console: Report an error when output buffer is exhausted

If the console output buffer is exhausted, characters are silently dropped
from the end. Detect this condition and report an error when reading back
the characters.

Signed-off-by: Simon Glass <sjg@chromium.org>

4 files changed, 58 insertions, 16 deletions

diff --git a/common/console.c b/common/console.c
index 561cdf36a7..73edb28799 100644
--- a/common/console.c
+++ b/common/console.c
@@ -95,16 +95,22 @@ static void console_record_putc(const char c)
 {
 	if (!(gd->flags & GD_FLG_RECORD))
 		return;
-	if  (gd->console_out.start)
-		membuff_putbyte((struct membuff *)&gd->console_out, c);
+	if  (gd->console_out.start &&
+	     !membuff_putbyte((struct membuff *)&gd->console_out, c))
+		gd->flags |= GD_FLG_RECORD_OVF;
 }
 
 static void console_record_puts(const char *s)
 {
 	if (!(gd->flags & GD_FLG_RECORD))
 		return;
-	if  (gd->console_out.start)
-		membuff_put((struct membuff *)&gd->console_out, s, strlen(s));
+	if  (gd->console_out.start) {
+		int len = strlen(s);
+
+		if (membuff_put((struct membuff *)&gd->console_out, s, len) !=
+		    len)
+			gd->flags |= GD_FLG_RECORD_OVF;
+	}
 }
 
 static int console_record_getc(void)
@@ -742,6 +748,7 @@ void console_record_reset(void)
 {
 	membuff_purge((struct membuff *)&gd->console_out);
 	membuff_purge((struct membuff *)&gd->console_in);
+	gd->flags &= ~GD_FLG_RECORD_OVF;
 }
 
 int console_record_reset_enable(void)
@@ -754,6 +761,9 @@ int console_record_reset_enable(void)
 
 int console_record_readline(char *str, int maxlen)
 {
+	if (gd->flags & GD_FLG_RECORD_OVF)
+		return -ENOSPC;
+
 	return membuff_readline((struct membuff *)&gd->console_out, str,
 				maxlen, ' ');
 }
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 47921d27b1..e278d4c941 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -572,29 +572,33 @@ enum gd_flags {
 	 */
 	GD_FLG_RECORD = 0x01000,
 	/**
+	 * @GD_FLG_RECORD_OVF: record console overflow
+	 */
+	GD_FLG_RECORD_OVF = 0x02000,
+	/**
 	 * @GD_FLG_ENV_DEFAULT: default variable flag
 	 */
-	GD_FLG_ENV_DEFAULT = 0x02000,
+	GD_FLG_ENV_DEFAULT = 0x04000,
 	/**
 	 * @GD_FLG_SPL_EARLY_INIT: early SPL initialization is done
 	 */
-	GD_FLG_SPL_EARLY_INIT = 0x04000,
+	GD_FLG_SPL_EARLY_INIT = 0x08000,
 	/**
 	 * @GD_FLG_LOG_READY: log system is ready for use
 	 */
-	GD_FLG_LOG_READY = 0x08000,
+	GD_FLG_LOG_READY = 0x10000,
 	/**
 	 * @GD_FLG_WDT_READY: watchdog is ready for use
 	 */
-	GD_FLG_WDT_READY = 0x10000,
+	GD_FLG_WDT_READY = 0x20000,
 	/**
 	 * @GD_FLG_SKIP_LL_INIT: don't perform low-level initialization
 	 */
-	GD_FLG_SKIP_LL_INIT = 0x20000,
+	GD_FLG_SKIP_LL_INIT = 0x40000,
 	/**
 	 * @GD_FLG_SMP_READY: SMP initialization is complete
 	 */
-	GD_FLG_SMP_READY = 0x40000,
+	GD_FLG_SMP_READY = 0x80000,
 };
 
 #endif /* __ASSEMBLY__ */
diff --git a/include/console.h b/include/console.h
index 7e628c0cf8..f848bcbf03 100644
--- a/include/console.h
+++ b/include/console.h
@@ -72,7 +72,8 @@ int console_record_reset_enable(void);
  *
  * @str: Place to put string
  * @maxlen: Maximum length of @str including nul terminator
- * @return length of string returned
+ * @return length of string returned, or -ENOSPC if the console buffer was
+ *	overflowed by the output
  */
 int console_record_readline(char *str, int maxlen);
 
diff --git a/test/ut.c b/test/ut.c
index ea0af153e4..a0fe5facac 100644
--- a/test/ut.c
+++ b/test/ut.c
@@ -51,14 +51,31 @@ long ut_check_delta(ulong last)
 	return ut_check_free() - last;
 }
 
+static int readline_check(struct unit_test_state *uts)
+{
+	int ret;
+
+	ret = console_record_readline(uts->actual_str, sizeof(uts->actual_str));
+	if (ret == -ENOSPC) {
+		ut_fail(uts, __FILE__, __LINE__, __func__,
+			"Console record buffer too small - increase CONFIG_CONSOLE_RECORD_OUT_SIZE");
+		return ret;
+	}
+
+	return 0;
+}
+
 int ut_check_console_line(struct unit_test_state *uts, const char *fmt, ...)
 {
 	va_list args;
+	int ret;
 
 	va_start(args, fmt);
 	vsnprintf(uts->expect_str, sizeof(uts->expect_str), fmt, args);
 	va_end(args);
-	console_record_readline(uts->actual_str, sizeof(uts->actual_str));
+	ret = readline_check(uts);
+	if (ret < 0)
+		return ret;
 
 	return strcmp(uts->expect_str, uts->actual_str);
 }
@@ -66,11 +83,14 @@ int ut_check_console_line(struct unit_test_state *uts, const char *fmt, ...)
 int ut_check_console_linen(struct unit_test_state *uts, const char *fmt, ...)
 {
 	va_list args;
+	int ret;
 
 	va_start(args, fmt);
 	vsnprintf(uts->expect_str, sizeof(uts->expect_str), fmt, args);
 	va_end(args);
-	console_record_readline(uts->actual_str, sizeof(uts->actual_str));
+	ret = readline_check(uts);
+	if (ret < 0)
+		return ret;
 
 	return strncmp(uts->expect_str, uts->actual_str,
 		       strlen(uts->expect_str));
@@ -78,19 +98,26 @@ int ut_check_console_linen(struct unit_test_state *uts, const char *fmt, ...)
 
 int ut_check_skipline(struct unit_test_state *uts)
 {
+	int ret;
+
 	if (!console_record_avail())
 		return -ENFILE;
-	console_record_readline(uts->actual_str, sizeof(uts->actual_str));
+	ret = readline_check(uts);
+	if (ret < 0)
+		return ret;
 
 	return 0;
 }
 
 int ut_check_console_end(struct unit_test_state *uts)
 {
+	int ret;
+
 	if (!console_record_avail())
 		return 0;
-
-	console_record_readline(uts->actual_str, sizeof(uts->actual_str));
+	ret = readline_check(uts);
+	if (ret < 0)
+		return ret;
 
 	return 1;
 }