Some code pathes rely on preempt_disable() to prevent migration on a non RT
enabled kernel. These preempt_disable/enable() pairs are substituted by
migrate_disable/enable() pairs or other forms of RT specific protection. On
RT these protections prevent migration but not preemption. Obviously a
cant_sleep() check in such a section will trigger on RT because preemption
is not disabled.

Provide a cant_migrate() macro which maps to cant_sleep() on a non RT
kernel and an empty placeholder for RT for now. The placeholder will be
changed to a proper debug check along with the RT specific migration
protection mechanism.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200214161503.070487511@linutronix.de

Code which solely needs to prevent migration of a task uses
preempt_disable()/enable() pairs. This is the only reliable way to do so
as setting the task affinity to a single CPU can be undone by a
setaffinity operation from a different task/process.

RT provides a seperate migrate_disable/enable() mechanism which does not
disable preemption to achieve the semantic requirements of a (almost) fully
preemptible kernel.

As it is unclear from looking at a given code path whether the intention is
to disable preemption or migration, introduce migrate_disable/enable()
inline functions which can be used to annotate code which merely needs to
disable migration. Map them to preempt_disable/enable() for now. The RT
substitution will be provided later.

Code which is annotated that way documents that it has no requirement to
protect against reentrancy of a preempting task. Either this is not
required at all or the call sites are already serialized by other means.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/878slclv1u.fsf@nanos.tec.linutronix.de

Eliminate all kernel-doc and Sphinx warnings in
<linux/netdevice.h>.  Fixes these warnings:

../include/linux/netdevice.h:2100: warning: Function parameter or member 'gso_partial_features' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'l3mdev_ops' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'xfrmdev_ops' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'tlsdev_ops' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'name_assign_type' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'ieee802154_ptr' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'mpls_ptr' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'xdp_prog' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'gro_flush_timeout' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'xdp_bulkq' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'xps_cpus_map' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'xps_rxqs_map' not described in 'net_device'
../include/linux/netdevice.h:2100: warning: Function parameter or member 'qdisc_hash' not described in 'net_device'
../include/linux/netdevice.h:3552: WARNING: Inline emphasis start-string without end-string.
../include/linux/netdevice.h:3552: WARNING: Inline emphasis start-string without end-string.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This introduces a helper function to be called only by network drivers
that wraps calls to icmp[v6]_send in a conntrack transformation, in case
NAT has been used. We don't want to pollute the non-driver path, though,
so we introduce this as a helper to be called by places that actually
make use of this, as suggested by Florian.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix kernel-doc warnings in struct pipe_inode_info after @wait was
split into @rd_wait and @wr_wait.

  include/linux/pipe_fs_i.h:66: warning: Function parameter or member 'rd_wait' not described in 'pipe_inode_info'
  include/linux/pipe_fs_i.h:66: warning: Function parameter or member 'wr_wait' not described in 'pipe_inode_info'

Fixes: 0ddad21d ("pipe: use exclusive waits when reading or writing")
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a dentry was not initially looked up while we were holding a
delegation, then we do still need to revalidate that it still holds
the same name. If there are multiple hard links to the same file,
then all the hard links need validation.
Reported-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: NBenjamin Coddington <bcodding@redhat.com>
Tested-by: NBenjamin Coddington <bcodding@redhat.com>
[Anna: Put nfs_unset_verifier_delegated() under CONFIG_NFS_V4]
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

It is theoretically possible for the ACPI EC GPE to be set after the
s2idle_ops->wake() called from s2idle_loop() has returned and before
the subsequent pm_wakeup_pending() check is carried out.  If that
happens, the resulting wakeup event will cause the system to resume
even though it may be a spurious one.

To avoid that race, first make the ->wake() callback in struct
platform_s2idle_ops return a bool value indicating whether or not
to let the system resume and rearrange s2idle_loop() to use that
value instad of the direct pm_wakeup_pending() call if ->wake() is
present.

Next, rework acpi_s2idle_wake() to process EC events and check
pm_wakeup_pending() before re-arming the SCI for system wakeup
to prevent it from triggering prematurely and add comments to
that function to explain the rationale for the new code flow.

Fixes: 56b99184 ("PM: sleep: Simplify suspend-to-idle control flow")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move the checking, buffer reserve and buffer commit code in
synth_event_trace_start/end() into inline functions
__synth_event_trace_start/end() so they can also be used by
synth_event_trace() and synth_event_trace_array(), and then have all
those functions use them.

Also, change synth_event_trace_state.enabled to disabled so it only
needs to be set if the event is disabled, which is not normally the
case.

Link: http://lkml.kernel.org/r/b1f3108d0f450e58192955a300e31d0405ab4149.1581374549.git.zanussi@kernel.orgSigned-off-by: NTom Zanussi <zanussi@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

This makes the pipe code use separate wait-queues and exclusive waiting
for readers and writers, avoiding a nasty thundering herd problem when
there are lots of readers waiting for data on a pipe (or, less commonly,
lots of writers waiting for a pipe to have space).

While this isn't a common occurrence in the traditional "use a pipe as a
data transport" case, where you typically only have a single reader and
a single writer process, there is one common special case: using a pipe
as a source of "locking tokens" rather than for data communication.

In particular, the GNU make jobserver code ends up using a pipe as a way
to limit parallelism, where each job consumes a token by reading a byte
from the jobserver pipe, and releases the token by writing a byte back
to the pipe.

This pattern is fairly traditional on Unix, and works very well, but
will waste a lot of time waking up a lot of processes when only a single
reader needs to be woken up when a writer releases a new token.

A simplified test-case of just this pipe interaction is to create 64
processes, and then pass a single token around between them (this
test-case also intentionally passes another token that gets ignored to
test the "wake up next" logic too, in case anybody wonders about it):

    #include <unistd.h>

    int main(int argc, char **argv)
    {
        int fd[2], counters[2];

        pipe(fd);
        counters[0] = 0;
        counters[1] = -1;
        write(fd[1], counters, sizeof(counters));

        /* 64 processes */
        fork(); fork(); fork(); fork(); fork(); fork();

        do {
                int i;
                read(fd[0], &i, sizeof(i));
                if (i < 0)
                        continue;
                counters[0] = i+1;
                write(fd[1], counters, (1+(i & 1)) *sizeof(int));
        } while (counters[0] < 1000000);
        return 0;
    }

and in a perfect world, passing that token around should only cause one
context switch per transfer, when the writer of a token causes a
directed wakeup of just a single reader.

But with the "writer wakes all readers" model we traditionally had, on
my test box the above case causes more than an order of magnitude more
scheduling: instead of the expected ~1M context switches, "perf stat"
shows

        231,852.37 msec task-clock                #   15.857 CPUs utilized
        11,250,961      context-switches          #    0.049 M/sec
           616,304      cpu-migrations            #    0.003 M/sec
             1,648      page-faults               #    0.007 K/sec
 1,097,903,998,514      cycles                    #    4.735 GHz
   120,781,778,352      instructions              #    0.11  insn per cycle
    27,997,056,043      branches                  #  120.754 M/sec
       283,581,233      branch-misses             #    1.01% of all branches

      14.621273891 seconds time elapsed

       0.018243000 seconds user
       3.611468000 seconds sys

before this commit.

After this commit, I get

          5,229.55 msec task-clock                #    3.072 CPUs utilized
         1,212,233      context-switches          #    0.232 M/sec
           103,951      cpu-migrations            #    0.020 M/sec
             1,328      page-faults               #    0.254 K/sec
    21,307,456,166      cycles                    #    4.074 GHz
    12,947,819,999      instructions              #    0.61  insn per cycle
     2,881,985,678      branches                  #  551.096 M/sec
        64,267,015      branch-misses             #    2.23% of all branches

       1.702148350 seconds time elapsed

       0.004868000 seconds user
       0.110786000 seconds sys

instead. Much better.

[ Note! This kernel improvement seems to be very good at triggering a
  race condition in the make jobserver (in GNU make 4.2.1) for me. It's
  a long known bug that was fixed back in June 2017 by GNU make commit
  b552b0525198 ("[SV 51159] Use a non-blocking read with pselect to
  avoid hangs.").

  But there wasn't a new release of GNU make until 4.3 on Jan 19 2020,
  so a number of distributions may still have the buggy version. Some
  have backported the fix to their 4.2.1 release, though, and even
  without the fix it's quite timing-dependent whether the bug actually
  is hit. ]

Josh Triplett says:
 "I've been hammering on your pipe fix patch (switching to exclusive
  wait queues) for a month or so, on several different systems, and I've
  run into no issues with it. The patch *substantially* improves
  parallel build times on large (~100 CPU) systems, both with parallel
  make and with other things that use make's pipe-based jobserver.

  All current distributions (including stable and long-term stable
  distributions) have versions of GNU make that no longer have the
  jobserver bug"
Tested-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, we will not set vpe_l1_page for the current RD if we can
inherit the vPE configuration table from another RD (or ITS), which
results in an inconsistency between RDs within the same CommonLPIAff
group.

Let's rename it to vpe_l1_base to indicate the base address of the
vPE configuration table of this RD, and set it properly for *all*
v4.1 redistributors.
Signed-off-by: NZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200206075711.1275-3-yuzenghui@huawei.com

called errorfc/infofc/warnfc/invalfc
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Don't bother with "mixed" options that would allow both the
form with and without argument (i.e. both -o foo and -o foo=bar).
Rather than trying to shove both into a single fs_parameter_spec,
allow having with-argument and no-argument specs with the same
name and teach fs_parse to handle that.

There are very few options of that sort, and they are actually
easier to handle that way - callers end up with less postprocessing.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The former contains nothing but a pointer to an array of the latter...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Unused now.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... turning it into struct p_log embedded into fs_context.  Initialize
the prefix with fs_type->name, turning fs_parse() into a trivial
inline wrapper for __fs_parse().

This makes fs_parameter_description->name completely unused.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and now errorf() et.al. are never called with NULL fs_context,
so we can get rid of conditional in those.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs_parse() analogue taking p_log instead of fs_context.
fs_parse() turned into a wrapper, callers in ceph_common and rbd
switched to __fs_parse().

As the result, fs_parse() never gets NULL fs_context and neither
do fs_context-based logging primitives
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

primitives for prefixed logging
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Its behaviour is identical to that of fs_value_is_filename.
It makes no sense, anyway - LOOKUP_EMPTY affects nothing
whatsoever once the pathname has been imported from userland.
And both fs_value_is_filename and fs_value_is_filename_empty
carry an already imported pathname.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Have the arrays of constant_table self-terminated (by NULL ->name
in the final entry).  Simplifies lookup_constant() and allows to
reuse the search for enum params as well.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no real difference now
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Don't do a single array; attach them to fsparam_enum() entry
instead.  And don't bother trying to embed the names into those -
it actually loses memory, with no real speedup worth mentioning.

Simplifies validation as well.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

As it is, vfs_parse_fs_string() makes "foo" and "foo=" indistinguishable;
both get fs_value_is_string for ->type and NULL for ->string.  To make
it even more unpleasant, that combination is impossible to produce with
fsconfig().

Much saner rules would be
        "foo"           => fs_value_is_flag, NULL
	"foo="          => fs_value_is_string, ""
	"foo=bar"       => fs_value_is_string, "bar"
All cases are distinguishable, all results are expressable by fsconfig(),
->has_value checks are much simpler that way (to the point of the field
being useless) and quite a few regressions go away (gfs2 has no business
accepting -o nodebug=, for example).

Partially based upon patches from Miklos.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Deprecate the generic TLS cap bit, use the new TX-specific
TLS cap bit instead.

Fixes: a12ff35e ("net/mlx5: Introduce TLS TX offload hardware bits and structures")
Signed-off-by: NTariq Toukan <tariqt@mellanox.com>
Reviewed-by: NEran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

sk_buff.qlen can be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg

 read to 0xffff8a1b1d8a81c0 of 4 bytes by task 5371 on cpu 96:
  unix_dgram_sendmsg+0x9a9/0xb70 include/linux/skbuff.h:1821
				 net/unix/af_unix.c:1761
  ____sys_sendmsg+0x33e/0x370
  ___sys_sendmsg+0xa6/0xf0
  __sys_sendmsg+0x69/0xf0
  __x64_sys_sendmsg+0x51/0x70
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 write to 0xffff8a1b1d8a81c0 of 4 bytes by task 1 on cpu 99:
  __skb_try_recv_from_queue+0x327/0x410 include/linux/skbuff.h:2029
  __skb_try_recv_datagram+0xbe/0x220
  unix_dgram_recvmsg+0xee/0x850
  ____sys_recvmsg+0x1fb/0x210
  ___sys_recvmsg+0xa2/0xf0
  __sys_recvmsg+0x66/0xf0
  __x64_sys_recvmsg+0x51/0x70
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Since only the read is operating as lockless, it could introduce a logic
bug in unix_recvq_full() due to the load tearing. Fix it by adding
a lockless variant of skb_queue_len() and unix_recvq_full() where
READ_ONCE() is on the read while WRITE_ONCE() is on the write similar to
the commit d7d16a89 ("net: add skb_queue_empty_lockless()").
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Depending on include order:

    include/linux/of_clk.h:11:45: warning: ‘struct device_node’ declared inside parameter list will not be visible outside of this definition or declaration
     unsigned int of_clk_get_parent_count(struct device_node *np);
						 ^~~~~~~~~~~
    include/linux/of_clk.h:12:43: warning: ‘struct device_node’ declared inside parameter list will not be visible outside of this definition or declaration
     const char *of_clk_get_parent_name(struct device_node *np, int index);
					       ^~~~~~~~~~~
    include/linux/of_clk.h:13:31: warning: ‘struct of_device_id’ declared inside parameter list will not be visible outside of this definition or declaration
     void of_clk_init(const struct of_device_id *matches);
				   ^~~~~~~~~~~~

Fix this by adding forward declarations for struct device_node and
struct of_device_id.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/20200205194649.31309-1-geert+renesas@glider.beSigned-off-by: NStephen Boyd <sboyd@kernel.org>

Replace with appropriate types.h.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace with appropriate types.h.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the directory is large and it's being modified by one client
while another client is doing the 'ls -l' on the same directory then
the cache page invalidation from nfs_force_use_readdirplus causes
the reading client to keep restarting READDIRPLUS from cookie 0
which causes the 'ls -l' to take a very long time to complete,
possibly never completing.

Currently when nfs_force_use_readdirplus is called to switch from
READDIR to READDIRPLUS, it invalidates all the cached pages of the
directory. This cache page invalidation causes the next nfs_readdir
to re-read the directory content from cookie 0.

This patch is to optimise the cache invalidation in
nfs_force_use_readdirplus by only truncating the cached pages from
last page index accessed to the end the file. It also marks the
inode to delay invalidating all the cached page of the directory
until the next initial nfs_readdir of the next 'ls' instance.
Signed-off-by: NDai Ngo <dai.ngo@oracle.com>
Reviewed-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
[Anna - Fix conflicts with Trond's readdir patches]
[Anna - Remove redundant call to nfs_zap_mapping()]
[Anna - Replace d_inode(file_dentry(desc->file)) with file_inode(desc->file)]
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

New design of inner bitmap_parse() allows to avoid calculating the size of
a null-terminated string.

Link: http://lkml.kernel.org/r/20200102043031.30357-8-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: "Tobin C . Harding" <tobin@kernel.org>
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bitmap_parse() is ineffective and full of opaque variables and opencoded
parts.  It leads to hard understanding and usage of it.  This rework
includes:

- remove bitmap_shift_left() call from the cycle.  Now it makes the
  complexity of the algorithm as O(nbits^2).  In the suggested approach
  the input string is parsed in reverse direction, so no shifts needed;

- relax requirement on a single comma and no white spaces between
  chunks.  It is considered useful in scripting, and it aligns with
  bitmap_parselist();

- split bitmap_parse() to small readable helpers;

- make an explicit calculation of the end of input line at the
  beginning, so users of the bitmap_parse() won't bother doing this.

Link: http://lkml.kernel.org/r/20200102043031.30357-6-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: "Tobin C . Harding" <tobin@kernel.org>
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce BITS_TO_U64, BITS_TO_U32 and BITS_TO_BYTES as they are handy in
the following patches (BITS_TO_U32 specifically).  Reimplement tools/
version of the macros according to the kernel implementation.

Also fix indentation for BITS_PER_TYPE definition.

Link: http://lkml.kernel.org/r/20200102043031.30357-3-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: "Tobin C . Harding" <tobin@kernel.org>
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "lib: rework bitmap_parse", v5.

Similarl to the recently revisited bitmap_parselist(), bitmap_parse() is
ineffective and overcomplicated.  This series reworks it, aligns its
interface with bitmap_parselist() and makes it simpler to use.

The series also adds a test for the function and fixes usage of it in
cpumask_parse() according to the new design - drops the calculating of
length of an input string.

bitmap_parse() takes the array of numbers to be put into the map in the BE
order which is reversed to the natural LE order for bitmaps.  For example,
to construct bitmap containing a bit on the position 42, we have to put a
line '400,0'.  Current implementation reads chunk one by one from the
beginning ('400' before '0') and makes bitmap shift after each successful
parse.  It makes the complexity of the whole process as O(n^2).  We can do
it in reverse direction ('0' before '400') and avoid shifting, but it
requires reverse parsing helpers.

This patch (of 7):

New function works like strchrnul() with a length limited string.

Link: http://lkml.kernel.org/r/20200102043031.30357-2-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Amritha Nambiar <amritha.nambiar@intel.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Tobin C . Harding" <tobin@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently core /proc code uses "struct file_operations" for custom hooks,
however, VFS doesn't directly call them.  Every time VFS expands
file_operations hook set, /proc code bloats for no reason.

Introduce "struct proc_ops" which contains only those hooks which /proc
allows to call into (open, release, read, write, ioctl, mmap, poll).  It
doesn't contain module pointer as well.

Save ~184 bytes per usage:

	add/remove: 26/26 grow/shrink: 1/4 up/down: 1922/-6674 (-4752)
	Function                                     old     new   delta
	sysvipc_proc_ops                               -      72     +72
				...
	config_gz_proc_ops                             -      72     +72
	proc_get_inode                               289     339     +50
	proc_reg_get_unmapped_area                   110     107      -3
	close_pdeo                                   227     224      -3
	proc_reg_open                                289     284      -5
	proc_create_data                              60      53      -7
	rt_cpu_seq_fops                              256       -    -256
				...
	default_affinity_proc_fops                   256       -    -256
	Total: Before=5430095, After=5425343, chg -0.09%

Link: http://lkml.kernel.org/r/20191225172228.GA13378@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

struct mm_struct is quite large (~1664 bytes) and so allocating on the
stack may cause problems as the kernel stack size is small.

Since ptdump_walk_pgd_level_core() was only allocating the structure so
that it could modify the pgd argument we can instead introduce a pgd
override in struct mm_walk and pass this down the call stack to where it
is needed.

Since the correct mm_struct is now being passed down, it is now also
unnecessary to take the mmap_sem semaphore because ptdump_walk_pgd() will
now take the semaphore on the real mm.

[steven.price@arm.com: restore missed arm64 changes]
  Link: http://lkml.kernel.org/r/20200108145710.34314-1-steven.price@arm.com
Link: http://lkml.kernel.org/r/20200108145710.34314-1-steven.price@arm.comSigned-off-by: NSteven Price <steven.price@arm.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rather than having to increment the 'depth' number by 1 in ptdump_hole(),
let's change the meaning of 'level' in note_page() since that makes the
code simplier.

Note that for x86, the level numbers were previously increased by 1 in
commit 45dcd209 ("x86/mm/dump_pagetables: Fix printout of p4d level")
and the comment "Bit 7 has a different meaning" was not updated, so this
change also makes the code match the comment again.

Link: http://lkml.kernel.org/r/20191218162402.45610-24-steven.price@arm.comSigned-off-by: NSteven Price <steven.price@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a generic version of page table dumping that architectures can opt-in
to.

Link: http://lkml.kernel.org/r/20191218162402.45610-20-steven.price@arm.comSigned-off-by: NSteven Price <steven.price@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>