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 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 *
25 * Copyright 2018 Joyent, Inc.
26 * Copyright 2025 Oxide Computer Company
27 */
28
29 /*
30 * Libkvm Kernel Target Intel 32-bit component
31 *
32 * This file provides the ISA-dependent portion of the libkvm kernel target.
33 * For more details on the implementation refer to mdb_kvm.c.
34 */
35
36 #include <sys/types.h>
37 #include <sys/regset.h>
38 #include <sys/frame.h>
39 #include <sys/stack.h>
40 #include <sys/sysmacros.h>
41 #include <sys/panic.h>
42 #include <strings.h>
43
44 #include <mdb/mdb_target_impl.h>
45 #include <mdb/mdb_disasm.h>
46 #include <mdb/mdb_modapi.h>
47 #include <mdb/mdb_conf.h>
48 #include <mdb/mdb_stack.h>
49 #include <mdb/mdb_kreg_impl.h>
50 #include <mdb/mdb_isautil.h>
51 #include <mdb/mdb_ia32util.h>
52 #include <mdb/kvm_isadep.h>
53 #include <mdb/mdb_kvm.h>
54 #include <mdb/mdb_err.h>
55 #include <mdb/mdb_debug.h>
56 #include <mdb/mdb.h>
57
58
59 /*ARGSUSED*/
60 int
kt_regs(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)61 kt_regs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
62 {
63 mdb_ia32_printregs((const mdb_tgt_gregset_t *)addr);
64 return (DCMD_OK);
65 }
66
67 static int
kt_stack_common(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv,mdb_stack_frame_flags_t sflags,mdb_tgt_stack_f * func)68 kt_stack_common(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv,
69 mdb_stack_frame_flags_t sflags, mdb_tgt_stack_f *func)
70 {
71 mdb_tgt_t *t = mdb.m_target;
72 kt_data_t *kt = t->t_data;
73 mdb_tgt_gregset_t gregs, *grp;
74 mdb_stack_frame_hdl_t *hdl;
75 uint_t arglim = mdb.m_nargs;
76 int i;
77
78 if (flags & DCMD_ADDRSPEC) {
79 bzero(&gregs, sizeof (gregs));
80 gregs.kregs[KREG_EBP] = addr;
81 grp = &gregs;
82 } else
83 grp = kt->k_regs;
84
85 i = mdb_getopts(argc, argv,
86 'n', MDB_OPT_SETBITS, MSF_ADDR, &sflags,
87 's', MDB_OPT_SETBITS, MSF_SIZES, &sflags,
88 't', MDB_OPT_SETBITS, MSF_TYPES, &sflags,
89 'v', MDB_OPT_SETBITS, MSF_VERBOSE, &sflags,
90 NULL);
91
92 argc -= i;
93 argv += i;
94
95 if (argc != 0) {
96 if (argv->a_type == MDB_TYPE_CHAR || argc > 1)
97 return (DCMD_USAGE);
98
99 arglim = mdb_argtoull(argv);
100 }
101
102 if ((hdl = mdb_stack_frame_init(t, arglim, sflags)) == NULL) {
103 mdb_warn("failed to init stack frame\n");
104 return (DCMD_ERR);
105 }
106
107 (void) mdb_ia32_kvm_stack_iter(mdb.m_target, grp, func, (void *)hdl);
108 return (DCMD_OK);
109 }
110
111 int
kt_stack(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)112 kt_stack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
113 {
114 return (kt_stack_common(addr, flags, argc, argv, 0,
115 mdb_ia32_kvm_frame));
116 }
117
118 int
kt_stackv(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)119 kt_stackv(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
120 {
121 return (kt_stack_common(addr, flags, argc, argv, MSF_VERBOSE,
122 mdb_ia32_kvm_frame));
123 }
124
125 const mdb_tgt_ops_t kt_ia32_ops = {
126 .t_setflags = kt_setflags,
127 .t_setcontext = kt_setcontext,
128 .t_activate = kt_activate,
129 .t_deactivate = kt_deactivate,
130 .t_periodic = (void (*)())(uintptr_t)mdb_tgt_nop,
131 .t_destroy = kt_destroy,
132 .t_name = kt_name,
133 .t_isa = (const char *(*)())mdb_conf_isa,
134 .t_platform = kt_platform,
135 .t_uname = kt_uname,
136 .t_dmodel = kt_dmodel,
137 .t_aread = kt_aread,
138 .t_awrite = kt_awrite,
139 .t_vread = kt_vread,
140 .t_vwrite = kt_vwrite,
141 .t_pread = kt_pread,
142 .t_pwrite = kt_pwrite,
143 .t_fread = kt_fread,
144 .t_fwrite = kt_fwrite,
145 .t_ioread = (ssize_t (*)())mdb_tgt_notsup,
146 .t_iowrite = (ssize_t (*)())mdb_tgt_notsup,
147 .t_vtop = kt_vtop,
148 .t_lookup_by_name = kt_lookup_by_name,
149 .t_lookup_by_addr = kt_lookup_by_addr,
150 .t_symbol_iter = kt_symbol_iter,
151 .t_mapping_iter = kt_mapping_iter,
152 .t_object_iter = kt_object_iter,
153 .t_addr_to_map = kt_addr_to_map,
154 .t_name_to_map = kt_name_to_map,
155 .t_addr_to_ctf = kt_addr_to_ctf,
156 .t_name_to_ctf = kt_name_to_ctf,
157 .t_status = kt_status,
158 .t_run = (int (*)())mdb_tgt_notsup,
159 .t_step = (int (*)())mdb_tgt_notsup,
160 .t_step_out = (int (*)())mdb_tgt_notsup,
161 .t_next = (int (*)())mdb_tgt_notsup,
162 .t_cont = (int (*)())mdb_tgt_notsup,
163 .t_signal = (int (*)())mdb_tgt_notsup,
164 .t_add_vbrkpt = (int (*)())(uintptr_t)mdb_tgt_null,
165 .t_add_sbrkpt = (int (*)())(uintptr_t)mdb_tgt_null,
166 .t_add_pwapt = (int (*)())(uintptr_t)mdb_tgt_null,
167 .t_add_vwapt = (int (*)())(uintptr_t)mdb_tgt_null,
168 .t_add_iowapt = (int (*)())(uintptr_t)mdb_tgt_null,
169 .t_add_sysenter = (int (*)())(uintptr_t)mdb_tgt_null,
170 .t_add_sysexit = (int (*)())(uintptr_t)mdb_tgt_null,
171 .t_add_signal = (int (*)())(uintptr_t)mdb_tgt_null,
172 .t_add_fault = (int (*)())(uintptr_t)mdb_tgt_null,
173 .t_getareg = kt_getareg,
174 .t_putareg = kt_putareg,
175 .t_stack_iter = mdb_ia32_kvm_stack_iter,
176 .t_auxv = (int (*)())mdb_tgt_notsup,
177 .t_thread_name = (int (*)())(uintptr_t)mdb_tgt_notsup,
178 };
179
180 void
kt_regs_to_kregs(struct regs * regs,mdb_tgt_gregset_t * gregs)181 kt_regs_to_kregs(struct regs *regs, mdb_tgt_gregset_t *gregs)
182 {
183 gregs->kregs[KREG_SAVFP] = regs->r_savfp;
184 gregs->kregs[KREG_SAVPC] = regs->r_savpc;
185 gregs->kregs[KREG_EAX] = regs->r_eax;
186 gregs->kregs[KREG_EBX] = regs->r_ebx;
187 gregs->kregs[KREG_ECX] = regs->r_ecx;
188 gregs->kregs[KREG_EDX] = regs->r_edx;
189 gregs->kregs[KREG_ESI] = regs->r_esi;
190 gregs->kregs[KREG_EDI] = regs->r_edi;
191 gregs->kregs[KREG_EBP] = regs->r_ebp;
192 gregs->kregs[KREG_ESP] = regs->r_esp;
193 gregs->kregs[KREG_CS] = regs->r_cs;
194 gregs->kregs[KREG_DS] = regs->r_ds;
195 gregs->kregs[KREG_SS] = regs->r_ss;
196 gregs->kregs[KREG_ES] = regs->r_es;
197 gregs->kregs[KREG_FS] = regs->r_fs;
198 gregs->kregs[KREG_GS] = regs->r_gs;
199 gregs->kregs[KREG_EFLAGS] = regs->r_efl;
200 gregs->kregs[KREG_EIP] = regs->r_eip;
201 gregs->kregs[KREG_UESP] = regs->r_uesp;
202 gregs->kregs[KREG_TRAPNO] = regs->r_trapno;
203 gregs->kregs[KREG_ERR] = regs->r_err;
204 }
205
206 void
kt_ia32_init(mdb_tgt_t * t)207 kt_ia32_init(mdb_tgt_t *t)
208 {
209 kt_data_t *kt = t->t_data;
210 panic_data_t pd;
211 label_t label;
212 struct regs regs;
213 kreg_t *kregs;
214 uintptr_t addr;
215
216 /*
217 * Initialize the machine-dependent parts of the kernel target
218 * structure. Once this is complete and we fill in the ops
219 * vector, the target is now fully constructed and we can use
220 * the target API itself to perform the rest of our initialization.
221 */
222 kt->k_rds = mdb_ia32_kregs;
223 kt->k_regs = mdb_zalloc(sizeof (mdb_tgt_gregset_t), UM_SLEEP);
224 kt->k_regsize = sizeof (mdb_tgt_gregset_t);
225 kt->k_dcmd_regs = kt_regs;
226 kt->k_dcmd_stack = kt_stack;
227 kt->k_dcmd_stackv = kt_stackv;
228 kt->k_dcmd_stackr = kt_stackv;
229 kt->k_dcmd_cpustack = kt_cpustack;
230 kt->k_dcmd_cpuregs = kt_cpuregs;
231
232 t->t_ops = &kt_ia32_ops;
233 kregs = kt->k_regs->kregs;
234
235 (void) mdb_dis_select("ia32");
236
237 /*
238 * Lookup the symbols corresponding to subroutines in locore.s where
239 * we expect a saved regs structure to be pushed on the stack. When
240 * performing stack tracebacks we will attempt to detect interrupt
241 * frames by comparing the %eip value to these symbols.
242 */
243 (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
244 "cmnint", &kt->k_intr_sym, NULL);
245
246 (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
247 "cmntrap", &kt->k_trap_sym, NULL);
248
249 /*
250 * Don't attempt to load any thread or register information if
251 * we're examining the live operating system.
252 */
253 if (kt->k_symfile != NULL && strcmp(kt->k_symfile, "/dev/ksyms") == 0)
254 return;
255
256 /*
257 * If the panicbuf symbol is present and we can consume a panicbuf
258 * header of the appropriate version from this address, then we can
259 * initialize our current register set based on its contents.
260 * Prior to the re-structuring of panicbuf, our only register data
261 * was the panic_regs label_t, into which a setjmp() was performed,
262 * or the panic_reg register pointer, which was only non-zero if
263 * the system panicked as a result of a trap calling die().
264 */
265 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &pd, sizeof (pd),
266 MDB_TGT_OBJ_EXEC, "panicbuf") == sizeof (pd) &&
267 pd.pd_version == PANICBUFVERS) {
268
269 size_t pd_size = MIN(PANICBUFSIZE, pd.pd_msgoff);
270 panic_data_t *pdp = mdb_zalloc(pd_size, UM_SLEEP);
271 uint_t i, n;
272
273 (void) mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, pdp, pd_size,
274 MDB_TGT_OBJ_EXEC, "panicbuf");
275
276 n = (pd_size - (sizeof (panic_data_t) -
277 sizeof (panic_nv_t))) / sizeof (panic_nv_t);
278
279 for (i = 0; i < n; i++) {
280 (void) kt_putareg(t, kt->k_tid,
281 pdp->pd_nvdata[i].pnv_name,
282 pdp->pd_nvdata[i].pnv_value);
283 }
284
285 mdb_free(pdp, pd_size);
286
287 return;
288 }
289
290 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &addr, sizeof (addr),
291 MDB_TGT_OBJ_EXEC, "panic_reg") == sizeof (addr) && addr != 0 &&
292 mdb_tgt_vread(t, ®s, sizeof (regs), addr) == sizeof (regs)) {
293 kt_regs_to_kregs(®s, kt->k_regs);
294 return;
295 }
296
297 /*
298 * If we can't read any panic regs, then our penultimate try is for any
299 * CPU context that may have been stored (for example, in Xen core
300 * dumps). As this can only succeed for kernels with the above
301 * methods available, we let it over-ride the older panic_regs method,
302 * which will always manage to read the label_t, even if there's
303 * nothing useful there.
304 */
305 if (kt_kvmregs(t, 0, kt->k_regs) == 0)
306 return;
307
308 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &label, sizeof (label),
309 MDB_TGT_OBJ_EXEC, "panic_regs") == sizeof (label)) {
310 kregs[KREG_EDI] = label.val[0];
311 kregs[KREG_ESI] = label.val[1];
312 kregs[KREG_EBX] = label.val[2];
313 kregs[KREG_EBP] = label.val[3];
314 kregs[KREG_ESP] = label.val[4];
315 kregs[KREG_EIP] = label.val[5];
316 return;
317 }
318
319 warn("failed to read panicbuf, panic_reg and panic_regs -- "
320 "current register set will be unavailable\n");
321 }
322