gdbstub: split out softmmu/user specifics for syscall handling

Most of the syscall code is config agnostic aside from the size of
target_ulong. In preparation for the next patch move the final bits
of specialisation into the appropriate user and softmmu helpers.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230302190846.2593720-26-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-26-richard.henderson@linaro.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/gdbstub/user.c b/gdbstub/user.c
index 3da410e221..80488b6bb9 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -472,3 +472,17 @@ void gdb_breakpoint_remove_all(CPUState *cs)
 {
     cpu_breakpoint_remove_all(cs, BP_GDB);
 }
+
+/*
+ * For user-mode syscall support we send the system call immediately
+ * and then return control to gdb for it to process the syscall request.
+ * Since the protocol requires that gdb hands control back to us
+ * using a "here are the results" F packet, we don't need to check
+ * gdb_handlesig's return value (which is the signal to deliver if
+ * execution was resumed via a continue packet).
+ */
+void gdb_syscall_handling(const char *syscall_packet)
+{
+    gdb_put_packet(syscall_packet);
+    gdb_handlesig(gdbserver_state.c_cpu, 0);
+}