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-rw-r--r--gdbstub.c42
1 files changed, 27 insertions, 15 deletions
diff --git a/gdbstub.c b/gdbstub.c
index f4e97f7370..6a7e2c4934 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -284,7 +284,6 @@ enum RSState {
RS_GETLINE,
RS_CHKSUM1,
RS_CHKSUM2,
- RS_SYSCALL,
};
typedef struct GDBState {
CPUArchState *c_cpu; /* current CPU for step/continue ops */
@@ -304,6 +303,8 @@ typedef struct GDBState {
CharDriverState *chr;
CharDriverState *mon_chr;
#endif
+ 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
@@ -346,8 +347,6 @@ static int get_char(GDBState *s)
}
#endif
-static gdb_syscall_complete_cb gdb_current_syscall_cb;
-
static enum {
GDB_SYS_UNKNOWN,
GDB_SYS_ENABLED,
@@ -2097,8 +2096,10 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
if (*p == ',')
p++;
type = *p;
- if (gdb_current_syscall_cb)
- gdb_current_syscall_cb(s->c_cpu, ret, err);
+ if (s->current_syscall_cb) {
+ s->current_syscall_cb(s->c_cpu, ret, err);
+ s->current_syscall_cb = NULL;
+ }
if (type == 'C') {
put_packet(s, "T02");
} else {
@@ -2398,7 +2399,12 @@ static void gdb_vm_state_change(void *opaque, int running, RunState state)
const char *type;
int ret;
- if (running || s->state == RS_INACTIVE || s->state == RS_SYSCALL) {
+ if (running || s->state == RS_INACTIVE) {
+ return;
+ }
+ /* Is there a GDB syscall waiting to be sent? */
+ if (s->current_syscall_cb) {
+ put_packet(s, s->syscall_buf);
return;
}
switch (state) {
@@ -2468,8 +2474,8 @@ send_packet:
void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
{
va_list va;
- char buf[256];
char *p;
+ char *p_end;
target_ulong addr;
uint64_t i64;
GDBState *s;
@@ -2477,14 +2483,13 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
s = gdbserver_state;
if (!s)
return;
- gdb_current_syscall_cb = cb;
- s->state = RS_SYSCALL;
+ s->current_syscall_cb = cb;
#ifndef CONFIG_USER_ONLY
vm_stop(RUN_STATE_DEBUG);
#endif
- s->state = RS_IDLE;
va_start(va, fmt);
- p = buf;
+ p = s->syscall_buf;
+ p_end = &s->syscall_buf[sizeof(s->syscall_buf)];
*(p++) = 'F';
while (*fmt) {
if (*fmt == '%') {
@@ -2492,17 +2497,17 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
switch (*fmt++) {
case 'x':
addr = va_arg(va, target_ulong);
- p += snprintf(p, &buf[sizeof(buf)] - p, TARGET_FMT_lx, addr);
+ p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
break;
case 'l':
if (*(fmt++) != 'x')
goto bad_format;
i64 = va_arg(va, uint64_t);
- p += snprintf(p, &buf[sizeof(buf)] - p, "%" PRIx64, i64);
+ p += snprintf(p, p_end - p, "%" PRIx64, i64);
break;
case 's':
addr = va_arg(va, target_ulong);
- p += snprintf(p, &buf[sizeof(buf)] - p, TARGET_FMT_lx "/%x",
+ p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
addr, va_arg(va, int));
break;
default:
@@ -2517,10 +2522,16 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
}
*p = 0;
va_end(va);
- put_packet(s, buf);
#ifdef CONFIG_USER_ONLY
+ put_packet(s, s->syscall_buf);
gdb_handlesig(s->c_cpu, 0);
#else
+ /* In this case wait to send the syscall packet until notification that
+ the CPU has stopped. This must be done because if the packet is sent
+ now the reply from the syscall request could be received while the CPU
+ is still in the running state, which can cause packets to be dropped
+ and state transition 'T' packets to be sent while the syscall is still
+ being processed. */
cpu_exit(s->c_cpu);
#endif
}
@@ -2919,6 +2930,7 @@ int gdbserver_start(const char *device)
s->chr = chr;
s->state = chr ? RS_IDLE : RS_INACTIVE;
s->mon_chr = mon_chr;
+ s->current_syscall_cb = NULL;
return 0;
}