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fa593d66 PA |
1 | /* GNU/Linux/x86 specific low level interface, for the in-process |
2 | agent library for GDB. | |
3 | ||
ecd75fc8 | 4 | Copyright (C) 2010-2014 Free Software Foundation, Inc. |
fa593d66 PA |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "server.h" | |
405f8e94 SS |
22 | #include <stdint.h> |
23 | #include <sys/mman.h> | |
7c3a12ca | 24 | #include "tracepoint.h" |
fa593d66 PA |
25 | |
26 | /* GDB register numbers. */ | |
27 | ||
28 | enum i386_gdb_regnum | |
29 | { | |
30 | I386_EAX_REGNUM, /* %eax */ | |
31 | I386_ECX_REGNUM, /* %ecx */ | |
32 | I386_EDX_REGNUM, /* %edx */ | |
33 | I386_EBX_REGNUM, /* %ebx */ | |
34 | I386_ESP_REGNUM, /* %esp */ | |
35 | I386_EBP_REGNUM, /* %ebp */ | |
36 | I386_ESI_REGNUM, /* %esi */ | |
37 | I386_EDI_REGNUM, /* %edi */ | |
38 | I386_EIP_REGNUM, /* %eip */ | |
39 | I386_EFLAGS_REGNUM, /* %eflags */ | |
40 | I386_CS_REGNUM, /* %cs */ | |
41 | I386_SS_REGNUM, /* %ss */ | |
42 | I386_DS_REGNUM, /* %ds */ | |
43 | I386_ES_REGNUM, /* %es */ | |
44 | I386_FS_REGNUM, /* %fs */ | |
45 | I386_GS_REGNUM, /* %gs */ | |
46 | I386_ST0_REGNUM /* %st(0) */ | |
47 | }; | |
48 | ||
49 | #define i386_num_regs 16 | |
50 | ||
51 | /* Defined in auto-generated file i386-linux.c. */ | |
52 | void init_registers_i386_linux (void); | |
3aee8918 | 53 | extern const struct target_desc *tdesc_i386_linux; |
fa593d66 PA |
54 | |
55 | #define FT_CR_EAX 15 | |
56 | #define FT_CR_ECX 14 | |
57 | #define FT_CR_EDX 13 | |
58 | #define FT_CR_EBX 12 | |
59 | #define FT_CR_UESP 11 | |
60 | #define FT_CR_EBP 10 | |
61 | #define FT_CR_ESI 9 | |
62 | #define FT_CR_EDI 8 | |
63 | #define FT_CR_EIP 7 | |
64 | #define FT_CR_EFL 6 | |
65 | #define FT_CR_DS 5 | |
66 | #define FT_CR_ES 4 | |
67 | #define FT_CR_FS 3 | |
68 | #define FT_CR_GS 2 | |
69 | #define FT_CR_SS 1 | |
70 | #define FT_CR_CS 0 | |
71 | ||
72 | /* Mapping between the general-purpose registers in jump tracepoint | |
73 | format and GDB's register array layout. */ | |
74 | ||
75 | static const int i386_ft_collect_regmap[] = | |
76 | { | |
77 | FT_CR_EAX * 4, FT_CR_ECX * 4, FT_CR_EDX * 4, FT_CR_EBX * 4, | |
78 | FT_CR_UESP * 4, FT_CR_EBP * 4, FT_CR_ESI * 4, FT_CR_EDI * 4, | |
79 | FT_CR_EIP * 4, FT_CR_EFL * 4, FT_CR_CS * 4, FT_CR_SS * 4, | |
80 | FT_CR_DS * 4, FT_CR_ES * 4, FT_CR_FS * 4, FT_CR_GS * 4 | |
81 | }; | |
82 | ||
83 | void | |
84 | supply_fast_tracepoint_registers (struct regcache *regcache, | |
85 | const unsigned char *buf) | |
86 | { | |
87 | int i; | |
88 | ||
89 | for (i = 0; i < i386_num_regs; i++) | |
90 | { | |
91 | int regval; | |
92 | ||
93 | if (i >= I386_CS_REGNUM && i <= I386_GS_REGNUM) | |
94 | regval = *(short *) (((char *) buf) + i386_ft_collect_regmap[i]); | |
95 | else | |
96 | regval = *(int *) (((char *) buf) + i386_ft_collect_regmap[i]); | |
97 | ||
98 | supply_register (regcache, i, ®val); | |
99 | } | |
100 | } | |
101 | ||
6a271cae PA |
102 | ULONGEST __attribute__ ((visibility("default"), used)) |
103 | gdb_agent_get_raw_reg (unsigned char *raw_regs, int regnum) | |
104 | { | |
105 | /* This should maybe be allowed to return an error code, or perhaps | |
106 | better, have the emit_reg detect this, and emit a constant zero, | |
107 | or something. */ | |
108 | ||
109 | if (regnum > i386_num_regs) | |
110 | return 0; | |
111 | else if (regnum >= I386_CS_REGNUM && regnum <= I386_GS_REGNUM) | |
112 | return *(short *) (raw_regs + i386_ft_collect_regmap[regnum]); | |
113 | else | |
114 | return *(int *) (raw_regs + i386_ft_collect_regmap[regnum]); | |
115 | } | |
116 | ||
0fb4aa4b PA |
117 | #ifdef HAVE_UST |
118 | ||
119 | #include <ust/processor.h> | |
120 | ||
121 | /* "struct registers" is the UST object type holding the registers at | |
122 | the time of the static tracepoint marker call. This doesn't | |
123 | contain EIP, but we know what it must have been (the marker | |
124 | address). */ | |
125 | ||
126 | #define ST_REGENTRY(REG) \ | |
127 | { \ | |
128 | offsetof (struct registers, REG), \ | |
129 | sizeof (((struct registers *) NULL)->REG) \ | |
130 | } | |
131 | ||
132 | static struct | |
133 | { | |
134 | int offset; | |
135 | int size; | |
136 | } i386_st_collect_regmap[] = | |
137 | { | |
138 | ST_REGENTRY(eax), | |
139 | ST_REGENTRY(ecx), | |
140 | ST_REGENTRY(edx), | |
141 | ST_REGENTRY(ebx), | |
142 | ST_REGENTRY(esp), | |
143 | ST_REGENTRY(ebp), | |
144 | ST_REGENTRY(esi), | |
145 | ST_REGENTRY(edi), | |
146 | { -1, 0 }, /* eip */ | |
147 | ST_REGENTRY(eflags), | |
148 | ST_REGENTRY(cs), | |
149 | ST_REGENTRY(ss), | |
150 | }; | |
151 | ||
152 | #define i386_NUM_ST_COLLECT_GREGS \ | |
153 | (sizeof (i386_st_collect_regmap) / sizeof (i386_st_collect_regmap[0])) | |
154 | ||
155 | void | |
156 | supply_static_tracepoint_registers (struct regcache *regcache, | |
157 | const unsigned char *buf, | |
158 | CORE_ADDR pc) | |
159 | { | |
160 | int i; | |
161 | unsigned int newpc = pc; | |
162 | ||
163 | supply_register (regcache, I386_EIP_REGNUM, &newpc); | |
164 | ||
165 | for (i = 0; i < i386_NUM_ST_COLLECT_GREGS; i++) | |
166 | if (i386_st_collect_regmap[i].offset != -1) | |
167 | { | |
168 | switch (i386_st_collect_regmap[i].size) | |
169 | { | |
170 | case 4: | |
171 | supply_register (regcache, i, | |
172 | ((char *) buf) | |
173 | + i386_st_collect_regmap[i].offset); | |
174 | break; | |
175 | case 2: | |
176 | { | |
177 | unsigned long reg | |
178 | = * (short *) (((char *) buf) | |
179 | + i386_st_collect_regmap[i].offset); | |
180 | reg &= 0xffff; | |
181 | supply_register (regcache, i, ®); | |
182 | } | |
183 | break; | |
184 | default: | |
b481f9e0 | 185 | internal_error (__FILE__, __LINE__, "unhandled register size: %d", |
0fb4aa4b PA |
186 | i386_st_collect_regmap[i].size); |
187 | } | |
188 | } | |
189 | } | |
190 | ||
191 | #endif /* HAVE_UST */ | |
192 | ||
193 | ||
fa593d66 PA |
194 | /* This is only needed because reg-i386-linux-lib.o references it. We |
195 | may use it proper at some point. */ | |
196 | const char *gdbserver_xmltarget; | |
197 | ||
405f8e94 SS |
198 | /* Attempt to allocate memory for trampolines in the first 64 KiB of |
199 | memory to enable smaller jump patches. */ | |
200 | ||
201 | static void | |
202 | initialize_fast_tracepoint_trampoline_buffer (void) | |
203 | { | |
204 | const CORE_ADDR buffer_end = 64 * 1024; | |
205 | /* Ensure that the buffer will be at least 1 KiB in size, which is | |
206 | enough space for over 200 fast tracepoints. */ | |
207 | const int min_buffer_size = 1024; | |
208 | char buf[IPA_BUFSIZ]; | |
209 | CORE_ADDR mmap_min_addr = buffer_end + 1; | |
210 | ULONGEST buffer_size; | |
211 | FILE *f = fopen ("/proc/sys/vm/mmap_min_addr", "r"); | |
212 | ||
213 | if (!f) | |
214 | { | |
215 | snprintf (buf, sizeof (buf), "mmap_min_addr open failed: %s", | |
216 | strerror (errno)); | |
217 | set_trampoline_buffer_space (0, 0, buf); | |
218 | return; | |
219 | } | |
220 | ||
221 | if (fgets (buf, IPA_BUFSIZ, f)) | |
222 | sscanf (buf, "%llu", &mmap_min_addr); | |
223 | ||
224 | fclose (f); | |
225 | ||
226 | buffer_size = buffer_end - mmap_min_addr; | |
227 | ||
228 | if (buffer_size >= min_buffer_size) | |
229 | { | |
230 | if (mmap ((void *) (uintptr_t) mmap_min_addr, buffer_size, | |
231 | PROT_READ | PROT_EXEC | PROT_WRITE, | |
232 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, | |
233 | -1, 0) | |
234 | != MAP_FAILED) | |
235 | set_trampoline_buffer_space (mmap_min_addr, buffer_end, NULL); | |
236 | else | |
237 | { | |
238 | snprintf (buf, IPA_BUFSIZ, "low-64K-buffer mmap() failed: %s", | |
239 | strerror (errno)); | |
240 | set_trampoline_buffer_space (0, 0, buf); | |
241 | } | |
242 | } | |
243 | else | |
244 | { | |
245 | snprintf (buf, IPA_BUFSIZ, "mmap_min_addr is %d, must be %d or less", | |
246 | (int) mmap_min_addr, (int) buffer_end - min_buffer_size); | |
247 | set_trampoline_buffer_space (0, 0, buf); | |
248 | } | |
249 | } | |
250 | ||
fa593d66 PA |
251 | void |
252 | initialize_low_tracepoint (void) | |
253 | { | |
254 | init_registers_i386_linux (); | |
3aee8918 | 255 | ipa_tdesc = tdesc_i386_linux; |
405f8e94 | 256 | initialize_fast_tracepoint_trampoline_buffer (); |
fa593d66 | 257 | } |