Using "git diff | ./scripts/checkpatch -" does not have an
easy mechanism to see the files and lines actually modified.

Add --showfile to see the file and line specified in the diff.

When --showfile is used without --terse, the second line of each
message output is redundant, so it is removed.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add optional colors to make seeing message types a bit easier.

Add --color command line switch, default:on

Error is RED, warning is YELLOW, check is GREEN.  The message type, if
shown, is BLUE.
Signed-off-by: NJoe Perches <joe@perches.com>
Tested-by: NPetr Mladek <pmladek@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If there are multiple patches/files on the command line,
use a prefix before the patch/file message output like:
        --------------
        patch/filename
        --------------
to make the identifying which messages go with which
file/patch a bit easier to parse.

Move the perl version and false positive messages after
all the files have been scanned so that they are emitted
only once.

Standardize the NOTE: <...> form to always emit a blank
line before the NOTE and always use print << "EOM" style.
Signed-off-by: NJoe Perches <joe@perches.com>
Suggested-by: NPetr Mladek <pmladek@suse.cz>
Tested-by: NPetr Mladek <pmladek@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many lines of code extend beyond the maximum line length.  Some of these
are possibly justified by use type.

For instance:

structure definitions where comments are added per member like:
struct foo {
	type member;		/* some long description */

And lines that don't fit the typical logging message style
where a string constant is used like:

        SOME_MACRO(args, "Some long string");

Categorize these long line types so that checkpatch can use a command-line
--ignore=<type> option to avoid emitting some long line warnings.

One of the existing checkpatch exclusions allowed kernel-doc argument
documentation to exceed 80 columns because old versions of kernel-doc
required single line documentation.  The requirement was removed in 2009
so remove that exclusion.

Add documentation to make the test a bit clearer.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Michael Shuey <shuey@purdue.edu>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

String detection where a source line with a string constant is converted
can either have an X or a space.

Some of the string detection regexes do not allow the space character, but
there is a handy $String variable that does.

Convert the remaining uses of string detection regexes to use the $String
variable to reduce possible false negatives.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

checkpatch uses various cues in its input patches and files to discover
the names of user-defined types and modifiers.  It then uses that
information when processing expressions to discover potential style
issues.

Unfortunately, in rare cases, this means that checkpatch may give
different results if you run it on several input files in one execution,
or one by one!

The reason is that it may identify a type (or something that looks like a
type) in one file, and then carry this information over when processing a
different file.

For example, drivers/staging/media/bcm2048/radio-bcm2048.c contains this
line (in a macro):

	size value;

and drivers/staging/media/davinci_vpfe/vpfe_video.c has this line:

	while (size * *nbuffers > vpfe_dev->video_limit)

If checkpatch processes these 2 files in a single command like:
	./scripts/checkpatch.pl -f $file1 $file2
the (spurious) "size" type detected in the first file will cause it to flag
the second file for improper use of the pointer dereference operator.

To fix this, store types and modifiers found in a file in separate arrays
from built-in ones, and reset the arrays of types and modifiers found in
files at the beginning of each new source file.
Signed-off-by: NAlex Dowad <alexinbeijing@gmail.com>
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NAndy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Using declarations like u_int16_t in kernel code is not preferred.

Suggest the kernel sized types instead of the c99 types when not in the
uapi directory.

Add a $typeC99Typedefs variable for the types to check and neaten the
other typedef variables.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Linus sayeth:

: Pretty much every single time people use this "if
: (waitqueue_active())" model, it tends to be a bug, because it means
: that there is zero serialization with people who are just about to go
: to sleep. It's fundamentally racy against all the "wait_event()" loops
: that carefully do memory barriers between testing conditions and going
: to sleep, because the memory barriers now don't exist on the waking
: side.
:
: So I'm making a new rule: if you use waitqueue_active(), I want an
: explanation for why it's not racy with the waiter. A big comment about
: the memory ordering, or about higher-level locks that are held by the
: caller, or something.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix kernel-doc format validation to be able to use kernel-doc script for
checking it.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This makes a very large function a little smaller.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In one case, we eliminate a local variable; in the other a strlen()
call and some .text.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's no point in starting over when we meet a '/'.  This also
eliminates a stack variable and a little .text.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This eliminates a little .text and avoids repeating the strchr call when
we meet a '!' (which will happen at least once).
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's probably not many slashes in the name, but starting over when
we see one feels wrong.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Part of the disassembly of do_blk_trace_setup:

    231b:       e8 00 00 00 00          callq  2320 <do_blk_trace_setup+0x50>
                        231c: R_X86_64_PC32     strlen+0xfffffffffffffffc
    2320:       eb 0a                   jmp    232c <do_blk_trace_setup+0x5c>
    2322:       66 0f 1f 44 00 00       nopw   0x0(%rax,%rax,1)
    2328:       48 83 c3 01             add    $0x1,%rbx
    232c:       48 39 d8                cmp    %rbx,%rax
    232f:       76 47                   jbe    2378 <do_blk_trace_setup+0xa8>
    2331:       41 80 3c 1c 2f          cmpb   $0x2f,(%r12,%rbx,1)
    2336:       75 f0                   jne    2328 <do_blk_trace_setup+0x58>
    2338:       41 c6 04 1c 5f          movb   $0x5f,(%r12,%rbx,1)
    233d:       4c 89 e7                mov    %r12,%rdi
    2340:       e8 00 00 00 00          callq  2345 <do_blk_trace_setup+0x75>
                        2341: R_X86_64_PC32     strlen+0xfffffffffffffffc
    2345:       eb e1                   jmp    2328 <do_blk_trace_setup+0x58>

Yep, that's right: gcc isn't smart enough to realize that replacing '/' by
'_' cannot change the strlen(), so we call it again and again (at least
when a '/' is found).  Even if gcc were that smart, this construction
would still loop over the string twice, once for the initial strlen() call
and then the open-coded loop.

Let's simply use strreplace() instead.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Liked-by: NJens Axboe <axboe@fb.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's no point in starting over every time we see a ','...
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Strings are sometimes sanitized by replacing a certain character (often
'/') by another (often '!').  In a few places, this is done the same way
Schlemiel the Painter would do it.  Others are slightly smarter but still
do multiple strchr() calls.  Introduce strreplace() to do this using a
single function call and a single pass over the string.

One would expect the return value to be one of three things: void, s, or
the number of replacements made.  I chose the fourth, returning a pointer
to the end of the string.  This is more likely to be useful (for example
allowing the caller to avoid a strlen call).
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently we use per-cpu array to hold pointers to preallocated nodes.
Let's replace it with linked list.  On x86_64 it saves 256 bytes in
per-cpu ELF section which may translate into freeing up 2MB of memory for
NR_CPUS==8192.

[akpm@linux-foundation.org: fix comment, coding style]
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bitmap_print_to_pagebuf uses scnprintf to copy the cpumask/list to page
buffer.  It handles the newline and trailing null character explicitly.

It's unnecessary and also partially duplicated as scnprintf already adds
trailing null character.  The newline can be passed through format
string to scnprintf.  This patch does that simplification.

However theoretically there's one behavior difference: when the buffer
is too small, the original code would still output '\n' at the end while
the new code(with this patch) would just continue to print the formatted
string.  Since this function is dealing with only page buffers, it's
highly unlikely to hit that corner case.

This patch will help in auditing the users of bitmap_print_to_pagebuf to
verify that the buffer passed is large enough and get rid of it
completely by replacing them with direct scnprintf()

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Suggested-by: NPawel Moll <Pawel.Moll@arm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In case the call side is not providing a swap function, we either use a
32 bit or a generic swap function.  When swapping around pointers on 64
bit architectures falling back to use the generic swap function seems
like an unnecessary waste.

There at least 9 users ('sort' is of difficult to grep for) of sort()
and all of them use the sort function without a customized swap
function.  Furthermore, they are all using pointers to swap around:

arch/x86/kernel/e820.c:sanitize_e820_map()
arch/x86/mm/extable.c:sort_extable()
drivers/acpi/fan.c:acpi_fan_get_fps()
fs/btrfs/super.c:btrfs_descending_sort_devices()
fs/xfs/libxfs/xfs_dir2_block.c:xfs_dir2_sf_to_block()
kernel/range.c:clean_sort_range()
mm/memcontrol.c:__mem_cgroup_usage_register_event()
sound/pci/hda/hda_auto_parser.c:snd_hda_parse_pin_defcfg()
sound/pci/hda/hda_auto_parser.c:sort_pins_by_sequence()

Obviously, we could improve the swap for other sizes as well
but this is overkill at this point.

A simple test shows sorting a 400 element array (try to stay in one
page) with either with u32_swap() or u64_swap() show that the theory
actually works. This test was done on a x86_64 (Intel Xeon E5-4610)
machine.

- swap_32:

NumSamples = 100; Min = 48.00; Max = 49.00
Mean = 48.320000; Variance = 0.217600; SD = 0.466476; Median 48.000000
each * represents a count of 1
   48.0000 -    48.1000 [    68]: ********************************************************************
   48.1000 -    48.2000 [     0]:
   48.2000 -    48.3000 [     0]:
   48.3000 -    48.4000 [     0]:
   48.4000 -    48.5000 [     0]:
   48.5000 -    48.6000 [     0]:
   48.6000 -    48.7000 [     0]:
   48.7000 -    48.8000 [     0]:
   48.8000 -    48.9000 [     0]:
   48.9000 -    49.0000 [    32]: ********************************

- swap_64:

NumSamples = 100; Min = 44.00; Max = 63.00
Mean = 48.250000; Variance = 18.687500; SD = 4.322904; Median 47.000000
each * represents a count of 1
   44.0000 -    45.9000 [    15]: ***************
   45.9000 -    47.8000 [    37]: *************************************
   47.8000 -    49.7000 [    39]: ***************************************
   49.7000 -    51.6000 [     0]:
   51.6000 -    53.5000 [     0]:
   53.5000 -    55.4000 [     0]:
   55.4000 -    57.3000 [     0]:
   57.3000 -    59.2000 [     1]: *
   59.2000 -    61.1000 [     3]: ***
   61.1000 -    63.0000 [     5]: *****

- swap_72:

NumSamples = 100; Min = 53.00; Max = 71.00
Mean = 55.070000; Variance = 21.565100; SD = 4.643824; Median 53.000000
each * represents a count of 1
   53.0000 -    54.8000 [    73]: *************************************************************************
   54.8000 -    56.6000 [     9]: *********
   56.6000 -    58.4000 [     9]: *********
   58.4000 -    60.2000 [     0]:
   60.2000 -    62.0000 [     0]:
   62.0000 -    63.8000 [     0]:
   63.8000 -    65.6000 [     0]:
   65.6000 -    67.4000 [     1]: *
   67.4000 -    69.2000 [     4]: ****
   69.2000 -    71.0000 [     4]: ****

- test program:

static int cmp_32(const void *a, const void *b)
{
	u32 l = *(u32 *)a;
	u32 r = *(u32 *)b;

	if (l < r)
		return -1;
	if (l > r)
		return 1;
	return 0;
}

static int cmp_64(const void *a, const void *b)
{
	u64 l = *(u64 *)a;
	u64 r = *(u64 *)b;

	if (l < r)
		return -1;
	if (l > r)
		return 1;
	return 0;
}

static int cmp_72(const void *a, const void *b)
{
	u32 l = get_unaligned((u32 *) a);
	u32 r = get_unaligned((u32 *) b);

	if (l < r)
		return -1;
	if (l > r)
		return 1;
	return 0;
}

static void init_array32(void *array)
{
	u32 *a = array;
	int i;

	a[0] = 3821;
	for (i = 1; i < ARRAY_ELEMENTS; i++)
		a[i] = next_pseudo_random32(a[i-1]);
}

static void init_array64(void *array)
{
	u64 *a = array;
	int i;

	a[0] = 3821;
	for (i = 1; i < ARRAY_ELEMENTS; i++)
		a[i] = next_pseudo_random32(a[i-1]);
}

static void init_array72(void *array)
{
	char *p;
	u32 v;
	int i;

	v = 3821;
	for (i = 0; i < ARRAY_ELEMENTS; i++) {
		p = (char *)array + (i * 9);
		put_unaligned(v, (u32*) p);
		v = next_pseudo_random32(v);
	}
}

static void sort_test(void (*init)(void *array),
		      int (*cmp) (const void *, const void *),
		      void *array, size_t size)
{
	ktime_t start, stop;
	int i;

	for (i = 0; i < 10000; i++) {
		init(array);

		local_irq_disable();
		start = ktime_get();

		sort(array, ARRAY_ELEMENTS, size, cmp, NULL);

		stop = ktime_get();
		local_irq_enable();

		if (i > 10000 - 101)
		  pr_info("%lld\n",  ktime_to_us(ktime_sub(stop, start)));
	}
}

static void *create_array(size_t size)
{
	void *array;

	array = kmalloc(ARRAY_ELEMENTS * size, GFP_KERNEL);
	if (!array)
		return NULL;

	return array;
}

static int perform_test(size_t size)
{
	void *array;

	array = create_array(size);
	if (!array)
		return -ENOMEM;

	pr_info("test element size %d bytes\n", (int)size);
	switch (size) {
	case 4:
		sort_test(init_array32, cmp_32, array, size);
		break;
	case 8:
		sort_test(init_array64, cmp_64, array, size);
		break;
	case 9:
		sort_test(init_array72, cmp_72, array, size);
		break;
	}
	kfree(array);

	return 0;
}

static int __init sort_tests_init(void)
{
	int err;

	err = perform_test(sizeof(u32));
	if (err)
		return err;

	err = perform_test(sizeof(u64));
	if (err)
		return err;

	err = perform_test(sizeof(u64)+1);
	if (err)
		return err;

	return 0;
}

static void __exit sort_tests_exit(void)
{
}

module_init(sort_tests_init);
module_exit(sort_tests_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Daniel Wagner");
MODULE_DESCRIPTION("sort perfomance tests");
Signed-off-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The test data arrays, containing pointers to test strings, are never
modified, so they can be const, too.  Hence mark them "const" and
"__initconst".

This moves 28 pointers from ".init.data" to ".init.rodata".
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in
the mask.  The same bug is visible in cpumask_parselist() since it is
layered on top of the bitmask code, e.g.  if you boot with "isolcpus=",
you will actually end up with cpu zero isolated.

The bug was introduced in commit 4b060420 ("bitmap, irq: add
smp_affinity_list interface to /proc/irq") when bitmap_parselist() was
generalized to support userspace as well as kernelspace.

Fixes: 4b060420 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reported-by: NRob Landley <rob@landley.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This makes it easier to copy/paste names with periods to email clients.

All the other names with commas already have quotation marks.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This makes it easier to copy/paste names with periods to email clients.

All the other names with periods already have quotation marks.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a few inconsistent annotations to show that the alsa-devel mailing
list is moderated for non-subscribers.
Signed-off-by: NJim Davis <jim.epost@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Perl 5.22 emits a deprecated message when "\C" is used in a regex.  Perl
5.24 will disallow it altogether.

Fix it by using [A-Z] instead of \C.
Signed-off-by: NJoe Perches <joe@perches.com>
Reported-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu>
Tested-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Section headers can be quite long and some are very long and duplicated
for many initial characters.

The current maximum length emitted for a section header is 20 bytes (or
17 bytes then ...  when the section header length is > 20).

Change that length to 50 so more of the section is shown.

Example new output:
$ ./scripts/get_maintainer.pl -f drivers/net/ethernet/broadcom/bnx2x/
Ariel Elior <ariel.elior@qlogic.com> (supporter:BROADCOM BNX2X 10 GIGABIT ETHERNET DRIVER)
netdev@vger.kernel.org (open list:BROADCOM BNX2X 10 GIGABIT ETHERNET DRIVER)
linux-kernel@vger.kernel.org (open list)

Old:
$ ./scripts/get_maintainer.pl -f drivers/net/ethernet/broadcom/bnx2x/
Ariel Elior <ariel.elior@qlogic.com> (supporter:BROADCOM BNX2X 10...)
netdev@vger.kernel.org (open list:BROADCOM BNX2X 10...)
linux-kernel@vger.kernel.org (open list)
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some people prefer not to be cc'd on patches.  Add an ability to have a
file (.get_maintainer.ignore) with names and email addresses that are
excluded from being listed except when specifically listed as a maintainer
in a section.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch fixes drawbacks in heck_syslog_permissions() noticed by AKPM:
"from_file handling makes me cry.

That's not a boolean - it's an enumerated value with two values
currently defined.

But the code in check_syslog_permissions() treats it as a boolean and
also hardwires the knowledge that SYSLOG_FROM_PROC == 1 (or == `true`).

And the name is wrong: it should be called from_proc to match
SYSLOG_FROM_PROC."
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The final version of commit 637241a9 ("kmsg: honor dmesg_restrict
sysctl on /dev/kmsg") lost few hooks, as result security_syslog() are
processed incorrectly:

- open of /dev/kmsg checks syslog access permissions by using
  check_syslog_permissions() where security_syslog() is not called if
  dmesg_restrict is set.

- syslog syscall and /proc/kmsg calls do_syslog() where security_syslog
  can be executed twice (inside check_syslog_permissions() and then
  directly in do_syslog())

With this patch security_syslog() is called once only in all
syslog-related operations regardless of dmesg_restrict value.

Fixes: 637241a9 ("kmsg: honor dmesg_restrict sysctl on /dev/kmsg")
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

printk logbuf keeps various metadata and optional key=value dictionary for
structured messages, both of which are stripped when messages are handed
to regular console drivers.

It can be useful to have this metadata and dictionary available to
netconsole consumers.  This obviously makes logging via netconsole more
complete and the sequence number in particular is useful in environments
where messages may be lost or reordered in transit - e.g.  when netconsole
is used to collect messages in a large cluster where packets may have to
travel congested hops to reach the aggregator.  The lost and reordered
messages can easily be identified and handled accordingly using the
sequence numbers.

printk recently added extended console support which can be selected by
setting CON_EXTENDED flag.  From console driver side, not much changes.
The only difference is that the text passed to the write callback is
formatted the same way as /dev/kmsg.

This patch implements extended console support for netconsole which can be
enabled by either prepending "+" to a netconsole boot param entry or
echoing 1 to "extended" file in configfs.  When enabled, netconsole
transmits extended log messages with headers identical to /dev/kmsg
output.

There's one complication due to message fragments.  netconsole limits the
maximum message size to 1k and messages longer than that are split into
multiple fragments.  As all extended console messages should carry
matching headers and be uniquely identifiable, each extended message
fragment carries full copy of the metadata and an extra header field to
identify the specific fragment.  The optional header is of the form
"ncfrag=OFF/LEN" where OFF is the byte offset into the message body and
LEN is the total length.

To avoid unnecessarily making printk format extended messages, Extended
netconsole is registered with printk when the first extended netconsole is
configured.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, each dynamic netconsole_target uses its own separate mutex to
synchronize the configuration operations.

This patch replaces the per-netconsole_target mutexes with a single
mutex - dynamic_netconsole_mutex.  The reduced granularity doesn't hurt
anything, the code is minutely simpler and this'd allow adding
operations which should be synchronized across all dynamic netconsoles.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

netconsole uses both bool and int for boolean values.  Let's convert
nt->enabled to bool for consistency.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

write_msg() grabs target_list_lock and walks target_list invoking
netpool_send_udp() on each target.  Curiously, it protects each iteration
with netconsole_target_get/put() even though it never releases
target_list_lock which protects all the members.

While this doesn't harm anything, it doesn't serve any purpose either.
The items on the list can't go away while target_list_lock is held.
Remove the unnecessary get/put pair.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

printk log_buf keeps various metadata for each message including its
sequence number and timestamp.  The metadata is currently available only
through /dev/kmsg and stripped out before passed onto console drivers.  We
want this metadata to be available to console drivers too so that console
consumers can get full information including the metadata and dictionary,
which among other things can be used to detect whether messages got lost
in transit.

This patch implements support for extended console drivers.  Consoles can
indicate that they want extended messages by setting the new CON_EXTENDED
flag and they'll be fed messages formatted the same way as /dev/kmsg.

 "<level>,<sequnum>,<timestamp>,<contflag>;<message text>\n"

If extended consoles exist, in-kernel fragment assembly is disabled.  This
ensures that all messages emitted to consoles have full metadata including
sequence number.  The contflag carries enough information to reassemble
the fragments from the reader side trivially.  Note that this only affects
/dev/kmsg.  Regular console and /proc/kmsg outputs are not affected by
this change.

* Extended message formatting for console drivers is enabled iff there
  are registered extended consoles.

* Comment describing /dev/kmsg message format updated to add missing
  contflag field and help distinguishing variable from verbatim terms.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: NPetr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The extended message formatting used for /dev/kmsg will be used implement
extended consoles.  Factor out msg_print_ext_header() and
msg_print_ext_body() from devkmsg_read().

This is pure restructuring.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: NPetr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patchset updates netconsole so that it can emit messages with the
same header as used in /dev/kmsg which gives neconsole receiver full log
information which enables things like structured logging and detection
of lost messages.

This patch (of 7):

devkmsg_read() uses 8k buffer and assumes that the formatted output
message won't overrun which seems safe given LOG_LINE_MAX, the current use
of dict and the escaping method being used; however, we're planning to use
devkmsg formatting wider and accounting for the buffer size properly isn't
that complicated.

This patch defines CONSOLE_EXT_LOG_MAX as 8192 and updates devkmsg_read()
so that it limits output accordingly.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: NPetr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The KERN_INFO prefix is being prepended to KERN_DEBUG when using the
dprink macro, Remove it as it is extraneous since we are printing the
message out as debug via dprintk().

Fixes smatch warning:

drivers/misc/altera-stapl/altera.c:2454 altera_init()
   warn: KERN_* level not at start of string
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Igor M. Liplianin <liplianin@netup.ru>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

clone has some of the quirkiest syscall handling in the kernel, with a
pile of special cases, historical curiosities, and architecture-specific
calling conventions.  In particular, clone with CLONE_SETTLS accepts a
parameter "tls" that the C entry point completely ignores and some
assembly entry points overwrite; instead, the low-level arch-specific
code pulls the tls parameter out of the arch-specific register captured
as part of pt_regs on entry to the kernel.  That's a massive hack, and
it makes the arch-specific code only work when called via the specific
existing syscall entry points; because of this hack, any new clone-like
system call would have to accept an identical tls argument in exactly
the same arch-specific position, rather than providing a unified system
call entry point across architectures.

The first patch allows architectures to handle the tls argument via
normal C parameter passing, if they opt in by selecting
HAVE_COPY_THREAD_TLS.  The second patch makes 32-bit and 64-bit x86 opt
into this.

These two patches came out of the clone4 series, which isn't ready for
this merge window, but these first two cleanup patches were entirely
uncontroversial and have acks.  I'd like to go ahead and submit these
two so that other architectures can begin building on top of this and
opting into HAVE_COPY_THREAD_TLS.  However, I'm also happy to wait and
send these through the next merge window (along with v3 of clone4) if
anyone would prefer that.

This patch (of 2):

clone with CLONE_SETTLS accepts an argument to set the thread-local
storage area for the new thread.  sys_clone declares an int argument
tls_val in the appropriate point in the argument list (based on the
various CLONE_BACKWARDS variants), but doesn't actually use or pass along
that argument.  Instead, sys_clone calls do_fork, which calls
copy_process, which calls the arch-specific copy_thread, and copy_thread
pulls the corresponding syscall argument out of the pt_regs captured at
kernel entry (knowing what argument of clone that architecture passes tls
in).

Apart from being awful and inscrutable, that also only works because only
one code path into copy_thread can pass the CLONE_SETTLS flag, and that
code path comes from sys_clone with its architecture-specific
argument-passing order.  This prevents introducing a new version of the
clone system call without propagating the same architecture-specific
position of the tls argument.

However, there's no reason to pull the argument out of pt_regs when
sys_clone could just pass it down via C function call arguments.

Introduce a new CONFIG_HAVE_COPY_THREAD_TLS for architectures to opt into,
and a new copy_thread_tls that accepts the tls parameter as an additional
unsigned long (syscall-argument-sized) argument.  Change sys_clone's tls
argument to an unsigned long (which does not change the ABI), and pass
that down to copy_thread_tls.

Architectures that don't opt into copy_thread_tls will continue to ignore
the C argument to sys_clone in favor of the pt_regs captured at kernel
entry, and thus will be unable to introduce new versions of the clone
syscall.

Patch co-authored by Josh Triplett and Thiago Macieira.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Acked-by: NAndy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>