From: H Hartley Sweeten Date: Thu, 6 Mar 2014 19:02:57 +0000 (-0700) Subject: staging: comedi: comedi_fops: introduce __comedi_get_user_chanlist() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c6cd0eefb27b47a3f67ec0adbea14b4f97d72ec9;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git staging: comedi: comedi_fops: introduce __comedi_get_user_chanlist() The COMEDI_CMD and COMEDI_CMDTEST ioctl functions both copy the chanlist passed by the user from __user memory space to kernel memory space. They then do some sanity checking of the chanlist with comedi_check_chanlist() before the subdevice (*do_cmdtest) and (*do_cmd) operations are called. Introduce a helper function to handle the memdup_user() and the sanity checking. Also, remove the unnecessary dev_dbg() when the memdup_user() or comedi_check_chanlist() fail. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index bf5265a083f6..ea6dc36d753b 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1455,6 +1455,35 @@ static int __comedi_get_user_cmd(struct comedi_device *dev, return 0; } +static int __comedi_get_user_chanlist(struct comedi_device *dev, + struct comedi_subdevice *s, + unsigned int __user *user_chanlist, + struct comedi_cmd *cmd) +{ + unsigned int *chanlist; + int ret; + + /* user_chanlist could be NULL for do_cmdtest ioctls */ + if (!user_chanlist) + return 0; + + chanlist = memdup_user(user_chanlist, + cmd->chanlist_len * sizeof(unsigned int)); + if (IS_ERR(chanlist)) + return PTR_ERR(chanlist); + + /* make sure each element in channel/gain list is valid */ + ret = comedi_check_chanlist(s, cmd->chanlist_len, chanlist); + if (ret < 0) { + kfree(chanlist); + return ret; + } + + cmd->chanlist = chanlist; + + return 0; +} + static int do_cmd_ioctl(struct comedi_device *dev, struct comedi_cmd __user *arg, void *file) { @@ -1496,26 +1525,11 @@ static int do_cmd_ioctl(struct comedi_device *dev, async->cmd = cmd; async->cmd.data = NULL; - /* load channel/gain list */ - async->cmd.chanlist = memdup_user(user_chanlist, - async->cmd.chanlist_len * - sizeof(int)); - if (IS_ERR(async->cmd.chanlist)) { - ret = PTR_ERR(async->cmd.chanlist); - async->cmd.chanlist = NULL; - dev_dbg(dev->class_dev, "memdup_user failed with code %d\n", - ret); - goto cleanup; - } - /* make sure each element in channel/gain list is valid */ - ret = comedi_check_chanlist(s, - async->cmd.chanlist_len, - async->cmd.chanlist); - if (ret < 0) { - dev_dbg(dev->class_dev, "bad chanlist\n"); + /* load channel/gain list */ + ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &async->cmd); + if (ret) goto cleanup; - } ret = s->do_cmdtest(dev, s, &async->cmd); @@ -1598,26 +1612,9 @@ static int do_cmdtest_ioctl(struct comedi_device *dev, s = &dev->subdevices[cmd.subdev]; /* load channel/gain list */ - if (cmd.chanlist) { - chanlist = memdup_user(user_chanlist, - cmd.chanlist_len * sizeof(int)); - if (IS_ERR(chanlist)) { - ret = PTR_ERR(chanlist); - chanlist = NULL; - dev_dbg(dev->class_dev, - "memdup_user exited with code %d", ret); - goto cleanup; - } - - /* make sure each element in channel/gain list is valid */ - ret = comedi_check_chanlist(s, cmd.chanlist_len, chanlist); - if (ret < 0) { - dev_dbg(dev->class_dev, "bad chanlist\n"); - goto cleanup; - } - - cmd.chanlist = chanlist; - } + ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &cmd); + if (ret) + return ret; ret = s->do_cmdtest(dev, s, &cmd); @@ -1627,9 +1624,8 @@ static int do_cmdtest_ioctl(struct comedi_device *dev, if (copy_to_user(arg, &cmd, sizeof(cmd))) { dev_dbg(dev->class_dev, "bad cmd address\n"); ret = -EFAULT; - goto cleanup; } -cleanup: + kfree(chanlist); return ret;