1 /* Tracepoint code for remote server for GDB.
2    Copyright (C) 1993-2021 Free Software Foundation, Inc.
3 
4    This file is part of GDB.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18 
19 #ifndef GDBSERVER_TRACEPOINT_H
20 #define GDBSERVER_TRACEPOINT_H
21 
22 /* Size for a small buffer to report problems from the in-process
23    agent back to GDBserver.  */
24 #define IPA_BUFSIZ 100
25 
26 void initialize_tracepoint (void);
27 
28 #if defined(__GNUC__)
29 # define ATTR_USED __attribute__((used))
30 # define ATTR_NOINLINE __attribute__((noinline))
31 #else
32 # define ATTR_USED
33 # define ATTR_NOINLINE
34 #endif
35 
36 /* How to make symbol public/exported.  */
37 
38 #if defined _WIN32 || defined __CYGWIN__
39 # define EXPORTED_SYMBOL __declspec (dllexport)
40 #else
41 # if __GNUC__ >= 4
42 #  define EXPORTED_SYMBOL __attribute__ ((visibility ("default")))
43 # else
44 #  define EXPORTED_SYMBOL
45 # endif
46 #endif
47 
48 /* Use these to make sure the functions and variables the IPA needs to
49    export (symbols GDBserver needs to query GDB about) are visible and
50    have C linkage.
51 
52    Tag exported functions with IP_AGENT_EXPORT_FUNC, tag the
53    definitions of exported variables with IP_AGENT_EXPORT_VAR, and
54    variable declarations with IP_AGENT_EXPORT_VAR_DECL.  Variables
55    must also be exported with C linkage.  As we can't both use extern
56    "C" and initialize a variable in the same statement, variables that
57    don't have a separate declaration must use
58    EXTERN_C_PUSH/EXTERN_C_POP around their definition.  */
59 
60 #ifdef IN_PROCESS_AGENT
61 # define IP_AGENT_EXPORT_FUNC EXTERN_C EXPORTED_SYMBOL ATTR_NOINLINE ATTR_USED
62 # define IP_AGENT_EXPORT_VAR EXPORTED_SYMBOL ATTR_USED
63 # define IP_AGENT_EXPORT_VAR_DECL EXTERN_C EXPORTED_SYMBOL
64 #else
65 # define IP_AGENT_EXPORT_FUNC static
66 # define IP_AGENT_EXPORT_VAR
67 # define IP_AGENT_EXPORT_VAR_DECL extern
68 #endif
69 
70 IP_AGENT_EXPORT_VAR_DECL int tracing;
71 
72 extern int disconnected_tracing;
73 
74 void tracepoint_look_up_symbols (void);
75 
76 void stop_tracing (void);
77 
78 int handle_tracepoint_general_set (char *own_buf);
79 int handle_tracepoint_query (char *own_buf);
80 
81 int tracepoint_finished_step (struct thread_info *tinfo, CORE_ADDR stop_pc);
82 int tracepoint_was_hit (struct thread_info *tinfo, CORE_ADDR stop_pc);
83 
84 void release_while_stepping_state_list (struct thread_info *tinfo);
85 
86 int in_readonly_region (CORE_ADDR addr, ULONGEST length);
87 int traceframe_read_mem (int tfnum, CORE_ADDR addr,
88 			 unsigned char *buf, ULONGEST length,
89 			 ULONGEST *nbytes);
90 int fetch_traceframe_registers (int tfnum,
91 				struct regcache *regcache,
92 				int regnum);
93 
94 int traceframe_read_sdata (int tfnum, ULONGEST offset,
95 			   unsigned char *buf, ULONGEST length,
96 			   ULONGEST *nbytes);
97 
98 int traceframe_read_info (int tfnum, struct buffer *buffer);
99 
100 /* If a thread is determined to be collecting a fast tracepoint, this
101    structure holds the collect status.  */
102 
103 struct fast_tpoint_collect_status
104 {
105   /* The tracepoint that is presently being collected.  */
106   int tpoint_num;
107   CORE_ADDR tpoint_addr;
108 
109   /* The address range in the jump pad of where the original
110      instruction the tracepoint jump was inserted was relocated
111      to.  */
112   CORE_ADDR adjusted_insn_addr;
113   CORE_ADDR adjusted_insn_addr_end;
114 };
115 
116 /* The possible states a thread can be in, related to the collection of fast
117    tracepoint.  */
118 
119 enum class fast_tpoint_collect_result
120 {
121   /* Not collecting a fast tracepoint.  */
122   not_collecting,
123 
124   /* In the jump pad, but before the relocated instruction.  */
125   before_insn,
126 
127   /* In the jump pad, but at (or after) the relocated instruction.  */
128   at_insn,
129 };
130 
131 fast_tpoint_collect_result fast_tracepoint_collecting
132   (CORE_ADDR thread_area, CORE_ADDR stop_pc,
133    struct fast_tpoint_collect_status *status);
134 
135 void force_unlock_trace_buffer (void);
136 
137 int handle_tracepoint_bkpts (struct thread_info *tinfo, CORE_ADDR stop_pc);
138 
139 #ifdef IN_PROCESS_AGENT
140 void initialize_low_tracepoint (void);
141 const struct target_desc *get_ipa_tdesc (int idx);
142 void supply_fast_tracepoint_registers (struct regcache *regcache,
143 				       const unsigned char *regs);
144 void supply_static_tracepoint_registers (struct regcache *regcache,
145 					 const unsigned char *regs,
146 					 CORE_ADDR pc);
147 void set_trampoline_buffer_space (CORE_ADDR begin, CORE_ADDR end,
148 				  char *errmsg);
149 void *alloc_jump_pad_buffer (size_t size);
150 #ifndef HAVE_GETAUXVAL
151 unsigned long getauxval (unsigned long type);
152 #endif
153 #else
154 void stop_tracing (void);
155 
156 int claim_trampoline_space (ULONGEST used, CORE_ADDR *trampoline);
157 int have_fast_tracepoint_trampoline_buffer (char *msgbuf);
158 void gdb_agent_about_to_close (int pid);
159 #endif
160 
161 struct traceframe;
162 struct eval_agent_expr_context;
163 
164 /* Do memory copies for bytecodes.  */
165 /* Do the recording of memory blocks for actions and bytecodes.  */
166 
167 int agent_mem_read (struct eval_agent_expr_context *ctx,
168 		    unsigned char *to, CORE_ADDR from,
169 		    ULONGEST len);
170 
171 LONGEST agent_get_trace_state_variable_value (int num);
172 void agent_set_trace_state_variable_value (int num, LONGEST val);
173 
174 /* Record the value of a trace state variable.  */
175 
176 int agent_tsv_read (struct eval_agent_expr_context *ctx, int n);
177 int agent_mem_read_string (struct eval_agent_expr_context *ctx,
178 			   unsigned char *to,
179 			   CORE_ADDR from,
180 			   ULONGEST len);
181 
182 /* The prototype the get_raw_reg function in the IPA.  Each arch's
183    bytecode compiler emits calls to this function.  */
184 ULONGEST get_raw_reg (const unsigned char *raw_regs, int regnum);
185 
186 /* Returns the address of the get_raw_reg function in the IPA.  */
187 CORE_ADDR get_raw_reg_func_addr (void);
188 /* Returns the address of the get_trace_state_variable_value
189    function in the IPA.  */
190 CORE_ADDR get_get_tsv_func_addr (void);
191 /* Returns the address of the set_trace_state_variable_value
192    function in the IPA.  */
193 CORE_ADDR get_set_tsv_func_addr (void);
194 
195 #endif /* GDBSERVER_TRACEPOINT_H */
196