[PATCH] fix memory leak in ramoops_init

[nixiaoming]

1, memory leak in ramoops_register_dummy.
   dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
   but no free when platform_device_register_data return fail

2, if kzalloc(sizeof(*dummy_data), GFP_KERNEL) return NULL,
    but platform_driver_register(&ramoops_driver) return 0
   kfree(NULL) in ramoops_exit
so, add return val for ramoops_register_dummy, and check it in ramoops_init

3, memory leak in ramoops_init.
   miss platform_device_unregister(dummy) and kfree(dummy_data)
   when platform_driver_register(&ramoops_driver) return fail

Signed-off-by: nixiaoming <nixiaom...@huawei.com>
---
 fs/pstore/ram.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index bd9812e..331b600 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -604,17 +604,17 @@ static struct platform_driver ramoops_driver = {
        },
 };
 
-static void ramoops_register_dummy(void)
+static int ramoops_register_dummy(void)
 {
        if (!mem_size)
-               return;
+               return -EINVAL;
 
        pr_info("using module parameters\n");
 
        dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
        if (!dummy_data) {
                pr_info("could not allocate pdata\n");
-               return;
+               return -ENOMEM;
        }
 
        dummy_data->mem_size = mem_size;
@@ -636,13 +636,25 @@ static void ramoops_register_dummy(void)
        if (IS_ERR(dummy)) {
                pr_info("could not create platform device: %ld\n",
                        PTR_ERR(dummy));
+               kfree(dummy_data);
+               return PTR_ERR(dummy);
        }
+       return 0;
 }
 
 static int __init ramoops_init(void)
 {
-       ramoops_register_dummy();
-       return platform_driver_register(&ramoops_driver);
+       int ret = ramoops_register_dummy();
+
+       if (ret != 0)
+               return ret;
+
+       ret = platform_driver_register(&ramoops_driver);
+       if (ret != 0) {
+               platform_device_unregister(dummy);
+               kfree(dummy_data);
+       }
+       return ret;
 }
 postcore_initcall(ramoops_init);
 
-- 
1.9.0