[PATCH 2/3] watchdog: imgpdc: Fix probe NULL pointer dereference

[PATCH 2/3] watchdog: imgpdc: Fix probe NULL pointer dereference

[Fernando Ramos]

From: James Hogan <james.hogan@imgtec.com>

The IMG PDC watchdog probe function calls pdc_wdt_stop() prior to
watchdog_set_drvdata(), causing a NULL pointer dereference when
pdc_wdt_stop() retrieves the struct pdc_wdt_dev pointer using
watchdog_get_drvdata() and reads the register base address through it.

Fix by moving the watchdog_set_drvdata() call earlier, to where various
other pdc_wdt->wdt_dev fields are initialised.

Fixes: 93937669e9b5 ("watchdog: ImgTec PDC Watchdog Timer Driver")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
Cc: Jude Abraham <Jude.Abraham@imgtec.com>
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
---
 drivers/watchdog/imgpdc_wdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/imgpdc_wdt.c b/drivers/watchdog/imgpdc_wdt.c
index c8def68..32c35eb 100644
--- a/drivers/watchdog/imgpdc_wdt.c
+++ b/drivers/watchdog/imgpdc_wdt.c
@@ -191,6 +191,7 @@ static int pdc_wdt_probe(struct platform_device *pdev)
 	pdc_wdt->wdt_dev.ops = &pdc_wdt_ops;
 	pdc_wdt->wdt_dev.max_timeout = 1 << PDC_WDT_CONFIG_DELAY_MASK;
 	pdc_wdt->wdt_dev.parent = &pdev->dev;
+	watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt);
 
 	ret = watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, &pdev->dev);
 	if (ret < 0) {
@@ -232,7 +233,6 @@ static int pdc_wdt_probe(struct platform_device *pdev)
 	watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout);
 
 	platform_set_drvdata(pdev, pdc_wdt);
-	watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt);
 
 	ret = watchdog_register_device(&pdc_wdt->wdt_dev);
 	if (ret)
-- 
2.10.2

[PATCH 3/3] watchdog: imgpdc: Fix default heartbeat

[Fernando Ramos]

From: James Hogan <james.hogan@imgtec.com>

The IMG PDC watchdog driver heartbeat module parameter has no default so
it is initialised to zero. This results in the following warning during
probe:

imgpdc-wdt 2006000.wdt: Initial timeout out of range! setting max timeout

The module parameter description implies that the default value should
be PDC_WDT_DEF_TIMEOUT, which isn't yet used, so initialise it to that.

Also tweak the heartbeat module parameter description for consistency.

Fixes: 93937669e9b5 ("watchdog: ImgTec PDC Watchdog Timer Driver")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
Cc: Jude Abraham <Jude.Abraham@imgtec.com>
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
---
 drivers/watchdog/imgpdc_wdt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/imgpdc_wdt.c b/drivers/watchdog/imgpdc_wdt.c
index 32c35eb..0deaa4f 100644
--- a/drivers/watchdog/imgpdc_wdt.c
+++ b/drivers/watchdog/imgpdc_wdt.c
@@ -42,10 +42,10 @@
 #define PDC_WDT_MIN_TIMEOUT		1
 #define PDC_WDT_DEF_TIMEOUT		64
 
-static int heartbeat;
+static int heartbeat = PDC_WDT_DEF_TIMEOUT;
 module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
-	"(default = " __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")");
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds "
+	"(default=" __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")");
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
-- 
2.10.2