checkpatch: add test for long udelay

Holger reported:

: The macro udelay cannot handle large values because of loss-of-precision.
:
: IMHO udelay on ARM is broken, because it also cannot work with fast
: ARM processors (where bogomips >= 3355, which is in sight now). It's
: just not broken enough that someone did something against it ...   so
: the current kludge is good enough.

Until then, warn on long udelay uses.

Also fix uses of $line that should have been $herecurr.

Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Holger Schurig <holgerschurig@gmail.com>
Cc: Sujith Manoharan <sujith@msujith.org>
Cc: John Linville <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: don't warn on some function pointer return styles

Checks for some function pointer return styles are too strict.  Fix
them.

Multiple spaces after function pointer return types are allowed.
	int  (*foo)(int bar)

Spaces after function pointer returns of pointer types are not required.
	int *(*foo)(int bar)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: add checks for constant non-octal permissions

umode_t permissions are sometimes mistakenly written with decimal
constants.  Verify that numeric permissions are using octal.

Add a list of the most commonly used functions and macros that have
umode_t permissions and the argument position.

Add a $Octal type to $Constant.
Allow $LvalOrFunc to be a pointer indirection too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: warn on uses of __constant_<foo> functions

Emit a warning when using any of these __constant_<foo> forms:

	__constant_cpu_to_be[x]
	__constant_cpu_to_le[x]
	__constant_be[x]_to_cpu
	__constant_le[x]_to_cpu
	__constant_htons
	__constant_ntohs

Using any of these outside of include/uapi/ isn't preferred as using the
function without __constant_ is identical when the argument is a
constant.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: update octal permissions warning

When checking permissions, make sure 4 octal digits are used, but allow
a single 0 too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: avoid sscanf test duplicated messages

Change a test of $dstat to $line to avoid possibly emitting the sscanf
warning multiple times.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: fix jiffies comparison and others

checkpatch could not distinguish between a variable in a struct named
jiffies and the normal jiffies.

	foo->jiffies

would emit a "Comparing jiffies" arning.

Update the $Compare variable to do a negative look-behind for "-" when
finding a ">" so that a pointer dereference like -> isn't a comparison.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: add test for char * arrays that could be static const

static const char* arrays create smaller text as each function call does
not have to populate the array.

Emit a warning when char *arrays aren't static const and the array is
not apparently global by being declared in the first column.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: use a more consistent function argument style

Instead of array indexing $_, use temporary variables like all the other
subroutines in the script use.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: ignore networking block comment style first lines in file

It's very common to have normal block comments for the initial comments
of a file description preface.

So for files in drivers/net and net/ don't emit a warning when the first
comment block in the file uses the normal block comment style and not
the networking block comment style.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: make "return is not a function" test quieter

This test is a bit noisy and opinions seem to agree that it should not
warn in a lot more situations.

It seems people agree that:

	return (foo || bar);
and
	return foo || bar;

are both acceptable style and checkpatch should be silent about them.

For now, it warns on parentheses around a simple constant or a single
function or a ternary.

	return (foo);
	return (foo(bar));
	return (foo ? bar : baz);

The last ternary test may be quieted in the future.

Modify the deparenthesize function to only strip balanced leading and
trailing parentheses.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Monam Agarwal <monamagarwal123@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch.pl: modify warning message for printk usage

Modify warning message when printk is used in a patch.  It mentions to
use subsystem_dbg instead of netdev_dbg as the first preferred format of
logging debug messages.

Signed-off-by: Yogesh Chaudhari <mr.yogesh@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: improve octal permissions test speed

The current octal permissions test is very slow.

When patch ("checkpatch: add checks for constant non-octal permissions")
was added, processing time approximately tripled.

Regain almost all of the performance by not looping through all the
possible functions unless the line contains one of the functions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: check vendor compatible with dashes

The current vendor compatible check will not match vendors with dashes,
like:

  compatible="asahi-kasei"

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Reported-by: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: fix spurious vendor compatible warnings

With a compatible string like

  compatible = "foo";

checkpatch will currently try to find "foo" in vendor-prefixes.txt,
which is wrong since the vendor prefix is empty in this specific case.

Skip the vendor test if the compatible is not like

  compatible = "vendor,something";

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Cc: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: check compatible strings in .c and .h too

Look for ".compatible = "foo" strings not only in .dts files, but
in .c and .h too.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Cc: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: improve the compatible vendor match

Improve the vendor name match in vendor-prefix.txt by only matching the
exact vendor name at the beginning of lines.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Cc: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch: net and drivers/net: warn on missing blank line after variable declaration

Networking prefers this style, so warn when it's not used.

Networking uses:

    void foo(int bar)
    {
        int baz;

        code...
   }

not

    void foo(int bar)
    {
        int baz;
        code...
    }

There are a limited number of false positives when using macros to
declare variables like:

  WARNING: networking uses a blank line after declarations
  #330: FILE: net/ipv4/inet_hashtables.c:330:
  +	int dif = sk->sk_bound_dev_if;
  +	INET_ADDR_COOKIE(acookie, saddr, daddr)

Signed-off-by: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
scripts/checkpatch.pl: __GFP_NOFAIL isn't going away

Revert commit 7e4915e78992 ("checkpatch: add warning of future
__GFP_NOFAIL use").

There are no plans to remove __GFP_NOFAIL.

__GFP_NOFAIL exists to

a) centralise the retry-allocation-for-ever operation into the core
   allocator, which is the appropriate implementation site and

b) permit us to identify code sites which aren't handling memory
   exhaustion appropriately.

Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch.pl: add check for Change-Id

A commit hook for the Gerrit code review server [1] inserts change
identifiers so Gerrit can track patches through multiple revisions.
These identifiers are noise in the context of the upstream kernel.
(Many Gerrit servers are private.  Even given a public instance, given
only a Change-Id, one must guess which server a change was tracked on.
Patches submitted to the Linux kernel mailing lists should be able to
stand on their own.  If it's truly useful to reference code review on a
Gerrit server, a URL is a much clearer way to do so.) Thus, issue an
error when a Change-Id line is encountered before the Signed-off-by.

1. https://gerrit.googlesource.com/gerrit/+/master/gerrit-server/src/main/resources/com/google/gerrit/server/tools/root/hooks/commit-msg

Signed-off-by: Christopher Covington <cov@codeaurora.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>