The upcoming follow-fork-mode child support will require disabling
gdbstub in the parent process, which may have multiple threads (which
are represented as CPUs).

Loop over all CPUs in order to remove watchpoints and disable
single-step. Move the respective code into a separate function.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 gdbstub/user.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/gdbstub/user.c b/gdbstub/user.c
index 8f3affbad47..e6809da2243 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -356,16 +356,27 @@ int gdbserver_start(const char *port_or_path)
     return -1;
 }
 
+static void disable_gdbstub(void)
+{
+    CPUState *cpu;
+
+    close(gdbserver_user_state.fd);
+    gdbserver_user_state.fd = -1;
+    CPU_FOREACH(cpu) {
+        cpu_breakpoint_remove_all(cpu, BP_GDB);
+        /* no cpu_watchpoint_remove_all for user-mode */
+        cpu_single_step(cpu, 0);
+        tb_flush(cpu);
+    }
+}
+
 /* 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 */
+    disable_gdbstub();
 }
 
 /*
-- 
2.43.0