[PATCH 02/29] gdbstub: Support disablement in a multi-threaded process

[Alex Bennée]

From: Ilya Leoshkevich <iii@linux.ibm.com>

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 breakpoints and disable
single-step. Move the respective code into a separate function.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-2-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 gdbstub/user.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/gdbstub/user.c b/gdbstub/user.c
index 14918d1a217..3ce20b7bbfc 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(CPUState *thread_cpu)
+{
+    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(thread_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(cpu);
 }
 
 /*
-- 
2.39.2