Add a structure GDBProcess that represent processes from the GDB
semantic point of view.
CPUs can be split into different processes, by grouping them under
different cpu-cluster objects. Each occurrence of a cpu-cluster object
implies the existence of the corresponding process in the GDB stub. The
GDB process ID is derived from the corresponding cluster ID as follows:
GDB PID = cluster ID + 1
This is because PIDs -1 and 0 are reserved in GDB and cannot be used by
processes.
When no such container are found, all the CPUs are put in a unique GDB
process (create_unique_process()). This is also the case when compiled
in user mode, where multi-processes do not make much sense for now.
Signed-off-by: Luc Michel <luc.mic...@greensocs.com>
Acked-by: Alistair Francis <alistair.fran...@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.igles...@xilinx.com>
---
gdbstub.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 87 insertions(+)
diff --git a/gdbstub.c b/gdbstub.c
index c4e4f9f082..26f5a7449a 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -27,10 +27,11 @@
#include "monitor/monitor.h"
#include "chardev/char.h"
#include "chardev/char-fe.h"
#include "sysemu/sysemu.h"
#include "exec/gdbstub.h"
+#include "hw/cpu/cluster.h"
#endif
#define MAX_PACKET_LENGTH 4096
#include "qemu/sockets.h"
@@ -294,10 +295,15 @@ typedef struct GDBRegisterState {
gdb_reg_cb set_reg;
const char *xml;
struct GDBRegisterState *next;
} GDBRegisterState;
+typedef struct GDBProcess {
+ uint32_t pid;
+ bool attached;
+} GDBProcess;
+
enum RSState {
RS_INACTIVE,
RS_IDLE,
RS_GETLINE,
RS_GETLINE_ESC,
@@ -322,10 +328,13 @@ typedef struct GDBState {
int running_state;
#else
CharBackend chr;
Chardev *mon_chr;
#endif
+ bool multiprocess;
+ GDBProcess *processes;
+ int process_num;
char syscall_buf[256];
gdb_syscall_complete_cb current_syscall_cb;
} GDBState;
/* By default use no IRQs and no timers while single stepping so as to
@@ -1749,10 +1758,24 @@ void gdb_exit(CPUArchState *env, int code)
#ifndef CONFIG_USER_ONLY
qemu_chr_fe_deinit(&s->chr, true);
#endif
}
+/*
+ * Create a unique process containing all the CPUs.
+ */
+static void create_unique_process(GDBState *s)
+{
+ GDBProcess *process;
+
+ s->processes = g_malloc0(sizeof(GDBProcess));
+ s->process_num = 1;
+ process = &s->processes[0];
+
+ process->pid = 1;
+}
+
#ifdef CONFIG_USER_ONLY
int
gdb_handlesig(CPUState *cpu, int sig)
{
GDBState *s;
@@ -1846,10 +1869,11 @@ static bool gdb_accept(void)
}
s = g_malloc0(sizeof(GDBState));
s->c_cpu = first_cpu;
s->g_cpu = first_cpu;
+ create_unique_process(s);
s->fd = fd;
gdb_has_xml = false;
gdbserver_state = s;
return true;
@@ -2002,10 +2026,69 @@ static const TypeInfo char_gdb_type_info = {
.name = TYPE_CHARDEV_GDB,
.parent = TYPE_CHARDEV,
.class_init = char_gdb_class_init,
};
+static int find_cpu_clusters(Object *child, void *opaque)
+{
+ if (object_dynamic_cast(child, TYPE_CPU_CLUSTER)) {
+ GDBState *s = (GDBState *) opaque;
+ CPUClusterState *cluster = CPU_CLUSTER(child);
+ GDBProcess *process;
+
+ s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
+
+ process = &s->processes[s->process_num - 1];
+
+ /*
+ * GDB process IDs -1 and 0 are reserved. To avoid subtle errors at
+ * runtime, we enforce here that the machine does not use a cluster ID
+ * that would lead to PID 0. */
+ assert(process->pid != UINT32_MAX);
+ process->pid = cluster->cluster_id + 1;
+ process->attached = false;
+
+ return 0;
+ }
+
+ return object_child_foreach(child, find_cpu_clusters, opaque);
+}
+
+static int pid_order(const void *a, const void *b)
+{
+ GDBProcess *pa = (GDBProcess *) a;
+ GDBProcess *pb = (GDBProcess *) b;
+
+ if (pa->pid < pb->pid) {
+ return -1;
+ } else if (pa->pid > pb->pid) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+static void create_processes(GDBState *s)
+{
+ object_child_foreach(object_get_root(), find_cpu_clusters, s);
+
+ if (!s->processes) {
+ /* No CPU cluster specified by the machine */
+ create_unique_process(s);
+ } else {
+ /* Sort by PID */
+ qsort(s->processes, s->process_num, sizeof(s->processes[0]),
pid_order);
+ }
+}
+
+static void cleanup_processes(GDBState *s)
+{
+ g_free(s->processes);
+ s->process_num = 0;
+ s->processes = NULL;
+}
+
int gdbserver_start(const char *device)
{
trace_gdbstub_op_start(device);
GDBState *s;
@@ -2058,15 +2141,19 @@ int gdbserver_start(const char *device)
NULL, &error_abort);
monitor_init(mon_chr, 0);
} else {
qemu_chr_fe_deinit(&s->chr, true);
mon_chr = s->mon_chr;
+ cleanup_processes(s);
memset(s, 0, sizeof(GDBState));
s->mon_chr = mon_chr;
}
s->c_cpu = first_cpu;
s->g_cpu = first_cpu;
+
+ create_processes(s);
+
if (chr) {
qemu_chr_fe_init(&s->chr, chr, &error_abort);
qemu_chr_fe_set_handlers(&s->chr, gdb_chr_can_receive, gdb_chr_receive,
gdb_chr_event, NULL, NULL, NULL, true);
}
--
2.19.1
