xref: /dragonfly/gnu/usr.bin/gdb/kgdb/trgt_x86_64.c (revision e5a92d33)
1 /*
2  * Copyright (c) 2004 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD: src/gnu/usr.bin/gdb/kgdb/trgt_amd64.c,v 1.10 2008/05/01 20:36:48 jhb Exp $
27  */
28 
29 #include <sys/cdefs.h>
30 
31 #include <sys/types.h>
32 #include <sys/thread.h>
33 #include <machine/pcb.h>
34 #include <machine/frame.h>
35 #include <err.h>
36 #include <kvm.h>
37 #include <string.h>
38 
39 #include <defs.h>
40 #include <target.h>
41 #include <gdbthread.h>
42 #include <inferior.h>
43 #include <regcache.h>
44 #include <frame-unwind.h>
45 #include <amd64-tdep.h>
46 
47 #include "kgdb.h"
48 
49 static int
50 kgdb_trgt_trapframe_sniffer(const struct frame_unwind *self,
51 			    struct frame_info *next_frame,
52 			    void **this_prologue_cache);
53 
54 void
55 kgdb_trgt_fetch_registers(struct target_ops *target_ops, struct regcache *regcache, int regno)
56 {
57 	struct kthr *kt;
58 	struct pcb pcb;
59 
60 	kt = kgdb_thr_lookup_tid(ptid_get_tid(inferior_ptid));
61 	if (kt == NULL) {
62 		regcache_raw_supply(regcache, regno, NULL);
63 		return;
64 	}
65 
66 	/*
67 	 * kt->pcb == 0 is a marker for "non-dumping kernel thread".
68 	 */
69 	if (kt->pcb == 0) {
70 		uintptr_t regs[7];
71 		uintptr_t addr;
72 		uintptr_t sp;
73 
74 		addr = kt->kaddr + offsetof(struct thread, td_sp);
75 		kvm_read(kvm, addr, &sp, sizeof(sp));
76 		/*
77 		 * Stack is:
78 		 * -2 ret
79 		 * -1 popfq
80 		 * 0 popq %r15	edi
81 		 * 1 popq %r14
82 		 * 2 popq %r13
83 		 * 3 popq %r12
84 		 * 4 popq %rbx
85 		 * 5 popq %rbp
86 		 * 6 ret
87 		 */
88 		if (kvm_read(kvm, sp + 2 * sizeof(regs[0]), regs, sizeof(regs)) != sizeof(regs)) {
89 			warnx("kvm_read: %s", kvm_geterr(kvm));
90 			memset(regs, 0, sizeof(regs));
91 		}
92 		regcache_raw_supply(regcache, AMD64_R8_REGNUM + 7, &regs[0]);
93 		regcache_raw_supply(regcache, AMD64_R8_REGNUM + 6, &regs[1]);
94 		regcache_raw_supply(regcache, AMD64_R8_REGNUM + 5, &regs[2]);
95 		regcache_raw_supply(regcache, AMD64_R8_REGNUM + 4, &regs[3]);
96 		regcache_raw_supply(regcache, AMD64_RBX_REGNUM, &regs[4]);
97 		regcache_raw_supply(regcache, AMD64_RBP_REGNUM, &regs[5]);
98 		regcache_raw_supply(regcache, AMD64_RIP_REGNUM, &regs[6]);
99 		sp += 9 * sizeof(regs[0]);
100 		regcache_raw_supply(regcache, AMD64_RSP_REGNUM, &sp);
101 		return;
102 	}
103 
104 	if (kvm_read(kvm, kt->pcb, &pcb, sizeof(pcb)) != sizeof(pcb)) {
105 		warnx("kvm_read: %s", kvm_geterr(kvm));
106 		memset(&pcb, 0, sizeof(pcb));
107 	}
108 
109 	regcache_raw_supply(regcache, AMD64_RBX_REGNUM, (char *)&pcb.pcb_rbx);
110 	regcache_raw_supply(regcache, AMD64_RBP_REGNUM, (char *)&pcb.pcb_rbp);
111 	regcache_raw_supply(regcache, AMD64_RSP_REGNUM, (char *)&pcb.pcb_rsp);
112 	regcache_raw_supply(regcache, AMD64_R8_REGNUM + 4, (char *)&pcb.pcb_r12);
113 	regcache_raw_supply(regcache, AMD64_R8_REGNUM + 5, (char *)&pcb.pcb_r13);
114 	regcache_raw_supply(regcache, AMD64_R8_REGNUM + 6, (char *)&pcb.pcb_r14);
115 	regcache_raw_supply(regcache, AMD64_R15_REGNUM, (char *)&pcb.pcb_r15);
116 	regcache_raw_supply(regcache, AMD64_RIP_REGNUM, (char *)&pcb.pcb_rip);
117 }
118 
119 struct kgdb_frame_cache {
120 	int		frame_type;
121 	CORE_ADDR	pc;
122 	CORE_ADDR	sp;
123 };
124 
125 #define FT_NORMAL		1
126 #define FT_INTRFRAME		2
127 /*#define	FT_INTRTRAPFRAME        3*/
128 #define FT_TIMERFRAME		4
129 #define FT_CALLTRAP		5
130 
131 static int kgdb_trgt_frame_offset[20] = {
132 	offsetof(struct trapframe, tf_rax),
133 	offsetof(struct trapframe, tf_rbx),
134 	offsetof(struct trapframe, tf_rcx),
135 	offsetof(struct trapframe, tf_rdx),
136 	offsetof(struct trapframe, tf_rsi),
137 	offsetof(struct trapframe, tf_rdi),
138 	offsetof(struct trapframe, tf_rbp),
139 	offsetof(struct trapframe, tf_rsp),
140 	offsetof(struct trapframe, tf_r8),
141 	offsetof(struct trapframe, tf_r9),
142 	offsetof(struct trapframe, tf_r10),
143 	offsetof(struct trapframe, tf_r11),
144 	offsetof(struct trapframe, tf_r12),
145 	offsetof(struct trapframe, tf_r13),
146 	offsetof(struct trapframe, tf_r14),
147 	offsetof(struct trapframe, tf_r15),
148 	offsetof(struct trapframe, tf_rip),
149 	offsetof(struct trapframe, tf_rflags),
150 	offsetof(struct trapframe, tf_cs),
151 	offsetof(struct trapframe, tf_ss)
152 };
153 
154 static struct kgdb_frame_cache *
155 kgdb_trgt_frame_cache(struct frame_info *next_frame, void **this_cache)
156 {
157 	struct kgdb_frame_cache *cache;
158 	const char *pname;
159 
160 	cache = *this_cache;
161 	if (cache == NULL) {
162 		cache = FRAME_OBSTACK_ZALLOC(struct kgdb_frame_cache);
163 		*this_cache = cache;
164 		cache->pc = get_frame_address_in_block(next_frame);
165 		cache->sp = get_frame_sp(next_frame);
166 		find_pc_partial_function(cache->pc, &pname, NULL, NULL);
167 
168 		if (strcmp(pname, "calltrap") == 0)
169 			cache->frame_type = FT_CALLTRAP;
170 		else if (pname[0] != 'X')
171 			cache->frame_type = FT_NORMAL;
172 		else if (strcmp(pname, "Xtimerint") == 0)
173 			cache->frame_type = FT_TIMERFRAME;
174 		else
175 			cache->frame_type = FT_INTRFRAME;
176 	}
177 	return (cache);
178 }
179 
180 static void
181 kgdb_trgt_trapframe_this_id(struct frame_info *next_frame, void **this_cache,
182     struct frame_id *this_id)
183 {
184 	struct kgdb_frame_cache *cache;
185 
186 	cache = kgdb_trgt_frame_cache(next_frame, this_cache);
187 	*this_id = frame_id_build(cache->sp, cache->pc);
188 }
189 
190 static struct value *
191 kgdb_trgt_trapframe_prev_register(struct frame_info *next_frame,
192     void **this_cache, int regnum)
193 {
194 	CORE_ADDR addrp;
195 	struct kgdb_frame_cache *cache;
196 	int ofs;
197 
198 	if (regnum < AMD64_RAX_REGNUM || regnum > AMD64_EFLAGS_REGNUM + 2)
199 		return frame_unwind_got_register(next_frame, regnum, regnum);
200 
201 	ofs = kgdb_trgt_frame_offset[regnum];
202 
203 	cache = kgdb_trgt_frame_cache(next_frame, this_cache);
204 
205 	switch (cache->frame_type) {
206 	case FT_NORMAL:
207 		break;
208 	case FT_INTRFRAME:
209 		ofs += 8;
210 		break;
211 	case FT_TIMERFRAME:
212 		break;
213 		/*
214 	case FT_INTRTRAPFRAME:
215 		ofs -= ofs_fix;
216 		break;
217 		*/
218 	case FT_CALLTRAP:
219 		ofs += 0;
220 		break;
221 	default:
222 		fprintf_unfiltered(gdb_stderr, "Correct FT_XXX frame offsets "
223 		   "for %d\n", cache->frame_type);
224 		break;
225 	}
226 
227 	addrp = cache->sp + ofs;
228 	return frame_unwind_got_memory(next_frame, regnum, addrp);
229 }
230 
231 static enum unwind_stop_reason
232 kgdb_trgt_trapframe_unwind_reason(struct frame_info *next_frame,
233     void **this_cache)
234 {
235     /* XXX marino : populate logic to determine unwind stoppage */
236     return UNWIND_NO_REASON;
237 }
238 
239 const struct frame_unwind kgdb_trgt_trapframe_unwind = {
240         NORMAL_FRAME,
241         &kgdb_trgt_trapframe_unwind_reason,
242         &kgdb_trgt_trapframe_this_id,
243         &kgdb_trgt_trapframe_prev_register,
244 	.sniffer = kgdb_trgt_trapframe_sniffer
245 };
246 
247 static int
248 kgdb_trgt_trapframe_sniffer(const struct frame_unwind *self,
249 			    struct frame_info *next_frame,
250 			    void **this_prologue_cache)
251 {
252 	const char *pname;
253 	CORE_ADDR pc;
254 
255 	pc = get_frame_address_in_block(next_frame);
256 	pname = NULL;
257 	find_pc_partial_function(pc, &pname, NULL, NULL);
258 	if (pname == NULL)
259 		return (0);
260 	if (strcmp(pname, "calltrap") == 0 ||
261 	    strcmp(pname, "dblfault_handler") == 0 ||
262 	    strcmp(pname, "nmi_calltrap") == 0 ||
263 	    (pname[0] == 'X' && pname[1] != '_'))
264 		return (1);
265 	return (0);
266 }
267