Commit Graph

779619 Commits

Author SHA1 Message Date
Luc Van Oostenryck
6ad018e3ca init/: remove ineffective sparse disabling
Sparse checking used to be disabled on init/do_mounts.c and a few related
files because "Many of the syscalls used in this file expect some of the
arguments to be __user pointers not __kernel pointers".

However since 28128c61e ("kconfig.h: Include compiler types to avoid
missed struct attributes") the checks are, in fact, not disabled anymore
because of the more early include of "linux/compiler_types.h"

So remove the now ineffective #undefery that was done to disable these
warnings, as well as the associated comment.

Link: http://lkml.kernel.org/r/20180617115355.53799-1-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Davidlohr Bueso
992991c03c fs/eventpoll.c: simplify ep_is_linked() callers
Instead of having each caller pass the rdllink explicitly, just have
ep_is_linked() pass it while the callers just need the epi pointer.  This
helper is all about the rdllink, and this change, furthermore, improves
the function's self documentation.

Link: http://lkml.kernel.org/r/20180727053432.16679-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Davidlohr Bueso
679abf381a fs/eventpoll.c: loosen irq safety in ep_poll()
Similar to other calls, ep_poll() is not called with interrupts disabled,
and we can therefore avoid the irq save/restore dance and just disable
local irqs.  In fact, the call should never be called in irq context at
all, considering that the only path is

epoll_wait(2) -> do_epoll_wait() -> ep_poll().

When running on a 2 socket 40-core (ht) IvyBridge a common pipe based
epoll_wait(2) microbenchmark, the following performance improvements are
seen:

    # threads       vanilla         dirty
	 1          1805587	    2106412
	 2          1854064	    2090762
	 4          1805484	    2017436
	 8          1751222	    1974475
	 16         1725299	    1962104
	 32         1378463	    1571233
	 64          787368	     900784

Which is a pretty constantly near 15%.

Also add a lockdep check such that we detect any mischief before
deadlocking.

Link: http://lkml.kernel.org/r/20180727053432.16679-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Davidlohr Bueso
514056d506 fs/eventpoll.c: simply CONFIG_NET_RX_BUSY_POLL ifdefery
... 'tis easier on the eye.

[akpm@linux-foundation.org: use inlines rather than macros]
Link: http://lkml.kernel.org/r/20180725185620.11020-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Rob Herring
133712a2ec checkpatch: DT bindings should be a separate patch
Devicetree bindings should be their own patch as documented in
Documentation/devicetree/bindings/submitting-patches.txt section I.1.
This is because bindings are logically independent from a driver
implementation, they have a different maintainer (even though they often
are applied via the same tree), and it makes for a cleaner history in the
DT only tree created with git-filter-branch.

[robh@kernel.org: add doc pointer to warning, simplify logic]
  Link: http://lkml.kernel.org/r/20180810170513.26284-1-robh@kernel.org
[robh@kernel.org: v3]
  Link: http://lkml.kernel.org/r/20180810225049.20452-1-robh@kernel.org
Link: http://lkml.kernel.org/r/20180809205032.22205-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Joe Perches
809e082e97 checkpatch: warn on unnecessary int declarations
On Sun, 2018-08-05 at 08:52 -0700, Linus Torvalds wrote:
> "long unsigned int" isn't _technically_ wrong. But we normally
> call that type "unsigned long".

So add a checkpatch test for it.

Link: http://lkml.kernel.org/r/7bbd97dc0a1e5896a0251fada7bb68bb33643f77.camel@perches.com
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>
2018-08-22 10:52:49 -07:00
Michal Zylowski
6ad724e2a4 checkpatch: check for space after "else" keyword
Current checkpatch implementation permits notation like

	} else{

in kernel code.  It looks like oversight and inconsistency in checkpatch
rules (e.g.  instruction like 'do' is tested).

Add regex for checking space after 'else' keyword and trigger error if
space is not present.

Link: http://lkml.kernel.org/r/1533545753-8870-1-git-send-email-michal.zylowski@intel.com
Signed-off-by: Michal Zylowski <michal.zylowski@intel.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Joe Perches
5629411279 checkpatch: fix SPDX license check with --root=<path>
checkpatch uses the in-kernel script spdxcheck.py to validate the specific
license in a file or script.

This check can currently fail for a couple reasons:

o spdxcheck.py assumes the existence of git tree that may not
  exist for a bare source tree from something like a tarball
o the spdxcheck.py must be run from the top level root directory

So add a git existence test and set the subprocess subdirectory.

Link: http://lkml.kernel.org/r/2b32864324ae9c92948b002ec4c0c22409ed98f1.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Charlemagne Lasse <charlemagnelasse@gmail.com>
Tested-by: Charlemagne Lasse <charlemagnelasse@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Joe Perches
490b292c83 checkpatch: warn when a patch doesn't have a description
Potential patches should have a commit description.  Emit a warning when
there isn't one.

[akpm@linux-foundation.org: s/else if/elsif/]
Link: http://lkml.kernel.org/r/1b099f4d8373aa583a17011992676bf0f3f09eee.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Prakruthi Deepak Heragu
60f8901055 checkpatch: check for #if 0/#if 1
The #if 0 or #if 1 is used to toggle features. Warn if #if 0 or #if 1
is present and suggest that they can be removed.

[akpm@linux-foundation.org: fix spacing around periods, per Joe\
Link: http://lkml.kernel.org/r/1532625218-24321-1-git-send-email-pheragu@codeaurora.org
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
4cab63cea3 checkpatch: fix krealloc reuse test
The current krealloc test does not function correctly when the temporary
pointer return name contains the original pointer name.

Fix that by maximally matching the return pointer name and the original
pointer name and doing a separate comparison of the both names.

Link: http://lkml.kernel.org/r/e617ecb8c019a9c4c56540a1bec16c8aed43a4e4.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Manish Narani <manish.narani@xilinx.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
3b6e8ac9e7 checkpatch: validate SPDX license with spdxcheck.py
Use the existing scripts/spdxcheck.py to validate any
SPDX-License-Identifier found in line 1 or 2 of patches or files.

Miscellanea:

o Properly indent the existing SPDX-License-Identifier block.

Link: http://lkml.kernel.org/r/05b832407b24e0a27e419906187cd863bc1617c7.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
8c8c45cfdd checkpatch: fix macro argument reuse test
Multiple line macro definitions where the arguments are separated by line
continuations can cause checkpatch to emit invalid syntax regex tests.

This can occur when a single argument is modified in a part of a patch.

For example: (to not add a diff in the commit message)

$ ./scripts/checkpatch.pl --git db023296f0
Unterminated \g... pattern in regex; <very long regex omitted>

And, the test does not work correctly when these arguments are all new as
the initial patch line addition "+" is used in the argument name.

Fix this by stripping the line continuations and any "+" from the list of
arguments.

Link: http://lkml.kernel.org/r/86cdb43a4db70670c102020093f7fb4eb3003e01.camel@perches.com
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>
2018-08-22 10:52:48 -07:00
Geert Uytterhoeven
cd2614967d checkpatch: warn if missing author Signed-off-by
Print a warning if none of the Signed-off-by lines cover the patch author.

Non-ASCII quoted printable encoding in From: headers and (lack of) double
quotes are handled.  Split From: headers are not fully handled: only the
first part is compared.

[geert+renesas@glider.be: only encode UTF-8 quoted printable mail headers]
  Link: http://lkml.kernel.org/r/20180718145254.4770-1-geert+renesas@glider.be
Link: http://lkml.kernel.org/r/20180712100323.26684-1-geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Joe Perches <joe@perches.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Geert Uytterhoeven
33aa4597dd checkpatch: update section keywords
As of commit bd721ea73e ("treewide: replace obsolete _refok by
__ref"), __init_refok no longer exists, so it can be removed.  While at
it, add the modern variants that were still missing.

Link: http://lkml.kernel.org/r/20180706084205.26367-1-geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
5b57980de6 checkpatch: improve runtime execution speed a little
checkpatch repeatedly uses a runtime minimum version check that validates
the minimum perl version required for a regex match by using a "$^V ge
5.10.0" runtime string match.

Only perform that minimum version test once and store the result to reduce
string matching time.

This reduces runtime execution time for patches or files with high line
counts.

An example runtime improvement:

new: $ time ./scripts/checkpatch.pl -f drivers/net/ethernet/intel/i40e/i40e_main.c > /dev/null

real	0m11.856s
user	0m11.831s
sys	0m0.025s

old: $ time ./scripts/checkpatch.pl -f drivers/net/ethernet/intel/i40e/i40e_main.c > /dev/null

real	0m13.330s
user	0m13.282s
sys	0m0.049s

Link: http://lkml.kernel.org/r/db21aa9703833bad65ab70cc4e8a78da5b399138.camel@perches.com
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>
2018-08-22 10:52:48 -07:00
Joe Perches
79682c0c00 checkpatch: add --fix for CONCATENATED_STRING and STRING_FRAGMENTS
Add the ability to --fix these string issues.

e.g.:
	printk(KERN_INFO"bar" "baz"QUX);
converts to
	printk(KERN_INFO "barbaz" QUX);

Link: http://lkml.kernel.org/r/a9fb505ccfedffc5869d08832a7ff05a21d85621.camel@perches.com
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>
2018-08-22 10:52:48 -07:00
Joe Perches
d729593e49 checkpatch: add a --strict test for structs with bool member definitions
A struct with a bool member can have different sizes on various
architectures because neither bool size nor alignment is standardized.

So emit a message on the use of bool in structs only in .h files and not
.c files.

There is the real possibility that this test could have a false positive
when a bool is declared as an automatic, so limit the test to .h files
where the only false positive is for declarations in static inline
functions.

Link: http://lkml.kernel.org/r/95477c93db187bab6da8a8ba7c57836868446179.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Christophe Leroy
de9df3993c lib/test_hexdump.c: fix failure on big endian cpu
On a big endian cpu, test_hexdump fails as follows.  The logs show that
bytes are expected in reversed order.

  [...]
  test_hexdump: Len: 24 buflen: 130 strlen: 97
  test_hexdump: Result: 97 'be32db7b 0a1893b2 70bac424 7d83349b a69c31ad 9c0face9                    .2.{....p..$}.4...1.....'
  test_hexdump: Expect: 97 '7bdb32be b293180a 24c4ba70 9b34837d ad319ca6 e9ac0f9c                    .2.{....p..$}.4...1.....'
  test_hexdump: Len: 8 buflen: 130 strlen: 77
  test_hexdump: Result: 77 'be32db7b0a1893b2                                                     .2.{....'
  test_hexdump: Expect: 77 'b293180a7bdb32be                                                     .2.{....'
  test_hexdump: Len: 6 buflen: 131 strlen: 87
  test_hexdump: Result: 87 'be32 db7b 0a18                                                                   .2.{..'
  test_hexdump: Expect: 87 '32be 7bdb 180a                                                                   .2.{..'
  test_hexdump: Len: 24 buflen: 131 strlen: 97
  test_hexdump: Result: 97 'be32db7b 0a1893b2 70bac424 7d83349b a69c31ad 9c0face9                    .2.{....p..$}.4...1.....'
  test_hexdump: Expect: 97 '7bdb32be b293180a 24c4ba70 9b34837d ad319ca6 e9ac0f9c                    .2.{....p..$}.4...1.....'
  test_hexdump: Len: 32 buflen: 131 strlen: 101
  test_hexdump: Result: 101 'be32db7b0a1893b2 70bac4247d83349b a69c31ad9c0face9 4cd1199943b1af0c  .2.{....p..$}.4...1.....L...C...'
  test_hexdump: Expect: 101 'b293180a7bdb32be 9b34837d24c4ba70 e9ac0f9cad319ca6 0cafb1439919d14c  .2.{....p..$}.4...1.....L...C...'
  test_hexdump: failed 801 out of 1184 tests

This patch fixes it.

Link: http://lkml.kernel.org/r/f3112437f62c2f48300535510918e8be1dceacfb.1533610877.git.christophe.leroy@c-s.fr
Fixes: 64d1d77a44 ("hexdump: introduce test suite")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: rashmica <rashmicy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Andy Shevchenko
fd7338ef62 lib/Kconfig: remove 'default n' for tests
It seems contributors follow the style of Kconfig entries where explicit
'default n' is present.  The default 'default' is 'n' already, thus, drop
these lines from Kconfig to make it more clear.

Link: http://lkml.kernel.org/r/20180719085131.79541-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Coly Li
d23599630b bcache: use routines from lib/crc64.c for CRC64 calculation
Now we have crc64 calculation in lib/crc64.c, it is unnecessary for
bcache to use its own version.  This patch changes bcache code to use
crc64 routines in lib/crc64.c.

Link: http://lkml.kernel.org/r/20180718165545.1622-3-colyli@suse.de
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Noah Massey <noah.massey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Coly Li
feba04fd2c lib: add crc64 calculation routines
Patch series "add crc64 calculation as kernel library", v5.

This patchset adds basic implementation of crc64 calculation as a Linux
kernel library.  Since bcache already does crc64 by itself, this patchset
also modifies bcache code to use the new crc64 library routine.

Currently bcache is the only user of crc64 calculation, another potential
user is bcachefs which is on the way to be in mainline kernel.  Therefore
it makes sense to make crc64 calculation to be a public library.

bcache uses crc64 as storage checksum, if a change of crc lib routines
results an inconsistent result, the unmatched checksum may make bcache
'think' the on-disk is corrupted, such a change should be avoided or
detected as early as possible.  Therefore a patch is being prepared which
adds a crc test framework, to check consistency of different calculations.

This patch (of 2):

Add the re-write crc64 calculation routines for Linux kernel.  The CRC64
polynomical arithmetic follows ECMA-182 specification, inspired by CRC
paper of Dr.  Ross N.  Williams (see
http://www.ross.net/crc/download/crc_v3.txt) and other public domain
implementations.

All the changes work in this way,
- When Linux kernel is built, host program lib/gen_crc64table.c will be
  compiled to lib/gen_crc64table and executed.
- The output of gen_crc64table execution is an array called as lookup
  table (a.k.a POLY 0x42f0e1eba9ea369) which contain 256 64-bit long
  numbers, this table is dumped into header file lib/crc64table.h.
- Then the header file is included by lib/crc64.c for normal 64bit crc
  calculation.
- Function declaration of the crc64 calculation routines is placed in
  include/linux/crc64.h

Currently bcache is the only user of crc64_be(), another potential user is
bcachefs which is on the way to be in mainline kernel.  Therefore it makes
sense to move crc64 calculation into lib/crc64.c as public code.

[colyli@suse.de: fix review comments from v4]
  Link: http://lkml.kernel.org/r/20180726053352.2781-2-colyli@suse.de
Link: http://lkml.kernel.org/r/20180718165545.1622-2-colyli@suse.de
Signed-off-by: Coly Li <colyli@suse.de>
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Noah Massey <noah.massey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Colin Ian King
b15f5f1ae1 lib/test_debug_virtual.c: make struct pointer foo static
The pointer foo is local to the source and does not need to be
in global scope, so make it static.

Cleans up sparse warning:
symbol 'foo' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20180624112206.5722-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Chris Wilson
9144d75e22 include/linux/bitops.h: introduce BITS_PER_TYPE
net_dim.h has a rather useful extension to BITS_PER_BYTE to compute the
number of bits in a type (BITS_PER_BYTE * sizeof(T)), so promote the macro
to bitops.h, alongside BITS_PER_BYTE, for wider usage.

Link: http://lkml.kernel.org/r/20180706094458.14116-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andy Gospodarek <gospo@broadcom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Andy Shevchenko
ccf7a6d457 lib/bitmap.c: drop unnecessary 0 check for u32 array operations
nbits == 0 is safe to be supplied to the function body, so remove
unnecessary checks in bitmap_to_arr32() and bitmap_from_arr32().

Link: http://lkml.kernel.org/r/20180531131914.44352-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
0fbd75fd7f get_maintainer: allow option --mpath <directory> to read all files in <directory>
There is an external use case for multiple private MAINTAINER style files
in a separate directory.  Allow it.

--mpath has a default of "./MAINTAINERS".

The value entered can be either a file or a directory.

The behaviors are now:

--mpath <file>          Read only the specific file as <MAINTAINER_TYPE> file
--mpath <directory>     Read all files in <directory> as <MAINTAINER_TYPE> files
--mpath <directory> --find-maintainer-files
                        Recurse through <directory> and read all files named MAINTAINERS

Link: http://lkml.kernel.org/r/991b2f20112d53863cd79e61d908f1d26d3e1971.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Joe Perches
5f0baf95b1 get_maintainer.pl: add -mpath=<path or file> for MAINTAINERS file location
Add the ability to have an override for the location of the MAINTAINERS
file.

Miscellanea:

o Properly indent a few lines with leading spaces

Link: http://lkml.kernel.org/r/a86e69195076ed3c4c526fddc76b86c28e0a1e37.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:48 -07:00
Antonio Nino Diaz
31bb82c9ca get_maintainer: allow usage outside of kernel tree
Add option '--no-tree' to get_maintainer.pl script to allow using this
script in projects that aren't the Linux kernel if they use the same
format for their MAINTAINERS file.  This command is also available in
checkpatch.pl, for example.

Link: http://lkml.kernel.org/r/04452ac6-1575-f612-72c6-6ea88e70a9d5@arm.com
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.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>
2018-08-22 10:52:47 -07:00
Davidlohr Bueso
92e6417840 s/epoll: robustify irq safety with lockdep_assert_irqs_enabled()
Sprinkle lockdep_assert_irqs_enabled() checks in the functions that do not
save and restore interrupts when dealing with the ep->wq.lock.  These are
ep_scan_ready_list() and those called by epoll_ctl(): ep_insert, ep_modify
and ep_remove.

[akpm@linux-foundation.org: remove too-obvious comments]
Link: http://lkml.kernel.org/r/20180721183127.3busfa335zlcjeox@linux-r8p5
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Davidlohr Bueso
304b18b8d6 fs/epoll: loosen irq safety in epoll_insert() and epoll_remove()
Both functions are similar to the context of ep_modify(), called via
epoll_ctl(2).  Just like ep_modify(), saving and restoring interrupts is
an overkill in these calls as it will never be called with irqs disabled.
While ep_remove() can be called directly from EPOLL_CTL_DEL, it can also
be called when releasing the file, but this also complies with the above.

Link: http://lkml.kernel.org/r/20180720172956.2883-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Davidlohr Bueso
002b343669 fs/epoll: loosen irq safety in ep_scan_ready_list()
Patch series "fs/epoll: loosen irq safety when possible".

Both patches replace saving+restoring interrupts when taking the ep->lock
(now the waitqueue lock), with just disabling local irqs.  This shows
immediate performance benefits in patch 1 for an epoll workload running on
Xen.  The main concern we need to have with this sort of changes in epoll
is the ep_poll_callback() which is passed to the wait queue wakeup and is
done very often under irq context, this patch does not touch this call.

Patches have been tested pretty heavily with the customer workload,
microbenchmarks, ltp testcases and two high level workloads that use epoll
under the hood: nginx and libevent benchmarks.

This patch (of 2):

Saving and restoring interrupts in ep_scan_ready_list() is an
overkill as it is never called with interrupts disabled. Loosen
this to simply disabling local irqs such that archs where managing
irqs is expensive or virtual environments. This patch yields
some throughput improvements on a workload that is epoll intensive
running on a single Xen DomU.

1 Job	 7500	-->    8800 enq/s  (+17%)
2 Jobs	14000   -->   15200 enq/s  (+8%)
3 Jobs	20500	-->   22300 enq/s  (+8%)
4 Jobs	25000   -->   28000 enq/s  (+8-12)%

On bare metal:

For a 2-socket 40-core (ht) IvyBridge on a few workloads, unfortunately I
don't have a xen environment and the results for Xen I do have (which
numbers are in patch 1) I don't have the actual workload, so cannot
compare them directly.

1) Different configurations were used for a epoll_wait (pipes io)
   microbench (http://linux-scalability.org/epoll/epoll-test.c) and shows
   around a 7-10% improvement in overall total number of times the
   epoll_wait() loops when using both regular and nested epolls, so very
   raw numbers, but measurable nonetheless.

# threads	vanilla		dirty
     1		1677717		1805587
     2		1660510		1854064
     4		1610184		1805484
     8		1577696		1751222
     16		1568837		1725299
     32		1291532		1378463
     64		 752584		 787368

   Note that stddev is pretty small.

2) Another pipe test, which shows no real measurable improvement.
   (http://www.xmailserver.org/linux-patches/pipetest.c)

Link: http://lkml.kernel.org/r/20180720172956.2883-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Christoph Hellwig
e05a8e4d88 sched/wait: assert the wait_queue_head lock is held in __wake_up_common
Better ensure we actually hold the lock using lockdep than just commenting
on it.  Due to the various exported _locked interfaces it is far too easy
to get the locking wrong.

Link: http://lkml.kernel.org/r/20171214152344.6880-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Matthew Wilcox
c430d1e848 userfaultfd: use fault_wqh lock
The userfaultfd code currently uses the unlocked waitqueue helpers for
managing fault_wqh, but instead of holding the waitqueue lock for this
waitqueue around these calls, it the waitqueue lock of
fault_pending_wq, which is a different waitqueue instance.  Given that
the waitqueue is not exposed to the rest of the kernel this actually
works ok at the moment, but prevents the userfaultfd locking rules from
being enforced using lockdep.

Switch to the internally locked waitqueue helpers instead.  This means
that the lock inside fault_wqh now nests inside the fault_pending_wqh
lock, but that's not a problem since it was entirely unused before.

[hch@lst.de: slight changelog updates]
[rppt@linux.vnet.ibm.com: spotted changelog spellos]
Link: http://lkml.kernel.org/r/20171214152344.6880-3-hch@lst.de
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Christoph Hellwig
ee8ef0a4b1 epoll: use the waitqueue lock to protect ep->wq
Patch series "waitqueue lockdep annotation", v3.

This series adds a strategic lockdep_assert_held to __wake_up_common to
ensure callers really do hold the wait_queue_head lock when calling the
unlocked wake_up variants.  It turns out epoll did not do this for a
fairly common path (hit all the time by systemd during bootup), so the
second patch fixed this instance as well.

This patch (of 3):

The epoll code currently uses the unlocked waitqueue helpers for managing
ep->wq, but instead of holding the waitqueue lock around these calls, it
uses its own ep->lock spinlock.  Given that the waitqueue is not exposed
to the rest of the kernel this actually works ok at the moment, but
prevents the epoll locking rules from being enforced using lockdep.
Remove ep->lock and use the waitqueue lock to not only reduce the size of
struct eventpoll but also to make sure we can assert locking invariants in
the waitqueue code.

Link: http://lkml.kernel.org/r/20171214152344.6880-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Baron <jbaron@akamai.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
46e0c9be20 kernel: tracepoints: add support for relative references
To avoid the need for relocating absolute references to tracepoint
structures at boot time when running relocatable kernels (which may
take a disproportionate amount of space), add the option to emit
these tables as relative references instead.

Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
c9d8b55fa0 PCI: Add support for relative addressing in quirk tables
Allow the PCI quirk tables to be emitted in a way that avoids absolute
references to the hook functions. This reduces the size of the entries,
and, more importantly, makes them invariant under runtime relocation
(e.g., for KASLR)

Link: http://lkml.kernel.org/r/20180704083651.24360-6-ard.biesheuvel@linaro.org
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
1b1eeca7e4 init: allow initcall tables to be emitted using relative references
Allow the initcall tables to be emitted using relative references that
are only half the size on 64-bit architectures and don't require fixups
at runtime on relocatable kernels.

Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.org
Acked-by: James Morris <james.morris@microsoft.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
7290d58095 module: use relative references for __ksymtab entries
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries,
each consisting of two 64-bit fields containing absolute references, to
the symbol itself and to a char array containing its name, respectively.

When we build the same configuration with KASLR enabled, we end up with an
additional ~192 KB of relocations in the .init section, i.e., one 24 byte
entry for each absolute reference, which all need to be processed at boot
time.

Given how the struct kernel_symbol that describes each entry is completely
local to module.c (except for the references emitted by EXPORT_SYMBOL()
itself), we can easily modify it to contain two 32-bit relative references
instead.  This reduces the size of the __ksymtab section by 50% for all
64-bit architectures, and gets rid of the runtime relocations entirely for
architectures implementing KASLR, either via standard PIE linking (arm64)
or using custom host tools (x86).

Note that the binary search involving __ksymtab contents relies on each
section being sorted by symbol name.  This is implemented based on the
input section names, not the names in the ksymtab entries, so this patch
does not interfere with that.

Given that the use of place-relative relocations requires support both in
the toolchain and in the module loader, we cannot enable this feature for
all architectures.  So make it dependent on whether
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined.

Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
f922c4abdf module: allow symbol exports to be disabled
To allow existing C code to be incorporated into the decompressor or the
UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx
declarations into nops, and #define it in places where such exports are
undesirable.  Note that this gets rid of a rather dodgy redefine of
linux/export.h's header guard.

Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Ard Biesheuvel
271ca78877 arch: enable relative relocations for arm64, power and x86
Patch series "add support for relative references in special sections", v10.

This adds support for emitting special sections such as initcall arrays,
PCI fixups and tracepoints as relative references rather than absolute
references.  This reduces the size by 50% on 64-bit architectures, but
more importantly, it removes the need for carrying relocation metadata for
these sections in relocatable kernels (e.g., for KASLR) that needs to be
fixed up at boot time.  On arm64, this reduces the vmlinux footprint of
such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs
4 byte relative reference)

Patch #3 was sent out before as a single patch.  This series supersedes
the previous submission.  This version makes relative ksymtab entries
dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather
than trying to infer from kbuild test robot replies for which
architectures it should be blacklisted.

Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS,
and sets it for the main architectures that are expected to benefit the
most from this feature, i.e., 64-bit architectures or ones that use
runtime relocations.

Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of
ksymtab/kcrctab sections in decompressor and EFI stub objects when
rebuilding existing C files to run in a different context.

Patches #4 - #6 implement relative references for initcalls, PCI fixups
and tracepoints, respectively, all of which produce sections with order
~1000 entries on an arm64 defconfig kernel with tracing enabled.  This
means we save about 28 KB of vmlinux space for each of these patches.

[From the v7 series blurb, which included the jump_label patches as well]:

  For the arm64 kernel, all patches combined reduce the memory footprint
  of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has
  KASLR enabled), of which ~1 MB is the size reduction of the RELA section
  in .init, and the remaining 300 KB is reduction of .text/.data.

This patch (of 6):

Before updating certain subsystems to use place relative 32-bit
relocations in special sections, to save space and reduce the number of
absolute relocations that need to be processed at runtime by relocatable
kernels, introduce the Kconfig symbol and define it for some architectures
that should be able to support and benefit from it.

Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: James Morris <jmorris@namei.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Cc: James Morris <james.morris@microsoft.com>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Colin Ian King
bc63804619 spelling.txt: add more spellings to spelling.txt
Here are some of the more common spelling mistakes and typos that I've
found while fixing up spelling mistakes in the kernel over the past 6
months.

Link: http://lkml.kernel.org/r/20180629150603.1159-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.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>
2018-08-22 10:52:47 -07:00
Dmitry Vyukov
a2e5144538 kernel/hung_task.c: allow to set checking interval separately from timeout
Currently task hung checking interval is equal to timeout, as the result
hung is detected anywhere between timeout and 2*timeout.  This is fine for
most interactive environments, but this hurts automated testing setups
(syzbot).  In an automated setup we need to strictly order CPU lockup <
RCU stall < workqueue lockup < task hung < silent loss, so that RCU stall
is not detected as task hung and task hung is not detected as silent
machine loss.  The large variance in task hung detection timeout requires
setting silent machine loss timeout to a very large value (e.g.  if task
hung is 3 mins, then silent loss need to be set to ~7 mins).  The
additional 3 minutes significantly reduce testing efficiency because
usually we crash kernel within a minute, and this can add hours to bug
localization process as it needs to do dozens of tests.

Allow setting checking interval separately from timeout.  This allows to
set timeout to, say, 3 minutes, but checking interval to 10 secs.

The interval is controlled via a new hung_task_check_interval_secs sysctl,
similar to the existing hung_task_timeout_secs sysctl.  The default value
of 0 results in the current behavior: checking interval is equal to
timeout.

[akpm@linux-foundation.org: update hung_task_timeout_max's comment]
Link: http://lkml.kernel.org/r/20180611111004.203513-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Arnd Bergmann
91bc9aaf74 kernel/crash_core.c: print timestamp using time64_t
The get_seconds() call returns a 32-bit timestamp on some architectures,
and will overflow in the future.  The newer ktime_get_real_seconds()
always returns a 64-bit timestamp that does not suffer from this problem.

Link: http://lkml.kernel.org/r/20180618150329.941903-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Rasmus Villemoes
203583990c linux/compiler.h: don't use bool
Appararently, it's possible to have a non-trivial TU include a few
headers, including linux/build_bug.h, without ending up with
linux/types.h.  So the 0day bot sent me

config: um-x86_64_defconfig (attached as .config)

>> include/linux/compiler.h:316:3: error: unknown type name 'bool'; did you mean '_Bool'?
      bool __cond = !(condition);    \

for something I'm working on.

Rather than contributing to the #include madness and including
linux/types.h from compiler.h, just use int.

Link: http://lkml.kernel.org/r/20180817101036.20969-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Christopher Li <sparse@chrisli.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Anna-Maria Gleixner
ce0a568d32 userns: use irqsave variant of refcount_dec_and_lock()
The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock.  With this variant the call of
local_irq_save/restore is no longer required.

[bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g]
Link: http://lkml.kernel.org/r/20180703200141.28415-7-bigeasy@linutronix.de
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Sebastian Andrzej Siewior
fc37191272 userns: use refcount_t for reference counting instead atomic_t
refcount_t type and corresponding API should be used instead of atomic_t
wh en the variable is used as a reference counter.  This avoids accidental
refcounter overflows that might lead to use-after-free situations.

Link: http://lkml.kernel.org/r/20180703200141.28415-6-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Anna-Maria Gleixner
060288a732 bdi: use irqsave variant of refcount_dec_and_lock()
The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock.  With this variant the call of
local_irq_save/restore is no longer required.

[bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g]
Link: http://lkml.kernel.org/r/20180703200141.28415-5-bigeasy@linutronix.de
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Sebastian Andrzej Siewior
e58dd0de5e bdi: use refcount_t for reference counting instead atomic_t
refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.  This permits avoiding
accidental refcounter overflows that might lead to use-after-free
situations.

Link: http://lkml.kernel.org/r/20180703200141.28415-4-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Kees Cook
cedc5b6aab kernel.h: documentation for roundup() vs round_up()
Things like 3619dec510 ("dh key: fix rounding up KDF output length")
expose the lack of explicit documentation for roundup() vs round_up().  At
least we can try to document it better if anyone goes looking.

Link: http://lkml.kernel.org/r/20180703041950.GA43464@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00
Dmitry Vyukov
96c6a32ccb include/asm-generic/bug.h: clarify valid uses of WARN()
Explicitly state that WARN*() should be used only for recoverable kernel
issues/bugs and that it should not be used for any kind of invalid
external inputs or transient conditions.

Motivation: it's a very useful capability to be able to understand if a
particular kernel splat means a kernel bug or simply an invalid user-space
program.  For the former one wants to notify kernel developers, while
notifying kernel developers for the latter is annoying.  Even a kernel
developer may not know what to do with a WARNING in an unfamiliar
subsystem.  This is especially critical for any automated testing systems
that may use panic_on_warn and mail kernel developers.

The clear separation also serves as an additional documentation: is it a
condition that must never occur because of additional checks/logic
elsewhere?  or is it simply a check for invalid inputs or unfortunate
conditions?

Use of pr_err() for user messages also leads to better error messages.
"Something is wrong in file foo on line X" is not particularly useful
message for end user.  pr_err() forces developers to write more meaningful
error messages for user.

As of now we are almost there.  We are doing systematic kernel testing
with panic_on_warn and are not seeing massive amounts of false positives.
But every now and then another WARN on ENOMEM or invalid inputs pops up
and leads to a lengthy argument each time.  The goal of this change is to
officially document the rules.

Link: http://lkml.kernel.org/r/20180620103716.61636-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:46 -07:00