rtc: fix potential race condition

RTC drivers must not return an error after device registration.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Reported-by: Ales Novak <alnovak@suse.cz>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Srikanth Srinivasan <srikanth.srinivasan@freescale.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 files changed, 70 insertions, 65 deletions

diff --git a/drivers/rtc/rtc-ds1305.c b/drivers/rtc/rtc-ds1305.c
index 2dd586a19b59..129add77065d 100644
--- a/drivers/rtc/rtc-ds1305.c
+++ b/drivers/rtc/rtc-ds1305.c
@@ -756,19 +756,17 @@ static int ds1305_probe(struct spi_device *spi)
                 status = devm_request_irq(&spi->dev, spi->irq, ds1305_irq,
                                 0, dev_name(&ds1305->rtc->dev), ds1305);
                 if (status < 0) {
-                        dev_dbg(&spi->dev, "request_irq %d --> %d\n",
+                        dev_err(&spi->dev, "request_irq %d --> %d\n",
                                         spi->irq, status);
-                        return status;
+                } else {
+                        device_set_wakeup_capable(&spi->dev, 1);
                 }
-
-                device_set_wakeup_capable(&spi->dev, 1);
         }
 
         /* export NVRAM */
         status = sysfs_create_bin_file(&spi->dev.kobj, &nvram);
         if (status < 0) {
-                dev_dbg(&spi->dev, "register nvram --> %d\n", status);
-                return status;
+                dev_err(&spi->dev, "register nvram --> %d\n", status);
         }
 
         return 0;
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 4e75345a559a..9e2aad68f96d 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -930,52 +930,58 @@ read_rtc:
         ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
                                 &ds13xx_rtc_ops, THIS_MODULE);
         if (IS_ERR(ds1307->rtc)) {
-                err = PTR_ERR(ds1307->rtc);
-                dev_err(&client->dev,
-                        "unable to register the class device\n");
-                goto exit;
+                return PTR_ERR(ds1307->rtc);
         }
 
         if (want_irq) {
                 err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
                           ds1307->rtc->name, client);
                 if (err) {
-                        dev_err(&client->dev,
-                                "unable to request IRQ!\n");
-                        goto exit;
-                }
+                        client->irq = 0;
+                        dev_err(&client->dev, "unable to request IRQ!\n");
+                } else {
 
-                device_set_wakeup_capable(&client->dev, 1);
-                set_bit(HAS_ALARM, &ds1307->flags);
-                dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+                        device_set_wakeup_capable(&client->dev, 1);
+                        set_bit(HAS_ALARM, &ds1307->flags);
+                        dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+                }
         }
 
         if (chip->nvram_size) {
+
                 ds1307->nvram = devm_kzalloc(&client->dev,
                                         sizeof(struct bin_attribute),
                                         GFP_KERNEL);
                 if (!ds1307->nvram) {
-                        err = -ENOMEM;
-                        goto err_irq;
+                        dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
+                } else {
+
+                        ds1307->nvram->attr.name = "nvram";
+                        ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
+
+                        sysfs_bin_attr_init(ds1307->nvram);
+
+                        ds1307->nvram->read = ds1307_nvram_read;
+                        ds1307->nvram->write = ds1307_nvram_write;
+                        ds1307->nvram->size = chip->nvram_size;
+                        ds1307->nvram_offset = chip->nvram_offset;
+
+                        err = sysfs_create_bin_file(&client->dev.kobj,
+                                                    ds1307->nvram);
+                        if (err) {
+                                dev_err(&client->dev,
+                                        "unable to create sysfs file: %s\n",
+                                        ds1307->nvram->attr.name);
+                        } else {
+                                set_bit(HAS_NVRAM, &ds1307->flags);
+                                dev_info(&client->dev, "%zu bytes nvram\n",
+                                         ds1307->nvram->size);
+                        }
                 }
-                ds1307->nvram->attr.name = "nvram";
-                ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
-                sysfs_bin_attr_init(ds1307->nvram);
-                ds1307->nvram->read = ds1307_nvram_read;
-                ds1307->nvram->write = ds1307_nvram_write;
-                ds1307->nvram->size = chip->nvram_size;
-                ds1307->nvram_offset = chip->nvram_offset;
-                err = sysfs_create_bin_file(&client->dev.kobj, ds1307->nvram);
-                if (err)
-                        goto err_irq;
-                set_bit(HAS_NVRAM, &ds1307->flags);
-                dev_info(&client->dev, "%zu bytes nvram\n", ds1307->nvram->size);
         }
 
         return 0;
 
-err_irq:
-        free_irq(client->irq, client);
 exit:
         return err;
 }
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
index bc7b4fcf603c..4ff20f9dc212 100644
--- a/drivers/rtc/rtc-ds1511.c
+++ b/drivers/rtc/rtc-ds1511.c
@@ -473,7 +473,6 @@ static struct bin_attribute ds1511_nvram_attr = {
 
 static int ds1511_rtc_probe(struct platform_device *pdev)
 {
-        struct rtc_device *rtc;
         struct resource *res;
         struct rtc_plat_data *pdata;
         int ret = 0;
@@ -512,6 +511,12 @@ static int ds1511_rtc_probe(struct platform_device *pdev)
 
         spin_lock_init(&pdata->lock);
         platform_set_drvdata(pdev, pdata);
+
+        pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+                                              &ds1511_rtc_ops, THIS_MODULE);
+        if (IS_ERR(pdata->rtc))
+                return PTR_ERR(pdata->rtc);
+
         /*
          * if the platform has an interrupt in mind for this device,
          * then by all means, set it
@@ -526,15 +531,12 @@ static int ds1511_rtc_probe(struct platform_device *pdev)
                 }
         }
 
-        rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &ds1511_rtc_ops,
-                                        THIS_MODULE);
-        if (IS_ERR(rtc))
-                return PTR_ERR(rtc);
-        pdata->rtc = rtc;
-
         ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
+        if (ret)
+                dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
+                        ds1511_nvram_attr.attr.name);
 
-        return ret;
+        return 0;
 }
 
 static int ds1511_rtc_remove(struct platform_device *pdev)
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
index fd31571941f5..9ac2fa07dffa 100644
--- a/drivers/rtc/rtc-ds1553.c
+++ b/drivers/rtc/rtc-ds1553.c
@@ -278,7 +278,6 @@ static struct bin_attribute ds1553_nvram_attr = {
 
 static int ds1553_rtc_probe(struct platform_device *pdev)
 {
-        struct rtc_device *rtc;
         struct resource *res;
         unsigned int cen, sec;
         struct rtc_plat_data *pdata;
@@ -311,6 +310,12 @@ static int ds1553_rtc_probe(struct platform_device *pdev)
         spin_lock_init(&pdata->lock);
         pdata->last_jiffies = jiffies;
         platform_set_drvdata(pdev, pdata);
+
+        pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+                                  &ds1553_rtc_ops, THIS_MODULE);
+        if (IS_ERR(pdata->rtc))
+                return PTR_ERR(pdata->rtc);
+
         if (pdata->irq > 0) {
                 writeb(0, ioaddr + RTC_INTERRUPTS);
                 if (devm_request_irq(&pdev->dev, pdata->irq,
@@ -321,15 +326,12 @@ static int ds1553_rtc_probe(struct platform_device *pdev)
                 }
         }
 
-        rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
-                                  &ds1553_rtc_ops, THIS_MODULE);
-        if (IS_ERR(rtc))
-                return PTR_ERR(rtc);
-        pdata->rtc = rtc;
-
         ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
+        if (ret)
+                dev_err(&pdev->dev, "unable to create sysfs file: %s\n",
+                        ds1553_nvram_attr.attr.name);
 
-        return ret;
+        return 0;
 }
 
 static int ds1553_rtc_remove(struct platform_device *pdev)
diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c
index 18e2d8471472..a4888dbca2e1 100644
--- a/drivers/rtc/rtc-ds1672.c
+++ b/drivers/rtc/rtc-ds1672.c
@@ -177,8 +177,9 @@ static int ds1672_probe(struct i2c_client *client,
 
         /* read control register */
         err = ds1672_get_control(client, &control);
-        if (err)
-                goto exit_devreg;
+        if (err) {
+                dev_warn(&client->dev, "Unable to read the control register\n");
+        }
 
         if (control & DS1672_REG_CONTROL_EOSC)
                 dev_warn(&client->dev, "Oscillator not enabled. "
@@ -187,12 +188,10 @@ static int ds1672_probe(struct i2c_client *client,
         /* Register sysfs hooks */
         err = device_create_file(&client->dev, &dev_attr_control);
         if (err)
-                goto exit_devreg;
+                dev_err(&client->dev, "Unable to create sysfs entry: %s\n",
+                        dev_attr_control.attr.name);
 
         return 0;
-
- exit_devreg:
-        return err;
 }
 
 static struct i2c_device_id ds1672_id[] = {
diff --git a/drivers/rtc/rtc-ds1742.c b/drivers/rtc/rtc-ds1742.c
index 5a1f3b2a8f1e..942103dac30f 100644
--- a/drivers/rtc/rtc-ds1742.c
+++ b/drivers/rtc/rtc-ds1742.c
@@ -204,8 +204,11 @@ static int ds1742_rtc_probe(struct platform_device *pdev)
                 return PTR_ERR(rtc);
 
         ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
+        if (ret)
+                dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
+                        pdata->nvram_attr.attr.name);
 
-        return ret;
+        return 0;
 }
 
 static int ds1742_rtc_remove(struct platform_device *pdev)
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index b83bb5a527f8..15497c578af5 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -414,7 +414,6 @@ static int ds3232_probe(struct i2c_client *client,
         ds3232->rtc = devm_rtc_device_register(&client->dev, client->name,
                                           &ds3232_rtc_ops, THIS_MODULE);
         if (IS_ERR(ds3232->rtc)) {
-                dev_err(&client->dev, "unable to register the class device\n");
                 return PTR_ERR(ds3232->rtc);
         }
 
@@ -423,7 +422,6 @@ static int ds3232_probe(struct i2c_client *client,
                                  "ds3232", client);
                 if (ret) {
                         dev_err(&client->dev, "unable to request IRQ\n");
-                        return ret;
                 }
         }
 
diff --git a/drivers/rtc/rtc-test.c b/drivers/rtc/rtc-test.c
index 7746e65b93f2..6599c20bc454 100644
--- a/drivers/rtc/rtc-test.c
+++ b/drivers/rtc/rtc-test.c
@@ -104,20 +104,17 @@ static int test_probe(struct platform_device *plat_dev)
         rtc = devm_rtc_device_register(&plat_dev->dev, "test",
                                 &test_rtc_ops, THIS_MODULE);
         if (IS_ERR(rtc)) {
-                err = PTR_ERR(rtc);
-                return err;
+                return PTR_ERR(rtc);
         }
 
         err = device_create_file(&plat_dev->dev, &dev_attr_irq);
         if (err)
-                goto err;
+                dev_err(&plat_dev->dev, "Unable to create sysfs entry: %s\n",
+                        dev_attr_irq.attr.name);
 
         platform_set_drvdata(plat_dev, rtc);
 
         return 0;
-
-err:
-        return err;
 }
 
 static int test_remove(struct platform_device *plat_dev)
diff --git a/drivers/rtc/rtc-x1205.c b/drivers/rtc/rtc-x1205.c
index 365dc6505148..b1de58e0b3d0 100644
--- a/drivers/rtc/rtc-x1205.c
+++ b/drivers/rtc/rtc-x1205.c
@@ -660,7 +660,7 @@ static int x1205_probe(struct i2c_client *client,
 
         err = x1205_sysfs_register(&client->dev);
         if (err)
-                return err;
+                dev_err(&client->dev, "Unable to create sysfs entries\n");
 
         return 0;
 }