[RFC] Resolving "false positive" error message from checkpatch.pl

Hi all

There is a "false positive" error reported by checkpatch.pl:

ERROR: Use 4 digit octal (0777) not decimal permissions
#272: FILE: drivers/staging/iio/meter/ade7759.c:272:
+static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH1OS);

ERROR: Use 4 digit octal (0777) not decimal permissions
#276: FILE: drivers/staging/iio/meter/ade7759.c:276:
+static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH2OS);

The same for the file drivers/staging/iio/meter/ade7753.c.

We can see that this macro is matched by the pattern "IIO_DEV_ATTR_[A-Z_]+" from
@mode_permission_funcs in checkpatch.pl.

My question is: how this should be fixed?

From what I can say, it's a false positive so the correct way to fix it is to

change the matching pattern: "IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+".

Or maybe the fix should be done in iio code - argument position inside this
macro?

-- 
Slawomir Stepien

On Fri, Feb 03, 2017 at 11:11:35AM +0100, Slawomir Stepien wrote:

Hi all

There is a "false positive" error reported by checkpatch.pl:

ERROR: Use 4 digit octal (0777) not decimal permissions
#272: FILE: drivers/staging/iio/meter/ade7759.c:272:
+static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH1OS);

ERROR: Use 4 digit octal (0777) not decimal permissions
#276: FILE: drivers/staging/iio/meter/ade7759.c:276:
+static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH2OS);

The same for the file drivers/staging/iio/meter/ade7753.c.

We can see that this macro is matched by the pattern "IIO_DEV_ATTR_[A-Z_]+" from
@mode_permission_funcs in checkpatch.pl.

My question is: how this should be fixed?

Why do you think this is a false-positive?

From what I can say, it's a false positive so the correct way to fix it is to
change the matching pattern: "IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+".

Huh?

Provide a patch to show what you are suggesting please.

thanks,

greg k-h

On Feb 03, 2017 11:27, Greg KH wrote:

On Fri, Feb 03, 2017 at 11:11:35AM +0100, Slawomir Stepien wrote:

quoted

Hi all

There is a "false positive" error reported by checkpatch.pl:

ERROR: Use 4 digit octal (0777) not decimal permissions
#272: FILE: drivers/staging/iio/meter/ade7759.c:272:
+static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH1OS);

ERROR: Use 4 digit octal (0777) not decimal permissions
#276: FILE: drivers/staging/iio/meter/ade7759.c:276:
+static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH2OS);

The same for the file drivers/staging/iio/meter/ade7753.c.

We can see that this macro is matched by the pattern "IIO_DEV_ATTR_[A-Z_]+" from
@mode_permission_funcs in checkpatch.pl.

My question is: how this should be fixed?

Why do you think this is a false-positive?

Because the 1st arg of that macro is not supposed to be a permissions flags.

quoted

From what I can say, it's a false positive so the correct way to fix it is to
change the matching pattern: "IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+".

Huh?

Provide a patch to show what you are suggesting please.

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8e96af53611c..0a1c6ec86caa 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl

@@ -525,7 +525,7 @@ our @mode_permission_funcs = (
 	["debugfs_create_(?:file|u8|u16|u32|u64|x8|x16|x32|x64|size_t|atomic_t|bool|blob|regset32|u32_array)", 2],
 	["proc_create(?:_data|)", 2],
 	["(?:CLASS|DEVICE|SENSOR|SENSOR_DEVICE|IIO_DEVICE)_ATTR", 2],
-	["IIO_DEV_ATTR_[A-Z_]+", 1],
+	["IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+", 1],
 	["SENSOR_(?:DEVICE_|)ATTR_2", 2],
 	["SENSOR_TEMPLATE(?:_2|)", 3],
 	["__ATTR", 2],

-- 
2.11.0

On Fri, Feb 03, 2017 at 01:10:20PM +0100, Slawomir Stepien wrote:

On Feb 03, 2017 11:27, Greg KH wrote:

quoted

On Fri, Feb 03, 2017 at 11:11:35AM +0100, Slawomir Stepien wrote:

quoted

Hi all

There is a "false positive" error reported by checkpatch.pl:

ERROR: Use 4 digit octal (0777) not decimal permissions
#272: FILE: drivers/staging/iio/meter/ade7759.c:272:
+static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH1OS);

ERROR: Use 4 digit octal (0777) not decimal permissions
#276: FILE: drivers/staging/iio/meter/ade7759.c:276:
+static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH2OS);

The same for the file drivers/staging/iio/meter/ade7753.c.

We can see that this macro is matched by the pattern "IIO_DEV_ATTR_[A-Z_]+" from
@mode_permission_funcs in checkpatch.pl.

My question is: how this should be fixed?

Why do you think this is a false-positive?

Because the 1st arg of that macro is not supposed to be a permissions flags.

Ah. I was thinking that the S_IWUSR needs to be replaced with an octal
value :)

thanks,

greg k-h

On Fri, 2017-02-03 at 13:10 +0100, Slawomir Stepien wrote:

There are many local MODE_DEV_ATTR_<foo> functions
that don't have permission in as the first argument.

$ grep -rPoh --include=*.[ch] "\bIIO_DEV_ATTR_[A-Z_]+\b" *|sort|uniq|wc -l
123

Maybe it'd be better to list the ones that do
or to change the argument order of the defines
and uses so mode _is_ the first argument.

$ grep -rPoh --include=*.[ch] "\bIIO_DEV_ATTR_[A-Z_]+\b" *|sort|uniq| \
  while read line ; do git grep -w $line | grep -w define ; done|grep _mode | grep -v "(_mode"
drivers/staging/iio/meter/meter.h:#define IIO_DEV_ATTR_CH_OFF(_num, _mode, _show, _store, _addr)		\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_FREQ(_channel, _num, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_FREQSYMBOL(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_OUT_ENABLE(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PHASE(_channel, _num, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PHASESYMBOL(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_EN(_channel, _mode, _show, _store, _addr)\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_FREQ_EN(_channel, _mode, _show, _store, _addr)\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_PHASE_EN(_channel, _mode, _show, _store, _addr)\

On Feb 03, 2017 04:39, Joe Perches wrote:

On Fri, 2017-02-03 at 13:10 +0100, Slawomir Stepien wrote:

quoted

On Feb 03, 2017 11:27, Greg KH wrote:

quoted

On Fri, Feb 03, 2017 at 11:11:35AM +0100, Slawomir Stepien wrote:

quoted

Hi all

There is a "false positive" error reported by checkpatch.pl:

ERROR: Use 4 digit octal (0777) not decimal permissions
#272: FILE: drivers/staging/iio/meter/ade7759.c:272:
+static IIO_DEV_ATTR_CH_OFF(1, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH1OS);

ERROR: Use 4 digit octal (0777) not decimal permissions
#276: FILE: drivers/staging/iio/meter/ade7759.c:276:
+static IIO_DEV_ATTR_CH_OFF(2, S_IWUSR | S_IRUGO,
+		ade7759_read_8bit,
+		ade7759_write_8bit,
+		ADE7759_CH2OS);

The same for the file drivers/staging/iio/meter/ade7753.c.

We can see that this macro is matched by the pattern "IIO_DEV_ATTR_[A-Z_]+" from
@mode_permission_funcs in checkpatch.pl.

My question is: how this should be fixed?

Why do you think this is a false-positive?

Because the 1st arg of that macro is not supposed to be a permissions flags.

quoted

quoted

From what I can say, it's a false positive so the correct way to fix it is to
change the matching pattern: "IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+".

Huh?

Provide a patch to show what you are suggesting please.

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8e96af53611c..0a1c6ec86caa 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl

@@ -525,7 +525,7 @@ our @mode_permission_funcs = (
 	["debugfs_create_(?:file|u8|u16|u32|u64|x8|x16|x32|x64|size_t|atomic_t|bool|blob|regset32|u32_array)", 2],
 	["proc_create(?:_data|)", 2],
 	["(?:CLASS|DEVICE|SENSOR|SENSOR_DEVICE|IIO_DEVICE)_ATTR", 2],
-	["IIO_DEV_ATTR_[A-Z_]+", 1],
+	["IIO_DEV_ATTR_(?!CH_OFF)[A-Z_]+", 1],
 	["SENSOR_(?:DEVICE_|)ATTR_2", 2],
 	["SENSOR_TEMPLATE(?:_2|)", 3],
 	["__ATTR", 2],

There are many local MODE_DEV_ATTR_<foo> functions
that don't have permission in as the first argument.

Yeah...I just found the ones in the drivers/staging/iio/frequency that you
pointed out.

$ grep -rPoh --include=*.[ch] "\bIIO_DEV_ATTR_[A-Z_]+\b" *|sort|uniq|wc -l
123

Maybe it'd be better to list the ones that do
or to change the argument order of the defines
and uses so mode _is_ the first argument.

That is my original question. What would be better here (especially that no we
can see that there are few more places where the error will pop)?

$ grep -rPoh --include=*.[ch] "\bIIO_DEV_ATTR_[A-Z_]+\b" *|sort|uniq| \
  while read line ; do git grep -w $line | grep -w define ; done|grep _mode | grep -v "(_mode"
drivers/staging/iio/meter/meter.h:#define IIO_DEV_ATTR_CH_OFF(_num, _mode, _show, _store, _addr)		\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_FREQ(_channel, _num, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_FREQSYMBOL(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_OUT_ENABLE(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PHASE(_channel, _num, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PHASESYMBOL(_channel, _mode, _show, _store, _addr)	\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_EN(_channel, _mode, _show, _store, _addr)\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_FREQ_EN(_channel, _mode, _show, _store, _addr)\
drivers/staging/iio/frequency/dds.h:#define IIO_DEV_ATTR_PINCONTROL_PHASE_EN(_channel, _mode, _show, _store, _addr)\

-- 
Slawomir Stepien