Re: [-next PATCH 4/4] treewide: Use DEVICE_ATTR_WO

[Borislav Petkov]

On Tue, Dec 19, 2017 at 10:15:09AM -0800, Joe Perches wrote:
> Convert DEVICE_ATTR uses to DEVICE_ATTR_WO where possible.
> 
> Done with perl script:
> 
> $ git grep -w --name-only DEVICE_ATTR | \
>   xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IWUSR\s*|\s*0200\s*)\)?\s*,\s*NULL\s*,\s*\s_store\s*\)/DEVICE_ATTR_WO(\1)/g; print;}'
> 
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
>  arch/s390/kernel/smp.c                 | 2 +-
>  arch/x86/kernel/cpu/microcode/core.c   | 2 +-
>  drivers/input/touchscreen/elants_i2c.c | 2 +-
>  drivers/net/ethernet/ibm/ibmvnic.c     | 2 +-
>  drivers/net/wimax/i2400m/sysfs.c       | 3 +--
>  drivers/scsi/lpfc/lpfc_attr.c          | 3 +--
>  drivers/thermal/thermal_sysfs.c        | 2 +-
>  7 files changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
> index b8c1a85bcf2d..a919b2f0141d 100644
> --- a/arch/s390/kernel/smp.c
> +++ b/arch/s390/kernel/smp.c
> @@ -1151,7 +1151,7 @@ static ssize_t __ref rescan_store(struct device *dev,
>  	rc = smp_rescan_cpus();
>  	return rc ? rc : count;
>  }
> -static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
> +static DEVICE_ATTR_WO(rescan);
>  #endif /* CONFIG_HOTPLUG_CPU */
>  
>  static int __init s390_smp_init(void)
> diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
> index c4fa4a85d4cb..09c74b0560dd 100644
> --- a/arch/x86/kernel/cpu/microcode/core.c
> +++ b/arch/x86/kernel/cpu/microcode/core.c
> @@ -560,7 +560,7 @@ static ssize_t pf_show(struct device *dev,
>  	return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
>  }
>  
> -static DEVICE_ATTR(reload, 0200, NULL, reload_store);
> +static DEVICE_ATTR_WO(reload);
>  static DEVICE_ATTR(version, 0400, version_show, NULL);
>  static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
>  

# cat /sys/devices/system/cpu/microcode/reload
cat: /sys/devices/system/cpu/microcode/reload: Permission denied

The reason for the code churn being?

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.