lib/vsprintf: replace link to Draft by final RFC number

The draft has evolved to RFC 5952.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
lib: make _tolower() public

This function is required by *printf and kstrto* functions that are
located in the different modules.  This patch makes _tolower() public.
However, it's good idea to not use the helper outside of mentioned
functions.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/kstrtox: common code between kstrto*() and simple_strto*() functions

Currently termination logic (\0 or \n\0) is hardcoded in _kstrtoull(),
avoid that for code reuse between kstrto*() and simple_strtoull().
Essentially, make them different only in termination logic.

simple_strtoull() (and scanf(), BTW) ignores integer overflow, that's a
bug we currently don't have guts to fix, making KSTRTOX_OVERFLOW hack
necessary.

Almost forgot: patch shrinks code size by about ~80 bytes on x86_64.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vsprintf: make %pV handling compatible with kasprintf()

kasprintf() (and potentially other functions that I didn't run across so
far) want to evaluate argument lists twice.  Caring to do so for the
primary list is obviously their job, but they can't reasonably be
expected to check the format string for instances of %pV, which however
need special handling too: On architectures like x86-64 (as opposed to
e.g.  ix86), using the same argument list twice doesn't produce the
expected results, as an internally managed cursor gets updated during
the first run.

Fix the problem by always acting on a copy of the original list when
handling %pV.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
procfs: add num_to_str() to speed up /proc/stat

== stat_check.py
num = 0
with open("/proc/stat") as f:
        while num < 1000 :
                data = f.read()
                f.seek(0, 0)
                num = num + 1
==

perf shows

    20.39%  stat_check.py  [kernel.kallsyms]    [k] format_decode
    13.41%  stat_check.py  [kernel.kallsyms]    [k] number
    12.61%  stat_check.py  [kernel.kallsyms]    [k] vsnprintf
    10.85%  stat_check.py  [kernel.kallsyms]    [k] memcpy
     4.85%  stat_check.py  [kernel.kallsyms]    [k] radix_tree_lookup
     4.43%  stat_check.py  [kernel.kallsyms]    [k] seq_printf

This patch removes most of calls to vsnprintf() by adding num_to_str()
and seq_print_decimal_ull(), which prints decimal numbers without rich
functions provided by printf().

On my 8cpu box.
== Before patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.150s
user    0m0.026s
sys     0m0.121s

== After patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.055s
user    0m0.022s
sys     0m0.030s

[akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()]
[andrea@betterlinux.com: avoid breaking the ABI in /proc/stat]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Turner <pjt@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
backported from Linux 3.4-rc4 to Linux 3.0.x by faux123
netfilter: xt_qtaguid: fix ipv6 protocol lookup

When updating the stats for a given uid it would incorrectly assume
IPV4 and pick up the wrong protocol when IPV6.

Change-Id: Iea4a635012b4123bf7aa93809011b7b2040bb3d5
Signed-off-by: JP Abgrall <jpa@google.com>
msm: cpufreq: Fix store_powersave_bias to account for sync' CPUs.

Current code assumes that all online CPUs runs their own timers to
collect CPU samples for demand based switching (dbs). But in case of
synchronous CPUs ondemand governor registers only one timer at init
time because both CPUs are accounted in the same timer call. Hence
trying to restart/cancel dbs timers for all online CPUs is not legal
for these CPUs. This change fixes above function to restart/cancel
timers only once for group of synchronous CPUs.

CRs-Fixed: 348502
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
(cherry picked from commit 3d5b6bd91f28ecbc90f233f3a2854e4496d619bc)

Change-Id: Ia69841655929f5e5306ca7e1865d7b0125cd8ead
Signed-off-by: Sunil Joseph <sunilj@codeaurora.org>
sched: fix OOPS when build_sched_domains percpu allocation fails

From: "he, bo" <bo.he@intel.com>

Under extreme memory used up situation, percpu allocation
might fails. We hit it when system go to suspend-to-ram.

EIP: [<c124411a>] build_sched_domains+0x23a/0xad0
SS:ESP 0068:de725d04
CR2: 0000000034811000
---[ end trace d6086359b670b975 ]---
Kernel panic - not syncing: Fatal exception
Pid: 3026, comm: kworker/u:3 Tainted: G      D W
3.0.8-137473-gf42fbef #1
Call Trace:
 [<c18cc4f2>] panic+0x66/0x16c
 [<c12521a1>] ? oops_exit+0x61/0x90
 [<c1205f89>] oops_end+0xb9/0xd0
 [<c1227796>] no_context+0xc6/0x1f0
 [<c1227958>] __bad_area_nosemaphore+0x98/0x140
 [<c1204ebf>] ? dump_trace+0x7f/0xf0
 [<c1227d30>] ? pgtable_bad+0x130/0x130
 [<c1227a17>] bad_area_nosemaphore+0x17/0x20
 [<c1227fa0>] do_page_fault+0x270/0x3c0
 [<c1306afa>] ? pcpu_alloc+0x12ca/0x1300
 [<c1227d30>] ? pgtable_bad+0x130/0x130
 [<c1227d30>] ? pgtable_bad+0x130/0x130
 [<c18d09d3>] error_code+0x5f/0x64
 [<c13000d8>] ? shmem_setattr+0x198/0x230
 [<c1227d30>] ? pgtable_bad+0x130/0x130
 [<c124411a>] ? build_sched_domains+0x23a/0xad0
 [<c18d01a6>] ? _raw_spin_unlock_irqrestore+0x26/0x50
 [<c1244c37>] partition_sched_domains+0x287/0x4b0
 [<c12a77be>] cpuset_update_active_cpus+0x1fe/0x210
 [<c1673017>] ? __cpufreq_remove_dev+0x167/0x360
 [<c18cf03c>] ? down_write+0x1c/0x40
 [<c123712d>] cpuset_cpu_inactive+0x1d/0x30
 [<c127dff2>] notifier_call_chain+0x52/0x90
 [<c127e04e>] __raw_notifier_call_chain+0x1e/0x30
 [<c18b37c9>] _cpu_down+0x89/0x230
 [<c12547f9>] disable_nonboot_cpus+0x79/0x100
 [<c1299fb3>] suspend_devices_and_enter+0x133/0x2e0
 [<c129a27d>] enter_state+0x11d/0x180
 [<c129a307>] pm_suspend+0x27/0x70
 [<c129b8b6>] suspend+0x96/0x1d0
 [<c1271aa3>] process_one_work+0x103/0x400
 [<c129b820>] ? power_suspend_late+0x90/0x90
 [<c12728ac>] worker_thread+0x12c/0x4b0
 [<c123748d>] ? sub_preempt_count+0x3d/0x50
 [<c18d01a6>] ? _raw_spin_unlock_irqrestore+0x26/0x50
 [<c1272780>] ? manage_workers+0x520/0x520
 [<c1276f44>] kthread+0x74/0x80
 [<c1276ed0>] ? __init_kthread_worker+0x30/0x30
 [<c18d113a>] kernel_thread_helper+0x6/0x10
Signed-off-by: he, bo <bo.he@intel.com>
Reviewed-by: Zhang, Yanmin <yanmin.zhang@intel.com>
backported for Linux 3.0 from Linux 3.4+ by faux123
timer: optimize apply_slack()

__fls(mask) is equivalent to find_last_bit(&mask, BITS_PER_LONG), but cheaper.
find_last_bit was showing up high on the list when I was profiling for stalls
on icache misses on a system with very small cache size (MIPS).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
lib: Sparc's strncpy_from_user is generic enough, move under
 lib/

To use this, an architecture simply needs to:

1) Provide a user_addr_max() implementation via asm/uaccess.h

2) Add "select GENERIC_STRNCPY_FROM_USER" to their arch Kcnfig

3) Remove the existing strncpy_from_user() implementation and symbol
   exports their architecture had.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
modified for Linux 3.0 Kernel from Linux 3.4+ by faux123
word-at-a-time: make the interfaces truly generic

This changes the interfaces in <asm/word-at-a-time.h> to be a bit more
complicated, but a lot more generic.

In particular, it allows us to really do the operations efficiently on
both little-endian and big-endian machines, pretty much regardless of
machine details.  For example, if you can rely on a fast population
count instruction on your architecture, this will allow you to make your
optimized <asm/word-at-a-time.h> file with that.

NOTE! The "generic" version in include/asm-generic/word-at-a-time.h is
not truly generic, it actually only works on big-endian.  Why? Because
on little-endian the generic algorithms are wasteful, since you can
inevitably do better. The x86 implementation is an example of that.

(The only truly non-generic part of the asm-generic implementation is
the "find_zero()" function, and you could make a little-endian version
of it.  And if the Kbuild infrastructure allowed us to pick a particular
header file, that would be lovely)

The <asm/word-at-a-time.h> functions are as follows:

 - WORD_AT_A_TIME_CONSTANTS: specific constants that the algorithm
   uses.

 - has_zero(): take a word, and determine if it has a zero byte in it.
   It gets the word, the pointer to the constant pool, and a pointer to
   an intermediate "data" field it can set.

   This is the "quick-and-dirty" zero tester: it's what is run inside
   the hot loops.

 - "prep_zero_mask()": take the word, the data that has_zero() produced,
   and the constant pool, and generate an *exact* mask of which byte had
   the first zero.  This is run directly *outside* the loop, and allows
   the "has_zero()" function to answer the "is there a zero byte"
   question without necessarily getting exactly *which* byte is the
   first one to contain a zero.

   If you do multiple byte lookups concurrently (eg "hash_name()", which
   looks for both NUL and '/' bytes), after you've done the prep_zero_mask()
   phase, the result of those can be or'ed together to get the "either
   or" case.

 - The result from "prep_zero_mask()" can then be fed into "find_zero()"
   (to find the byte offset of the first byte that was zero) or into
   "zero_bytemask()" (to find the bytemask of the bytes preceding the
   zero byte).

   The existence of zero_bytemask() is optional, and is not necessary
   for the normal string routines.  But dentry name hashing needs it, so
   if you enable DENTRY_WORD_AT_A_TIME you need to expose it.

This changes the generic strncpy_from_user() function and the dentry
hashing functions to use these modified word-at-a-time interfaces.  This
gets us back to the optimized state of the x86 strncpy that we lost in
the previous commit when moving over to the generic version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
modified for Linux 3.0 from Linux 3.4+ by faux123
lib: add generic strnlen_user() function

This adds a new generic optimized strnlen_user() function that uses the
<asm/word-at-a-time.h> infrastructure to portably do efficient string
handling.

In many ways, strnlen is much simpler than strncpy, and in particular we
can always pre-align the words we load from memory.  That means that all
the worries about alignment etc are a non-issue, so this one can easily
be used on any architecture.  You obviously do have to do the
appropriate word-at-a-time.h macros.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib: Fix generic strnlen_user for 32-bit big-endian machines

The aligned_byte_mask() definition is wrong for 32-bit big-endian
machines: the "7-(n)" part of the definition assumes a long is 8
bytes.  This fixes it by using BITS_PER_LONG - 8 instead of 8*7.
Tested on 32-bit and 64-bit PowerPC.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel: Move REPEAT_BYTE definition into linux/kernel.h

And make sure that everything using it explicitly includes
that header file.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
modified for Linux 3.0 from Linux 3.4+ by faux123
ARM: use generic strnlen_user and strncpy_from_user
 functions

This patch implements the word-at-a-time interface for ARM using the
same algorithm as x86. Although we have a clz instruction from ARMv5,
this only saves us one mov instruction when building with Thumb-2 and
makes no difference when targetting ARM, so we use the magic 0x0ff0001
constant for all CPUs. For big-endian configurations, we use the
implementation from asm-generic.

With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.

Signed-off-by: Will Deacon <will.deacon@arm.com>
modified for Linux 3.0 from Linux 3.4+ by faux123

Signed-off-by: task650 <task650@gmail.com>