xref: /openbmc/qemu/gdbstub/internals.h (revision 505601d5806a5b9a8acde140da5b507bdd03a794)
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     char syscall_buf[256];
65     gdb_syscall_complete_cb current_syscall_cb;
66     GString *str_buf;
67     GByteArray *mem_buf;
68     int sstep_flags;
69     int supported_sstep_flags;
70 } GDBState;
71 
72 /* lives in main gdbstub.c */
73 extern GDBState gdbserver_state;
74 
75 /*
76  * Inline utility function, convert from int to hex and back
77  */
78 
79 static inline int fromhex(int v)
80 {
81     if (v >= '0' && v <= '9') {
82         return v - '0';
83     } else if (v >= 'A' && v <= 'F') {
84         return v - 'A' + 10;
85     } else if (v >= 'a' && v <= 'f') {
86         return v - 'a' + 10;
87     } else {
88         return 0;
89     }
90 }
91 
92 static inline int tohex(int v)
93 {
94     if (v < 10) {
95         return v + '0';
96     } else {
97         return v - 10 + 'a';
98     }
99 }
100 
101 /*
102  * Connection helpers for both softmmu and user backends
103  */
104 
105 void gdb_put_strbuf(void);
106 int gdb_put_packet(const char *buf);
107 int gdb_put_packet_binary(const char *buf, int len, bool dump);
108 void gdb_hextomem(GByteArray *mem, const char *buf, int len);
109 void gdb_memtohex(GString *buf, const uint8_t *mem, int len);
110 void gdb_memtox(GString *buf, const char *mem, int len);
111 void gdb_read_byte(uint8_t ch);
112 
113 /*
114  * Packet acknowledgement - we handle this slightly differently
115  * between user and softmmu mode, mainly to deal with the differences
116  * between the flexible chardev and the direct fd approaches.
117  *
118  * We currently don't support a negotiated QStartNoAckMode
119  */
120 
121 /**
122  * gdb_got_immediate_ack() - check ok to continue
123  *
124  * Returns true to continue, false to re-transmit for user only, the
125  * softmmu stub always returns true.
126  */
127 bool gdb_got_immediate_ack(void);
128 /* utility helpers */
129 CPUState *gdb_first_attached_cpu(void);
130 void gdb_append_thread_id(CPUState *cpu, GString *buf);
131 int gdb_get_cpu_index(CPUState *cpu);
132 unsigned int gdb_get_max_cpus(void); /* both */
133 bool gdb_can_reverse(void); /* softmmu, stub for user */
134 
135 void gdb_create_default_process(GDBState *s);
136 
137 /* signal mapping, common for softmmu, specialised for user-mode */
138 int gdb_signal_to_target(int sig);
139 int gdb_target_signal_to_gdb(int sig);
140 
141 int gdb_get_char(void); /* user only */
142 
143 /**
144  * gdb_continue() - handle continue in mode specific way.
145  */
146 void gdb_continue(void);
147 
148 /**
149  * gdb_continue_partial() - handle partial continue in mode specific way.
150  */
151 int gdb_continue_partial(char *newstates);
152 
153 /*
154  * Helpers with separate softmmu and user implementations
155  */
156 void gdb_put_buffer(const uint8_t *buf, int len);
157 
158 /*
159  * Command handlers - either specialised or softmmu or user only
160  */
161 void gdb_init_gdbserver_state(void);
162 
163 typedef enum GDBThreadIdKind {
164     GDB_ONE_THREAD = 0,
165     GDB_ALL_THREADS,     /* One process, all threads */
166     GDB_ALL_PROCESSES,
167     GDB_READ_THREAD_ERR
168 } GDBThreadIdKind;
169 
170 typedef union GdbCmdVariant {
171     const char *data;
172     uint8_t opcode;
173     unsigned long val_ul;
174     unsigned long long val_ull;
175     struct {
176         GDBThreadIdKind kind;
177         uint32_t pid;
178         uint32_t tid;
179     } thread_id;
180 } GdbCmdVariant;
181 
182 #define get_param(p, i)    (&g_array_index(p, GdbCmdVariant, i))
183 
184 void gdb_handle_query_rcmd(GArray *params, void *user_ctx); /* softmmu */
185 void gdb_handle_query_offsets(GArray *params, void *user_ctx); /* user */
186 void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx); /*user */
187 
188 void gdb_handle_query_attached(GArray *params, void *user_ctx); /* both */
189 
190 /* softmmu only */
191 void gdb_handle_query_qemu_phy_mem_mode(GArray *params, void *user_ctx);
192 void gdb_handle_set_qemu_phy_mem_mode(GArray *params, void *user_ctx);
193 
194 /*
195  * Break/Watch point support - there is an implementation for softmmu
196  * and user mode.
197  */
198 bool gdb_supports_guest_debug(void);
199 int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len);
200 int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len);
201 void gdb_breakpoint_remove_all(CPUState *cs);
202 
203 /**
204  * gdb_target_memory_rw_debug() - handle debug access to memory
205  * @cs: CPUState
206  * @addr: nominal address, could be an entire physical address
207  * @buf: data
208  * @len: length of access
209  * @is_write: is it a write operation
210  *
211  * This function is specialised depending on the mode we are running
212  * in. For softmmu guests we can switch the interpretation of the
213  * address to a physical address.
214  */
215 int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr,
216                                uint8_t *buf, int len, bool is_write);
217 
218 #endif /* GDBSTUB_INTERNALS_H */
219