;
272 }
273
274 if (fp == tortoise_fp) {
275 err = EMDB_STKFRAME;
276 goto badfp;
277 }
278 }
279
280 advance_tortoise = !advance_tortoise;
281
282 if ((mdb_tgt_lookup_by_addr(t, pc, MDB_TGT_SYM_FUZZY,
283 NULL, 0, &s, &sip) == 0) &&
284 (mdb_ctf_func_info(&s, &sip, &mfp) == 0)) {
285 int return_type = mdb_ctf_type_kind(mfp.mtf_return);
286 mdb_ctf_id_t args_types[5];
287
288 argc = mfp.mtf_argc;
289
290 /*
291 * If the function returns a structure or union
292 * greater than 16 bytes in size %rdi contains the
293 * address in which to store the return value rather
294 * than for an argument.
295 */
296 if ((return_type == CTF_K_STRUCT ||
297 return_type == CTF_K_UNION) &&
298 mdb_ctf_type_size(mfp.mtf_return) > 16)
299 start_index = 1;
300 else
301 start_index = 0;
302
303 /*
304 * If any of the first 5 arguments are a structure
305 * less than 16 bytes in size, it will be passed
306 * spread across two argument registers, and we will
307 * not cope.
308 */
309 if (mdb_ctf_func_args(&mfp, 5, args_types) == CTF_ERR)
310 argc = 0;
311
312 for (i = 0; i < MIN(5, argc); i++) {
313 int t = mdb_ctf_type_kind(args_types[i]);
314
315 if (((t == CTF_K_STRUCT) ||
316 (t == CTF_K_UNION)) &&
317 mdb_ctf_type_size(args_types[i]) <= 16) {
318 argc = 0;
319 break;
320 }
321 }
322 } else {
323 argc = 0;
324 }
325
326 /*
327 * The number of instructions to search for argument saving is
328 * limited such that only instructions prior to %pc are
329 * considered such that we never read arguments from a
330 * function where the saving code has not in fact yet
331 * executed.
332 */
333 insnsize = MIN(MIN(s.st_size, SAVEARGS_INSN_SEQ_LEN),
334 pc - s.st_value);
335
336 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_I, ins, insnsize,
337 s.st_value) != insnsize)
338 argc = 0;
339
340 if ((argc != 0) &&
341 ((args_style = saveargs_has_args(ins, insnsize, argc,
342 start_index)) != SAVEARGS_NO_ARGS)) {
343 /* Up to 6 arguments are passed via registers */
344 reg_argc = MIN((6 - start_index), mfp.mtf_argc);
345 size = reg_argc * sizeof (long);
346
347 /*
348 * If Studio pushed a structure return address as an
349 * argument, we need to read one more argument than
350 * actually exists (the addr) to make everything line
351 * up.
352 */
353 if (args_style == SAVEARGS_STRUCT_ARGS)
354 size += sizeof (long);
355
356 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_S, fr_argv, size,
357 (fp - size)) != size)
358 return (-1); /* errno has been set for us */
359
360 /*
361 * Arrange the arguments in the right order for
362 * printing.
363 */
364 for (i = 0; i < (reg_argc / 2); i++) {
365 long t = fr_argv[i];
366
367 fr_argv[i] = fr_argv[reg_argc - i - 1];
368 fr_argv[reg_argc - i - 1] = t;
369 }
370
371 if (argc > reg_argc) {
372 size = MIN((argc - reg_argc) * sizeof (long),
373 sizeof (fr_argv) -
374 (reg_argc * sizeof (long)));
375
376 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_S,
377 &fr_argv[reg_argc], size,
378 fp + sizeof (fr)) != size)
379 return (-1); /* errno has been set */
380 }
381 } else {
382 argc = 0;
383 }
384
385 if (got_pc && func(arg, pc, argc, fr_argv, &gregs) != 0)
386 break;
387
388 kregs[KREG_RSP] = kregs[KREG_RBP];
389
390 lastfp = fp;
391 fp = fr.fr_savfp;
392 /*
393 * The Xen hypervisor marks a stack frame as belonging to
394 * an exception by inverting the bits of the pointer to
395 * that frame. We attempt to identify these frames by
396 * inverting the pointer and seeing if it is within 0xfff
397 * bytes of the last frame.
398 */
399 if (xpv_panic)
400 if ((fp != 0) && (fp < lastfp) &&
401 ((lastfp ^ ~fp) < 0xfff))
402 fp = ~fp;
403
404 kregs[KREG_RBP] = fp;
405 kregs[KREG_RIP] = pc = fr.fr_savpc;
406
407 got_pc = (pc != 0);
408 }
409
410 return (0);
411
412 badfp:
413 mdb_printf("%p [%s]", fp, mdb_strerror(err));
414 return (set_errno(err));
415 }
416
417 /*
418 * Determine the return address for the current frame. Typically this is the
419 * fr_savpc value from the current frame, but we also perform some special
420 * handling to see if we are stopped on one of the first two instructions of
421 * a typical function prologue, in which case %rbp will not be set up yet.
422 */
423 int
mdb_amd64_step_out(mdb_tgt_t * t,uintptr_t * p,kreg_t pc,kreg_t fp,kreg_t sp,mdb_instr_t curinstr)424 mdb_amd64_step_out(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, kreg_t fp, kreg_t sp,
425 mdb_instr_t curinstr)
426 {
427 struct frame fr;
428 GElf_Sym s;
429 char buf[1];
430
431 enum {
432 M_PUSHQ_RBP = 0x55, /* pushq %rbp */
433 M_REX_W = 0x48, /* REX prefix with only W set */
434 M_MOVL_RBP = 0x8b /* movq %rsp, %rbp with prefix */
435 };
436
437 if (mdb_tgt_lookup_by_addr(t, pc, MDB_TGT_SYM_FUZZY,
438 buf, 0, &s, NULL) == 0) {
439 if (pc == s.st_value && curinstr == M_PUSHQ_RBP)
440 fp = sp - 8;
441 else if (pc == s.st_value + 1 && curinstr == M_REX_W) {
442 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_I, &curinstr,
443 sizeof (curinstr), pc + 1) == sizeof (curinstr) &&
444 curinstr == M_MOVL_RBP)
445 fp = sp;
446 }
447 }
448
449 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_S, &fr, sizeof (fr), fp) ==
450 sizeof (fr)) {
451 *p = fr.fr_savpc;
452 return (0);
453 }
454
455 return (-1); /* errno is set for us */
456 }
457
458 /*ARGSUSED*/
459 int
mdb_amd64_next(mdb_tgt_t * t,uintptr_t * p,kreg_t pc,mdb_instr_t curinstr)460 mdb_amd64_next(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, mdb_instr_t curinstr)
461 {
462 mdb_tgt_addr_t npc;
463 mdb_tgt_addr_t callpc;
464
465 enum {
466 M_CALL_REL = 0xe8, /* call near with relative displacement */
467 M_CALL_REG = 0xff, /* call near indirect or call far register */
468
469 M_REX_LO = 0x40,
470 M_REX_HI = 0x4f
471 };
472
473 /*
474 * If the opcode is a near call with relative displacement, assume the
475 * displacement is a rel32 from the next instruction.
476 */
477 if (curinstr == M_CALL_REL) {
478 *p = pc + sizeof (mdb_instr_t) + sizeof (uint32_t);
479 return (0);
480 }
481
482 /* Skip the rex prefix, if any */
483 callpc = pc;
484 while (curinstr >= M_REX_LO && curinstr <= M_REX_HI) {
485 if (mdb_tgt_aread(t, MDB_TGT_AS_VIRT_I, &curinstr,
486 sizeof (curinstr), ++callpc) != sizeof (curinstr))
487 return (-1); /* errno is set for us */
488 }
489
490 if (curinstr != M_CALL_REG) {
491 /* It's not a call */
492 return (set_errno(EAGAIN));
493 }
494
495 npc = mdb_dis_nextins(mdb.m_disasm, t, MDB_TGT_AS_VIRT_I, pc);
496 if (npc == pc)
497 return (-1); /* errno is set for us */
498
499 *p = npc;
500 return (0);
501 }
502
503 /*ARGSUSED*/
504 int
mdb_amd64_kvm_frame(void * arglim,uintptr_t pc,uint_t argc,const long * argv,const mdb_tgt_gregset_t * gregs)505 mdb_amd64_kvm_frame(void *arglim, uintptr_t pc, uint_t argc, const long *argv,
506 const mdb_tgt_gregset_t *gregs)
507 {
508 argc = MIN(argc, (uintptr_t)arglim);
509 mdb_printf("%a(", pc);
510
511 if (argc != 0) {
512 mdb_printf("%lr", *argv++);
513 for (argc--; argc != 0; argc--)
514 mdb_printf(", %lr", *argv++);
515 }
516
517 mdb_printf(")\n");
518 return (0);
519 }
520
521 int
mdb_amd64_kvm_framev(void * arglim,uintptr_t pc,uint_t argc,const long * argv,const mdb_tgt_gregset_t * gregs)522 mdb_amd64_kvm_framev(void *arglim, uintptr_t pc, uint_t argc, const long *argv,
523 const mdb_tgt_gregset_t *gregs)
524 {
525 /*
526 * Historically adb limited stack trace argument display to a fixed-
527 * size number of arguments since no symbolic debugging info existed.
528 * On amd64 we can detect the true number of saved arguments so only
529 * respect an arglim of zero; otherwise display the entire argv[].
530 */
531 if (arglim == 0)
532 argc = 0;
533
534 mdb_printf("%0?lr %a(", gregs->kregs[KREG_RBP], pc);
535
536 if (argc != 0) {
537 mdb_printf("%lr", *argv++);
538 for (argc--; argc != 0; argc--)
539 mdb_printf(", %lr", *argv++);
540 }
541
542 mdb_printf(")\n");
543 return (0);
544 }
545