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gdbstub: move chunks of user code into own files

Browse Source 
The process was pretty similar to the softmmu move except we take the
time to split stuff between user.c and user-target.c to avoid as much
target specific compilation as possible. We also start to make use of
our shiny new header scheme so the user-only helpers can be included
without the rest of the exec/gsbstub.h cruft.

As before we split some functions into user and softmmu versions

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-12-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-12-richard.henderson@linaro.org>
This commit is contained in:
Alex Bennée 2023-03-02 18:57:47 -08:00
parent b6fa2ec238
commit d96bf49ba8
13 changed files with 790 additions and 696 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
MAINTAINERS
View File

@ -2743,6 +2743,7 @@ S: Maintained
F: docs/system/gdb.rst
F: gdbstub/*
F: include/exec/gdbstub.h
F: include/gdbstub/*
F: gdb-xml/
F: tests/tcg/multiarch/gdbstub/
F: scripts/feature_to_c.sh

1
bsd-user/main.c
View File

@ -44,6 +44,7 @@
#include "trace/control.h"
#include "crypto/init.h"
#include "qemu/guest-random.h"
#include "gdbstub/user.h"
#include "host-os.h"
#include "target_arch_cpu.h"

1
bsd-user/signal.c
View File

@ -21,6 +21,7 @@
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu.h"
#include "gdbstub/user.h"
#include "signal-common.h"
#include "trace.h"
#include "hw/core/tcg-cpu-ops.h"

678
gdbstub/gdbstub.c
View File

@ -30,13 +30,12 @@
#include "trace.h"
#include "exec/gdbstub.h"
#ifdef CONFIG_USER_ONLY
#include "qemu.h"
#include "gdbstub/user.h"
#else
#include "hw/cpu/cluster.h"
#include "hw/boards.h"
#endif
#include "qemu/sockets.h"
#include "sysemu/hw_accel.h"
#include "sysemu/runstate.h"
#include "semihosting/semihost.h"
@ -80,223 +79,6 @@ static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
}
/*
* Return the GDB index for a given vCPU state.
*
* For user mode this is simply the thread id.
*/
#if defined(CONFIG_USER_ONLY)
int gdb_get_cpu_index(CPUState *cpu)
{
TaskState *ts = (TaskState *) cpu->opaque;
return ts ? ts->ts_tid : -1;
}
#endif
#ifdef CONFIG_USER_ONLY
/* Map target signal numbers to GDB protocol signal numbers and vice
* versa. For user emulation's currently supported systems, we can
* assume most signals are defined.
*/
static int gdb_signal_table[] = {
0,
TARGET_SIGHUP,
TARGET_SIGINT,
TARGET_SIGQUIT,
TARGET_SIGILL,
TARGET_SIGTRAP,
TARGET_SIGABRT,
-1, /* SIGEMT */
TARGET_SIGFPE,
TARGET_SIGKILL,
TARGET_SIGBUS,
TARGET_SIGSEGV,
TARGET_SIGSYS,
TARGET_SIGPIPE,
TARGET_SIGALRM,
TARGET_SIGTERM,
TARGET_SIGURG,
TARGET_SIGSTOP,
TARGET_SIGTSTP,
TARGET_SIGCONT,
TARGET_SIGCHLD,
TARGET_SIGTTIN,
TARGET_SIGTTOU,
TARGET_SIGIO,
TARGET_SIGXCPU,
TARGET_SIGXFSZ,
TARGET_SIGVTALRM,
TARGET_SIGPROF,
TARGET_SIGWINCH,
-1, /* SIGLOST */
TARGET_SIGUSR1,
TARGET_SIGUSR2,
#ifdef TARGET_SIGPWR
TARGET_SIGPWR,
#else
-1,
#endif
-1, /* SIGPOLL */
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
#ifdef __SIGRTMIN
__SIGRTMIN + 1,
__SIGRTMIN + 2,
__SIGRTMIN + 3,
__SIGRTMIN + 4,
__SIGRTMIN + 5,
__SIGRTMIN + 6,
__SIGRTMIN + 7,
__SIGRTMIN + 8,
__SIGRTMIN + 9,
__SIGRTMIN + 10,
__SIGRTMIN + 11,
__SIGRTMIN + 12,
__SIGRTMIN + 13,
__SIGRTMIN + 14,
__SIGRTMIN + 15,
__SIGRTMIN + 16,
__SIGRTMIN + 17,
__SIGRTMIN + 18,
__SIGRTMIN + 19,
__SIGRTMIN + 20,
__SIGRTMIN + 21,
__SIGRTMIN + 22,
__SIGRTMIN + 23,
__SIGRTMIN + 24,
__SIGRTMIN + 25,
__SIGRTMIN + 26,
__SIGRTMIN + 27,
__SIGRTMIN + 28,
__SIGRTMIN + 29,
__SIGRTMIN + 30,
__SIGRTMIN + 31,
-1, /* SIGCANCEL */
__SIGRTMIN,
__SIGRTMIN + 32,
__SIGRTMIN + 33,
__SIGRTMIN + 34,
__SIGRTMIN + 35,
__SIGRTMIN + 36,
__SIGRTMIN + 37,
__SIGRTMIN + 38,
__SIGRTMIN + 39,
__SIGRTMIN + 40,
__SIGRTMIN + 41,
__SIGRTMIN + 42,
__SIGRTMIN + 43,
__SIGRTMIN + 44,
__SIGRTMIN + 45,
__SIGRTMIN + 46,
__SIGRTMIN + 47,
__SIGRTMIN + 48,
__SIGRTMIN + 49,
__SIGRTMIN + 50,
__SIGRTMIN + 51,
__SIGRTMIN + 52,
__SIGRTMIN + 53,
__SIGRTMIN + 54,
__SIGRTMIN + 55,
__SIGRTMIN + 56,
__SIGRTMIN + 57,
__SIGRTMIN + 58,
__SIGRTMIN + 59,
__SIGRTMIN + 60,
__SIGRTMIN + 61,
__SIGRTMIN + 62,
__SIGRTMIN + 63,
__SIGRTMIN + 64,
__SIGRTMIN + 65,
__SIGRTMIN + 66,
__SIGRTMIN + 67,
__SIGRTMIN + 68,
__SIGRTMIN + 69,
__SIGRTMIN + 70,
__SIGRTMIN + 71,
__SIGRTMIN + 72,
__SIGRTMIN + 73,
__SIGRTMIN + 74,
__SIGRTMIN + 75,
__SIGRTMIN + 76,
__SIGRTMIN + 77,
__SIGRTMIN + 78,
__SIGRTMIN + 79,
__SIGRTMIN + 80,
__SIGRTMIN + 81,
__SIGRTMIN + 82,
__SIGRTMIN + 83,
__SIGRTMIN + 84,
__SIGRTMIN + 85,
__SIGRTMIN + 86,
__SIGRTMIN + 87,
__SIGRTMIN + 88,
__SIGRTMIN + 89,
__SIGRTMIN + 90,
__SIGRTMIN + 91,
__SIGRTMIN + 92,
__SIGRTMIN + 93,
__SIGRTMIN + 94,
__SIGRTMIN + 95,
-1, /* SIGINFO */
-1, /* UNKNOWN */
-1, /* DEFAULT */
-1,
-1,
-1,
-1,
-1,
-1
#endif
};
#else
/* In system mode we only need SIGINT and SIGTRAP; other signals
are not yet supported. */
enum {
TARGET_SIGINT = 2,
TARGET_SIGTRAP = 5
};
static int gdb_signal_table[] = {
-1,
-1,
TARGET_SIGINT,
-1,
-1,
TARGET_SIGTRAP
};
#endif
#ifdef CONFIG_USER_ONLY
static int target_signal_to_gdb (int sig)
{
int i;
for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
if (gdb_signal_table[i] == sig)
return i;
return GDB_SIGNAL_UNKNOWN;
}
#endif
static int gdb_signal_to_target (int sig)
{
if (sig < ARRAY_SIZE (gdb_signal_table))
return gdb_signal_table[sig];
else
return -1;
}
typedef struct GDBRegisterState {
int base_reg;
int num_regs;
@ -306,15 +88,6 @@ typedef struct GDBRegisterState {
struct GDBRegisterState *next;
} GDBRegisterState;
#ifdef CONFIG_USER_ONLY
typedef struct {
int fd;
char *socket_path;
int running_state;
} GDBUserState;
static GDBUserState gdbserver_user_state;
#endif
GDBState gdbserver_state;
void gdb_init_gdbserver_state(void)
@ -338,34 +111,6 @@ void gdb_init_gdbserver_state(void)
bool gdb_has_xml;
#ifdef CONFIG_USER_ONLY
static int get_char(void)
{
uint8_t ch;
int ret;
for(;;) {
ret = recv(gdbserver_user_state.fd, &ch, 1, 0);
if (ret < 0) {
if (errno == ECONNRESET) {
gdbserver_user_state.fd = -1;
}
if (errno != EINTR) {
return -1;
}
} else if (ret == 0) {
close(gdbserver_user_state.fd);
gdbserver_user_state.fd = -1;
return -1;
} else {
break;
}
}
return ch;
}
#endif
/*
* Return true if there is a GDB currently connected to the stub
* and attached to a CPU
@ -410,104 +155,6 @@ static bool stub_can_reverse(void)
#endif
}
/* Resume execution. */
static void gdb_continue(void)
{
#ifdef CONFIG_USER_ONLY
gdbserver_user_state.running_state = 1;
trace_gdbstub_op_continue();
#else
if (!runstate_needs_reset()) {
trace_gdbstub_op_continue();
vm_start();
}
#endif
}
/*
* Resume execution, per CPU actions. For user-mode emulation it's
* equivalent to gdb_continue.
*/
static int gdb_continue_partial(char *newstates)
{
CPUState *cpu;
int res = 0;
#ifdef CONFIG_USER_ONLY
/*
* This is not exactly accurate, but it's an improvement compared to the
* previous situation, where only one CPU would be single-stepped.
*/
CPU_FOREACH(cpu) {
if (newstates[cpu->cpu_index] == 's') {
trace_gdbstub_op_stepping(cpu->cpu_index);
cpu_single_step(cpu, gdbserver_state.sstep_flags);
}
}
gdbserver_user_state.running_state = 1;
#else
int flag = 0;
if (!runstate_needs_reset()) {
bool step_requested = false;
CPU_FOREACH(cpu) {
if (newstates[cpu->cpu_index] == 's') {
step_requested = true;
break;
}
}
if (vm_prepare_start(step_requested)) {
return 0;
}
CPU_FOREACH(cpu) {
switch (newstates[cpu->cpu_index]) {
case 0:
case 1:
break; /* nothing to do here */
case 's':
trace_gdbstub_op_stepping(cpu->cpu_index);
cpu_single_step(cpu, gdbserver_state.sstep_flags);
cpu_resume(cpu);
flag = 1;
break;
case 'c':
trace_gdbstub_op_continue_cpu(cpu->cpu_index);
cpu_resume(cpu);
flag = 1;
break;
default:
res = -1;
break;
}
}
}
if (flag) {
qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
}
#endif
return res;
}
#ifdef CONFIG_USER_ONLY
void gdb_put_buffer(const uint8_t *buf, int len)
{
int ret;
while (len > 0) {
ret = send(gdbserver_user_state.fd, buf, len, 0);
if (ret < 0) {
if (errno != EINTR)
return;
} else {
buf += ret;
len -= ret;
}
}
}
#endif
/* writes 2*len+1 bytes in buf */
void gdb_memtohex(GString *buf, const uint8_t *mem, int len)
{
@ -593,7 +240,7 @@ int gdb_put_packet_binary(const char *buf, int len, bool dump)
gdbserver_state.last_packet->len);
#ifdef CONFIG_USER_ONLY
i = get_char();
i = gdb_get_char();
if (i < 0)
return -1;
if (i == '+')
@ -1950,23 +1597,6 @@ static void handle_query_thread_extra(GArray *params, void *user_ctx)
gdb_put_strbuf();
}
#ifdef CONFIG_USER_ONLY
static void handle_query_offsets(GArray *params, void *user_ctx)
{
TaskState *ts;
ts = gdbserver_state.c_cpu->opaque;
g_string_printf(gdbserver_state.str_buf,
"Text=" TARGET_ABI_FMT_lx
";Data=" TARGET_ABI_FMT_lx
";Bss=" TARGET_ABI_FMT_lx,
ts->info->code_offset,
ts->info->data_offset,
ts->info->data_offset);
gdb_put_strbuf();
}
#endif
static void handle_query_supported(GArray *params, void *user_ctx)
{
CPUClass *cc;
@ -2049,53 +1679,6 @@ static void handle_query_xfer_features(GArray *params, void *user_ctx)
gdbserver_state.str_buf->len, true);
}
#if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
static void handle_query_xfer_auxv(GArray *params, void *user_ctx)
{
TaskState *ts;
unsigned long offset, len, saved_auxv, auxv_len;
if (params->len < 2) {
gdb_put_packet("E22");
return;
}
offset = get_param(params, 0)->val_ul;
len = get_param(params, 1)->val_ul;
ts = gdbserver_state.c_cpu->opaque;
saved_auxv = ts->info->saved_auxv;
auxv_len = ts->info->auxv_len;
if (offset >= auxv_len) {
gdb_put_packet("E00");
return;
}
if (len > (MAX_PACKET_LENGTH - 5) / 2) {
len = (MAX_PACKET_LENGTH - 5) / 2;
}
if (len < auxv_len - offset) {
g_string_assign(gdbserver_state.str_buf, "m");
} else {
g_string_assign(gdbserver_state.str_buf, "l");
len = auxv_len - offset;
}
g_byte_array_set_size(gdbserver_state.mem_buf, len);
if (target_memory_rw_debug(gdbserver_state.g_cpu, saved_auxv + offset,
gdbserver_state.mem_buf->data, len, false)) {
gdb_put_packet("E14");
return;
}
gdb_memtox(gdbserver_state.str_buf,
(const char *)gdbserver_state.mem_buf->data, len);
gdb_put_packet_binary(gdbserver_state.str_buf->str,
gdbserver_state.str_buf->len, true);
}
#endif
static void handle_query_attached(GArray *params, void *user_ctx)
{
gdb_put_packet(GDB_ATTACHED);
@ -2173,7 +1756,7 @@ static const GdbCmdParseEntry gdb_gen_query_table[] = {
},
#ifdef CONFIG_USER_ONLY
{
.handler = handle_query_offsets,
.handler = gdb_handle_query_offsets,
.cmd = "Offsets",
},
#else
@ -2203,7 +1786,7 @@ static const GdbCmdParseEntry gdb_gen_query_table[] = {
},
#if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
{
.handler = handle_query_xfer_auxv,
.handler = gdb_handle_query_xfer_auxv,
.cmd = "Xfer:auxv:read::",
.cmd_startswith = 1,
.schema = "l,l0"
@ -2791,29 +2374,6 @@ void gdb_read_byte(uint8_t ch)
}
}
#ifdef CONFIG_USER_ONLY
/* Tell the remote gdb that the process has exited. */
void gdb_exit(int code)
{
char buf[4];
if (!gdbserver_state.init) {
return;
}
if (gdbserver_user_state.socket_path) {
unlink(gdbserver_user_state.socket_path);
}
if (gdbserver_user_state.fd < 0) {
return;
}
trace_gdbstub_op_exiting((uint8_t)code);
snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
gdb_put_packet(buf);
}
#endif
/*
* Create the process that will contain all the "orphan" CPUs (that are not
* part of a CPU cluster). Note that if this process contains no CPUs, it won't
@ -2839,233 +2399,3 @@ void gdb_create_default_process(GDBState *s)
process->target_xml[0] = '\0';
}
#ifdef CONFIG_USER_ONLY
int
gdb_handlesig(CPUState *cpu, int sig)
{
char buf[256];
int n;
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return sig;
}
/* disable single step if it was enabled */
cpu_single_step(cpu, 0);
tb_flush(cpu);
if (sig != 0) {
gdb_set_stop_cpu(cpu);
g_string_printf(gdbserver_state.str_buf,
"T%02xthread:", target_signal_to_gdb(sig));
gdb_append_thread_id(cpu, gdbserver_state.str_buf);
g_string_append_c(gdbserver_state.str_buf, ';');
gdb_put_strbuf();
}
/*
* gdb_put_packet() might have detected that the peer terminated the
* connection.
*/
if (gdbserver_user_state.fd < 0) {
return sig;
}
sig = 0;
gdbserver_state.state = RS_IDLE;
gdbserver_user_state.running_state = 0;
while (gdbserver_user_state.running_state == 0) {
n = read(gdbserver_user_state.fd, buf, 256);
if (n > 0) {
int i;
for (i = 0; i < n; i++) {
gdb_read_byte(buf[i]);
}
} else {
/* XXX: Connection closed. Should probably wait for another
connection before continuing. */
if (n == 0) {
close(gdbserver_user_state.fd);
}
gdbserver_user_state.fd = -1;
return sig;
}
}
sig = gdbserver_state.signal;
gdbserver_state.signal = 0;
return sig;
}
/* Tell the remote gdb that the process has exited due to SIG. */
void gdb_signalled(CPUArchState *env, int sig)
{
char buf[4];
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return;
}
snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
gdb_put_packet(buf);
}
static void gdb_accept_init(int fd)
{
gdb_init_gdbserver_state();
gdb_create_default_process(&gdbserver_state);
gdbserver_state.processes[0].attached = true;
gdbserver_state.c_cpu = gdb_first_attached_cpu();
gdbserver_state.g_cpu = gdbserver_state.c_cpu;
gdbserver_user_state.fd = fd;
gdb_has_xml = false;
}
static bool gdb_accept_socket(int gdb_fd)
{
int fd;
for(;;) {
fd = accept(gdb_fd, NULL, NULL);
if (fd < 0 && errno != EINTR) {
perror("accept socket");
return false;
} else if (fd >= 0) {
qemu_set_cloexec(fd);
break;
}
}
gdb_accept_init(fd);
return true;
}
static int gdbserver_open_socket(const char *path)
{
struct sockaddr_un sockaddr = {};
int fd, ret;
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0) {
perror("create socket");
return -1;
}
sockaddr.sun_family = AF_UNIX;
pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path);
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind socket");
close(fd);
return -1;
}
ret = listen(fd, 1);
if (ret < 0) {
perror("listen socket");
close(fd);
return -1;
}
return fd;
}
static bool gdb_accept_tcp(int gdb_fd)
{
struct sockaddr_in sockaddr = {};
socklen_t len;
int fd;
for(;;) {
len = sizeof(sockaddr);
fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len);
if (fd < 0 && errno != EINTR) {
perror("accept");
return false;
} else if (fd >= 0) {
qemu_set_cloexec(fd);
break;
}
}
/* set short latency */
if (socket_set_nodelay(fd)) {
perror("setsockopt");
close(fd);
return false;
}
gdb_accept_init(fd);
return true;
}
static int gdbserver_open_port(int port)
{
struct sockaddr_in sockaddr;
int fd, ret;
fd = socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return -1;
}
qemu_set_cloexec(fd);
socket_set_fast_reuse(fd);
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(port);
sockaddr.sin_addr.s_addr = 0;
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind");
close(fd);
return -1;
}
ret = listen(fd, 1);
if (ret < 0) {
perror("listen");
close(fd);
return -1;
}
return fd;
}
int gdbserver_start(const char *port_or_path)
{
int port = g_ascii_strtoull(port_or_path, NULL, 10);
int gdb_fd;
if (port > 0) {
gdb_fd = gdbserver_open_port(port);
} else {
gdb_fd = gdbserver_open_socket(port_or_path);
}
if (gdb_fd < 0) {
return -1;
}
if (port > 0 && gdb_accept_tcp(gdb_fd)) {
return 0;
} else if (gdb_accept_socket(gdb_fd)) {
gdbserver_user_state.socket_path = g_strdup(port_or_path);
return 0;
}
/* gone wrong */
close(gdb_fd);
return -1;
}
/* Disable gdb stub for child processes. */
void gdbserver_fork(CPUState *cpu)
{
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return;
}
close(gdbserver_user_state.fd);
gdbserver_user_state.fd = -1;
cpu_breakpoint_remove_all(cpu, BP_GDB);
cpu_watchpoint_remove_all(cpu, BP_GDB);
}
#endif

18
gdbstub/internals.h
View File

@ -117,6 +117,22 @@ int gdb_get_cpu_index(CPUState *cpu);
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
*/
@ -149,6 +165,8 @@ typedef union 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 */
/*
* Break/Watch point support - there is an implementation for softmmu

3
gdbstub/meson.build
View File

@ -7,3 +7,6 @@
specific_ss.add(files('gdbstub.c'))
softmmu_ss.add(files('softmmu.c'))
user_ss.add(files('user.c'))
# The user-target is specialised by the guest
specific_ss.add(when: 'CONFIG_USER_ONLY', if_true: files('user-target.c'))

90
gdbstub/softmmu.c
View File

@ -434,6 +434,96 @@ void gdb_handle_query_rcmd(GArray *params, void *user_ctx)
gdb_put_packet("OK");
}
/*
* Execution state helpers
*/
void gdb_continue(void)
{
if (!runstate_needs_reset()) {
trace_gdbstub_op_continue();
vm_start();
}
}
/*
* Resume execution, per CPU actions.
*/
int gdb_continue_partial(char *newstates)
{
CPUState *cpu;
int res = 0;
int flag = 0;
if (!runstate_needs_reset()) {
bool step_requested = false;
CPU_FOREACH(cpu) {
if (newstates[cpu->cpu_index] == 's') {
step_requested = true;
break;
}
}
if (vm_prepare_start(step_requested)) {
return 0;
}
CPU_FOREACH(cpu) {
switch (newstates[cpu->cpu_index]) {
case 0:
case 1:
break; /* nothing to do here */
case 's':
trace_gdbstub_op_stepping(cpu->cpu_index);
cpu_single_step(cpu, gdbserver_state.sstep_flags);
cpu_resume(cpu);
flag = 1;
break;
case 'c':
trace_gdbstub_op_continue_cpu(cpu->cpu_index);
cpu_resume(cpu);
flag = 1;
break;
default:
res = -1;
break;
}
}
}
if (flag) {
qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
}
return res;
}
/*
* Signal Handling - in system mode we only need SIGINT and SIGTRAP; other
* signals are not yet supported.
*/
enum {
TARGET_SIGINT = 2,
TARGET_SIGTRAP = 5
};
static int gdb_signal_table[] = {
-1,
-1,
TARGET_SIGINT,
-1,
-1,
TARGET_SIGTRAP
};
int gdb_signal_to_target(int sig)
{
if (sig < ARRAY_SIZE(gdb_signal_table)) {
return gdb_signal_table[sig];
} else {
return -1;
}
}
/*
* Break/Watch point helpers
*/

283
gdbstub/user-target.c Normal file
View File

@ -0,0 +1,283 @@
/*
* Target specific user-mode handling
*
* Copyright (c) 2003-2005 Fabrice Bellard
* Copyright (c) 2022 Linaro Ltd
*
* SPDX-License-Identifier: LGPL-2.0+
*/
#include "qemu/osdep.h"
#include "exec/gdbstub.h"
#include "qemu.h"
#include "internals.h"
/*
* Map target signal numbers to GDB protocol signal numbers and vice
* versa. For user emulation's currently supported systems, we can
* assume most signals are defined.
*/
static int gdb_signal_table[] = {
0,
TARGET_SIGHUP,
TARGET_SIGINT,
TARGET_SIGQUIT,
TARGET_SIGILL,
TARGET_SIGTRAP,
TARGET_SIGABRT,
-1, /* SIGEMT */
TARGET_SIGFPE,
TARGET_SIGKILL,
TARGET_SIGBUS,
TARGET_SIGSEGV,
TARGET_SIGSYS,
TARGET_SIGPIPE,
TARGET_SIGALRM,
TARGET_SIGTERM,
TARGET_SIGURG,
TARGET_SIGSTOP,
TARGET_SIGTSTP,
TARGET_SIGCONT,
TARGET_SIGCHLD,
TARGET_SIGTTIN,
TARGET_SIGTTOU,
TARGET_SIGIO,
TARGET_SIGXCPU,
TARGET_SIGXFSZ,
TARGET_SIGVTALRM,
TARGET_SIGPROF,
TARGET_SIGWINCH,
-1, /* SIGLOST */
TARGET_SIGUSR1,
TARGET_SIGUSR2,
#ifdef TARGET_SIGPWR
TARGET_SIGPWR,
#else
-1,
#endif
-1, /* SIGPOLL */
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
-1,
#ifdef __SIGRTMIN
__SIGRTMIN + 1,
__SIGRTMIN + 2,
__SIGRTMIN + 3,
__SIGRTMIN + 4,
__SIGRTMIN + 5,
__SIGRTMIN + 6,
__SIGRTMIN + 7,
__SIGRTMIN + 8,
__SIGRTMIN + 9,
__SIGRTMIN + 10,
__SIGRTMIN + 11,
__SIGRTMIN + 12,
__SIGRTMIN + 13,
__SIGRTMIN + 14,
__SIGRTMIN + 15,
__SIGRTMIN + 16,
__SIGRTMIN + 17,
__SIGRTMIN + 18,
__SIGRTMIN + 19,
__SIGRTMIN + 20,
__SIGRTMIN + 21,
__SIGRTMIN + 22,
__SIGRTMIN + 23,
__SIGRTMIN + 24,
__SIGRTMIN + 25,
__SIGRTMIN + 26,
__SIGRTMIN + 27,
__SIGRTMIN + 28,
__SIGRTMIN + 29,
__SIGRTMIN + 30,
__SIGRTMIN + 31,
-1, /* SIGCANCEL */
__SIGRTMIN,
__SIGRTMIN + 32,
__SIGRTMIN + 33,
__SIGRTMIN + 34,
__SIGRTMIN + 35,
__SIGRTMIN + 36,
__SIGRTMIN + 37,
__SIGRTMIN + 38,
__SIGRTMIN + 39,
__SIGRTMIN + 40,
__SIGRTMIN + 41,
__SIGRTMIN + 42,
__SIGRTMIN + 43,
__SIGRTMIN + 44,
__SIGRTMIN + 45,
__SIGRTMIN + 46,
__SIGRTMIN + 47,
__SIGRTMIN + 48,
__SIGRTMIN + 49,
__SIGRTMIN + 50,
__SIGRTMIN + 51,
__SIGRTMIN + 52,
__SIGRTMIN + 53,
__SIGRTMIN + 54,
__SIGRTMIN + 55,
__SIGRTMIN + 56,
__SIGRTMIN + 57,
__SIGRTMIN + 58,
__SIGRTMIN + 59,
__SIGRTMIN + 60,
__SIGRTMIN + 61,
__SIGRTMIN + 62,
__SIGRTMIN + 63,
__SIGRTMIN + 64,
__SIGRTMIN + 65,
__SIGRTMIN + 66,
__SIGRTMIN + 67,
__SIGRTMIN + 68,
__SIGRTMIN + 69,
__SIGRTMIN + 70,
__SIGRTMIN + 71,
__SIGRTMIN + 72,
__SIGRTMIN + 73,
__SIGRTMIN + 74,
__SIGRTMIN + 75,
__SIGRTMIN + 76,
__SIGRTMIN + 77,
__SIGRTMIN + 78,
__SIGRTMIN + 79,
__SIGRTMIN + 80,
__SIGRTMIN + 81,
__SIGRTMIN + 82,
__SIGRTMIN + 83,
__SIGRTMIN + 84,
__SIGRTMIN + 85,
__SIGRTMIN + 86,
__SIGRTMIN + 87,
__SIGRTMIN + 88,
__SIGRTMIN + 89,
__SIGRTMIN + 90,
__SIGRTMIN + 91,
__SIGRTMIN + 92,
__SIGRTMIN + 93,
__SIGRTMIN + 94,
__SIGRTMIN + 95,
-1, /* SIGINFO */
-1, /* UNKNOWN */
-1, /* DEFAULT */
-1,
-1,
-1,
-1,
-1,
-1
#endif
};
int gdb_signal_to_target(int sig)
{
if (sig < ARRAY_SIZE(gdb_signal_table)) {
return gdb_signal_table[sig];
} else {
return -1;
}
}
int gdb_target_signal_to_gdb(int sig)
{
int i;
for (i = 0; i < ARRAY_SIZE(gdb_signal_table); i++) {
if (gdb_signal_table[i] == sig) {
return i;
}
}
return GDB_SIGNAL_UNKNOWN;
}
int gdb_get_cpu_index(CPUState *cpu)
{
TaskState *ts = (TaskState *) cpu->opaque;
return ts ? ts->ts_tid : -1;
}
/*
* User-mode specific command helpers
*/
void gdb_handle_query_offsets(GArray *params, void *user_ctx)
{
TaskState *ts;
ts = gdbserver_state.c_cpu->opaque;
g_string_printf(gdbserver_state.str_buf,
"Text=" TARGET_ABI_FMT_lx
";Data=" TARGET_ABI_FMT_lx
";Bss=" TARGET_ABI_FMT_lx,
ts->info->code_offset,
ts->info->data_offset,
ts->info->data_offset);
gdb_put_strbuf();
}
#if defined(CONFIG_LINUX)
/* Partial user only duplicate of helper in gdbstub.c */
static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
uint8_t *buf, int len, bool is_write)
{
CPUClass *cc;
cc = CPU_GET_CLASS(cpu);
if (cc->memory_rw_debug) {
return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
}
return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
}
void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx)
{
TaskState *ts;
unsigned long offset, len, saved_auxv, auxv_len;
if (params->len < 2) {
gdb_put_packet("E22");
return;
}
offset = get_param(params, 0)->val_ul;
len = get_param(params, 1)->val_ul;
ts = gdbserver_state.c_cpu->opaque;
saved_auxv = ts->info->saved_auxv;
auxv_len = ts->info->auxv_len;
if (offset >= auxv_len) {
gdb_put_packet("E00");
return;
}
if (len > (MAX_PACKET_LENGTH - 5) / 2) {
len = (MAX_PACKET_LENGTH - 5) / 2;
}
if (len < auxv_len - offset) {
g_string_assign(gdbserver_state.str_buf, "m");
} else {
g_string_assign(gdbserver_state.str_buf, "l");
len = auxv_len - offset;
}
g_byte_array_set_size(gdbserver_state.mem_buf, len);
if (target_memory_rw_debug(gdbserver_state.g_cpu, saved_auxv + offset,
gdbserver_state.mem_buf->data, len, false)) {
gdb_put_packet("E14");
return;
}
gdb_memtox(gdbserver_state.str_buf,
(const char *)gdbserver_state.mem_buf->data, len);
gdb_put_packet_binary(gdbserver_state.str_buf->str,
gdbserver_state.str_buf->len, true);
}
#endif

344
gdbstub/user.c
View File

@ -10,10 +10,354 @@
*/
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "qemu/sockets.h"
#include "exec/hwaddr.h"
#include "exec/tb-flush.h"
#include "exec/gdbstub.h"
#include "gdbstub/user.h"
#include "hw/core/cpu.h"
#include "trace.h"
#include "internals.h"
/* User-mode specific state */
typedef struct {
int fd;
char *socket_path;
int running_state;
} GDBUserState;
static GDBUserState gdbserver_user_state;
int gdb_get_char(void)
{
uint8_t ch;
int ret;
for (;;) {
ret = recv(gdbserver_user_state.fd, &ch, 1, 0);
if (ret < 0) {
if (errno == ECONNRESET) {
gdbserver_user_state.fd = -1;
}
if (errno != EINTR) {
return -1;
}
} else if (ret == 0) {
close(gdbserver_user_state.fd);
gdbserver_user_state.fd = -1;
return -1;
} else {
break;
}
}
return ch;
}
void gdb_put_buffer(const uint8_t *buf, int len)
{
int ret;
while (len > 0) {
ret = send(gdbserver_user_state.fd, buf, len, 0);
if (ret < 0) {
if (errno != EINTR) {
return;
}
} else {
buf += ret;
len -= ret;
}
}
}
/* Tell the remote gdb that the process has exited. */
void gdb_exit(int code)
{
char buf[4];
if (!gdbserver_state.init) {
return;
}
if (gdbserver_user_state.socket_path) {
unlink(gdbserver_user_state.socket_path);
}
if (gdbserver_user_state.fd < 0) {
return;
}
trace_gdbstub_op_exiting((uint8_t)code);
snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
gdb_put_packet(buf);
}
int gdb_handlesig(CPUState *cpu, int sig)
{
char buf[256];
int n;
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return sig;
}
/* disable single step if it was enabled */
cpu_single_step(cpu, 0);
tb_flush(cpu);
if (sig != 0) {
gdb_set_stop_cpu(cpu);
g_string_printf(gdbserver_state.str_buf,
"T%02xthread:", gdb_target_signal_to_gdb(sig));
gdb_append_thread_id(cpu, gdbserver_state.str_buf);
g_string_append_c(gdbserver_state.str_buf, ';');
gdb_put_strbuf();
}
/*
* gdb_put_packet() might have detected that the peer terminated the
* connection.
*/
if (gdbserver_user_state.fd < 0) {
return sig;
}
sig = 0;
gdbserver_state.state = RS_IDLE;
gdbserver_user_state.running_state = 0;
while (gdbserver_user_state.running_state == 0) {
n = read(gdbserver_user_state.fd, buf, 256);
if (n > 0) {
int i;
for (i = 0; i < n; i++) {
gdb_read_byte(buf[i]);
}
} else {
/*
* XXX: Connection closed. Should probably wait for another
* connection before continuing.
*/
if (n == 0) {
close(gdbserver_user_state.fd);
}
gdbserver_user_state.fd = -1;
return sig;
}
}
sig = gdbserver_state.signal;
gdbserver_state.signal = 0;
return sig;
}
/* Tell the remote gdb that the process has exited due to SIG. */
void gdb_signalled(CPUArchState *env, int sig)
{
char buf[4];
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return;
}
snprintf(buf, sizeof(buf), "X%02x", gdb_target_signal_to_gdb(sig));
gdb_put_packet(buf);
}
static void gdb_accept_init(int fd)
{
gdb_init_gdbserver_state();
gdb_create_default_process(&gdbserver_state);
gdbserver_state.processes[0].attached = true;
gdbserver_state.c_cpu = gdb_first_attached_cpu();
gdbserver_state.g_cpu = gdbserver_state.c_cpu;
gdbserver_user_state.fd = fd;
gdb_has_xml = false;
}
static bool gdb_accept_socket(int gdb_fd)
{
int fd;
for (;;) {
fd = accept(gdb_fd, NULL, NULL);
if (fd < 0 && errno != EINTR) {
perror("accept socket");
return false;
} else if (fd >= 0) {
qemu_set_cloexec(fd);
break;
}
}
gdb_accept_init(fd);
return true;
}
static int gdbserver_open_socket(const char *path)
{
struct sockaddr_un sockaddr = {};
int fd, ret;
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0) {
perror("create socket");
return -1;
}
sockaddr.sun_family = AF_UNIX;
pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path);
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind socket");
close(fd);
return -1;
}
ret = listen(fd, 1);
if (ret < 0) {
perror("listen socket");
close(fd);
return -1;
}
return fd;
}
static bool gdb_accept_tcp(int gdb_fd)
{
struct sockaddr_in sockaddr = {};
socklen_t len;
int fd;
for (;;) {
len = sizeof(sockaddr);
fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len);
if (fd < 0 && errno != EINTR) {
perror("accept");
return false;
} else if (fd >= 0) {
qemu_set_cloexec(fd);
break;
}
}
/* set short latency */
if (socket_set_nodelay(fd)) {
perror("setsockopt");
close(fd);
return false;
}
gdb_accept_init(fd);
return true;
}
static int gdbserver_open_port(int port)
{
struct sockaddr_in sockaddr;
int fd, ret;
fd = socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return -1;
}
qemu_set_cloexec(fd);
socket_set_fast_reuse(fd);
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(port);
sockaddr.sin_addr.s_addr = 0;
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind");
close(fd);
return -1;
}
ret = listen(fd, 1);
if (ret < 0) {
perror("listen");
close(fd);
return -1;
}
return fd;
}
int gdbserver_start(const char *port_or_path)
{
int port = g_ascii_strtoull(port_or_path, NULL, 10);
int gdb_fd;
if (port > 0) {
gdb_fd = gdbserver_open_port(port);
} else {
gdb_fd = gdbserver_open_socket(port_or_path);
}
if (gdb_fd < 0) {
return -1;
}
if (port > 0 && gdb_accept_tcp(gdb_fd)) {
return 0;
} else if (gdb_accept_socket(gdb_fd)) {
gdbserver_user_state.socket_path = g_strdup(port_or_path);
return 0;
}
/* gone wrong */
close(gdb_fd);
return -1;
}
/* Disable gdb stub for child processes. */
void gdbserver_fork(CPUState *cpu)
{
if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
return;
}
close(gdbserver_user_state.fd);
gdbserver_user_state.fd = -1;
cpu_breakpoint_remove_all(cpu, BP_GDB);
/* no cpu_watchpoint_remove_all for user-mode */
}
/*
* Execution state helpers
*/
void gdb_continue(void)
{
gdbserver_user_state.running_state = 1;
trace_gdbstub_op_continue();
}
/*
* Resume execution, for user-mode emulation it's equivalent to
* gdb_continue.
*/
int gdb_continue_partial(char *newstates)
{
CPUState *cpu;
int res = 0;
/*
* This is not exactly accurate, but it's an improvement compared to the
* previous situation, where only one CPU would be single-stepped.
*/
CPU_FOREACH(cpu) {
if (newstates[cpu->cpu_index] == 's') {
trace_gdbstub_op_stepping(cpu->cpu_index);
cpu_single_step(cpu, gdbserver_state.sstep_flags);
}
}
gdbserver_user_state.running_state = 1;
return res;
}
/*
* Break/Watch point helpers
*/
bool gdb_supports_guest_debug(void)
{
/* user-mode == TCG == supported */

21
include/exec/gdbstub.h
View File

@ -103,27 +103,6 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...);
void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va);
int use_gdb_syscalls(void);
#ifdef CONFIG_USER_ONLY
/**
* gdb_handlesig: yield control to gdb
* @cpu: CPU
* @sig: if non-zero, the signal number which caused us to stop
*
* This function yields control to gdb, when a user-mode-only target
* needs to stop execution. If @sig is non-zero, then we will send a
* stop packet to tell gdb that we have stopped because of this signal.
*
* This function will block (handling protocol requests from gdb)
* until gdb tells us to continue target execution. When it does
* return, the return value is a signal to deliver to the target,
* or 0 if no signal should be delivered, ie the signal that caused
* us to stop should be ignored.
*/
int gdb_handlesig(CPUState *, int);
void gdb_signalled(CPUArchState *, int);
void gdbserver_fork(CPUState *);
#endif
/* Get or set a register. Returns the size of the register. */
typedef int (*gdb_get_reg_cb)(CPUArchState *env, GByteArray *buf, int reg);
typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);

43
include/gdbstub/user.h Normal file
View File

@ -0,0 +1,43 @@
/*
* gdbstub user-mode only APIs
*
* Copyright (c) 2022 Linaro Ltd
*
* SPDX-License-Identifier: LGPL-2.0+
*/
#ifndef GDBSTUB_USER_H
#define GDBSTUB_USER_H
/**
* gdb_handlesig() - yield control to gdb
* @cpu: CPU
* @sig: if non-zero, the signal number which caused us to stop
*
* This function yields control to gdb, when a user-mode-only target
* needs to stop execution. If @sig is non-zero, then we will send a
* stop packet to tell gdb that we have stopped because of this signal.
*
* This function will block (handling protocol requests from gdb)
* until gdb tells us to continue target execution. When it does
* return, the return value is a signal to deliver to the target,
* or 0 if no signal should be delivered, ie the signal that caused
* us to stop should be ignored.
*/
int gdb_handlesig(CPUState *, int);
/**
* gdb_signalled() - inform remote gdb of sig exit
* @as: current CPUArchState
* @sig: signal number
*/
void gdb_signalled(CPUArchState *as, int sig);
/**
* gdbserver_fork() - disable gdb stub for child processes.
* @cs: CPU
*/
void gdbserver_fork(CPUState *cs);
#endif /* GDBSTUB_USER_H */

1
linux-user/main.c
View File

@ -40,6 +40,7 @@
#include "qemu/plugin.h"
#include "exec/exec-all.h"
#include "exec/gdbstub.h"
#include "gdbstub/user.h"
#include "tcg/tcg.h"
#include "qemu/timer.h"
#include "qemu/envlist.h"

2
linux-user/signal.c
View File

@ -18,7 +18,7 @@
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "exec/gdbstub.h"
#include "gdbstub/user.h"
#include "hw/core/tcg-cpu-ops.h"
#include <sys/ucontext.h>