cortex-m*: Save panicinfo on non-exception panics

Make non-exception "software" panics such as stack overflow and assert
failure save a panic log. Log the panic type in r4, and misc. panic data
in r5 so that panic reasons can be distinguished.

BUG=chrome-os-partner:36744
TEST=Manual on samus_pd. Run 'crash divzero' then 'panicinfo' after
reboot. Verify that panic info is printed with "r4 :dead6660". Trigger
stack overflow, verify that panic info is printed with "r4 :dead6661".
BRANCH=Samus

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I5f7a8eb0a5c2ac5799d29bb241deb24fabf38f68
Reviewed-on: https://chromium-review.googlesource.com/249912
Tested-by: Alec Berg <alecaberg@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>

1 files changed, 58 insertions, 8 deletions

diff --git a/common/panic_output.c b/common/panic_output.c
index 4f0f22d00d..af98c5953d 100644
--- a/common/panic_output.c
+++ b/common/panic_output.c
@@ -6,6 +6,7 @@
 #include "common.h"
 #include "console.h"
 #include "cpu.h"
+#include "hooks.h"
 #include "host_command.h"
 #include "panic.h"
 #include "printf.h"
@@ -82,8 +83,11 @@ void panic_reboot(void)
 void panic_assert_fail(const char *fname, int linenum)
 {
 	panic_printf("\nASSERTION FAILURE at %s:%d\n", fname, linenum);
-
+#ifdef CONFIG_SOFTWARE_PANIC
+	software_panic(PANIC_SW_ASSERT, linenum);
+#else
 	panic_reboot();
+#endif
 }
 #else
 void panic_assert_fail(const char *msg, const char *func, const char *fname,
@@ -91,8 +95,11 @@ void panic_assert_fail(const char *msg, const char *func, const char *fname,
 {
 	panic_printf("\nASSERTION FAILURE '%s' in %s() at %s:%d\n",
 		     msg, func, fname, linenum);
-
+#ifdef CONFIG_SOFTWARE_PANIC
+	software_panic(PANIC_SW_ASSERT, linenum);
+#else
 	panic_reboot();
+#endif
 }
 #endif
 #endif
@@ -108,6 +115,37 @@ struct panic_data *panic_get_data(void)
 	return pdata_ptr->magic == PANIC_DATA_MAGIC ? pdata_ptr : NULL;
 }
 
+#ifdef CONFIG_SOFTWARE_PANIC
+static void panic_init(void)
+{
+	/* Log panic cause if watchdog caused reset */
+	if (system_get_reset_flags() & RESET_FLAG_WATCHDOG)
+		panic_log_watchdog();
+}
+DECLARE_HOOK(HOOK_INIT, panic_init, HOOK_PRIO_DEFAULT);
+#endif
+
+#ifdef CONFIG_CMD_STACKOVERFLOW
+static void stack_overflow_recurse(int n)
+{
+	ccprintf("+%d", n);
+
+	/*
+	 * Force task context switch, since that's where we do stack overflow
+	 * checking.
+	 */
+	msleep(10);
+
+	stack_overflow_recurse(n+1);
+
+	/*
+	 * Do work after the recursion, or else the compiler uses tail-chaining
+	 * and we don't actually consume additional stack.
+	 */
+	ccprintf("-%d", n);
+}
+#endif /* CONFIG_CMD_STACKOVERFLOW */
+
 /*****************************************************************************/
 /* Console commands */
 
@@ -116,14 +154,26 @@ static int command_crash(int argc, char **argv)
 	if (argc < 2)
 		return EC_ERROR_PARAM1;
 
-	if (!strcasecmp(argv[1], "divzero")) {
-		int a = 1, b = 0;
+	if (!strcasecmp(argv[1], "assert")) {
+		ASSERT(0);
+	} else if (!strcasecmp(argv[1], "divzero")) {
+		int zero = 0;
 
 		cflush();
-		ccprintf("%08x", a / b);
+		if (argc >= 3 && !strcasecmp(argv[2], "unsigned"))
+			ccprintf("%08x", (unsigned long)1 / zero);
+		else
+			ccprintf("%08x", (long)1 / zero);
+#ifdef CONFIG_CMD_STACKOVERFLOW
+	} else if (!strcasecmp(argv[1], "stack")) {
+		stack_overflow_recurse(1);
+#endif
 	} else if (!strcasecmp(argv[1], "unaligned")) {
 		cflush();
 		ccprintf("%08x", *(int *)0xcdef);
+	} else if (!strcasecmp(argv[1], "watchdog")) {
+		while (1)
+			;
 	} else {
 		return EC_ERROR_PARAM1;
 	}
@@ -132,9 +182,9 @@ static int command_crash(int argc, char **argv)
 	return EC_ERROR_UNKNOWN;
 }
 DECLARE_CONSOLE_COMMAND(crash, command_crash,
-			"[divzero | unaligned]",
-			"Crash the system (for testing)",
-			NULL);
+		"[assert | divzero | stack | unaligned | watchdog] [options]",
+		"Crash the system (for testing)",
+		NULL);
 
 static int command_panicinfo(int argc, char **argv)
 {