[U-Boot] [PATCH 3/3] ti: common: board_detect: Return a valid empty string for un-initialized eeprom

Nishanth Menon
2016-10-11T17:39:05Z

Current logic for query of revision, board_name, config returns
NULL. Users of these functions do a direct strncmp to compare.
Unfortunately, as per conventions require two valid strings to compare
against and the current implementation causes a crash when compared
with NULL.

We'd still like to maintain the simplistic usage of these APIs instead
of redundant if (string) res=strncmp(fn(),"cmp",n); flowing all over
the place.

Hence, since the version, name and config is already pre-initialized
with empty string, just dont check for invalid header in the first
place and return the empty string to the caller.

Reported-by: Brad Griffis <bgriffis@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
---
board/ti/common/board_detect.c | 12 +++---------
board/ti/common/board_detect.h | 6 +++---
2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/board/ti/common/board_detect.c b/board/ti/common/board_detect.c
index 13aac2f03037..6e7ca9196d22 100644
--- a/board/ti/common/board_detect.c
+++ b/board/ti/common/board_detect.c
@@ -231,9 +231,7 @@ char * __maybe_unused board_ti_get_rev(void)
{
struct ti_common_eeprom *ep = TI_EEPROM_DATA;

- if (ep->header == TI_DEAD_EEPROM_MAGIC)
- return NULL;
-
+ /* if ep->header == TI_DEAD_EEPROM_MAGIC, this is empty already */
return ep->version;
}

@@ -241,9 +239,7 @@ char * __maybe_unused board_ti_get_config(void)
{
struct ti_common_eeprom *ep = TI_EEPROM_DATA;

- if (ep->header == TI_DEAD_EEPROM_MAGIC)
- return NULL;
-
+ /* if ep->header == TI_DEAD_EEPROM_MAGIC, this is empty already */
return ep->config;
}

@@ -251,9 +247,7 @@ char * __maybe_unused board_ti_get_name(void)
{
struct ti_common_eeprom *ep = TI_EEPROM_DATA;

- if (ep->header == TI_DEAD_EEPROM_MAGIC)
- return NULL;
-
+ /* if ep->header == TI_DEAD_EEPROM_MAGIC, this is empty already */
return ep->name;
}

diff --git a/board/ti/common/board_detect.h b/board/ti/common/board_detect.h
index eb17f6f52a12..2ded3ed7764b 100644
--- a/board/ti/common/board_detect.h
+++ b/board/ti/common/board_detect.h
@@ -141,7 +141,7 @@ bool board_ti_rev_is(char *rev_tag, int cmp_len);
/**
* board_ti_get_rev() - Get board revision for TI EVMs
*
- * Return: NULL if eeprom was'nt read.
+ * Return: Empty string if eeprom was'nt read.
* Board revision otherwise
*/
char *board_ti_get_rev(void);
@@ -149,7 +149,7 @@ char *board_ti_get_rev(void);
/**
* board_ti_get_config() - Get board config for TI EVMs
*
- * Return: NULL if eeprom was'nt read.
+ * Return: Empty string if eeprom was'nt read.
* Board config otherwise
*/
char *board_ti_get_config(void);
@@ -157,7 +157,7 @@ char *board_ti_get_config(void);
/**
* board_ti_get_name() - Get board name for TI EVMs
*
- * Return: NULL if eeprom was'nt read.
+ * Return: Empty string if eeprom was'nt read.
* Board name otherwise
*/
char *board_ti_get_name(void);
--
2.10.0