xref: /openbmc/qemu/gdbstub/internals.h (revision 4f7b1ecb)
1 /*
2  * gdbstub internals
3  *
4  * Copyright (c) 2022 Linaro Ltd
5  *
6  * SPDX-License-Identifier: GPL-2.0-or-later
7  */
8 
9 #ifndef GDBSTUB_INTERNALS_H
10 #define GDBSTUB_INTERNALS_H
11 
12 #include "exec/cpu-common.h"
13 
14 #define MAX_PACKET_LENGTH 4096
15 
16 /*
17  * Shared structures and definitions
18  */
19 
20 enum {
21     GDB_SIGNAL_0 = 0,
22     GDB_SIGNAL_INT = 2,
23     GDB_SIGNAL_QUIT = 3,
24     GDB_SIGNAL_TRAP = 5,
25     GDB_SIGNAL_ABRT = 6,
26     GDB_SIGNAL_ALRM = 14,
27     GDB_SIGNAL_STOP = 17,
28     GDB_SIGNAL_IO = 23,
29     GDB_SIGNAL_XCPU = 24,
30     GDB_SIGNAL_UNKNOWN = 143
31 };
32 
33 typedef struct GDBProcess {
34     uint32_t pid;
35     bool attached;
36     char *target_xml;
37 } GDBProcess;
38 
39 enum RSState {
40     RS_INACTIVE,
41     RS_IDLE,
42     RS_GETLINE,
43     RS_GETLINE_ESC,
44     RS_GETLINE_RLE,
45     RS_CHKSUM1,
46     RS_CHKSUM2,
47 };
48 
49 typedef struct GDBState {
50     bool init;       /* have we been initialised? */
51     CPUState *c_cpu; /* current CPU for step/continue ops */
52     CPUState *g_cpu; /* current CPU for other ops */
53     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
54     enum RSState state; /* parsing state */
55     char line_buf[MAX_PACKET_LENGTH];
56     int line_buf_index;
57     int line_sum; /* running checksum */
58     int line_csum; /* checksum at the end of the packet */
59     GByteArray *last_packet;
60     int signal;
61     bool multiprocess;
62     GDBProcess *processes;
63     int process_num;
64     GString *str_buf;
65     GByteArray *mem_buf;
66     int sstep_flags;
67     int supported_sstep_flags;
68     /*
69      * Whether we are allowed to send a stop reply packet at this moment.
70      * Must be set off after sending the stop reply itself.
71      */
72     bool allow_stop_reply;
73 } GDBState;
74 
75 /* lives in main gdbstub.c */
76 extern GDBState gdbserver_state;
77 
78 /*
79  * Inline utility function, convert from int to hex and back
80  */
81 
82 static inline int fromhex(int v)
83 {
84     if (v >= '0' && v <= '9') {
85         return v - '0';
86     } else if (v >= 'A' && v <= 'F') {
87         return v - 'A' + 10;
88     } else if (v >= 'a' && v <= 'f') {
89         return v - 'a' + 10;
90     } else {
91         return 0;
92     }
93 }
94 
95 static inline int tohex(int v)
96 {
97     if (v < 10) {
98         return v + '0';
99     } else {
100         return v - 10 + 'a';
101     }
102 }
103 
104 /*
105  * Connection helpers for both system and user backends
106  */
107 
108 void gdb_put_strbuf(void);
109 int gdb_put_packet_binary(const char *buf, int len, bool dump);
110 void gdb_memtohex(GString *buf, const uint8_t *mem, int len);
111 void gdb_memtox(GString *buf, const char *mem, int len);
112 void gdb_read_byte(uint8_t ch);
113 
114 /*
115  * Packet acknowledgement - we handle this slightly differently
116  * between user and system mode, mainly to deal with the differences
117  * between the flexible chardev and the direct fd approaches.
118  *
119  * We currently don't support a negotiated QStartNoAckMode
120  */
121 
122 /**
123  * gdb_got_immediate_ack() - check ok to continue
124  *
125  * Returns true to continue, false to re-transmit for user only, the
126  * system stub always returns true.
127  */
128 bool gdb_got_immediate_ack(void);
129 /* utility helpers */
130 GDBProcess *gdb_get_process(uint32_t pid);
131 CPUState *gdb_get_first_cpu_in_process(GDBProcess *process);
132 CPUState *gdb_first_attached_cpu(void);
133 void gdb_append_thread_id(CPUState *cpu, GString *buf);
134 int gdb_get_cpu_index(CPUState *cpu);
135 unsigned int gdb_get_max_cpus(void); /* both */
136 bool gdb_can_reverse(void); /* system emulation, stub for user */
137 int gdb_target_sigtrap(void); /* user */
138 
139 void gdb_create_default_process(GDBState *s);
140 
141 /* signal mapping, common for system, specialised for user-mode */
142 int gdb_signal_to_target(int sig);
143 int gdb_target_signal_to_gdb(int sig);
144 
145 int gdb_get_char(void); /* user only */
146 
147 /**
148  * gdb_continue() - handle continue in mode specific way.
149  */
150 void gdb_continue(void);
151 
152 /**
153  * gdb_continue_partial() - handle partial continue in mode specific way.
154  */
155 int gdb_continue_partial(char *newstates);
156 
157 /*
158  * Helpers with separate system and user implementations
159  */
160 void gdb_put_buffer(const uint8_t *buf, int len);
161 
162 /*
163  * Command handlers - either specialised or system or user only
164  */
165 void gdb_init_gdbserver_state(void);
166 
167 void gdb_handle_query_rcmd(GArray *params, void *ctx); /* system */
168 void gdb_handle_query_offsets(GArray *params, void *user_ctx); /* user */
169 void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx); /*user */
170 void gdb_handle_query_xfer_siginfo(GArray *params, void *user_ctx); /*user */
171 void gdb_handle_v_file_open(GArray *params, void *user_ctx); /* user */
172 void gdb_handle_v_file_close(GArray *params, void *user_ctx); /* user */
173 void gdb_handle_v_file_pread(GArray *params, void *user_ctx); /* user */
174 void gdb_handle_v_file_readlink(GArray *params, void *user_ctx); /* user */
175 void gdb_handle_query_xfer_exec_file(GArray *params, void *user_ctx); /* user */
176 void gdb_handle_set_catch_syscalls(GArray *params, void *user_ctx); /* user */
177 void gdb_handle_query_supported_user(const char *gdb_supported); /* user */
178 bool gdb_handle_set_thread_user(uint32_t pid, uint32_t tid); /* user */
179 bool gdb_handle_detach_user(uint32_t pid); /* user */
180 
181 void gdb_handle_query_attached(GArray *params, void *ctx); /* both */
182 
183 /* system only */
184 void gdb_handle_query_qemu_phy_mem_mode(GArray *params, void *ctx);
185 void gdb_handle_set_qemu_phy_mem_mode(GArray *params, void *ctx);
186 
187 /* sycall handling */
188 void gdb_handle_file_io(GArray *params, void *user_ctx);
189 bool gdb_handled_syscall(void);
190 void gdb_disable_syscalls(void);
191 void gdb_syscall_reset(void);
192 
193 /* user/system specific syscall handling */
194 void gdb_syscall_handling(const char *syscall_packet);
195 
196 /*
197  * Break/Watch point support - there is an implementation for system
198  * and user mode.
199  */
200 bool gdb_supports_guest_debug(void);
201 int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len);
202 int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len);
203 void gdb_breakpoint_remove_all(CPUState *cs);
204 
205 /**
206  * gdb_target_memory_rw_debug() - handle debug access to memory
207  * @cs: CPUState
208  * @addr: nominal address, could be an entire physical address
209  * @buf: data
210  * @len: length of access
211  * @is_write: is it a write operation
212  *
213  * This function is specialised depending on the mode we are running
214  * in. For system guests we can switch the interpretation of the
215  * address to a physical address.
216  */
217 int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr,
218                                uint8_t *buf, int len, bool is_write);
219 
220 #endif /* GDBSTUB_INTERNALS_H */
221