[v4,07/12] gdbstub: Call gdbserver_fork() both in parent and in child

Commit Message

Ilya Leoshkevich Feb. 19, 2024, 2:15 p.m. UTC

The upcoming follow-fork-mode child support requires post-fork message
exchange between the parent and the child. Prepare gdbserver_fork() for
this purpose. Rename it to gdbserver_fork_end() to better reflect its
purpose.

Reviewed-by: Richard Henderson <[e-mail]>
Signed-off-by: Ilya Leoshkevich <[e-mail]>
---
 bsd-user/main.c        | 3 ++-
 gdbstub/user.c         | 5 ++---
 include/gdbstub/user.h | 5 +++--
 linux-user/main.c      | 2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

Patch

diff --git a/bsd-user/main.c b/bsd-user/main.c
index 9c5b5c7e1dc..9e23578c4e7 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -131,10 +131,11 @@  void fork_end(pid_t pid)
          */
         qemu_init_cpu_list();
         get_task_state(thread_cpu)->ts_tid = qemu_get_thread_id();
-        gdbserver_fork(thread_cpu, pid);
+        gdbserver_fork_end(thread_cpu, pid);
     } else {
         mmap_fork_end(child);
         cpu_list_unlock();
+        gdbserver_fork_end(thread_cpu, pid);
         end_exclusive();
     }
 }
diff --git a/gdbstub/user.c b/gdbstub/user.c
index c61e1a0d1f6..866a25f9c06 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -374,10 +374,9 @@  static void disable_gdbstub(CPUState *thread_cpu)
     tb_flush(thread_cpu);
 }
 
-/* Disable gdb stub for child processes.  */
-void gdbserver_fork(CPUState *cpu, pid_t pid)
+void gdbserver_fork_end(CPUState *cpu, pid_t pid)
 {
-    if (!gdbserver_state.init || gdbserver_user_state.fd < 0) {
+    if (pid != 0 || !gdbserver_state.init || gdbserver_user_state.fd < 0) {
         return;
     }
     disable_gdbstub(cpu);
diff --git a/include/gdbstub/user.h b/include/gdbstub/user.h
index 3f9f45946e0..4c4e5c4c582 100644
--- a/include/gdbstub/user.h
+++ b/include/gdbstub/user.h
@@ -51,10 +51,11 @@  void gdb_signalled(CPUArchState *as, int sig);
 void gdbserver_fork_start(void);
 
 /**
- * gdbserver_fork() - disable gdb stub for child processes.
+ * gdbserver_fork_end() - inform gdb of the completed fork()
  * @cs: CPU
+ * @pid: 0 if in child process, -1 if fork failed, child process pid otherwise
  */
-void gdbserver_fork(CPUState *cs, pid_t pid);
+void gdbserver_fork_end(CPUState *cs, pid_t pid);
 
 /**
  * gdb_syscall_entry() - inform gdb of syscall entry and yield control to it
diff --git a/linux-user/main.c b/linux-user/main.c
index bc78c1a4b03..b7294b9cee2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -164,10 +164,10 @@  void fork_end(pid_t pid)
         }
         qemu_init_cpu_list();
         get_task_state(thread_cpu)->ts_tid = qemu_get_thread_id();
-        gdbserver_fork(thread_cpu, pid);
     } else {
         cpu_list_unlock();
     }
+    gdbserver_fork_end(thread_cpu, pid);
     /*
      * qemu_init_cpu_list() reinitialized the child exclusive state, but we
      * also need to keep current_cpu consistent, so call end_exclusive() for