A new PMU type, perf_kprobe is added. Based on attr from perf_event_open(),
perf_kprobe creates a kprobe (or kretprobe) for the perf_event. This
kprobe is private to this perf_event, and thus not added to global
lists, and not available in tracefs.

Two functions, create_local_trace_kprobe() and
destroy_local_trace_kprobe()  are added to created and destroy these
local trace_kprobe.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NYonghong Song <yhs@fb.com>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Cc: <daniel@iogearbox.net>
Cc: <davem@davemloft.net>
Cc: <kernel-team@fb.com>
Cc: <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171206224518.3598254-6-songliubraving@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Two new perf types, perf_kprobe and perf_uprobe, will be added to allow
creating [k,u]probe with perf_event_open. These [k,u]probe are associated
with the file decriptor created by perf_event_open(), thus are easy to
clean when the file descriptor is destroyed.

kprobe_func and uprobe_path are added to union config1 for pointers to
function name for kprobe or binary path for uprobe.

kprobe_addr and probe_offset are added to union config2 for kernel
address (when kprobe_func is NULL), or [k,u]probe offset.
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NYonghong Song <yhs@fb.com>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Cc: <daniel@iogearbox.net>
Cc: <davem@davemloft.net>
Cc: <kernel-team@fb.com>
Cc: <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171206224518.3598254-4-songliubraving@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since i_version is mostly treated as an opaque value, we can exploit that
fact to avoid incrementing it when no one is watching. With that change,
we can avoid incrementing the counter on writes, unless someone has
queried for it since it was last incremented. If the a/c/mtime don't
change, and the i_version hasn't changed, then there's no need to dirty
the inode metadata on a write.

Convert the i_version counter to an atomic64_t, and use the lowest order
bit to hold a flag that will tell whether anyone has queried the value
since it was last incremented.

When we go to maybe increment it, we fetch the value and check the flag
bit.  If it's clear then we don't need to do anything if the update
isn't being forced.

If we do need to update, then we increment the counter by 2, and clear
the flag bit, and then use a CAS op to swap it into place. If that
works, we return true. If it doesn't then do it again with the value
that we fetch from the CAS operation.

On the query side, if the flag is already set, then we just shift the
value down by 1 bit and return it. Otherwise, we set the flag in our
on-stack value and again use cmpxchg to swap it into place if it hasn't
changed. If it has, then we use the value from the cmpxchg as the new
"old" value and try again.

This method allows us to avoid incrementing the counter on writes (and
dirtying the metadata) under typical workloads. We only need to increment
if it has been queried since it was last changed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Acked-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NKrzysztof Kozlowski <krzk@kernel.org>

The rationale for taking the i_lock when incrementing this value is
lost in antiquity. The readers of the field don't take it (at least
not universally), so my assumption is that it was only done here to
serialize incrementors.

If that is indeed the case, then we can drop the i_lock from this
codepath and treat it as a atomic64_t for the purposes of
incrementing it. This allows us to use inode_inc_iversion without
any danger of lock inversion.

Note that the read side is not fetched atomically with this change.
The assumption here is that that is not a critical issue since the
i_version is not fully synchronized with anything else anyway.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>

Add a documentation blob that explains what the i_version field is, how
it is expected to work, and how it is currently implemented by various
filesystems.

We already have inode_inc_iversion. Add several other functions for
manipulating and accessing the i_version counter. For now, the
implementation is trivial and basically works the way that all of the
open-coded i_version accesses work today.

Future patches will convert existing users of i_version to use the new
API, and then convert the backend implementation to do things more
efficiently.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>

In this patch, consumers are allowed to set suspend voltage, and this
actually just set the "uV" in constraint::regulator_state, when the
regulator_suspend_late() was called by PM core through callback when
the system is entering into suspend, the regulator device would act
suspend activity then.

And it assumes that if any consumer set suspend voltage, the regulator
device should be enabled in the suspend state.  And if the suspend
voltage of a regulator device for all consumers was set zero, the
regulator device would be off in the suspend state.

This patch also provides a new function hook to regulator devices for
resuming from suspend states.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Regualtor suspend/resume functions should only be called by PM suspend
core via registering dev_pm_ops, and regulator devices should implement
the callback functions.  Thus, any regulator consumer shouldn't call
the regulator suspend/resume functions directly.

In order to avoid compile errors, two empty functions with the same name
still be left for the time being.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The items "disabled" and "enabled" are a little redundant, since only one
of them would be set to record if the regulator device should keep on
or be switched to off in suspend states.

So in this patch, the "disabled" was removed, only leave the "enabled":
  - enabled == 1 for regulator-on-in-suspend
  - enabled == 0 for regulator-off-in-suspend
  - enabled == -1 means do nothing when entering suspend mode.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.

To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.

If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.

[ tglx: Massaged changelog ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org

Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to:
"BUG: unable to handle kernel NULL pointer dereference at           (null)"

Let's add a helper to check if update_pmtu is available before calling it.

Fixes: 52a589d5 ("geneve: update skb dst pmtu on tx path")
Fixes: a93bf0ff ("vxlan: update skb dst pmtu on tx path")
CC: Roman Kapl <code@rkapl.cz>
CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a tcp socket is closed, if it detects that its net namespace is
exiting, close immediately and do not wait for FIN sequence.

For normal sockets, a reference is taken to their net namespace, so it will
never exit while the socket is open.  However, kernel sockets do not take a
reference to their net namespace, so it may begin exiting while the kernel
socket is still open.  In this case if the kernel socket is a tcp socket,
it will stay open trying to complete its close sequence.  The sock's dst(s)
hold a reference to their interface, which are all transferred to the
namespace's loopback interface when the real interfaces are taken down.
When the namespace tries to take down its loopback interface, it hangs
waiting for all references to the loopback interface to release, which
results in messages like:

unregister_netdevice: waiting for lo to become free. Usage count = 1

These messages continue until the socket finally times out and closes.
Since the net namespace cleanup holds the net_mutex while calling its
registered pernet callbacks, any new net namespace initialization is
blocked until the current net namespace finishes exiting.

After this change, the tcp socket notices the exiting net namespace, and
closes immediately, releasing its dst(s) and their reference to the
loopback interface, which lets the net namespace continue exiting.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711407
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=97811Signed-off-by: NDan Streetman <ddstreet@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TCF_LAYER_LINK and TCF_LAYER_NETWORK returned the same pointer as
skb->data points to the network header.
Use skb_mac_header instead.
Signed-off-by: NWolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 6cfb521a.

Turns out distros do not want to make retpoline as part of their "ABI",
so this patch should not have been merged.  Sorry Andi, this was my
fault, I suggested it when your original patch was the "correct" way of
doing this instead.
Reported-by: NJiri Kosina <jikos@kernel.org>
Fixes: 6cfb521a ("module: Add retpoline tag to VERMAGIC")
Acked-by: NAndi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: rusty@rustcorp.com.au
Cc: arjan.van.de.ven@intel.com
Cc: jeyu@kernel.org
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tejun reported the following cpu-hotplug lock (percpu-rwsem) read recursion:

  tg_set_cfs_bandwidth()
    get_online_cpus()
      cpus_read_lock()

    cfs_bandwidth_usage_inc()
      static_key_slow_inc()
        cpus_read_lock()
Reported-by: NTejun Heo <tj@kernel.org>
Tested-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180122215328.GP3397@worktopSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 513674b5 ("net: reevalulate autoflowlabel setting after
sysctl setting") removed the initialisation of
ipv6_pinfo::autoflowlabel and added a second flag to indicate
whether this field or the net namespace default should be used.

The getsockopt() handling for this case was not updated, so it
currently returns 0 for all sockets for which IPV6_AUTOFLOWLABEL is
not explicitly enabled.  Fix it to return the effective value, whether
that has been set at the socket or net namespace level.

Fixes: 513674b5 ("net: reevalulate autoflowlabel setting after sysctl ...")
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function tracer can create a dynamically allocated trampoline that is
called by the function mcount or fentry hook that is used to call the
function callback that is registered. The problem is that the orc undwinder
will bail if it encounters one of these trampolines. This breaks the stack
trace of function callbacks, which include the stack tracer and setting the
stack trace for individual functions.

Since these dynamic trampolines are basically copies of the static ftrace
trampolines defined in ftrace_*.S, we do not need to create new orc entries
for the dynamic trampolines. Finding the return address on the stack will be
identical as the functions that were copied to create the dynamic
trampolines. When encountering a ftrace dynamic trampoline, we can just use
the orc entry of the ftrace static function that was copied for that
trampoline.
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

The UUID change by btrfstune sets SUPER_FLAG_CHANGING_FSID and resets it
only when changing fsid is complete. Its not a good idea to mount the
device anything in between, reading metadata blocks would fail with UUID
mismatch.

This patch doesn't add SUPER_FLAG_CHANGING_FSID into
BTRFS_SUPER_FLAG_SUPP list, so mount will fail (along with the fix in
the next patch) when SUPER_FLAG_CHANGING_FSID is set.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs-progs uses super flag bit BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34).
So just define that in kernel so that we know its been used.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Just a code spatial rearrangement, no functional change.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit 9036c102 ("Btrfs: update hole handling v2") added the
FLAG_VACANCY to denote holes, however there was already a consistent way
of flagging extents which represent hole - ->block_start =
EXTENT_MAP_HOLE. And also the only place where this flag is checked is
in the fiemap code, but the block_start value is also checked and every
other place in the filesystem detects holes by using block_start
value's. So remove the extra flag. This survived a full xfstest run.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Tetsuo reported random crashes under memory pressure on 32-bit x86
system and tracked down to change that introduced
page_vma_mapped_walk().

The root cause of the issue is the faulty pointer math in check_pte().
As ->pte may point to an arbitrary page we have to check that they are
belong to the section before doing math. Otherwise it may lead to weird
results.

It wasn't noticed until now as mem_map[] is virtually contiguous on
flatmem or vmemmap sparsemem. Pointer arithmetic just works against all
'struct page' pointers. But with classic sparsemem, it doesn't because
each section memap is allocated separately and so consecutive pfns
crossing two sections might have struct pages at completely unrelated
addresses.

Let's restructure code a bit and replace pointer arithmetic with
operations on pfns.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-and-tested-by: NTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Acked-by: NMichal Hocko <mhocko@suse.com>
Fixes: ace71a19 ("mm: introduce page_vma_mapped_walk()")
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The new firmware interfaces for branch prediction behaviour changes
are transparently available for the guest. Nevertheless, there is
new state attached that should be migrated and properly resetted.
Provide a mechanism for handling reset, migration and VSIE.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
[Changed capability number to 152. - Radim]
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

GCC-4.4.4 raises errors when assigning a parameter in an anonymous
union, leading to this kind of failure:

drivers/mtd/nand/marvell_nand.c:1936:
    warning: missing braces around initializer
    warning: (near initialization for '(anonymous)[1].<anonymous>')
    error: unknown field 'data' specified in initializer
    error: unknown field 'addr' specified in initializer

Work around the situation by naming these unions.

Fixes: 8878b126 ("mtd: nand: add ->exec_op() implementation")
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

The previous patch removed all users of these two functions. Hence
also remove the functions themselves.
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch avoids that workloads with large block sizes (megabytes)
can trigger the following call stack with the ib_srpt driver (that
driver is the only driver that chains scatterlists allocated by
sgl_alloc_order()):

BUG: Bad page state in process kworker/0:1H  pfn:2423a78
page:fffffb03d08e9e00 count:-3 mapcount:0 mapping:          (null) index:0x0
flags: 0x57ffffc0000000()
raw: 0057ffffc0000000 0000000000000000 0000000000000000 fffffffdffffffff
raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000
page dumped because: nonzero _count
CPU: 0 PID: 733 Comm: kworker/0:1H Tainted: G          I      4.15.0-rc7.bart+ #1
Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015
Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
Call Trace:
 dump_stack+0x5c/0x83
 bad_page+0xf5/0x10f
 get_page_from_freelist+0xa46/0x11b0
 __alloc_pages_nodemask+0x103/0x290
 sgl_alloc_order+0x101/0x180
 target_alloc_sgl+0x2c/0x40 [target_core_mod]
 srpt_alloc_rw_ctxs+0x173/0x2d0 [ib_srpt]
 srpt_handle_new_iu+0x61e/0x7f0 [ib_srpt]
 __ib_process_cq+0x55/0xa0 [ib_core]
 ib_cq_poll_work+0x1b/0x60 [ib_core]
 process_one_work+0x141/0x340
 worker_thread+0x47/0x3e0
 kthread+0xf5/0x130
 ret_from_fork+0x1f/0x30

Fixes: e80a0af4 ("lib/scatterlist: Introduce sgl_alloc() and sgl_free()")
Reported-by: NLaurence Oberman <loberman@redhat.com>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Without this patch, I drown in a sea of unknown attribute warnings

Link: http://lkml.kernel.org/r/20180117024539.27354-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace
information about the underlying machine's level of vulnerability
to the recently announced vulnerabilities CVE-2017-5715,
CVE-2017-5753 and CVE-2017-5754, and whether the machine provides
instructions to assist software to work around the vulnerabilities.

The ioctl returns two u64 words describing characteristics of the
CPU and required software behaviour respectively, plus two mask
words which indicate which bits have been filled in by the kernel,
for extensibility.  The bit definitions are the same as for the
new H_GET_CPU_CHARACTERISTICS hypercall.

There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which
indicates whether the new ioctl is available.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

These two functions are only called from inside the block layer so
unexport them.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

These users of lockdep_is_held() either wanted lockdep_is_held to
take a const pointer, or would benefit from providing a const pointer.
Signed-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Link: https://lkml.kernel.org/r/20180117151414.23686-4-willy@infradead.org

There are several places in the kernel which would like to pass a const
pointer to lockdep_is_held().  Constify the entire path so nobody has to
trick the compiler.
Signed-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Link: https://lkml.kernel.org/r/20180117151414.23686-3-willy@infradead.org

Like mmc_can_gpio_cd(), mmc_can_gpio_ro() will also be useful for host
drivers to know whether GPIO write-protect detection is supported.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Define the bit positions instead of macros using the magic values,
and move the expanded helpers to calculate the size and size unit into
the implementation C file.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>

Expand INIT_STRUCT_PID in the single place that uses it and then remove it.
There doesn't seem any point in the macro.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: NPalmer Dabbelt <palmer@sifive.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

There doesn't seem to be any need to have the INIT_SIGNALS and INIT_SIGHAND
macros, so expand them in their single places of use and remove them.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: NPalmer Dabbelt <palmer@sifive.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Expand various INIT_* macros into the single places they're used in
init/init_task.c and remove them.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: NPalmer Dabbelt <palmer@sifive.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

It's no longer necessary to have an INIT_TASK() macro, and this can be
expanded into the one place it is now used and removed.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: NPalmer Dabbelt <palmer@sifive.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Add a marker for retpoline to the module VERMAGIC. This catches the case
when a non RETPOLINE compiled module gets loaded into a retpoline kernel,
making it insecure.

It doesn't handle the case when retpoline has been runtime disabled.  Even
in this case the match of the retcompile status will be enforced.  This
implies that even with retpoline run time disabled all modules loaded need
to be recompiled.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Cc: rusty@rustcorp.com.au
Cc: arjan.van.de.ven@intel.com
Cc: jeyu@kernel.org
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@firstfloor.org

While working on fixing another bug, I ran into the following panic
on arm64 by simply attaching clsact qdisc, adding a filter and running
traffic on ingress to it:

  [...]
  [  178.188591] Unable to handle kernel read from unreadable memory at virtual address 810fb501f000
  [  178.197314] Mem abort info:
  [  178.200121]   ESR = 0x96000004
  [  178.203168]   Exception class = DABT (current EL), IL = 32 bits
  [  178.209095]   SET = 0, FnV = 0
  [  178.212157]   EA = 0, S1PTW = 0
  [  178.215288] Data abort info:
  [  178.218175]   ISV = 0, ISS = 0x00000004
  [  178.222019]   CM = 0, WnR = 0
  [  178.224997] user pgtable: 4k pages, 48-bit VAs, pgd = 0000000023cb3f33
  [  178.231531] [0000810fb501f000] *pgd=0000000000000000
  [  178.236508] Internal error: Oops: 96000004 [#1] SMP
  [...]
  [  178.311855] CPU: 73 PID: 2497 Comm: ping Tainted: G        W        4.15.0-rc7+ #5
  [  178.319413] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB18A 03/31/2017
  [  178.326887] pstate: 60400005 (nZCv daif +PAN -UAO)
  [  178.331685] pc : __netif_receive_skb_core+0x49c/0xac8
  [  178.336728] lr : __netif_receive_skb+0x28/0x78
  [  178.341161] sp : ffff00002344b750
  [  178.344465] x29: ffff00002344b750 x28: ffff810fbdfd0580
  [  178.349769] x27: 0000000000000000 x26: ffff000009378000
  [...]
  [  178.418715] x1 : 0000000000000054 x0 : 0000000000000000
  [  178.424020] Process ping (pid: 2497, stack limit = 0x000000009f0a3ff4)
  [  178.430537] Call trace:
  [  178.432976]  __netif_receive_skb_core+0x49c/0xac8
  [  178.437670]  __netif_receive_skb+0x28/0x78
  [  178.441757]  process_backlog+0x9c/0x160
  [  178.445584]  net_rx_action+0x2f8/0x3f0
  [...]

Reason is that sch_ingress and sch_clsact are doing mini_qdisc_pair_init()
which sets up miniq pointers to cpu_{b,q}stats from the underlying qdisc.
Problem is that this cannot work since they are actually set up right after
the qdisc ->init() callback in qdisc_create(), so first packet going into
sch_handle_ingress() tries to call mini_qdisc_bstats_cpu_update() and we
therefore panic.

In order to fix this, allocation of {b,q}stats needs to happen before we
call into ->init(). In net-next, there's already such option through commit
d59f5ffa ("net: sched: a dflt qdisc may be used with per cpu stats").
However, the bug needs to be fixed in net still for 4.15. Thus, include
these bits to reduce any merge churn and reuse the static_flags field to
set TCQ_F_CPUSTATS, and remove the allocation from qdisc_create() since
there is no other user left. Prashant Bhole ran into the same issue but
for net-next, thus adding him below as well as co-author. Same issue was
also reported by Sandipan Das when using bcc.

Fixes: 46209401 ("net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath")
Reference: https://lists.iovisor.org/pipermail/iovisor-dev/2018-January/001190.htmlReported-by: NSandipan Das <sandipan@linux.vnet.ibm.com>
Co-authored-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Co-authored-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some older compilers (gcc-4.4 through 4.6 in particular) struggle
with the way that blkg_rwstat_read() returns a structure, leading
to excessive stack usage and rather inefficient code:

block/blk-cgroup.c: In function 'blkg_destroy':
block/blk-cgroup.c:354:1: error: the frame size of 1296 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/cfq-iosched.c: In function 'cfqg_stats_add_aux':
block/cfq-iosched.c:753:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/bfq-cgroup.c: In function 'bfqg_stats_add_aux':
block/bfq-cgroup.c:299:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

I also notice that there is no point in using atomic accesses
for the local variables, so storing the temporaries in simple 'u64'
variables not only avoids the stack usage on older compilers but
also improves the object code on modern versions.

Fixes: e6269c44 ("blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it")
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch brings basic support for the Linux Driver Model to the
NuBus subsystem.

For flexibility, the matching of boards with drivers is left up to the
drivers. This is also the approach taken by NetBSD. A board may have
many functions, and drivers may have to consider many functional
resources and board resources in order to match a device.

This implementation does not bind drivers to resources (nor does it bind
many drivers to the same board). Apple's NuBus declaration ROM design
is flexible enough to allow that, but I don't see a need to support it
as we don't use the "slot zero" resources (in the main logic board ROM).

Eliminate the global nubus_boards linked list by rewriting the procfs
board iterator around bus_for_each_dev(). Hence the nubus device refcount
can be used to determine the lifespan of board objects.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: NStan Johnson <userm57@yahoo.com>
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>