gdbstub: don't use target_ulong while handling registers

This is a hangover from the original code. addr is misleading as it is
only really a register id. While len will never exceed
MAX_PACKET_LENGTH I've used size_t as that is what strlen returns.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-20-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-20-richard.henderson@linaro.org>

gdbstub/gdbstub.c

@@ -1193,7 +1193,8 @@ static void handle_read_mem(GArray *params, void *user_ctx)
 
 static void handle_write_all_regs(GArray *params, void *user_ctx)
 {
-    target_ulong addr, len;
+    int reg_id;
+    size_t len;
     uint8_t *registers;
     int reg_size;
 
@@ -1205,9 +1206,10 @@ static void handle_write_all_regs(GArray *params, void *user_ctx)
     len = strlen(get_param(params, 0)->data) / 2;
     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
     registers = gdbserver_state.mem_buf->data;
-    for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
-         addr++) {
-        reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, addr);
+    for (reg_id = 0;
+         reg_id < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
+         reg_id++) {
+        reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, reg_id);
         len -= reg_size;
         registers += reg_size;
     }
@@ -1216,15 +1218,16 @@ static void handle_write_all_regs(GArray *params, void *user_ctx)
 
 static void handle_read_all_regs(GArray *params, void *user_ctx)
 {
-    target_ulong addr, len;
+    int reg_id;
+    size_t len;
 
     cpu_synchronize_state(gdbserver_state.g_cpu);
     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
     len = 0;
-    for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs; addr++) {
+    for (reg_id = 0; reg_id < gdbserver_state.g_cpu->gdb_num_g_regs; reg_id++) {
         len += gdb_read_register(gdbserver_state.g_cpu,
                                  gdbserver_state.mem_buf,
-                                 addr);
+                                 reg_id);
     }
     g_assert(len == gdbserver_state.mem_buf->len);