[PATCH 2/2] soc: imx: gpc: Do not pass static memory as platform data

From: Andrey Smirnov
Date: Wed Jan 10 2018 - 11:16:53 EST


Platform device core assumes the ownership of dev.platform_data as
well as that it is dynamically allocated and it will try to kfree it
as a part of platform_device_release(). Change the code to pass
kzalloc'ed chunk of memory instead of a pointer to a static memory to
avoid causing a BUG() when calling platform_device_put().

The problem can be reproduced by artificially enabling the error path
of platform_device_add() call (around line 452).

Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
Cc: Stefan Agner <stefan@xxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---

This patch is a follow up to fix one of the bugs discussed in
lkml.kernel.org/r/3f836677c6e98aaf01bc1ac8c3410083@xxxxxxxx

drivers/soc/imx/gpc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
index 47e7aa963dbb..ec8b79abebac 100644
--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -18,6 +18,7 @@
#include <linux/pm_domain.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
+#include <linux/slab.h>

#define GPC_CNTR 0x000

@@ -428,13 +429,19 @@ static int imx_gpc_probe(struct platform_device *pdev)
if (domain_index >= of_id_data->num_domains)
continue;

- domain = &imx_gpc_domains[domain_index];
+ domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+ if (!domain) {
+ of_node_put(np);
+ return -ENOMEM;
+ }
+ memcpy(domain, &imx_gpc_domains[domain_index], sizeof(*domain));
domain->regmap = regmap;
domain->ipg_rate_mhz = ipg_rate_mhz;

pd_pdev = platform_device_alloc("imx-pgc-power-domain",
domain_index);
if (!pd_pdev) {
+ kfree(domain);
of_node_put(np);
return -ENOMEM;
}
--
2.14.3