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 2024 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_kreg_impl.h>
49 #include <mdb/mdb_isautil.h>
50 #include <mdb/mdb_ia32util.h>
51 #include <mdb/kvm_isadep.h>
52 #include <mdb/mdb_kvm.h>
53 #include <mdb/mdb_err.h>
54 #include <mdb/mdb_debug.h>
55 #include <mdb/mdb.h>
56
57
58 /*ARGSUSED*/
59 int
kt_regs(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)60 kt_regs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
61 {
62 mdb_ia32_printregs((const mdb_tgt_gregset_t *)addr);
63 return (DCMD_OK);
64 }
65
66 static int
kt_stack_common(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv,mdb_tgt_stack_f * func)67 kt_stack_common(uintptr_t addr, uint_t flags, int argc,
68 const mdb_arg_t *argv, mdb_tgt_stack_f *func)
69 {
70 kt_data_t *kt = mdb.m_target->t_data;
71 void *arg = (void *)mdb.m_nargs;
72 mdb_tgt_gregset_t gregs, *grp;
73
74 if (flags & DCMD_ADDRSPEC) {
75 bzero(&gregs, sizeof (gregs));
76 gregs.kregs[KREG_EBP] = addr;
77 grp = &gregs;
78 } else
79 grp = kt->k_regs;
80
81 if (argc != 0) {
82 if (argv->a_type == MDB_TYPE_CHAR || argc > 1)
83 return (DCMD_USAGE);
84
85 if (argv->a_type == MDB_TYPE_STRING)
86 arg = (void *)(uint_t)mdb_strtoull(argv->a_un.a_str);
87 else
88 arg = (void *)(uint_t)argv->a_un.a_val;
89 }
90
91 (void) mdb_ia32_kvm_stack_iter(mdb.m_target, grp, func, arg);
92 return (DCMD_OK);
93 }
94
95 int
kt_stack(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)96 kt_stack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
97 {
98 return (kt_stack_common(addr, flags, argc, argv, mdb_ia32_kvm_frame));
99 }
100
101 int
kt_stackv(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)102 kt_stackv(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
103 {
104 return (kt_stack_common(addr, flags, argc, argv, mdb_ia32_kvm_framev));
105 }
106
107 const mdb_tgt_ops_t kt_ia32_ops = {
108 .t_setflags = kt_setflags,
109 .t_setcontext = kt_setcontext,
110 .t_activate = kt_activate,
111 .t_deactivate = kt_deactivate,
112 .t_periodic = (void (*)())(uintptr_t)mdb_tgt_nop,
113 .t_destroy = kt_destroy,
114 .t_name = kt_name,
115 .t_isa = (const char *(*)())mdb_conf_isa,
116 .t_platform = kt_platform,
117 .t_uname = kt_uname,
118 .t_dmodel = kt_dmodel,
119 .t_aread = kt_aread,
120 .t_awrite = kt_awrite,
121 .t_vread = kt_vread,
122 .t_vwrite = kt_vwrite,
123 .t_pread = kt_pread,
124 .t_pwrite = kt_pwrite,
125 .t_fread = kt_fread,
126 .t_fwrite = kt_fwrite,
127 .t_ioread = (ssize_t (*)())mdb_tgt_notsup,
128 .t_iowrite = (ssize_t (*)())mdb_tgt_notsup,
129 .t_vtop = kt_vtop,
130 .t_lookup_by_name = kt_lookup_by_name,
131 .t_lookup_by_addr = kt_lookup_by_addr,
132 .t_symbol_iter = kt_symbol_iter,
133 .t_mapping_iter = kt_mapping_iter,
134 .t_object_iter = kt_object_iter,
135 .t_addr_to_map = kt_addr_to_map,
136 .t_name_to_map = kt_name_to_map,
137 .t_addr_to_ctf = kt_addr_to_ctf,
138 .t_name_to_ctf = kt_name_to_ctf,
139 .t_status = kt_status,
140 .t_run = (int (*)())mdb_tgt_notsup,
141 .t_step = (int (*)())mdb_tgt_notsup,
142 .t_step_out = (int (*)())mdb_tgt_notsup,
143 .t_next = (int (*)())mdb_tgt_notsup,
144 .t_cont = (int (*)())mdb_tgt_notsup,
145 .t_signal = (int (*)())mdb_tgt_notsup,
146 .t_add_vbrkpt = (int (*)())(uintptr_t)mdb_tgt_null,
147 .t_add_sbrkpt = (int (*)())(uintptr_t)mdb_tgt_null,
148 .t_add_pwapt = (int (*)())(uintptr_t)mdb_tgt_null,
149 .t_add_vwapt = (int (*)())(uintptr_t)mdb_tgt_null,
150 .t_add_iowapt = (int (*)())(uintptr_t)mdb_tgt_null,
151 .t_add_sysenter = (int (*)())(uintptr_t)mdb_tgt_null,
152 .t_add_sysexit = (int (*)())(uintptr_t)mdb_tgt_null,
153 .t_add_signal = (int (*)())(uintptr_t)mdb_tgt_null,
154 .t_add_fault = (int (*)())(uintptr_t)mdb_tgt_null,
155 .t_getareg = kt_getareg,
156 .t_putareg = kt_putareg,
157 .t_stack_iter = mdb_ia32_kvm_stack_iter,
158 .t_auxv = (int (*)())mdb_tgt_notsup,
159 .t_thread_name = (int (*)())(uintptr_t)mdb_tgt_notsup,
160 };
161
162 void
kt_regs_to_kregs(struct regs * regs,mdb_tgt_gregset_t * gregs)163 kt_regs_to_kregs(struct regs *regs, mdb_tgt_gregset_t *gregs)
164 {
165 gregs->kregs[KREG_SAVFP] = regs->r_savfp;
166 gregs->kregs[KREG_SAVPC] = regs->r_savpc;
167 gregs->kregs[KREG_EAX] = regs->r_eax;
168 gregs->kregs[KREG_EBX] = regs->r_ebx;
169 gregs->kregs[KREG_ECX] = regs->r_ecx;
170 gregs->kregs[KREG_EDX] = regs->r_edx;
171 gregs->kregs[KREG_ESI] = regs->r_esi;
172 gregs->kregs[KREG_EDI] = regs->r_edi;
173 gregs->kregs[KREG_EBP] = regs->r_ebp;
174 gregs->kregs[KREG_ESP] = regs->r_esp;
175 gregs->kregs[KREG_CS] = regs->r_cs;
176 gregs->kregs[KREG_DS] = regs->r_ds;
177 gregs->kregs[KREG_SS] = regs->r_ss;
178 gregs->kregs[KREG_ES] = regs->r_es;
179 gregs->kregs[KREG_FS] = regs->r_fs;
180 gregs->kregs[KREG_GS] = regs->r_gs;
181 gregs->kregs[KREG_EFLAGS] = regs->r_efl;
182 gregs->kregs[KREG_EIP] = regs->r_eip;
183 gregs->kregs[KREG_UESP] = regs->r_uesp;
184 gregs->kregs[KREG_TRAPNO] = regs->r_trapno;
185 gregs->kregs[KREG_ERR] = regs->r_err;
186 }
187
188 void
kt_ia32_init(mdb_tgt_t * t)189 kt_ia32_init(mdb_tgt_t *t)
190 {
191 kt_data_t *kt = t->t_data;
192 panic_data_t pd;
193 label_t label;
194 struct regs regs;
195 kreg_t *kregs;
196 uintptr_t addr;
197
198 /*
199 * Initialize the machine-dependent parts of the kernel target
200 * structure. Once this is complete and we fill in the ops
201 * vector, the target is now fully constructed and we can use
202 * the target API itself to perform the rest of our initialization.
203 */
204 kt->k_rds = mdb_ia32_kregs;
205 kt->k_regs = mdb_zalloc(sizeof (mdb_tgt_gregset_t), UM_SLEEP);
206 kt->k_regsize = sizeof (mdb_tgt_gregset_t);
207 kt->k_dcmd_regs = kt_regs;
208 kt->k_dcmd_stack = kt_stack;
209 kt->k_dcmd_stackv = kt_stackv;
210 kt->k_dcmd_stackr = kt_stackv;
211 kt->k_dcmd_cpustack = kt_cpustack;
212 kt->k_dcmd_cpuregs = kt_cpuregs;
213
214 t->t_ops = &kt_ia32_ops;
215 kregs = kt->k_regs->kregs;
216
217 (void) mdb_dis_select("ia32");
218
219 /*
220 * Lookup the symbols corresponding to subroutines in locore.s where
221 * we expect a saved regs structure to be pushed on the stack. When
222 * performing stack tracebacks we will attempt to detect interrupt
223 * frames by comparing the %eip value to these symbols.
224 */
225 (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
226 "cmnint", &kt->k_intr_sym, NULL);
227
228 (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
229 "cmntrap", &kt->k_trap_sym, NULL);
230
231 /*
232 * Don't attempt to load any thread or register information if
233 * we're examining the live operating system.
234 */
235 if (kt->k_symfile != NULL && strcmp(kt->k_symfile, "/dev/ksyms") == 0)
236 return;
237
238 /*
239 * If the panicbuf symbol is present and we can consume a panicbuf
240 * header of the appropriate version from this address, then we can
241 * initialize our current register set based on its contents.
242 * Prior to the re-structuring of panicbuf, our only register data
243 * was the panic_regs label_t, into which a setjmp() was performed,
244 * or the panic_reg register pointer, which was only non-zero if
245 * the system panicked as a result of a trap calling die().
246 */
247 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &pd, sizeof (pd),
248 MDB_TGT_OBJ_EXEC, "panicbuf") == sizeof (pd) &&
249 pd.pd_version == PANICBUFVERS) {
250
251 size_t pd_size = MIN(PANICBUFSIZE, pd.pd_msgoff);
252 panic_data_t *pdp = mdb_zalloc(pd_size, UM_SLEEP);
253 uint_t i, n;
254
255 (void) mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, pdp, pd_size,
256 MDB_TGT_OBJ_EXEC, "panicbuf");
257
258 n = (pd_size - (sizeof (panic_data_t) -
259 sizeof (panic_nv_t))) / sizeof (panic_nv_t);
260
261 for (i = 0; i < n; i++) {
262 (void) kt_putareg(t, kt->k_tid,
263 pdp->pd_nvdata[i].pnv_name,
264 pdp->pd_nvdata[i].pnv_value);
265 }
266
267 mdb_free(pdp, pd_size);
268
269 return;
270 }
271
272 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &addr, sizeof (addr),
273 MDB_TGT_OBJ_EXEC, "panic_reg") == sizeof (addr) && addr != 0 &&
274 mdb_tgt_vread(t, ®s, sizeof (regs), addr) == sizeof (regs)) {
275 kt_regs_to_kregs(®s, kt->k_regs);
276 return;
277 }
278
279 /*
280 * If we can't read any panic regs, then our penultimate try is for any
281 * CPU context that may have been stored (for example, in Xen core
282 * dumps). As this can only succeed for kernels with the above
283 * methods available, we let it over-ride the older panic_regs method,
284 * which will always manage to read the label_t, even if there's
285 * nothing useful there.
286 */
287 if (kt_kvmregs(t, 0, kt->k_regs) == 0)
288 return;
289
290 if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &label, sizeof (label),
291 MDB_TGT_OBJ_EXEC, "panic_regs") == sizeof (label)) {
292 kregs[KREG_EDI] = label.val[0];
293 kregs[KREG_ESI] = label.val[1];
294 kregs[KREG_EBX] = label.val[2];
295 kregs[KREG_EBP] = label.val[3];
296 kregs[KREG_ESP] = label.val[4];
297 kregs[KREG_EIP] = label.val[5];
298 return;
299 }
300
301 warn("failed to read panicbuf, panic_reg and panic_regs -- "
302 "current register set will be unavailable\n");
303 }
304