aoc: handle when crash string is empty

Bug: 281075359
Test: tested on device
Change-Id: I017085b59837d885525106bccb97f0687c4df473
Signed-off-by: Alex Iacobucci <alexiacobucci@google.com>

1 files changed, 22 insertions, 13 deletions

diff --git a/aoc.c b/aoc.c
index 9c6507c..3ff4973 100644
--- a/aoc.c
+++ b/aoc.c
@@ -2572,13 +2572,15 @@ static void aoc_watchdog(struct work_struct *work)
 	const int sscd_retry_ms = 1000;
 	int sscd_rc;
 	char crash_info[RAMDUMP_SECTION_CRASH_INFO_SIZE];
-	char ap_reset_reason[RAMDUMP_SECTION_CRASH_INFO_SIZE];
 	int restart_rc;
 	u32 section_flags;
 	bool ap_reset = false;
 
 	prvdata->total_restarts++;
 
+	/* Initialize crash_info[0] to identify if it has changed later in the function. */
+	crash_info[0] = 0;
+
 	if (prvdata->ap_triggered_reset) {
 		if ((ktime_get_real_ns() - prvdata->last_reset_time_ns) / 1000000
 			<= prvdata->reset_hysteresis_trigger_ms) {
@@ -2612,12 +2614,10 @@ static void aoc_watchdog(struct work_struct *work)
 	}
 
 	if (prvdata->ap_triggered_reset) {
+		dev_info(prvdata->dev, "AP triggered reset, reason: [%s]",
+			prvdata->ap_reset_reason);
 		prvdata->ap_triggered_reset = false;
 		ap_reset = true;
-
-		snprintf(ap_reset_reason, RAMDUMP_SECTION_CRASH_INFO_SIZE - 1,
-			"AP Reset: %s", prvdata->ap_reset_reason);
-
 		trigger_aoc_ramdump(prvdata);
 	}
 
@@ -2632,10 +2632,10 @@ static void aoc_watchdog(struct work_struct *work)
 		const char *crash_reason = (const char *)ramdump_header +
 			RAMDUMP_SECTION_CRASH_INFO_OFFSET;
 		bool crash_reason_valid = (strnlen(crash_reason,
-			RAMDUMP_SECTION_CRASH_INFO_SIZE) != 0);
+			sizeof(crash_info)) != 0);
 
 		dev_err(prvdata->dev, "aoc coredump timed out, coredump only contains DRAM\n");
-		snprintf(crash_info, RAMDUMP_SECTION_CRASH_INFO_SIZE,
+		snprintf(crash_info, sizeof(crash_info),
 			"AoC watchdog : %s (incomplete %u:%u)",
 			crash_reason_valid ? crash_reason : "unknown reason",
 			ramdump_header->breadcrumbs[0], ramdump_header->breadcrumbs[1]);
@@ -2645,7 +2645,7 @@ static void aoc_watchdog(struct work_struct *work)
 		dev_err(prvdata->dev,
 			"aoc coredump failed: invalid magic (corruption or incompatible firmware?)\n");
 		strscpy(crash_info, "AoC Watchdog : coredump corrupt",
-			RAMDUMP_SECTION_CRASH_INFO_SIZE);
+			sizeof(crash_info));
 	}
 
 	num_pages = DIV_ROUND_UP(prvdata->dram_size, PAGE_SIZE);
@@ -2670,18 +2670,27 @@ static void aoc_watchdog(struct work_struct *work)
 			RAMDUMP_SECTION_CRASH_INFO_OFFSET;
 
 		section_flags = ramdump_header->sections[RAMDUMP_SECTION_CRASH_INFO_INDEX].flags;
-		if (section_flags & RAMDUMP_FLAG_VALID)
-			strscpy(crash_info, crash_reason, RAMDUMP_SECTION_CRASH_INFO_SIZE);
-		else
+		if (section_flags & RAMDUMP_FLAG_VALID) {
+			dev_info(prvdata->dev, "aoc coredump has valid coredump header, crash reason [%s]",
+				crash_reason);
+			strscpy(crash_info, crash_reason, sizeof(crash_info));
+		} else {
+			dev_info(prvdata->dev, "aoc coredump has valid coredump header, but invalid crash reason");
 			strscpy(crash_info, "AoC Watchdog : invalid crash info",
-				RAMDUMP_SECTION_CRASH_INFO_SIZE);
+				sizeof(crash_info));
+		}
 	}
 
 	if (ap_reset) {
 		/* Prefer the user specified reason */
-		snprintf(crash_info, RAMDUMP_SECTION_CRASH_INFO_SIZE - 1, "%s", ap_reset_reason);
+		scnprintf(crash_info, sizeof(crash_info), "AP Reset: %s", prvdata->ap_reset_reason);
 	}
 
+	if (crash_info[0] == 0)
+		strscpy(crash_info, "AoC Watchdog: empty crash info string", sizeof(crash_info));
+
+	dev_info(prvdata->dev, "aoc crash info: [%s]", crash_info);
+
 	/* TODO(siqilin): Get paddr and vaddr base from firmware instead */
 	carveout_paddr_from_aoc = 0x98000000;
 	carveout_vaddr_from_aoc = 0x78000000;