panic: Add nesting support to crash console command

Add support for nesting to `crash` console command.
Calling the crash console command with multiple crash arguments
will result in nested crashes in the order specified. This is useful for
testing complex panic scenarios.

BUG=b:333916658
TEST=Nested crashes tested on volteer, zork and skyrim.
TEST=Twister test drivers/drivers.panic_output
TEST=Twister test drivers/drivers.console_cmd_crash

Change-Id: I65ff48c0a977f3451cbde6c1787bde74d11d7a83
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/5454818
Reviewed-by: Forest Mittelberg <[email protected]>
Code-Coverage: Zoss <[email protected]>
Tested-by: Rob Barnes <[email protected]>
Commit-Queue: Rob Barnes <[email protected]>
Reviewed-by: Jeremy Bettis <[email protected]>

Author: rbbrns

baseboard/kukui/baseboard.h

@@ -309,6 +309,7 @@
 #undef CONFIG_CMD_APTHROTTLE
 #undef CONFIG_CMD_CHARGE_SUPPLIER_INFO
 #undef CONFIG_CMD_CRASH
+#undef CONFIG_CMD_CRASH_NESTED
 #undef CONFIG_CMD_HCDEBUG
 #undef CONFIG_CMD_IDLE_STATS
 #undef CONFIG_CMD_KEYBOARD

board/pdeval-stm32f072/board.h

@@ -81,6 +81,7 @@
 #undef CONFIG_CONSOLE_HISTORY
 #undef CONFIG_HIBERNATE
 #undef CONFIG_CMD_CRASH
+#undef CONFIG_CMD_CRASH_NESTED
 
 /*
  * Allow dangerous commands all the time, since we don't have a write protect

board/servo_v4/board.h

@@ -91,6 +91,7 @@
 #undef CONFIG_CONSOLE_CMDHELP
 #undef CONFIG_CONSOLE_HISTORY
 #undef CONFIG_CMD_CRASH
+#undef CONFIG_CMD_CRASH_NESTED
 #undef CONFIG_CMD_ACCELSPOOF
 #undef CONFIG_CMD_FASTCHARGE
 #undef CONFIG_CMD_FLASHINFO

board/servo_v4p1/board.h

@@ -168,6 +168,7 @@
 #undef CONFIG_CONSOLE_CMDHELP
 #undef CONFIG_CONSOLE_HISTORY
 #undef CONFIG_CMD_CRASH
+#undef CONFIG_CMD_CRASH_NESTED
 #undef CONFIG_CMD_ACCELSPOOF
 #undef CONFIG_CMD_FASTCHARGE
 #undef CONFIG_CMD_FLASHINFO

board/volteer/board.h

@@ -166,6 +166,7 @@
 #undef CONFIG_CMD_CHARGER
 #undef CONFIG_CMD_CHARGE_SUPPLIER_INFO
 #undef CONFIG_CMD_CRASH
+#undef CONFIG_CMD_CRASH_NESTED
 #undef CONFIG_CMD_DEVICE_EVENT
 #undef CONFIG_CMD_FLASH_WP
 #undef CONFIG_CMD_HASH

common/panic_output.c

@@ -15,6 +15,7 @@
 #include "sysjump.h"
 #include "system.h"
 #include "task.h"
+#include "test_util.h"
 #include "timer.h"
 #include "uart.h"
 #include "usb_console.h"
@@ -366,13 +367,56 @@ ENABLE_CLANG_WARNING("-Winfinite-recursion")
 ENABLE_GCC_WARNING("-Winfinite-recursion")
 #endif
 
+#ifdef CONFIG_CMD_CRASH_NESTED
+static bool command_crash_nested_enabled;
+static int command_crash_nested_argc;
+static const char **command_crash_nested_argv;
+test_mockable_static void command_crash_nested_enable(int argc,
+						      const char **argv)
+{
+	command_crash_nested_argc = argc;
+	command_crash_nested_argv = argv;
+	command_crash_nested_enabled = true;
+}
+test_mockable_static void command_crash_nested_disable(void)
+{
+	command_crash_nested_enabled = false;
+}
+/* Forward declare command_crash so it can be referenced in
+ * command_crash_nested_handler.
+ */
+static int command_crash(int argc, const char **argv);
+/*
+ * Called from the panic handler.
+ * Triggers a nested crash when enabled.
+ */
+int command_crash_nested_handler(void)
+{
+	if (!command_crash_nested_enabled)
+		return EC_SUCCESS;
+	/* Must be re-enabled after each run */
+	command_crash_nested_enabled = false;
+	/* Decrement argc and shift argv */
+	return command_crash(command_crash_nested_argc - 1,
+			     command_crash_nested_argv + 1);
+}
+#endif /* CONFIG_CMD_CRASH_NESTED */
+
 /*****************************************************************************/
 /* Console commands */
 static int command_crash(int argc, const char **argv)
 {
 	if (argc < 2)
 		return EC_ERROR_PARAM1;
 
+	if (argc > 2) {
+		if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED)) {
+			command_crash_nested_enable(argc, argv);
+		} else {
+			return EC_ERROR_PARAM_COUNT;
+		}
+	}
+
 	if (!strcasecmp(argv[1], "assert")) {
 		ASSERT(0);
 	} else if (!strcasecmp(argv[1], "divzero")) {
@@ -417,17 +461,28 @@ static int command_crash(int argc, const char **argv)
 		cflush();
 		ccprintf("%08x\n", *(volatile unsigned int *)null_ptr);
 	} else {
+		/* Disable nested crash on error */
+		if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+			command_crash_nested_disable();
 		return EC_ERROR_PARAM1;
 	}
 
+	/* Disable nested crash on error */
+	if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+		command_crash_nested_disable();
+
 	/* Everything crashes, so shouldn't get back here */
 	return EC_ERROR_UNKNOWN;
 }
 
 DECLARE_CONSOLE_COMMAND(crash, command_crash,
 			"[assert | divzero | udivzero | stack"
 			" | unaligned | watchdog | hang | null]",
-			"Crash the system (for testing)");
+			"Crash the system (for testing)."
+#ifndef CONFIG_CMD_CRASH_NESTED
+			" Repeat argument for nested crashes."
+#endif /* CONFIG_CMD_CRASH_NESTED */
+);
 
 #ifdef TEST_BUILD
 int test_command_crash(int argc, const char **argv)

core/cortex-m/panic.c

@@ -375,6 +375,9 @@ void __keep report_panic(void)
 	if (IS_ENABLED(CONFIG_ARMV7M_CACHE))
 		cpu_clean_invalidate_dcache();
 
+	if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+		command_crash_nested_handler();
+
 	/* Start safe mode if possible */
 	if (IS_ENABLED(CONFIG_SYSTEM_SAFE_MODE)) {
 		/* Only start safe mode if panic occurred in thread context */

core/cortex-m0/panic.c

@@ -134,6 +134,10 @@ void __keep report_panic(void)
 	}
 
 	panic_data_print(pdata);
+
+	if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+		command_crash_nested_handler();
+
 	panic_reboot();
 }
 

core/nds32/panic.c

@@ -193,6 +193,9 @@ void report_panic(uint32_t *regs, uint32_t itype)
 
 	print_panic_information(regs, itype, regs[16], regs[17]);
 
+	if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+		command_crash_nested_handler();
+
 	if (IS_ENABLED(CONFIG_SYSTEM_SAFE_MODE)) {
 		if (get_interrupt_level() <= 1 &&
 		    start_system_safe_mode() == EC_SUCCESS) {

core/riscv-rv32i/panic.c

@@ -145,6 +145,10 @@ void report_panic(uint32_t *regs)
 		pdata->riscv.regs[i] = regs[i];
 
 	print_panic_information(regs, mcause, mepc);
+
+	if (IS_ENABLED(CONFIG_CMD_CRASH_NESTED))
+		command_crash_nested_handler();
+
 	panic_reboot();
 }