xref: /illumos-gate/usr/src/cmd/mdb/intel/mdb/kvm_ia32dep.c (revision 892ad1623e11186cba8b2eb40d70318d2cb89605)
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  */
27 
28 /*
29  * Libkvm Kernel Target Intel 32-bit component
30  *
31  * This file provides the ISA-dependent portion of the libkvm kernel target.
32  * For more details on the implementation refer to mdb_kvm.c.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/regset.h>
37 #include <sys/frame.h>
38 #include <sys/stack.h>
39 #include <sys/sysmacros.h>
40 #include <sys/panic.h>
41 #include <strings.h>
42 
43 #include <mdb/mdb_target_impl.h>
44 #include <mdb/mdb_disasm.h>
45 #include <mdb/mdb_modapi.h>
46 #include <mdb/mdb_conf.h>
47 #include <mdb/mdb_kreg_impl.h>
48 #include <mdb/mdb_ia32util.h>
49 #include <mdb/kvm_isadep.h>
50 #include <mdb/mdb_kvm.h>
51 #include <mdb/mdb_err.h>
52 #include <mdb/mdb_debug.h>
53 #include <mdb/mdb.h>
54 
55 
56 /*ARGSUSED*/
57 int
58 kt_regs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
59 {
60 	mdb_ia32_printregs((const mdb_tgt_gregset_t *)addr);
61 	return (DCMD_OK);
62 }
63 
64 static int
65 kt_stack_common(uintptr_t addr, uint_t flags, int argc,
66     const mdb_arg_t *argv, mdb_tgt_stack_f *func)
67 {
68 	kt_data_t *kt = mdb.m_target->t_data;
69 	void *arg = (void *)mdb.m_nargs;
70 	mdb_tgt_gregset_t gregs, *grp;
71 
72 	if (flags & DCMD_ADDRSPEC) {
73 		bzero(&gregs, sizeof (gregs));
74 		gregs.kregs[KREG_EBP] = addr;
75 		grp = &gregs;
76 	} else
77 		grp = kt->k_regs;
78 
79 	if (argc != 0) {
80 		if (argv->a_type == MDB_TYPE_CHAR || argc > 1)
81 			return (DCMD_USAGE);
82 
83 		if (argv->a_type == MDB_TYPE_STRING)
84 			arg = (void *)(uint_t)mdb_strtoull(argv->a_un.a_str);
85 		else
86 			arg = (void *)(uint_t)argv->a_un.a_val;
87 	}
88 
89 	(void) mdb_ia32_kvm_stack_iter(mdb.m_target, grp, func, arg);
90 	return (DCMD_OK);
91 }
92 
93 int
94 kt_stack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
95 {
96 	return (kt_stack_common(addr, flags, argc, argv, mdb_ia32_kvm_frame));
97 }
98 
99 int
100 kt_stackv(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
101 {
102 	return (kt_stack_common(addr, flags, argc, argv, mdb_ia32_kvm_framev));
103 }
104 
105 const mdb_tgt_ops_t kt_ia32_ops = {
106 	kt_setflags,				/* t_setflags */
107 	kt_setcontext,				/* t_setcontext */
108 	kt_activate,				/* t_activate */
109 	kt_deactivate,				/* t_deactivate */
110 	(void (*)()) mdb_tgt_nop,		/* t_periodic */
111 	kt_destroy,				/* t_destroy */
112 	kt_name,				/* t_name */
113 	(const char *(*)()) mdb_conf_isa,	/* t_isa */
114 	kt_platform,				/* t_platform */
115 	kt_uname,				/* t_uname */
116 	kt_dmodel,				/* t_dmodel */
117 	kt_aread,				/* t_aread */
118 	kt_awrite,				/* t_awrite */
119 	kt_vread,				/* t_vread */
120 	kt_vwrite,				/* t_vwrite */
121 	kt_pread,				/* t_pread */
122 	kt_pwrite,				/* t_pwrite */
123 	kt_fread,				/* t_fread */
124 	kt_fwrite,				/* t_fwrite */
125 	(ssize_t (*)()) mdb_tgt_notsup,		/* t_ioread */
126 	(ssize_t (*)()) mdb_tgt_notsup,		/* t_iowrite */
127 	kt_vtop,				/* t_vtop */
128 	kt_lookup_by_name,			/* t_lookup_by_name */
129 	kt_lookup_by_addr,			/* t_lookup_by_addr */
130 	kt_symbol_iter,				/* t_symbol_iter */
131 	kt_mapping_iter,			/* t_mapping_iter */
132 	kt_object_iter,				/* t_object_iter */
133 	kt_addr_to_map,				/* t_addr_to_map */
134 	kt_name_to_map,				/* t_name_to_map */
135 	kt_addr_to_ctf,				/* t_addr_to_ctf */
136 	kt_name_to_ctf,				/* t_name_to_ctf */
137 	kt_status,				/* t_status */
138 	(int (*)()) mdb_tgt_notsup,		/* t_run */
139 	(int (*)()) mdb_tgt_notsup,		/* t_step */
140 	(int (*)()) mdb_tgt_notsup,		/* t_step_out */
141 	(int (*)()) mdb_tgt_notsup,		/* t_next */
142 	(int (*)()) mdb_tgt_notsup,		/* t_cont */
143 	(int (*)()) mdb_tgt_notsup,		/* t_signal */
144 	(int (*)()) mdb_tgt_null,		/* t_add_vbrkpt */
145 	(int (*)()) mdb_tgt_null,		/* t_add_sbrkpt */
146 	(int (*)()) mdb_tgt_null,		/* t_add_pwapt */
147 	(int (*)()) mdb_tgt_null,		/* t_add_vwapt */
148 	(int (*)()) mdb_tgt_null,		/* t_add_iowapt */
149 	(int (*)()) mdb_tgt_null,		/* t_add_sysenter */
150 	(int (*)()) mdb_tgt_null,		/* t_add_sysexit */
151 	(int (*)()) mdb_tgt_null,		/* t_add_signal */
152 	(int (*)()) mdb_tgt_null,		/* t_add_fault */
153 	kt_getareg,				/* t_getareg */
154 	kt_putareg,				/* t_putareg */
155 	mdb_ia32_kvm_stack_iter,		/* t_stack_iter */
156 	(int (*)()) mdb_tgt_notsup		/* t_auxv */
157 };
158 
159 void
160 kt_regs_to_kregs(struct regs *regs, mdb_tgt_gregset_t *gregs)
161 {
162 	gregs->kregs[KREG_SAVFP] = regs->r_savfp;
163 	gregs->kregs[KREG_SAVPC] = regs->r_savpc;
164 	gregs->kregs[KREG_EAX] = regs->r_eax;
165 	gregs->kregs[KREG_EBX] = regs->r_ebx;
166 	gregs->kregs[KREG_ECX] = regs->r_ecx;
167 	gregs->kregs[KREG_EDX] = regs->r_edx;
168 	gregs->kregs[KREG_ESI] = regs->r_esi;
169 	gregs->kregs[KREG_EDI] = regs->r_edi;
170 	gregs->kregs[KREG_EBP] = regs->r_ebp;
171 	gregs->kregs[KREG_ESP] = regs->r_esp;
172 	gregs->kregs[KREG_CS] = regs->r_cs;
173 	gregs->kregs[KREG_DS] = regs->r_ds;
174 	gregs->kregs[KREG_SS] = regs->r_ss;
175 	gregs->kregs[KREG_ES] = regs->r_es;
176 	gregs->kregs[KREG_FS] = regs->r_fs;
177 	gregs->kregs[KREG_GS] = regs->r_gs;
178 	gregs->kregs[KREG_EFLAGS] = regs->r_efl;
179 	gregs->kregs[KREG_EIP] = regs->r_eip;
180 	gregs->kregs[KREG_UESP] = regs->r_uesp;
181 	gregs->kregs[KREG_TRAPNO] = regs->r_trapno;
182 	gregs->kregs[KREG_ERR] = regs->r_err;
183 }
184 
185 void
186 kt_ia32_init(mdb_tgt_t *t)
187 {
188 	kt_data_t *kt = t->t_data;
189 	panic_data_t pd;
190 	label_t label;
191 	struct regs regs;
192 	kreg_t *kregs;
193 	uintptr_t addr;
194 
195 	/*
196 	 * Initialize the machine-dependent parts of the kernel target
197 	 * structure.  Once this is complete and we fill in the ops
198 	 * vector, the target is now fully constructed and we can use
199 	 * the target API itself to perform the rest of our initialization.
200 	 */
201 	kt->k_rds = mdb_ia32_kregs;
202 	kt->k_regs = mdb_zalloc(sizeof (mdb_tgt_gregset_t), UM_SLEEP);
203 	kt->k_regsize = sizeof (mdb_tgt_gregset_t);
204 	kt->k_dcmd_regs = kt_regs;
205 	kt->k_dcmd_stack = kt_stack;
206 	kt->k_dcmd_stackv = kt_stackv;
207 	kt->k_dcmd_stackr = kt_stackv;
208 	kt->k_dcmd_cpustack = kt_cpustack;
209 	kt->k_dcmd_cpuregs = kt_cpuregs;
210 
211 	t->t_ops = &kt_ia32_ops;
212 	kregs = kt->k_regs->kregs;
213 
214 	(void) mdb_dis_select("ia32");
215 
216 	/*
217 	 * Lookup the symbols corresponding to subroutines in locore.s where
218 	 * we expect a saved regs structure to be pushed on the stack.  When
219 	 * performing stack tracebacks we will attempt to detect interrupt
220 	 * frames by comparing the %eip value to these symbols.
221 	 */
222 	(void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
223 	    "cmnint", &kt->k_intr_sym, NULL);
224 
225 	(void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
226 	    "cmntrap", &kt->k_trap_sym, NULL);
227 
228 	/*
229 	 * Don't attempt to load any thread or register information if
230 	 * we're examining the live operating system.
231 	 */
232 	if (kt->k_symfile != NULL && strcmp(kt->k_symfile, "/dev/ksyms") == 0)
233 		return;
234 
235 	/*
236 	 * If the panicbuf symbol is present and we can consume a panicbuf
237 	 * header of the appropriate version from this address, then we can
238 	 * initialize our current register set based on its contents.
239 	 * Prior to the re-structuring of panicbuf, our only register data
240 	 * was the panic_regs label_t, into which a setjmp() was performed,
241 	 * or the panic_reg register pointer, which was only non-zero if
242 	 * the system panicked as a result of a trap calling die().
243 	 */
244 	if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &pd, sizeof (pd),
245 	    MDB_TGT_OBJ_EXEC, "panicbuf") == sizeof (pd) &&
246 	    pd.pd_version == PANICBUFVERS) {
247 
248 		size_t pd_size = MIN(PANICBUFSIZE, pd.pd_msgoff);
249 		panic_data_t *pdp = mdb_zalloc(pd_size, UM_SLEEP);
250 		uint_t i, n;
251 
252 		(void) mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, pdp, pd_size,
253 		    MDB_TGT_OBJ_EXEC, "panicbuf");
254 
255 		n = (pd_size - (sizeof (panic_data_t) -
256 		    sizeof (panic_nv_t))) / sizeof (panic_nv_t);
257 
258 		for (i = 0; i < n; i++) {
259 			(void) kt_putareg(t, kt->k_tid,
260 			    pdp->pd_nvdata[i].pnv_name,
261 			    pdp->pd_nvdata[i].pnv_value);
262 		}
263 
264 		mdb_free(pdp, pd_size);
265 
266 		return;
267 	}
268 
269 	if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &addr, sizeof (addr),
270 	    MDB_TGT_OBJ_EXEC, "panic_reg") == sizeof (addr) && addr != 0 &&
271 	    mdb_tgt_vread(t, &regs, sizeof (regs), addr) == sizeof (regs)) {
272 		kt_regs_to_kregs(&regs, kt->k_regs);
273 		return;
274 	}
275 
276 	/*
277 	 * If we can't read any panic regs, then our penultimate try is for any
278 	 * CPU context that may have been stored (for example, in Xen core
279 	 * dumps).  As this can only succeed for kernels with the above
280 	 * methods available, we let it over-ride the older panic_regs method,
281 	 * which will always manage to read the label_t, even if there's
282 	 * nothing useful there.
283 	 */
284 	if (kt_kvmregs(t, 0, kt->k_regs) == 0)
285 		return;
286 
287 	if (mdb_tgt_readsym(t, MDB_TGT_AS_VIRT, &label, sizeof (label),
288 	    MDB_TGT_OBJ_EXEC, "panic_regs") == sizeof (label)) {
289 		kregs[KREG_EDI] = label.val[0];
290 		kregs[KREG_ESI] = label.val[1];
291 		kregs[KREG_EBX] = label.val[2];
292 		kregs[KREG_EBP] = label.val[3];
293 		kregs[KREG_ESP] = label.val[4];
294 		kregs[KREG_EIP] = label.val[5];
295 		return;
296 	}
297 
298 	warn("failed to read panicbuf, panic_reg and panic_regs -- "
299 	    "current register set will be unavailable\n");
300 }
301