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

On Tue, 2017-12-19 at 19:44 +0100, Borislav Petkov wrote:

On Tue, Dec 19, 2017 at 10:15:09AM -0800, Joe Perches wrote:

quoted

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;}'

[]

quoted

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c

[]

quoted

@@ -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

Not different behavior.  It was and remains write only.

The reason for the code churn being?

Consistency for easier grep by use-type.