[PATCH 2/2] fpga: do not access region struct after fpga_region_unregister

From: Alan Tull
Date: Wed Jul 25 2018 - 14:15:21 EST


The FPGA region class's dev_release handles freeing the struct
fpga_region when fpga_region_unregister() unregisters the device. A
couple drivers were accessing the region struct after it had been
freed. Save off the pointer to the mgr before the region struct gets
freed.

Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
---
drivers/fpga/dfl-fme-region.c | 4 +++-
drivers/fpga/of-fpga-region.c | 3 ++-
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index 0b7e19c..51a5ac2 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -14,6 +14,7 @@
*/

#include <linux/module.h>
+#include <linux/fpga/fpga-mgr.h>
#include <linux/fpga/fpga-region.h>

#include "dfl-fme-pr.h"
@@ -66,9 +67,10 @@ static int fme_region_probe(struct platform_device *pdev)
static int fme_region_remove(struct platform_device *pdev)
{
struct fpga_region *region = dev_get_drvdata(&pdev->dev);
+ struct fpga_manager *mgr = region->mgr;

fpga_region_unregister(region);
- fpga_mgr_put(region->mgr);
+ fpga_mgr_put(mgr);

return 0;
}
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index 35fabb8..052a134 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -437,9 +437,10 @@ static int of_fpga_region_probe(struct platform_device *pdev)
static int of_fpga_region_remove(struct platform_device *pdev)
{
struct fpga_region *region = platform_get_drvdata(pdev);
+ struct fpga_manager *mgr = region->mgr;

fpga_region_unregister(region);
- fpga_mgr_put(region->mgr);
+ fpga_mgr_put(mgr);

return 0;
}
--
2.7.4