[PATCH 1/2] gdbstub: Fix wrong CPUState pointer in breakpoint functions

[Roque Arcudia Hernandez]

In the context of using the remote gdb with multiple
processes/inferiors (multiple cluster machine) a given breakpoint
will target an specific inferior. If needed the remote protocol will
use the packet 'H op thread-id' with op = 'g' to change focus to the
inferior we want to insert/remove the breakpoint to, for instance
'Hgp3.3' and not 'Hcp3.3'.

This is supported by the documentation of the H packets:

 > 'H op thread-id'
 > Set thread for subsequent operations ('m', 'M', 'g', 'G',
 > et.al.). Depending on the operation to be performed, op should be
 > 'c' for step and continue operations (note that this is
 > deprecated, supporting the 'vCont' command is a better option),
 > and 'g' for other operations.

This can also be verified in the GDB source code file gdb/remote.c.
Functions remote_target::insert_breakpoint and
remote_target::remove_breakpoint will eventually call
remote_target::set_general_thread if it needs to change the process
focus and not remote_target::set_continue_thread.

This can be seen around a comment that says:

      /* Make sure the remote is pointing at the right process, if
         necessary.  */

Google-Bug-Id: 355027002
Signed-off-by: Roque Arcudia Hernandez <roqueh@google.com>
---
 gdbstub/gdbstub.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index d08568cea0..98574eba68 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1148,7 +1148,7 @@ static void handle_insert_bp(GArray *params, void 
*user_ctx)
         return;
     }
 
-    res = gdb_breakpoint_insert(gdbserver_state.c_cpu,
+    res = gdb_breakpoint_insert(gdbserver_state.g_cpu,
                                 gdb_get_cmd_param(params, 0)->val_ul,
                                 gdb_get_cmd_param(params, 1)->val_ull,
                                 gdb_get_cmd_param(params, 2)->val_ull);
@@ -1172,7 +1172,7 @@ static void handle_remove_bp(GArray *params, void 
*user_ctx)
         return;
     }
 
-    res = gdb_breakpoint_remove(gdbserver_state.c_cpu,
+    res = gdb_breakpoint_remove(gdbserver_state.g_cpu,
                                 gdb_get_cmd_param(params, 0)->val_ul,
                                 gdb_get_cmd_param(params, 1)->val_ull,
                                 gdb_get_cmd_param(params, 2)->val_ull);
-- 
2.46.0.469.g59c65b2a67-goog