esp8266: Disallow recursive calls to REPL.

pfalcon · pfalcon · commit 777232c9a5ce · 2016-04-01T12:53:50.000+03:00
Before this change, if REPL blocked executing some code, it was possible
to still input new statememts and excuting them, all leading to weird,
and portentially dangerous interaction.

TODO: Current implementation may have issues processing input accumulated
while REPL was blocked.
diff --git a/esp8266/uart.c b/esp8266/uart.c
@@ -234,6 +234,17 @@ void mp_keyboard_interrupt(void);
 
 int interrupt_char;
 void uart_task_handler(os_event_t *evt) {
+    if (pyexec_repl_active) {
+        // TODO: Just returning here isn't exactly right.
+        // What really should be done is something like
+        // enquing delayed event to itself, for another
+        // chance to feed data to REPL. Otherwise, there
+        // can be situation when buffer has bunch of data,
+        // and sits unprocessed, because we consumed all
+        // processing signals like this.
+        return;
+    }
+
     int c, ret = 0;
     while ((c = ringbuf_get(&input_buf)) >= 0) {
         if (c == interrupt_char) {
diff --git a/lib/utils/pyexec.c b/lib/utils/pyexec.c
@@ -277,12 +277,17 @@ exec: ;
     }
 }
 
+uint8_t pyexec_repl_active;
 int pyexec_event_repl_process_char(int c) {
+    pyexec_repl_active = 1;
+    int res;
     if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
-        return pyexec_raw_repl_process_char(c);
+        res = pyexec_raw_repl_process_char(c);
     } else {
-        return pyexec_friendly_repl_process_char(c);
+        res = pyexec_friendly_repl_process_char(c);
     }
+    pyexec_repl_active = 0;
+    return res;
 }
 
 #else // MICROPY_REPL_EVENT_DRIVEN
diff --git a/lib/utils/pyexec.h b/lib/utils/pyexec.h
@@ -42,6 +42,7 @@ int pyexec_file(const char *filename);
 int pyexec_frozen_module(const char *name);
 void pyexec_event_repl_init(void);
 int pyexec_event_repl_process_char(int c);
+extern uint8_t pyexec_repl_active;
 
 MP_DECLARE_CONST_FUN_OBJ(pyb_set_repl_info_obj);
 

Original file line number	Diff line number	Diff line change
`@@ -277,12 +277,17 @@ exec: ;`
`277`	`277`	`}`
`278`	`278`	`}`
`279`	`279`
	`280`	`+uint8_t pyexec_repl_active;`
`280`	`281`	`int pyexec_event_repl_process_char(int c) {`
	`282`	`+ pyexec_repl_active = 1;`
	`283`	`+ int res;`
`281`	`284`	`if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {`
`282`		`- return pyexec_raw_repl_process_char(c);`
	`285`	`+ res = pyexec_raw_repl_process_char(c);`
`283`	`286`	`} else {`
`284`		`- return pyexec_friendly_repl_process_char(c);`
	`287`	`+ res = pyexec_friendly_repl_process_char(c);`
`285`	`288`	`}`
	`289`	`+ pyexec_repl_active = 0;`
	`290`	`+ return res;`
`286`	`291`	`}`
`287`	`292`
`288`	`293`	`#else // MICROPY_REPL_EVENT_DRIVEN`