qemu/gdbstub/internals.h
Ilya Leoshkevich 046f143c51 gdbstub: Implement catching syscalls
GDB supports stopping on syscall entry and exit using the "catch
syscall" command. It relies on 3 packets, which are currently not
supported by QEMU:

* qSupported:QCatchSyscalls+ [1]
* QCatchSyscalls: [2]
* T05syscall_entry: and T05syscall_return: [3]

Implement generation and handling of these packets.

[1] https://sourceware.org/gdb/current/onlinedocs/gdb.html/General-Query-Packets.html#qSupported
[2] https://sourceware.org/gdb/current/onlinedocs/gdb.html/General-Query-Packets.html#QCatchSyscalls
[3] https://sourceware.org/gdb/current/onlinedocs/gdb.html/Stop-Reply-Packets.html

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240202152506.279476-5-iii@linux.ibm.com>
[AJB: GString -> g_strdup_printf]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240207163812.3231697-14-alex.bennee@linaro.org>
2024-02-09 17:52:40 +00:00

240 lines
6.5 KiB
C

/*
* gdbstub internals
*
* Copyright (c) 2022 Linaro Ltd
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef GDBSTUB_INTERNALS_H
#define GDBSTUB_INTERNALS_H
#include "exec/cpu-common.h"
#define MAX_PACKET_LENGTH 4096
/*
* Shared structures and definitions
*/
enum {
GDB_SIGNAL_0 = 0,
GDB_SIGNAL_INT = 2,
GDB_SIGNAL_QUIT = 3,
GDB_SIGNAL_TRAP = 5,
GDB_SIGNAL_ABRT = 6,
GDB_SIGNAL_ALRM = 14,
GDB_SIGNAL_STOP = 17,
GDB_SIGNAL_IO = 23,
GDB_SIGNAL_XCPU = 24,
GDB_SIGNAL_UNKNOWN = 143
};
typedef struct GDBProcess {
uint32_t pid;
bool attached;
char *target_xml;
} GDBProcess;
enum RSState {
RS_INACTIVE,
RS_IDLE,
RS_GETLINE,
RS_GETLINE_ESC,
RS_GETLINE_RLE,
RS_CHKSUM1,
RS_CHKSUM2,
};
typedef struct GDBState {
bool init; /* have we been initialised? */
CPUState *c_cpu; /* current CPU for step/continue ops */
CPUState *g_cpu; /* current CPU for other ops */
CPUState *query_cpu; /* for q{f|s}ThreadInfo */
enum RSState state; /* parsing state */
char line_buf[MAX_PACKET_LENGTH];
int line_buf_index;
int line_sum; /* running checksum */
int line_csum; /* checksum at the end of the packet */
GByteArray *last_packet;
int signal;
bool multiprocess;
GDBProcess *processes;
int process_num;
GString *str_buf;
GByteArray *mem_buf;
int sstep_flags;
int supported_sstep_flags;
/*
* Whether we are allowed to send a stop reply packet at this moment.
* Must be set off after sending the stop reply itself.
*/
bool allow_stop_reply;
} GDBState;
/* lives in main gdbstub.c */
extern GDBState gdbserver_state;
/*
* Inline utility function, convert from int to hex and back
*/
static inline int fromhex(int v)
{
if (v >= '0' && v <= '9') {
return v - '0';
} else if (v >= 'A' && v <= 'F') {
return v - 'A' + 10;
} else if (v >= 'a' && v <= 'f') {
return v - 'a' + 10;
} else {
return 0;
}
}
static inline int tohex(int v)
{
if (v < 10) {
return v + '0';
} else {
return v - 10 + 'a';
}
}
/*
* Connection helpers for both system and user backends
*/
void gdb_put_strbuf(void);
int gdb_put_packet(const char *buf);
int gdb_put_packet_binary(const char *buf, int len, bool dump);
void gdb_hextomem(GByteArray *mem, const char *buf, int len);
void gdb_memtohex(GString *buf, const uint8_t *mem, int len);
void gdb_memtox(GString *buf, const char *mem, int len);
void gdb_read_byte(uint8_t ch);
/*
* Packet acknowledgement - we handle this slightly differently
* between user and softmmu mode, mainly to deal with the differences
* between the flexible chardev and the direct fd approaches.
*
* We currently don't support a negotiated QStartNoAckMode
*/
/**
* gdb_got_immediate_ack() - check ok to continue
*
* Returns true to continue, false to re-transmit for user only, the
* softmmu stub always returns true.
*/
bool gdb_got_immediate_ack(void);
/* utility helpers */
GDBProcess *gdb_get_process(uint32_t pid);
CPUState *gdb_get_first_cpu_in_process(GDBProcess *process);
CPUState *gdb_first_attached_cpu(void);
void gdb_append_thread_id(CPUState *cpu, GString *buf);
int gdb_get_cpu_index(CPUState *cpu);
unsigned int gdb_get_max_cpus(void); /* both */
bool gdb_can_reverse(void); /* softmmu, stub for user */
int gdb_target_sigtrap(void); /* user */
void gdb_create_default_process(GDBState *s);
/* signal mapping, common for softmmu, specialised for user-mode */
int gdb_signal_to_target(int sig);
int gdb_target_signal_to_gdb(int sig);
int gdb_get_char(void); /* user only */
/**
* gdb_continue() - handle continue in mode specific way.
*/
void gdb_continue(void);
/**
* gdb_continue_partial() - handle partial continue in mode specific way.
*/
int gdb_continue_partial(char *newstates);
/*
* Helpers with separate softmmu and user implementations
*/
void gdb_put_buffer(const uint8_t *buf, int len);
/*
* Command handlers - either specialised or softmmu or user only
*/
void gdb_init_gdbserver_state(void);
typedef enum GDBThreadIdKind {
GDB_ONE_THREAD = 0,
GDB_ALL_THREADS, /* One process, all threads */
GDB_ALL_PROCESSES,
GDB_READ_THREAD_ERR
} GDBThreadIdKind;
typedef union GdbCmdVariant {
const char *data;
uint8_t opcode;
unsigned long val_ul;
unsigned long long val_ull;
struct {
GDBThreadIdKind kind;
uint32_t pid;
uint32_t tid;
} thread_id;
} GdbCmdVariant;
#define get_param(p, i) (&g_array_index(p, GdbCmdVariant, i))
void gdb_handle_query_rcmd(GArray *params, void *user_ctx); /* softmmu */
void gdb_handle_query_offsets(GArray *params, void *user_ctx); /* user */
void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx); /*user */
void gdb_handle_v_file_open(GArray *params, void *user_ctx); /* user */
void gdb_handle_v_file_close(GArray *params, void *user_ctx); /* user */
void gdb_handle_v_file_pread(GArray *params, void *user_ctx); /* user */
void gdb_handle_v_file_readlink(GArray *params, void *user_ctx); /* user */
void gdb_handle_query_xfer_exec_file(GArray *params, void *user_ctx); /* user */
void gdb_handle_set_catch_syscalls(GArray *params, void *user_ctx); /* user */
void gdb_handle_query_attached(GArray *params, void *user_ctx); /* both */
/* softmmu only */
void gdb_handle_query_qemu_phy_mem_mode(GArray *params, void *user_ctx);
void gdb_handle_set_qemu_phy_mem_mode(GArray *params, void *user_ctx);
/* sycall handling */
void gdb_handle_file_io(GArray *params, void *user_ctx);
bool gdb_handled_syscall(void);
void gdb_disable_syscalls(void);
void gdb_syscall_reset(void);
/* user/softmmu specific syscall handling */
void gdb_syscall_handling(const char *syscall_packet);
/*
* Break/Watch point support - there is an implementation for softmmu
* and user mode.
*/
bool gdb_supports_guest_debug(void);
int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len);
int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len);
void gdb_breakpoint_remove_all(CPUState *cs);
/**
* gdb_target_memory_rw_debug() - handle debug access to memory
* @cs: CPUState
* @addr: nominal address, could be an entire physical address
* @buf: data
* @len: length of access
* @is_write: is it a write operation
*
* This function is specialised depending on the mode we are running
* in. For system guests we can switch the interpretation of the
* address to a physical address.
*/
int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr,
uint8_t *buf, int len, bool is_write);
#endif /* GDBSTUB_INTERNALS_H */