xref: /openbmc/qemu/gdbstub/internals.h (revision 88693ab2)
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_IO = 23,
28     GDB_SIGNAL_XCPU = 24,
29     GDB_SIGNAL_UNKNOWN = 143
30 };
31 
32 typedef struct GDBProcess {
33     uint32_t pid;
34     bool attached;
35 
36     char target_xml[1024];
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 } GDBState;
69 
70 /* lives in main gdbstub.c */
71 extern GDBState gdbserver_state;
72 
73 /*
74  * Inline utility function, convert from int to hex and back
75  */
76 
77 static inline int fromhex(int v)
78 {
79     if (v >= '0' && v <= '9') {
80         return v - '0';
81     } else if (v >= 'A' && v <= 'F') {
82         return v - 'A' + 10;
83     } else if (v >= 'a' && v <= 'f') {
84         return v - 'a' + 10;
85     } else {
86         return 0;
87     }
88 }
89 
90 static inline int tohex(int v)
91 {
92     if (v < 10) {
93         return v + '0';
94     } else {
95         return v - 10 + 'a';
96     }
97 }
98 
99 /*
100  * Connection helpers for both softmmu and user backends
101  */
102 
103 void gdb_put_strbuf(void);
104 int gdb_put_packet(const char *buf);
105 int gdb_put_packet_binary(const char *buf, int len, bool dump);
106 void gdb_hextomem(GByteArray *mem, const char *buf, int len);
107 void gdb_memtohex(GString *buf, const uint8_t *mem, int len);
108 void gdb_memtox(GString *buf, const char *mem, int len);
109 void gdb_read_byte(uint8_t ch);
110 
111 /*
112  * Packet acknowledgement - we handle this slightly differently
113  * between user and softmmu mode, mainly to deal with the differences
114  * between the flexible chardev and the direct fd approaches.
115  *
116  * We currently don't support a negotiated QStartNoAckMode
117  */
118 
119 /**
120  * gdb_got_immediate_ack() - check ok to continue
121  *
122  * Returns true to continue, false to re-transmit for user only, the
123  * softmmu stub always returns true.
124  */
125 bool gdb_got_immediate_ack(void);
126 /* utility helpers */
127 CPUState *gdb_first_attached_cpu(void);
128 void gdb_append_thread_id(CPUState *cpu, GString *buf);
129 int gdb_get_cpu_index(CPUState *cpu);
130 unsigned int gdb_get_max_cpus(void); /* both */
131 bool gdb_can_reverse(void); /* softmmu, stub for user */
132 
133 void gdb_create_default_process(GDBState *s);
134 
135 /* signal mapping, common for softmmu, specialised for user-mode */
136 int gdb_signal_to_target(int sig);
137 int gdb_target_signal_to_gdb(int sig);
138 
139 int gdb_get_char(void); /* user only */
140 
141 /**
142  * gdb_continue() - handle continue in mode specific way.
143  */
144 void gdb_continue(void);
145 
146 /**
147  * gdb_continue_partial() - handle partial continue in mode specific way.
148  */
149 int gdb_continue_partial(char *newstates);
150 
151 /*
152  * Helpers with separate softmmu and user implementations
153  */
154 void gdb_put_buffer(const uint8_t *buf, int len);
155 
156 /*
157  * Command handlers - either specialised or softmmu or user only
158  */
159 void gdb_init_gdbserver_state(void);
160 
161 typedef enum GDBThreadIdKind {
162     GDB_ONE_THREAD = 0,
163     GDB_ALL_THREADS,     /* One process, all threads */
164     GDB_ALL_PROCESSES,
165     GDB_READ_THREAD_ERR
166 } GDBThreadIdKind;
167 
168 typedef union GdbCmdVariant {
169     const char *data;
170     uint8_t opcode;
171     unsigned long val_ul;
172     unsigned long long val_ull;
173     struct {
174         GDBThreadIdKind kind;
175         uint32_t pid;
176         uint32_t tid;
177     } thread_id;
178 } GdbCmdVariant;
179 
180 #define get_param(p, i)    (&g_array_index(p, GdbCmdVariant, i))
181 
182 void gdb_handle_query_rcmd(GArray *params, void *user_ctx); /* softmmu */
183 void gdb_handle_query_offsets(GArray *params, void *user_ctx); /* user */
184 void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx); /*user */
185 
186 void gdb_handle_query_attached(GArray *params, void *user_ctx); /* both */
187 
188 /* softmmu only */
189 void gdb_handle_query_qemu_phy_mem_mode(GArray *params, void *user_ctx);
190 void gdb_handle_set_qemu_phy_mem_mode(GArray *params, void *user_ctx);
191 
192 /* sycall handling */
193 void gdb_handle_file_io(GArray *params, void *user_ctx);
194 bool gdb_handled_syscall(void);
195 void gdb_disable_syscalls(void);
196 void gdb_syscall_reset(void);
197 
198 /* user/softmmu specific syscall handling */
199 void gdb_syscall_handling(const char *syscall_packet);
200 
201 /*
202  * Break/Watch point support - there is an implementation for softmmu
203  * and user mode.
204  */
205 bool gdb_supports_guest_debug(void);
206 int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len);
207 int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len);
208 void gdb_breakpoint_remove_all(CPUState *cs);
209 
210 /**
211  * gdb_target_memory_rw_debug() - handle debug access to memory
212  * @cs: CPUState
213  * @addr: nominal address, could be an entire physical address
214  * @buf: data
215  * @len: length of access
216  * @is_write: is it a write operation
217  *
218  * This function is specialised depending on the mode we are running
219  * in. For softmmu guests we can switch the interpretation of the
220  * address to a physical address.
221  */
222 int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr,
223                                uint8_t *buf, int len, bool is_write);
224 
225 #endif /* GDBSTUB_INTERNALS_H */
226