Re: [PATCH V2 1/6] stm class: Add ioctl get_options interface

From	Alexander Shishkin <alexander.shishkin@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH V2 1/6] stm class: Add ioctl get_options interface
Date	2016-02-05 14:00 +0100
Message-ID	<qYO9s-lP-7@gated-at.bofh.it> (permalink)
References	<qY0Po-7NH-7@gated-at.bofh.it> <qY0Pp-7NH-25@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Chunyan Zhang <zhang.chunyan@linaro.org> writes:

> There is already an interface of set_options, but no get_options yet.
> Before setting any options, one would may want to see the current
> status of that option by means of get_options interface. This
> interface has been used in CoreSight STM driver.
>
> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
> ---
>  drivers/hwtracing/stm/core.c | 11 +++++++++++
>  include/linux/stm.h          |  3 +++
>  include/uapi/linux/stm.h     |  1 +
>  3 files changed, 15 insertions(+)
>
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index b6445d9..86bb4e3 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -571,6 +571,17 @@ stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  						    options);
>  
>  		break;
> +
> +	case STP_GET_OPTIONS:
> +		if (stm_data->get_options)
> +			err = stm_data->get_options(stm_data,
> +						    stmf->output.master,
> +						    stmf->output.channel,
> +						    stmf->output.nr_chans,
> +						    &options);
> +
> +		return copy_to_user((void __user *)arg, &options, sizeof(u64));

The return value of copy_to_user() is not what you assume it is.

Regards,
--
Alex

Thread

[PATCH V2 0/6] Introduce CoreSight STM support Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
  [PATCH V2 5/6] coresight-stm: Bindings for System Trace Macrocell Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
  [PATCH V2 4/6] Documentations: Add explanations of the case for non-configurable masters Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
  [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
    Re: [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2016-02-05 14:00 +0100
      RE: [PATCH V2 3/6] stm class: provision for statically assigned  masterIDs Mike Leach <Mike.Leach@arm.com> - 2016-02-05 17:40 +0100
        RE: [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2016-02-08 12:00 +0100
      Re: [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-05 19:10 +0100
        Re: [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2016-02-08 14:30 +0100
          Re: [PATCH V2 3/6] stm class: provision for statically assigned masterIDs Mathieu Poirier <mathieu.poirier@linaro.org> - 2016-02-08 18:10 +0100
            RE: [PATCH V2 3/6] stm class: provision for statically assigned  masterIDs Al Grant <Al.Grant@arm.com> - 2016-02-08 18:50 +0100
  [PATCH V2 1/6] stm class: Add ioctl get_options interface Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
    Re: [PATCH V2 1/6] stm class: Add ioctl get_options interface Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2016-02-05 14:00 +0100
  [PATCH V2 6/6] coresight-stm: adding driver for CoreSight STM component Chunyan Zhang <zhang.chunyan@linaro.org> - 2016-02-03 09:20 +0100
    Re: [PATCH V2 6/6] coresight-stm: adding driver for CoreSight STM component Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2016-02-05 14:10 +0100
      Re: [PATCH V2 6/6] coresight-stm: adding driver for CoreSight STM component Arnd Bergmann <arnd@arndb.de> - 2016-02-05 15:40 +0100

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