In commit f341861fb0 ("task_work: add a scheduling point in
task_work_run()") I fixed a latency problem adding a cond_resched()
call.
Later, commit ac3d0da8f3 added yet another loop to reverse a list,
bringing back the latency spike :
I've seen in some cases this loop taking 275 ms, if for example a
process with 2,000,000 files is killed.
We could add yet another cond_resched() in the reverse loop, or we
can simply remove the reversal, as I do not think anything
would depend on order of task_work_add() submitted works.
Fixes: ac3d0da8f3 ("task_work: Make task_work_add() lockless")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These two flags gets set in vma->vm_flags to tell the VM common code
if the userfaultfd is armed and in which mode (only tracking missing
faults, only tracking wrprotect faults or both). If neither flags is
set it means the userfaultfd is not armed on the vma.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds the vm_userfaultfd_ctx to the vm_area_struct.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
userfaultfd needs to wake all waitqueues (pass 0 as nr parameter), instead
of the current hardcoded 1 (that would wake just the first waitqueue in
the head list).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename watchdog_suspend() to lockup_detector_suspend() and
watchdog_resume() to lockup_detector_resume() to avoid confusion with the
watchdog subsystem and to be consistent with the existing name
lockup_detector_init().
Also provide comment blocks to explain the watchdog_running and
watchdog_suspended variables and their relationship.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove watchdog_nmi_disable_all() and watchdog_nmi_enable_all() since
these functions are no longer needed. If a subsystem has a need to
deactivate the watchdog temporarily, it should utilize the
watchdog_suspend() and watchdog_resume() functions.
[akpm@linux-foundation.org: fix build with CONFIG_LOCKUP_DETECTOR=m]
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove update_watchdog() and restart_watchdog_hrtimer() since these
functions are no longer needed. Changes of parameters such as the sample
period are honored at the time when the watchdog threads are being
unparked.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This interface can be utilized to deactivate the hard and soft lockup
detector temporarily. Callers are expected to minimize the duration of
deactivation. Multiple deactivations are allowed to occur in parallel but
should be rare in practice.
[akpm@linux-foundation.org: remove unneeded static initialization]
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Originally watchdog_nmi_enable(cpu) and watchdog_nmi_disable(cpu) were
only called in watchdog thread context. However, the following commits
utilize these functions outside of watchdog thread context too.
commit 9809b18fcf
Author: Michal Hocko <mhocko@suse.cz>
Date: Tue Sep 24 15:27:30 2013 -0700
watchdog: update watchdog_thresh properly
commit b3738d2932
Author: Stephane Eranian <eranian@google.com>
Date: Mon Nov 17 20:07:03 2014 +0100
watchdog: Add watchdog enable/disable all functions
Hence, it is now possible that these functions execute concurrently with
the same 'cpu' argument. This concurrency is problematic because per-cpu
'watchdog_ev' can be accessed/modified without adequate synchronization.
The patch series aims to address the above problem. However, instead of
introducing locks to protect per-cpu 'watchdog_ev' a different approach is
taken: Invoke these functions by parking and unparking the watchdog
threads (to ensure they are always called in watchdog thread context).
static struct smp_hotplug_thread watchdog_threads = {
...
.park = watchdog_disable, // calls watchdog_nmi_disable()
.unpark = watchdog_enable, // calls watchdog_nmi_enable()
};
Both previously mentioned commits call these functions in a similar way
and thus in principle contain some duplicate code. The patch series also
avoids this duplication by providing a commonly usable mechanism.
- Patch 1/4 introduces the watchdog_{park|unpark}_threads functions that
park/unpark all watchdog threads specified in 'watchdog_cpumask'. They
are intended to be called inside of kernel/watchdog.c only.
- Patch 2/4 introduces the watchdog_{suspend|resume} functions which can
be utilized by external callers to deactivate the hard and soft lockup
detector temporarily.
- Patch 3/4 utilizes watchdog_{park|unpark}_threads to replace some code
that was introduced by commit 9809b18fcf.
- Patch 4/4 utilizes watchdog_{suspend|resume} to replace some code that
was introduced by commit b3738d2932.
A few corner cases should be mentioned here for completeness.
- kthread_park() of watchdog/N could hang if cpu N is already locked up.
However, if watchdog is enabled the lockup will be detected anyway.
- kthread_unpark() of watchdog/N could hang if cpu N got locked up after
kthread_park(). The occurrence of this scenario should be _very_ rare
in practice, in particular because it is not expected that temporary
deactivation will happen frequently, and if it happens at all it is
expected that the duration of deactivation will be short.
This patch (of 4): introduce watchdog_park_threads() and watchdog_unpark_threads()
These functions are intended to be used only from inside kernel/watchdog.c
to park/unpark all watchdog threads that are specified in
watchdog_cpumask.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel's NMI watchdog has nothing to do with the watchdog subsystem.
Its header declarations should be in linux/nmi.h, not linux/watchdog.h.
The code provided two sets of dummy functions if HARDLOCKUP_DETECTOR is
not configured, one in the include file and one in kernel/watchdog.c.
Remove the dummy functions from kernel/watchdog.c and use those from the
include file.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
housekeeping_mask gathers all the CPUs that aren't part of the nohz_full
set. This is exactly what we want the watchdog to be affine to without
the need to use complicated cpumask operations.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It makes the registration cheaper and simpler for the smpboot per-cpu
kthread users that don't need to always update the cpumask after threads
creation.
[sfr@canb.auug.org.au: fix for allow passing the cpumask on per-cpu thread registration]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The per-cpu kthread cleanup() callback is the mirror of the setup()
callback. When the per-cpu kthread is started, it first calls setup()
to initialize the resources which are then released by cleanup() when
the kthread exits.
Now since the introduction of a per-cpu kthread cpumask, the kthreads
excluded by the cpumask on boot may happen to be parked immediately
after their creation without taking the setup() stage, waiting to be
asked to unpark to do so. Then when smpboot_unregister_percpu_thread()
is later called, the kthread is stopped without having ever called
setup().
But this triggers a bug as the kthread unconditionally calls cleanup()
on exit but this doesn't mirror any setup(). Thus the kernel crashes
because we try to free resources that haven't been initialized, as in
the watchdog case:
WATCHDOG disable 0
WATCHDOG disable 1
WATCHDOG disable 2
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: hrtimer_active+0x26/0x60
[...]
Call Trace:
hrtimer_try_to_cancel+0x1c/0x280
hrtimer_cancel+0x1d/0x30
watchdog_disable+0x56/0x70
watchdog_cleanup+0xe/0x10
smpboot_thread_fn+0x23c/0x2c0
kthread+0xf8/0x110
ret_from_fork+0x3f/0x70
This bug is currently masked with explicit kthread unparking before
kthread_stop() on smpboot_destroy_threads(). This forces a call to
setup() and then unpark().
We could fix this by unconditionally calling setup() on kthread entry.
But setup() isn't always cheap. In the case of watchdog it launches
hrtimer, perf events, etc... So we may as well like to skip it if there
are chances the kthread will never be used, as in a reduced cpumask value.
So let's simply do a state machine check before calling cleanup() that
makes sure setup() has been called before mirroring it.
And remove the nasty hack workaround.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cpumask is allocated before threads get created. If the latter step
fails, we need to free the cpumask.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g. new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else. This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.
Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use
of "sudo" is something more sneaky:
$ BASE="ovl"
$ MNT="$BASE/mnt"
$ LOW="$BASE/lower"
$ UP="$BASE/upper"
$ WORK="$BASE/work/ 0 0
none /proc fuse.pwn user_id=1000"
$ mkdir -p "$LOW" "$UP" "$WORK"
$ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
$ cat /proc/mounts
none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
none /proc fuse.pwn user_id=1000 0 0
$ fusermount -u /proc
$ cat /proc/mounts
cat: /proc/mounts: No such file or directory
This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed. Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.
[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: J. R. Okajima <hooanon05g@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Credit where credit is due: this idea comes from Christoph Lameter with
a lot of valuable input from Serge Hallyn. This patch is heavily based
on Christoph's patch.
===== The status quo =====
On Linux, there are a number of capabilities defined by the kernel. To
perform various privileged tasks, processes can wield capabilities that
they hold.
Each task has four capability masks: effective (pE), permitted (pP),
inheritable (pI), and a bounding set (X). When the kernel checks for a
capability, it checks pE. The other capability masks serve to modify
what capabilities can be in pE.
Any task can remove capabilities from pE, pP, or pI at any time. If a
task has a capability in pP, it can add that capability to pE and/or pI.
If a task has CAP_SETPCAP, then it can add any capability to pI, and it
can remove capabilities from X.
Tasks are not the only things that can have capabilities; files can also
have capabilities. A file can have no capabilty information at all [1].
If a file has capability information, then it has a permitted mask (fP)
and an inheritable mask (fI) as well as a single effective bit (fE) [2].
File capabilities modify the capabilities of tasks that execve(2) them.
A task that successfully calls execve has its capabilities modified for
the file ultimately being excecuted (i.e. the binary itself if that
binary is ELF or for the interpreter if the binary is a script.) [3] In
the capability evolution rules, for each mask Z, pZ represents the old
value and pZ' represents the new value. The rules are:
pP' = (X & fP) | (pI & fI)
pI' = pI
pE' = (fE ? pP' : 0)
X is unchanged
For setuid binaries, fP, fI, and fE are modified by a moderately
complicated set of rules that emulate POSIX behavior. Similarly, if
euid == 0 or ruid == 0, then fP, fI, and fE are modified differently
(primary, fP and fI usually end up being the full set). For nonroot
users executing binaries with neither setuid nor file caps, fI and fP
are empty and fE is false.
As an extra complication, if you execute a process as nonroot and fE is
set, then the "secure exec" rules are in effect: AT_SECURE gets set,
LD_PRELOAD doesn't work, etc.
This is rather messy. We've learned that making any changes is
dangerous, though: if a new kernel version allows an unprivileged
program to change its security state in a way that persists cross
execution of a setuid program or a program with file caps, this
persistent state is surprisingly likely to allow setuid or file-capped
programs to be exploited for privilege escalation.
===== The problem =====
Capability inheritance is basically useless.
If you aren't root and you execute an ordinary binary, fI is zero, so
your capabilities have no effect whatsoever on pP'. This means that you
can't usefully execute a helper process or a shell command with elevated
capabilities if you aren't root.
On current kernels, you can sort of work around this by setting fI to
the full set for most or all non-setuid executable files. This causes
pP' = pI for nonroot, and inheritance works. No one does this because
it's a PITA and it isn't even supported on most filesystems.
If you try this, you'll discover that every nonroot program ends up with
secure exec rules, breaking many things.
This is a problem that has bitten many people who have tried to use
capabilities for anything useful.
===== The proposed change =====
This patch adds a fifth capability mask called the ambient mask (pA).
pA does what most people expect pI to do.
pA obeys the invariant that no bit can ever be set in pA if it is not
set in both pP and pI. Dropping a bit from pP or pI drops that bit from
pA. This ensures that existing programs that try to drop capabilities
still do so, with a complication. Because capability inheritance is so
broken, setting KEEPCAPS, using setresuid to switch to nonroot uids, and
then calling execve effectively drops capabilities. Therefore,
setresuid from root to nonroot conditionally clears pA unless
SECBIT_NO_SETUID_FIXUP is set. Processes that don't like this can
re-add bits to pA afterwards.
The capability evolution rules are changed:
pA' = (file caps or setuid or setgid ? 0 : pA)
pP' = (X & fP) | (pI & fI) | pA'
pI' = pI
pE' = (fE ? pP' : pA')
X is unchanged
If you are nonroot but you have a capability, you can add it to pA. If
you do so, your children get that capability in pA, pP, and pE. For
example, you can set pA = CAP_NET_BIND_SERVICE, and your children can
automatically bind low-numbered ports. Hallelujah!
Unprivileged users can create user namespaces, map themselves to a
nonzero uid, and create both privileged (relative to their namespace)
and unprivileged process trees. This is currently more or less
impossible. Hallelujah!
You cannot use pA to try to subvert a setuid, setgid, or file-capped
program: if you execute any such program, pA gets cleared and the
resulting evolution rules are unchanged by this patch.
Users with nonzero pA are unlikely to unintentionally leak that
capability. If they run programs that try to drop privileges, dropping
privileges will still work.
It's worth noting that the degree of paranoia in this patch could
possibly be reduced without causing serious problems. Specifically, if
we allowed pA to persist across executing non-pA-aware setuid binaries
and across setresuid, then, naively, the only capabilities that could
leak as a result would be the capabilities in pA, and any attacker
*already* has those capabilities. This would make me nervous, though --
setuid binaries that tried to privilege-separate might fail to do so,
and putting CAP_DAC_READ_SEARCH or CAP_DAC_OVERRIDE into pA could have
unexpected side effects. (Whether these unexpected side effects would
be exploitable is an open question.) I've therefore taken the more
paranoid route. We can revisit this later.
An alternative would be to require PR_SET_NO_NEW_PRIVS before setting
ambient capabilities. I think that this would be annoying and would
make granting otherwise unprivileged users minor ambient capabilities
(CAP_NET_BIND_SERVICE or CAP_NET_RAW for example) much less useful than
it is with this patch.
===== Footnotes =====
[1] Files that are missing the "security.capability" xattr or that have
unrecognized values for that xattr end up with has_cap set to false.
The code that does that appears to be complicated for no good reason.
[2] The libcap capability mask parsers and formatters are dangerously
misleading and the documentation is flat-out wrong. fE is *not* a mask;
it's a single bit. This has probably confused every single person who
has tried to use file capabilities.
[3] Linux very confusingly processes both the script and the interpreter
if applicable, for reasons that elude me. The results from thinking
about a script's file capabilities and/or setuid bits are mostly
discarded.
Preliminary userspace code is here, but it needs updating:
https://git.kernel.org/cgit/linux/kernel/git/luto/util-linux-playground.git/commit/?h=cap_ambient&id=7f5afbd175d2
Here is a test program that can be used to verify the functionality
(from Christoph):
/*
* Test program for the ambient capabilities. This program spawns a shell
* that allows running processes with a defined set of capabilities.
*
* (C) 2015 Christoph Lameter <cl@linux.com>
* Released under: GPL v3 or later.
*
*
* Compile using:
*
* gcc -o ambient_test ambient_test.o -lcap-ng
*
* This program must have the following capabilities to run properly:
* Permissions for CAP_NET_RAW, CAP_NET_ADMIN, CAP_SYS_NICE
*
* A command to equip the binary with the right caps is:
*
* setcap cap_net_raw,cap_net_admin,cap_sys_nice+p ambient_test
*
*
* To get a shell with additional caps that can be inherited by other processes:
*
* ./ambient_test /bin/bash
*
*
* Verifying that it works:
*
* From the bash spawed by ambient_test run
*
* cat /proc/$$/status
*
* and have a look at the capabilities.
*/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <cap-ng.h>
#include <sys/prctl.h>
#include <linux/capability.h>
/*
* Definitions from the kernel header files. These are going to be removed
* when the /usr/include files have these defined.
*/
#define PR_CAP_AMBIENT 47
#define PR_CAP_AMBIENT_IS_SET 1
#define PR_CAP_AMBIENT_RAISE 2
#define PR_CAP_AMBIENT_LOWER 3
#define PR_CAP_AMBIENT_CLEAR_ALL 4
static void set_ambient_cap(int cap)
{
int rc;
capng_get_caps_process();
rc = capng_update(CAPNG_ADD, CAPNG_INHERITABLE, cap);
if (rc) {
printf("Cannot add inheritable cap\n");
exit(2);
}
capng_apply(CAPNG_SELECT_CAPS);
/* Note the two 0s at the end. Kernel checks for these */
if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap, 0, 0)) {
perror("Cannot set cap");
exit(1);
}
}
int main(int argc, char **argv)
{
int rc;
set_ambient_cap(CAP_NET_RAW);
set_ambient_cap(CAP_NET_ADMIN);
set_ambient_cap(CAP_SYS_NICE);
printf("Ambient_test forking shell\n");
if (execv(argv[1], argv + 1))
perror("Cannot exec");
return 0;
}
Signed-off-by: Christoph Lameter <cl@linux.com> # Original author
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Aaron Jones <aaronmdjones@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Markku Savela <msa@moth.iki.fi>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Make it clear that the `node' arg refers to memory allocations only:
kthread_create_on_node() does not pin the new thread to that node's
CPUs.
- Encourage the use of NUMA_NO_NODE.
[nzimmer@sgi.com: use NUMA_NO_NODE in kthread_create() also]
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull locking and atomic updates from Ingo Molnar:
"Main changes in this cycle are:
- Extend atomic primitives with coherent logic op primitives
(atomic_{or,and,xor}()) and deprecate the old partial APIs
(atomic_{set,clear}_mask())
The old ops were incoherent with incompatible signatures across
architectures and with incomplete support. Now every architecture
supports the primitives consistently (by Peter Zijlstra)
- Generic support for 'relaxed atomics':
- _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
- atomic_read_acquire()
- atomic_set_release()
This came out of porting qwrlock code to arm64 (by Will Deacon)
- Clean up the fragile static_key APIs that were causing repeat bugs,
by introducing a new one:
DEFINE_STATIC_KEY_TRUE(name);
DEFINE_STATIC_KEY_FALSE(name);
which define a key of different types with an initial true/false
value.
Then allow:
static_branch_likely()
static_branch_unlikely()
to take a key of either type and emit the right instruction for the
case. To be able to know the 'type' of the static key we encode it
in the jump entry (by Peter Zijlstra)
- Static key self-tests (by Jason Baron)
- qrwlock optimizations (by Waiman Long)
- small futex enhancements (by Davidlohr Bueso)
- ... and misc other changes"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
jump_label/x86: Work around asm build bug on older/backported GCCs
locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
locking/static_keys: Make verify_keys() static
jump label, locking/static_keys: Update docs
locking/static_keys: Provide a selftest
jump_label: Provide a self-test
s390/uaccess, locking/static_keys: employ static_branch_likely()
x86, tsc, locking/static_keys: Employ static_branch_likely()
locking/static_keys: Add selftest
locking/static_keys: Add a new static_key interface
locking/static_keys: Rework update logic
locking/static_keys: Add static_key_{en,dis}able() helpers
...
Pull networking updates from David Miller:
"Another merge window, another set of networking changes. I've heard
rumblings that the lightweight tunnels infrastructure has been voted
networking change of the year. But what do I know?
1) Add conntrack support to openvswitch, from Joe Stringer.
2) Initial support for VRF (Virtual Routing and Forwarding), which
allows the segmentation of routing paths without using multiple
devices. There are some semantic kinks to work out still, but
this is a reasonably strong foundation. From David Ahern.
3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov.
4) Ignore route nexthops with a link down state in ipv6, just like
ipv4. From Andy Gospodarek.
5) Remove spinlock from fast path of act_gact and act_mirred, from
Eric Dumazet.
6) Document the DSA layer, from Florian Fainelli.
7) Add netconsole support to bcmgenet, systemport, and DSA. Also
from Florian Fainelli.
8) Add Mellanox Switch Driver and core infrastructure, from Jiri
Pirko.
9) Add support for "light weight tunnels", which allow for
encapsulation and decapsulation without bearing the overhead of a
full blown netdevice. From Thomas Graf, Jiri Benc, and a cast of
others.
10) Add Identifier Locator Addressing support for ipv6, from Tom
Herbert.
11) Support fragmented SKBs in iwlwifi, from Johannes Berg.
12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia.
13) Add BQL support to 3c59x driver, from Loganaden Velvindron.
14) Stop using a zero TX queue length to mean that a device shouldn't
have a qdisc attached, use an explicit flag instead. From Phil
Sutter.
15) Use generic geneve netdevice infrastructure in openvswitch, from
Pravin B Shelar.
16) Add infrastructure to avoid re-forwarding a packet in software
that was already forwarded by a hardware switch. From Scott
Feldman.
17) Allow AF_PACKET fanout function to be implemented in a bpf
program, from Willem de Bruijn"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits)
netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled
net: fec: clear receive interrupts before processing a packet
ipv6: fix exthdrs offload registration in out_rt path
xen-netback: add support for multicast control
bgmac: Update fixed_phy_register()
sock, diag: fix panic in sock_diag_put_filterinfo
flow_dissector: Use 'const' where possible.
flow_dissector: Fix function argument ordering dependency
ixgbe: Resolve "initialized field overwritten" warnings
ixgbe: Remove bimodal SR-IOV disabling
ixgbe: Add support for reporting 2.5G link speed
ixgbe: fix bounds checking in ixgbe_setup_tc for 82598
ixgbe: support for ethtool set_rxfh
ixgbe: Avoid needless PHY access on copper phys
ixgbe: cleanup to use cached mask value
ixgbe: Remove second instance of lan_id variable
ixgbe: use kzalloc for allocating one thing
flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c
ixgbe: Remove unused PCI bus types
...
The commit a4543a2fa9 "ring-buffer: Get timestamp after event is
allocated" is needed for some future work. But after adding it, there is a
race somewhere that causes the saved timestamp to have a slight shift, and
get ahead of the actual timestamp and make it look like time goes backwards.
I'm still looking into why this happens, but in the mean time, this is
holding up other work to get in. I'm reverting the change for now (which
makes the problem go away), and will add it back after I know what is wrong
and fix it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
cpu_cluster_pm_exit() must be sent after cpu_cluster_pm_enter() has been
sent for the cluster and before any cpu_pm_exit() notifications are sent
for any CPU.
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull core block updates from Jens Axboe:
"This first core part of the block IO changes contains:
- Cleanup of the bio IO error signaling from Christoph. We used to
rely on the uptodate bit and passing around of an error, now we
store the error in the bio itself.
- Improvement of the above from myself, by shrinking the bio size
down again to fit in two cachelines on x86-64.
- Revert of the max_hw_sectors cap removal from a revision again,
from Jeff Moyer. This caused performance regressions in various
tests. Reinstate the limit, bump it to a more reasonable size
instead.
- Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
Most devices have huge trim limits, which can cause nasty latencies
when deleting files. Enable the admin to configure the size down.
We will look into having a more sane default instead of UINT_MAX
sectors.
- Improvement of the SGP gaps logic from Keith Busch.
- Enable the block core to handle arbitrarily sized bios, which
enables a nice simplification of bio_add_page() (which is an IO hot
path). From Kent.
- Improvements to the partition io stats accounting, making it
faster. From Ming Lei.
- Also from Ming Lei, a basic fixup for overflow of the sysfs pending
file in blk-mq, as well as a fix for a blk-mq timeout race
condition.
- Ming Lin has been carrying Kents above mentioned patches forward
for a while, and testing them. Ming also did a few fixes around
that.
- Sasha Levin found and fixed a use-after-free problem introduced by
the bio->bi_error changes from Christoph.
- Small blk cgroup cleanup from Viresh Kumar"
* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
blk: Fix bio_io_vec index when checking bvec gaps
block: Replace SG_GAPS with new queue limits mask
block: bump BLK_DEF_MAX_SECTORS to 2560
Revert "block: remove artifical max_hw_sectors cap"
blk-mq: fix race between timeout and freeing request
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
Documentation: update notes in biovecs about arbitrarily sized bios
block: remove bio_get_nr_vecs()
fs: use helper bio_add_page() instead of open coding on bi_io_vec
block: kill merge_bvec_fn() completely
md/raid5: get rid of bio_fits_rdev()
md/raid5: split bio for chunk_aligned_read
block: remove split code in blkdev_issue_{discard,write_same}
btrfs: remove bio splitting and merge_bvec_fn() calls
bcache: remove driver private bio splitting code
block: simplify bio_add_page()
block: make generic_make_request handle arbitrarily sized bios
blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
block: don't access bio->bi_error after bio_put()
block: shrink struct bio down to 2 cache lines again
...
Pull cgroup updates from Tejun Heo:
- a new PIDs controller is added. It turns out that PIDs are actually
an independent resource from kmem due to the limited PID space.
- more core preparations for the v2 interface. Once cpu side interface
is settled, it should be ready for lifting the devel mask.
for-4.3-unified-base was temporarily branched so that other trees
(block) can pull cgroup core changes that blkcg changes depend on.
- a non-critical idr_preload usage bug fix.
* 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: pids: fix invalid get/put usage
cgroup: introduce cgroup_subsys->legacy_name
cgroup: don't print subsystems for the default hierarchy
cgroup: make cftype->private a unsigned long
cgroup: export cgrp_dfl_root
cgroup: define controller file conventions
cgroup: fix idr_preload usage
cgroup: add documentation for the PIDs controller
cgroup: implement the PIDs subsystem
cgroup: allow a cgroup subsystem to reject a fork
Pull workqueue updates from Tejun Heo:
"Only three trivial changes for workqueue this time - doc, MAINTAINERS
and EXPORT_SYMBOL updates"
* 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix some docbook warnings
workqueue: Make flush_workqueue() available again to non GPL modules
workqueue: add myself as a dedicated reviwer
The code ensures that when nohz full is running, at least the
boot CPU serves as a housekeeper and it can't be later offlined.
Let's assert this assumption to make sure that we have CPUs to
handle unbound jobs like workqueues and timers while nohz full
CPUs run undisturbed.
Also improve the comments on housekeeper offlining prevention.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Vatika Harlalka <vatikaharlalka@gmail.com>
Link: http://lkml.kernel.org/r/1441119060-2230-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The problem addressed in this patch is about affining unpinned
timers. Adaptive or Full Dynticks CPUs are currently disturbed
by unnecessary jitter due to firing of such timers on them.
This patch will affine timers to online CPUs which are not full
dynticks in NOHZ_FULL configured systems. It should not
introduce overhead in nohz full off case due to static keys.
Signed-off-by: Vatika Harlalka <vatikaharlalka@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1441119060-2230-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- ACPICA update to upstream revision 20150818 including method
tracing extensions to allow more in-depth AML debugging in the
kernel and a number of assorted fixes and cleanups (Bob Moore,
Lv Zheng, Markus Elfring).
- ACPI sysfs code updates and a documentation update related to
AML method tracing (Lv Zheng).
- ACPI EC driver fix related to serialized evaluations of _Qxx
methods and ACPI tools updates allowing the EC userspace tool
to be built from the kernel source (Lv Zheng).
- ACPI processor driver updates preparing it for future
introduction of CPPC support and ACPI PCC mailbox driver
updates (Ashwin Chaugule).
- ACPI interrupts enumeration fix for a regression related
to the handling of IRQ attribute conflicts between MADT
and the ACPI namespace (Jiang Liu).
- Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar).
- ACPI device registration code reorganization to separate the
sysfs-related code and bus type operations from the rest (Rafael
J Wysocki).
- Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
- ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups
(Pan Xinhui, Rafael J Wysocki).
- cpufreq core cleanups on top of the previous changes allowing it
to preseve its sysfs directories over system suspend/resume (Viresh
Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
- cpufreq fixes and cleanups related to governors (Viresh Kumar).
- cpufreq updates (core and the cpufreq-dt driver) related to the
turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
- New DT bindings for Operating Performance Points (OPP), support
for them in the OPP framework and in the cpufreq-dt driver plus
related OPP framework fixes and cleanups (Viresh Kumar).
- cpufreq powernv driver updates (Shilpasri G Bhat).
- New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
- Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
- intel_pstate driver updates including Skylake-S support, support
for enabling HW P-states per CPU and an additional vendor bypass
list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
- cpuidle core fixes related to the handling of coupled idle states
(Xunlei Pang).
- intel_idle driver updates including Skylake Client support and
support for freeze-mode-specific idle states (Len Brown).
- Driver core updates related to power management (Andy Shevchenko,
Rafael J Wysocki).
- Generic power domains framework fixes and cleanups (Jon Hunter,
Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
- Device PM QoS framework update to allow the latency tolerance
setting to be exposed to user space via sysfs (Mika Westerberg).
- devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
- System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
- rockchip-io AVS support updates (Heiko Stuebner).
- PM core clocks support fixup (Colin Ian King).
- Power capping RAPL driver update including support for Skylake H/S
and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
- Generic device properties framework fixes related to the handling
of static (driver-provided) property sets (Andy Shevchenko).
- turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
Shreyas B Prabhu).
/
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Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"From the number of commits perspective, the biggest items are ACPICA
and cpufreq changes with the latter taking the lead (over 50 commits).
On the cpufreq front, there are many cleanups and minor fixes in the
core and governors, driver updates etc. We also have a new cpufreq
driver for Mediatek MT8173 chips.
ACPICA mostly updates its debug infrastructure and adds a number of
fixes and cleanups for a good measure.
The Operating Performance Points (OPP) framework is updated with new
DT bindings and support for them among other things.
We have a few updates of the generic power domains framework and a
reorganization of the ACPI device enumeration code and bus type
operations.
And a lot of fixes and cleanups all over.
Included is one branch from the MFD tree as it contains some
PM-related driver core and ACPI PM changes a few other commits are
based on.
Specifics:
- ACPICA update to upstream revision 20150818 including method
tracing extensions to allow more in-depth AML debugging in the
kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
Zheng, Markus Elfring).
- ACPI sysfs code updates and a documentation update related to AML
method tracing (Lv Zheng).
- ACPI EC driver fix related to serialized evaluations of _Qxx
methods and ACPI tools updates allowing the EC userspace tool to be
built from the kernel source (Lv Zheng).
- ACPI processor driver updates preparing it for future introduction
of CPPC support and ACPI PCC mailbox driver updates (Ashwin
Chaugule).
- ACPI interrupts enumeration fix for a regression related to the
handling of IRQ attribute conflicts between MADT and the ACPI
namespace (Jiang Liu).
- Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
Kasagar).
- ACPI device registration code reorganization to separate the
sysfs-related code and bus type operations from the rest (Rafael J
Wysocki).
- Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
- ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
Xinhui, Rafael J Wysocki).
- cpufreq core cleanups on top of the previous changes allowing it to
preseve its sysfs directories over system suspend/resume (Viresh
Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
- cpufreq fixes and cleanups related to governors (Viresh Kumar).
- cpufreq updates (core and the cpufreq-dt driver) related to the
turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
- New DT bindings for Operating Performance Points (OPP), support for
them in the OPP framework and in the cpufreq-dt driver plus related
OPP framework fixes and cleanups (Viresh Kumar).
- cpufreq powernv driver updates (Shilpasri G Bhat).
- New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
- Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
- intel_pstate driver updates including Skylake-S support, support
for enabling HW P-states per CPU and an additional vendor bypass
list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
- cpuidle core fixes related to the handling of coupled idle states
(Xunlei Pang).
- intel_idle driver updates including Skylake Client support and
support for freeze-mode-specific idle states (Len Brown).
- Driver core updates related to power management (Andy Shevchenko,
Rafael J Wysocki).
- Generic power domains framework fixes and cleanups (Jon Hunter,
Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
- Device PM QoS framework update to allow the latency tolerance
setting to be exposed to user space via sysfs (Mika Westerberg).
- devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
- System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
- rockchip-io AVS support updates (Heiko Stuebner).
- PM core clocks support fixup (Colin Ian King).
- Power capping RAPL driver update including support for Skylake H/S
and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
- Generic device properties framework fixes related to the handling
of static (driver-provided) property sets (Andy Shevchenko).
- turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
Shreyas B Prabhu)"
* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
cpufreq: speedstep-lib: Use monotonic clock
cpufreq: powernv: Increase the verbosity of OCC console messages
cpufreq: sfi: use kmemdup rather than duplicating its implementation
cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
cpufreq: remove redundant 'policy' field from user_policy
cpufreq: remove redundant 'governor' field from user_policy
cpufreq: update user_policy.* on success
cpufreq: use memcpy() to copy policy
cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
cpufreq: mediatek: Add MT8173 cpufreq driver
dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
PM / Domains: Fix typo in description of genpd_dev_pm_detach()
PM / Domains: Remove unusable governor dummies
PM / Domains: Make pm_genpd_init() available to modules
PM / domains: Align column headers and data in pm_genpd_summary output
powercap / RAPL: disable the 2nd power limit properly
tools: cpupower: Fix error when running cpupower monitor
PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
PM / OPP: Fix static checker warning (broken 64bit big endian systems)
...
Pull user namespace updates from Eric Biederman:
"This finishes up the changes to ensure proc and sysfs do not start
implementing executable files, as the there are application today that
are only secure because such files do not exist.
It akso fixes a long standing misfeature of /proc/<pid>/mountinfo that
did not show the proper source for files bind mounted from
/proc/<pid>/ns/*.
It also straightens out the handling of clone flags related to user
namespaces, fixing an unnecessary failure of unshare(CLONE_NEWUSER)
when files such as /proc/<pid>/environ are read while <pid> is calling
unshare. This winds up fixing a minor bug in unshare flag handling
that dates back to the first version of unshare in the kernel.
Finally, this fixes a minor regression caused by the introduction of
sysfs_create_mount_point, which broke someone's in house application,
by restoring the size of /sys/fs/cgroup to 0 bytes. Apparently that
application uses the directory size to determine if a tmpfs is mounted
on /sys/fs/cgroup.
The bind mount escape fixes are present in Al Viros for-next branch.
and I expect them to come from there. The bind mount escape is the
last of the user namespace related security bugs that I am aware of"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
fs: Set the size of empty dirs to 0.
userns,pidns: Force thread group sharing, not signal handler sharing.
unshare: Unsharing a thread does not require unsharing a vm
nsfs: Add a show_path method to fix mountinfo
mnt: fs_fully_visible enforce noexec and nosuid if !SB_I_NOEXEC
vfs: Commit to never having exectuables on proc and sysfs.
Pull irq updates from Thomas Gleixner:
"This updated pull request does not contain the last few GIC related
patches which were reported to cause a regression. There is a fix
available, but I let it breed for a couple of days first.
The irq departement provides:
- new infrastructure to support non PCI based MSI interrupts
- a couple of new irq chip drivers
- the usual pile of fixlets and updates to irq chip drivers
- preparatory changes for removal of the irq argument from interrupt
flow handlers
- preparatory changes to remove IRQF_VALID"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources
irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2
irqchip: Add documentation for the bcm2836 interrupt controller
irqchip/bcm2835: Add support for being used as a second level controller
irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ
PCI: xilinx: Fix typo in function name
irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance
irqchip/gic: Only allow the primary GIC to set the CPU map
PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove
unicore32/irq: Prepare puv3_gpio_handler for irq argument removal
tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal
m68k/irq: Prepare irq handlers for irq argument removal
C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal
blackfin: Prepare irq handlers for irq argument removal
arc/irq: Prepare idu_cascade_isr for irq argument removal
sparc/irq: Use access helper irq_data_get_affinity_mask()
sparc/irq: Use helper irq_data_get_irq_handler_data()
parisc/irq: Use access helper irq_data_get_affinity_mask()
mn10300/irq: Use access helper irq_data_get_affinity_mask()
irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal
...
Pull timer updates from Thomas Gleixner:
"Rather large, but nothing exiting:
- new range check for settimeofday() to prevent that boot time
becomes negative.
- fix for file time rounding
- a few simplifications of the hrtimer code
- fix for the proc/timerlist code so the output of clock realtime
timers is accurate
- more y2038 work
- tree wide conversion of clockevent drivers to the new callbacks"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
hrtimer: Handle failure of tick_init_highres() gracefully
hrtimer: Unconfuse switch_hrtimer_base() a bit
hrtimer: Simplify get_target_base() by returning current base
hrtimer: Drop return code of hrtimer_switch_to_hres()
time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
time: Introduce current_kernel_time64()
time: Introduce struct itimerspec64
time: Add the common weak version of update_persistent_clock()
time: Always make sure wall_to_monotonic isn't positive
time: Fix nanosecond file time rounding in timespec_trunc()
timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
cris/time: Migrate to new 'set-state' interface
kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
xtensa/time: Migrate to new 'set-state' interface
unicore/time: Migrate to new 'set-state' interface
um/time: Migrate to new 'set-state' interface
sparc/time: Migrate to new 'set-state' interface
sh/localtimer: Migrate to new 'set-state' interface
score/time: Migrate to new 'set-state' interface
s390/time: Migrate to new 'set-state' interface
...
Pull x86 asm changes from Ingo Molnar:
"The biggest changes in this cycle were:
- Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC)
primitives. (Andy Lutomirski)
- Add new, comprehensible entry and exit handlers written in C.
(Andy Lutomirski)
- vm86 mode cleanups and fixes. (Brian Gerst)
- 32-bit compat code cleanups. (Brian Gerst)
The amount of simplification in low level assembly code is already
palpable:
arch/x86/entry/entry_32.S | 130 +----
arch/x86/entry/entry_64.S | 197 ++-----
but more simplifications are planned.
There's also the usual laudry mix of low level changes - see the
changelog for details"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits)
x86/asm: Drop repeated macro of X86_EFLAGS_AC definition
x86/asm/msr: Make wrmsrl() a function
x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
x86/asm: Add MONITORX/MWAITX instruction support
x86/traps: Weaken context tracking entry assertions
x86/asm/tsc: Add rdtscll() merge helper
selftests/x86: Add syscall_nt selftest
selftests/x86: Disable sigreturn_64
x86/vdso: Emit a GNU hash
x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks
x86/entry/32: Migrate to C exit path
x86/entry/32: Remove 32-bit syscall audit optimizations
x86/vm86: Rename vm86->v86flags and v86mask
x86/vm86: Rename vm86->vm86_info to user_vm86
x86/vm86: Clean up vm86.h includes
x86/vm86: Move the vm86 IRQ definitions to vm86.h
x86/vm86: Use the normal pt_regs area for vm86
x86/vm86: Eliminate 'struct kernel_vm86_struct'
x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'
x86/vm86: Move vm86 fields out of 'thread_struct'
...
* pm-sleep:
PM / suspend: make sync() on suspend-to-RAM build-time optional
PM / sleep: Allow devices without runtime PM to do direct-complete
PM / autosleep: Use workqueue for user space wakeup sources garbage collector
* pm-domains:
PM / Domains: Fix typo in description of genpd_dev_pm_detach()
PM / Domains: Remove unusable governor dummies
PM / Domains: Make pm_genpd_init() available to modules
PM / domains: Align column headers and data in pm_genpd_summary output
PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain
PM / Domains: Correct unit address in power-controller example
PM / Domains: Remove intermediate states from the power off sequence
* pm-avs:
PM / AVS: rockchip-io: add io selectors and supplies for rk3368
PM / AVS: rockchip-io: depend on CONFIG_POWER_AVS
Pull NOHZ updates from Ingo Molnar:
"The main changes, mostly written by Frederic Weisbecker, include:
- Fix some jiffies based cputime assumptions. (No real harm because
the concerned code isn't used by full dynticks.)
- Simplify jiffies <-> usecs conversions. Remove dead code.
- Remove early hacks on nohz full code that avoided messing up idle
nohz internals. Now nohz integrates well full and idle and such
hack have become needless.
- Restart nohz full tick from irq exit. (A simplification and a
preparation for future optimization on scheduler kick to nohz
full)
- Code cleanups.
- Tile driver isolation enhancement on top of nohz. (Chris Metcalf)"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
nohz: Remove useless argument on tick_nohz_task_switch()
nohz: Move tick_nohz_restart_sched_tick() above its users
nohz: Restart nohz full tick from irq exit
nohz: Remove idle task special case
nohz: Prevent tilegx network driver interrupts
alpha: Fix jiffies based cputime assumption
apm32: Fix cputime == jiffies assumption
jiffies: Remove HZ > USEC_PER_SEC special case
Pull scheduler fix from Ingo Molnar:
"This is a leftover scheduler fix from the v4.2 cycle"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix cpu_active_mask/cpu_online_mask race
Pull scheduler updates from Ingo Molnar:
"The biggest change in this cycle is the rewrite of the main SMP load
balancing metric: the CPU load/utilization. The main goal was to make
the metric more precise and more representative - see the changelog of
this commit for the gory details:
9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")
It is done in a way that significantly reduces complexity of the code:
5 files changed, 249 insertions(+), 494 deletions(-)
and the performance testing results are encouraging. Nevertheless we
need to keep an eye on potential regressions, since this potentially
affects every SMP workload in existence.
This work comes from Yuyang Du.
Other changes:
- SCHED_DL updates. (Andrea Parri)
- Simplify architecture callbacks by removing finish_arch_switch().
(Peter Zijlstra et al)
- cputime accounting: guarantee stime + utime == rtime. (Peter
Zijlstra)
- optimize idle CPU wakeups some more - inspired by Facebook server
loads. (Mike Galbraith)
- stop_machine fixes and updates. (Oleg Nesterov)
- Introduce the 'trace_sched_waking' tracepoint. (Peter Zijlstra)
- sched/numa tweaks. (Srikar Dronamraju)
- misc fixes and small cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
sched/deadline: Fix comment in enqueue_task_dl()
sched/deadline: Fix comment in push_dl_tasks()
sched: Change the sched_class::set_cpus_allowed() calling context
sched: Make sched_class::set_cpus_allowed() unconditional
sched: Fix a race between __kthread_bind() and sched_setaffinity()
sched: Ensure a task has a non-normalized vruntime when returning back to CFS
sched/numa: Fix NUMA_DIRECT topology identification
tile: Reorganize _switch_to()
sched, sparc32: Update scheduler comments in copy_thread()
sched: Remove finish_arch_switch()
sched, tile: Remove finish_arch_switch
sched, sh: Fold finish_arch_switch() into switch_to()
sched, score: Remove finish_arch_switch()
sched, avr32: Remove finish_arch_switch()
sched, MIPS: Get rid of finish_arch_switch()
sched, arm: Remove finish_arch_switch()
sched/fair: Clean up load average references
sched/fair: Provide runnable_load_avg back to cfs_rq
sched/fair: Remove task and group entity load when they are dead
sched/fair: Init cfs_rq's sched_entity load average
...
Pull perf updates from Ingo Molnar:
"Main perf kernel side changes:
- uprobes updates/fixes. (Oleg Nesterov)
- Add PERF_RECORD_SWITCH to indicate context switches and use it in
tooling. (Adrian Hunter)
- Support BPF programs attached to uprobes and first steps for BPF
tooling support. (Wang Nan)
- x86 generic x86 MSR-to-perf PMU driver. (Andy Lutomirski)
- x86 Intel PT, LBR and BTS updates. (Alexander Shishkin)
- x86 Intel Skylake support. (Andi Kleen)
- x86 Intel Knights Landing (KNL) RAPL support. (Dasaratharaman
Chandramouli)
- x86 Intel Broadwell-DE uncore support. (Kan Liang)
- x86 hw breakpoints robustization (Andy Lutomirski)
Main perf tooling side changes:
- Support Intel PT in several tools, enabling the use of the
processor trace feature introduced in Intel Broadwell processors:
(Adrian Hunter)
# dmesg | grep Performance
# [0.188477] Performance Events: PEBS fmt2+, 16-deep LBR, Broadwell events, full-width counters, Intel PMU driver.
# perf record -e intel_pt//u -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.216 MB perf.data ]
# perf script # then navigate in the tool output to some area, like this one:
184 1030 dl_main (/usr/lib64/ld-2.17.so) => 7f21ba661440 dl_main (/usr/lib64/ld-2.17.so)
185 1457 dl_main (/usr/lib64/ld-2.17.so) => 7f21ba669f10 _dl_new_object (/usr/lib64/ld-2.17.so)
186 9f37 _dl_new_object (/usr/lib64/ld-2.17.so) => 7f21ba677b90 strlen (/usr/lib64/ld-2.17.so)
187 7ba3 strlen (/usr/lib64/ld-2.17.so) => 7f21ba677c75 strlen (/usr/lib64/ld-2.17.so)
188 7c78 strlen (/usr/lib64/ld-2.17.so) => 7f21ba669f3c _dl_new_object (/usr/lib64/ld-2.17.so)
189 9f8a _dl_new_object (/usr/lib64/ld-2.17.so) => 7f21ba65fab0 calloc@plt (/usr/lib64/ld-2.17.so)
190 fab0 calloc@plt (/usr/lib64/ld-2.17.so) => 7f21ba675e70 calloc (/usr/lib64/ld-2.17.so)
191 5e87 calloc (/usr/lib64/ld-2.17.so) => 7f21ba65fa90 malloc@plt (/usr/lib64/ld-2.17.so)
192 fa90 malloc@plt (/usr/lib64/ld-2.17.so) => 7f21ba675e60 malloc (/usr/lib64/ld-2.17.so)
193 5e68 malloc (/usr/lib64/ld-2.17.so) => 7f21ba65fa80 __libc_memalign@plt (/usr/lib64/ld-2.17.so)
194 fa80 __libc_memalign@plt (/usr/lib64/ld-2.17.so) => 7f21ba675d50 __libc_memalign (/usr/lib64/ld-2.17.so)
195 5d63 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675e20 __libc_memalign (/usr/lib64/ld-2.17.so)
196 5e40 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675d73 __libc_memalign (/usr/lib64/ld-2.17.so)
197 5d97 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675e18 __libc_memalign (/usr/lib64/ld-2.17.so)
198 5e1e __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675df9 __libc_memalign (/usr/lib64/ld-2.17.so)
199 5e10 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba669f8f _dl_new_object (/usr/lib64/ld-2.17.so)
200 9fc2 _dl_new_object (/usr/lib64/ld-2.17.so) => 7f21ba678e70 memcpy (/usr/lib64/ld-2.17.so)
201 8e8c memcpy (/usr/lib64/ld-2.17.so) => 7f21ba678ea0 memcpy (/usr/lib64/ld-2.17.so)
- Add support for using several Intel PT features (CYC, MTC packets),
the relevant documentation was updated in:
tools/perf/Documentation/intel-pt.txt
briefly describing those packets, its purposes, how to configure
them in the event config terms and relevant external documentation
for further reading. (Adrian Hunter)
- Introduce support for probing at an absolute address, for user and
kernel 'perf probe's, useful when one have the symbol maps on a
developer machine but not on an embedded system. (Wang Nan)
- Add Intel BTS support, with a call-graph script to show it and PT
in use in a GUI using 'perf script' python scripting with
postgresql and Qt. (Adrian Hunter)
- Allow selecting the type of callchains per event, including
disabling callchains in all but one entry in an event list, to save
space, and also to ask for the callchains collected in one event to
be used in other events. (Kan Liang)
- Beautify more syscall arguments in 'perf trace': (Arnaldo Carvalho
de Melo)
* A bunch more translate file/pathnames from pointers to strings.
* Convert numbers to strings for the 'keyctl' syscall 'option'
arg.
* Add missing 'clockid' entries.
- Introduce 'srcfile' sort key: (Andi Kleen)
# perf record -F 10000 usleep 1
# perf report --stdio --dsos '[kernel.vmlinux]' -s srcfile
<SNIP>
# Overhead Source File
26.49% copy_page_64.S
5.49% signal.c
0.51% msr.h
#
It can be combined with other fields, for instance, experiment with
'-s srcfile,symbol'.
There are some oddities in some distros and with some specific
DSOs, being investigated, so your mileage may vary.
- Support per-event 'freq' term: (Namhyung Kim)
$ perf record -e 'cpu/instructions,freq=1234/',cycles -c 1000 sleep 1
$ perf evlist -F
cpu/instructions,freq=1234/: sample_freq=1234
cycles: sample_period=1000
$
- Deref sys_enter pointer args with contents from probe:vfs_getname,
showing pathnames instead of pointers in many syscalls in 'perf
trace'. (Arnaldo Carvalho de Melo)
- Stop collecting /proc/kallsyms in perf.data files, saving about
4.5MB on a typical x86-64 system, use the the symbol resolution
routines used in all the other tools (report, top, etc) now that we
can ask libtraceevent to use perf's symbol resolution code.
(Arnaldo Carvalho de Melo)
- Allow filtering out of perf's PID via 'perf record --exclude-perf'.
(Wang Nan)
- 'perf trace' now supports syscall groups, like strace, i.e:
$ trace -e file touch file
Will expand 'file' into multiple, file related, syscalls. More
work needed to add extra groups for other syscall groups, and also
to complement what was added for the 'file' group, included as a
proof of concept. (Arnaldo Carvalho de Melo)
- Add lock_pi stresser to 'perf bench futex', to test the kernel code
related to FUTEX_(UN)LOCK_PI. (Davidlohr Bueso)
- Let user have timestamps with per-thread recording in 'perf record'
(Adrian Hunter)
- ... and tons of other changes, see the shortlog and the Git log for
details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (240 commits)
perf evlist: Add backpointer for perf_env to evlist
perf tools: Rename perf_session_env to perf_env
perf tools: Do not change lib/api/fs/debugfs directly
perf tools: Add tracing_path and remove unneeded functions
perf buildid: Introduce sysfs/filename__sprintf_build_id
perf evsel: Add a backpointer to the evlist a evsel is in
perf trace: Add header with copyright and background info
perf scripts python: Add new compaction-times script
perf stat: Get correct cpu id for print_aggr
tools lib traceeveent: Allow for negative numbers in print format
perf script: Add --[no-]-demangle/--[no-]-demangle-kernel
tracing/uprobes: Do not print '0x (null)' when offset is 0
perf probe: Support probing at absolute address
perf probe: Fix error reported when offset without function
perf probe: Fix list result when address is zero
perf probe: Fix list result when symbol can't be found
tools build: Allow duplicate objects in the object list
perf tools: Remove export.h from MANIFEST
perf probe: Prevent segfault when reading probe point with absolute address
perf tools: Update Intel PT documentation
...
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle are:
- the combination of tree geometry-initialization simplifications and
OS-jitter-reduction changes to expedited grace periods. These two
are stacked due to the large number of conflicts that would
otherwise result.
- privatize smp_mb__after_unlock_lock().
This commit moves the definition of smp_mb__after_unlock_lock() to
kernel/rcu/tree.h, in recognition of the fact that RCU is the only
thing using this, that nothing else is likely to use it, and that
it is likely to go away completely.
- documentation updates.
- torture-test updates.
- misc fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
rcu,locking: Privatize smp_mb__after_unlock_lock()
rcu: Silence lockdep false positive for expedited grace periods
rcu: Don't disable CPU hotplug during OOM notifiers
scripts: Make checkpatch.pl warn on expedited RCU grace periods
rcu: Update MAINTAINERS entry
rcu: Clarify CONFIG_RCU_EQS_DEBUG help text
rcu: Fix backwards RCU_LOCKDEP_WARN() in synchronize_rcu_tasks()
rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()
rcu: Make rcu_is_watching() really notrace
cpu: Wait for RCU grace periods concurrently
rcu: Create a synchronize_rcu_mult()
rcu: Fix obsolete priority-boosting comment
rcu: Use WRITE_ONCE in RCU_INIT_POINTER
rcu: Hide RCU_NOCB_CPU behind RCU_EXPERT
rcu: Add RCU-sched flavors of get-state and cond-sync
rcu: Add fastpath bypassing funnel locking
rcu: Rename RCU_GP_DONE_FQS to RCU_GP_DOING_FQS
rcu: Pull out wait_event*() condition into helper function
documentation: Describe new expedited stall warnings
rcu: Add stall warnings to synchronize_sched_expedited()
...
Here is the new patches for the driver core / sysfs for 4.3-rc1.
Very small number of changes here, all the details are in the shortlog,
nothing major happening at all this kernel release, which is nice to
see.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the new patches for the driver core / sysfs for 4.3-rc1.
Very small number of changes here, all the details are in the
shortlog, nothing major happening at all this kernel release, which is
nice to see"
* tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
bus: subsys: update return type of ->remove_dev() to void
driver core: correct device's shutdown order
driver core: fix docbook for device_private.device
selftests: firmware: skip timeout checks for kernels without user mode helper
kernel, cpu: Remove bogus __ref annotations
cpu: Remove bogus __ref annotation of cpu_subsys_online()
firmware: fix wrong memory deallocation in fw_add_devm_name()
sysfs.txt: update show method notes about sprintf/snprintf/scnprintf usage
devres: fix devres_get()
Here's the "big" char/misc driver update for 4.3-rc1.
Not much really interesting here, just a number of little changes all
over the place, and some nice consolidation of the nvmem drivers to a
common framework. As usual, the mei drivers stand out as the largest
"churn" to handle new devices and features in their hardware.
All have been in linux-next for a while with no issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver patches from Greg KH:
"Here's the "big" char/misc driver update for 4.3-rc1.
Not much really interesting here, just a number of little changes all
over the place, and some nice consolidation of the nvmem drivers to a
common framework. As usual, the mei drivers stand out as the largest
"churn" to handle new devices and features in their hardware.
All have been in linux-next for a while with no issues"
* tag 'char-misc-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits)
auxdisplay: ks0108: initialize local parport variable
extcon: palmas: Fix build break due to devm_gpiod_get_optional API change
extcon: palmas: Support GPIO based USB ID detection
extcon: Fix signedness bugs about break error handling
extcon: Drop owner assignment from i2c_driver
extcon: arizona: Simplify pdata symantics for micd_dbtime
extcon: arizona: Declare 3-pole jack if we detect open circuit on mic
extcon: Add exception handling to prevent the NULL pointer access
extcon: arizona: Ensure variables are set for headphone detection
extcon: arizona: Use gpiod inteface to handle micd_pol_gpio gpio
extcon: arizona: Add basic microphone detection DT/ACPI bindings
extcon: arizona: Update to use the new device properties API
extcon: palmas: Remove the mutually_exclusive array
extcon: Remove optional print_state() function pointer of struct extcon_dev
extcon: Remove duplicate header file in extcon.h
extcon: max77843: Clear IRQ bits state before request IRQ
toshiba laptop: replace ioremap_cache with ioremap
misc: eeprom: max6875: clean up max6875_read()
misc: eeprom: clean up eeprom_read()
misc: eeprom: 93xx46: clean up eeprom_93xx46_bin_read/write
...
generalize FETCH_FUNC_NAME(memory, string) into
strncpy_from_unsafe() and fix sparse warnings that were
present in original implementation.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This behaves like devm_memremap except that it ensures we have page
structures available that can back the region.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[djbw: catch attempts to remap RAM, drop flags]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Fix incorrect usage of css_get and css_put to put a different css in
pids_{cancel_,}attach() than the one grabbed in pids_can_attach(). This
could lead to quite serious memory leakage (and unsafe operations on the
putted css).
tj: minor comment update
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
There is a race condition in SMP bootup code, which may result
in
WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
workqueue_cpu_up_callback()
or
kernel BUG at kernel/smpboot.c:135!
It can be triggered with a bit of luck in Linux guests running
on busy hosts.
CPU0 CPUn
==== ====
_cpu_up()
__cpu_up()
start_secondary()
set_cpu_online()
cpumask_set_cpu(cpu,
to_cpumask(cpu_online_bits));
cpu_notify(CPU_ONLINE)
<do stuff, see below>
cpumask_set_cpu(cpu,
to_cpumask(cpu_active_bits));
During the various CPU_ONLINE callbacks CPUn is online but not
active. Several things can go wrong at that point, depending on
the scheduling of tasks on CPU0.
Variant 1:
cpu_notify(CPU_ONLINE)
workqueue_cpu_up_callback()
rebind_workers()
set_cpus_allowed_ptr()
This call fails because it requires an active CPU; rebind_workers()
ends with a warning:
WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
workqueue_cpu_up_callback()
Variant 2:
cpu_notify(CPU_ONLINE)
smpboot_thread_call()
smpboot_unpark_threads()
..
__kthread_unpark()
__kthread_bind()
wake_up_state()
..
select_task_rq()
select_fallback_rq()
The ->wake_cpu of the unparked thread is not allowed, making a call
to select_fallback_rq() necessary. Then, select_fallback_rq() cannot
find an allowed, active CPU and promptly resets the allowed CPUs, so
that the task in question ends up on CPU0.
When those unparked tasks are eventually executed, they run
immediately into a BUG:
kernel BUG at kernel/smpboot.c:135!
Just changing the order in which the online/active bits are set
(and adding some memory barriers), would solve the two issues
above. However, it would change the order of operations back to
the one before commit 6acbfb9697 ("sched: Fix hotplug vs.
set_cpus_allowed_ptr()"), thus, reintroducing that particular
problem.
Going further back into history, we have at least the following
commits touching this topic:
- commit 2baab4e904 ("sched: Fix select_fallback_rq() vs cpu_active/cpu_online")
- commit 5fbd036b55 ("sched: Cleanup cpu_active madness")
Together, these give us the following non-working solutions:
- secondary CPU sets active before online, because active is assumed to
be a subset of online;
- secondary CPU sets online before active, because the primary CPU
assumes that an online CPU is also active;
- secondary CPU sets online and waits for primary CPU to set active,
because it might deadlock.
Commit 875ebe940d ("powerpc/smp: Wait until secondaries are
active & online") introduces an arch-specific solution to this
arch-independent problem.
Now, go for a more general solution without explicit waiting and
simply set active twice: once on the secondary CPU after online
was set and once on the primary CPU after online was seen.
set_cpus_allowed_ptr()")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Wilson <msw@amazon.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6acbfb9697 ("sched: Fix hotplug vs. set_cpus_allowed_ptr()")
Link: http://lkml.kernel.org/r/1439408156-18840-1-git-send-email-jschoenh@amazon.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU cleanup from Paul E. McKenney:
"Privatize smp_mb__after_unlock_lock(). This commit moves the
definition of smp_mb__after_unlock_lock() to kernel/rcu/tree.h,
in recognition of the fact that RCU is the only thing using
this, that nothing else is likely to use it, and that it is
likely to go away completely."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull irq fixes from Thomas Gleixner:
"A series of small fixlets for a regression visible on OMAP devices
caused by the conversion of the OMAP interrupt chips to hierarchical
interrupt domains. Mostly one liners on the driver side plus a small
helper function in the core to avoid open coded mess in the drivers"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/crossbar: Restore set_wake functionality
irqchip/crossbar: Restore the mask on suspend behaviour
ARM: OMAP: wakeupgen: Restore the irq_set_type() mechanism
irqchip/crossbar: Restore the irq_set_type() mechanism
genirq: Introduce irq_chip_set_type_parent() helper
genirq: Don't return ENOSYS in irq_chip_retrigger_hierarchy
Pull timer fixes from Thomas Gleixner:
"Two minimalistic fixes for 4.2 regressions:
- Eric fixed a thinko in the timer_list base switching code caused by
the overhaul of the timer wheel. It can cause a cpu to see the
wrong base for a timer while we move the timer around.
- Guenter fixed a regression for IMX if booted w/o device tree, where
the timer interrupt is not initialized and therefor the machine
fails to boot"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/imx: Fix boot with non-DT systems
timer: Write timer->flags atomically
Commit 75e3b37d05 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
drops the return code of hrtimer_switch_to_hres(). While doing so, it also
drops the return statement itself on failure. This may cause a system hang.
Seen when running arm:multi_v7_defconfig in qemu with devicetree file
vexpress-v2p-ca9.
Fixes: 75e3b37d05 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/1440231047-16256-1-git-send-email-linux@roeck-us.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This helper is required for irq chips which do not implement a
irq_set_type callback and need to call down the irq domain hierarchy
for the actual trigger type change.
This helper is required to fix further wreckage caused by the
conversion of TI OMAP to hierarchical irq domains and therefor tagged
for stable.
[ tglx: Massaged changelog ]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <tony@atomide.com>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-3-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irq_chip_retrigger_hierarchy() returns -ENOSYS if it was not able to
find at least one .irq_retrigger() callback implemented in the IRQ
domain hierarchy.
That's wrong, because check_irq_resend() expects a 0 return value from
the callback in case that the hardware assisted resend was not
possible. If the return value is non zero the core code assumes
hardware resend success and the software resend is not invoked.
This results in lost interrupts on platforms where none of the parent
irq chips in the hierarchy implements the retrigger callback.
This is observable on TI OMAP, where the hierarchy is:
ARM GIC <- OMAP wakeupgen <- TI Crossbar
Return 0 instead so the software resend mechanism gets invoked.
[ tglx: Massaged changelog ]
Fixes: 85f08c17de ('genirq: Introduce helper functions...')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <tony@atomide.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-2-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This allows cgroup subsystems to use a different name on the unified
hierarchy. cgroup_subsys->name is used on the unified hierarchy,
->legacy_name elsewhere. If ->legacy_name is not explicitly set, it's
automatically set to ->name and the userland visible behavior remains
unchanged.
v2: Make parse_cgroupfs_options() only consider ->legacy_name as mount
options are used only on legacy hierarchies. Suggested by Li
Zefan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
It doesn't make sense to print subsystems on mount option or
/proc/PID/cgroup for the default hierarchy.
* cgroup.controllers file at the root of the default hierarchy lists
the currently attached controllers.
* The default hierarchy is catch-all for unmounted subsystems.
* The default hierarchy doesn't accept any mount options.
Suppress subsystem printing on mount options and /proc/PID/cgroup for
the default hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
The variable called "this_base" is confusing because its name suggests
it's of "struct hrtimer_clock_base" type, along with "base" and "new_base"
which doesn't help understanding this complicated function.
Make its name clearer and fix the misleading comment while at it.
[ tglx: Fixed the comment for real ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1439907509-9553-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
lock_timer_base() cannot prevent the following :
CPU1 ( in __mod_timer()
timer->flags |= TIMER_MIGRATING;
spin_unlock(&base->lock);
base = new_base;
spin_lock(&base->lock);
// The next line clears TIMER_MIGRATING
timer->flags &= ~TIMER_BASEMASK;
CPU2 (in lock_timer_base())
see timer base is cpu0 base
spin_lock_irqsave(&base->lock, *flags);
if (timer->flags == tf)
return base; // oops, wrong base
timer->flags |= base->cpu // too late
We must write timer->flags in one go, otherwise we can fool other cpus.
Fixes: bc7a34b8b9 ("timer: Reduce timer migration overhead if disabled")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Christopherson <jon@jons.org>
Cc: David Miller <davem@davemloft.net>
Cc: xen-devel@lists.xen.org
Cc: david.vrabel@citrix.com
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Link: http://lkml.kernel.org/r/1439831928.32680.11.camel@edumazet-glaptop2.roam.corp.google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Pull cgroup fix from Tejun Heo:
"A fix for a subtle bug introduced back during 3.17 cycle which
interferes with setting configurations under specific conditions"
* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: use trialcs->mems_allowed as a temp variable
The conversion between struct timespec and jiffies is not year 2038
safe on 32bit systems. Introduce timespec64_to_jiffies() and
jiffies_to_timespec64() functions which use struct timespec64 to
make it ready for 2038 issue.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The current_kernel_time() is not year 2038 safe on 32bit systems
since it returns a timespec value. Introduce current_kernel_time64()
which returns a timespec64 value.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The weak update_persistent_clock64() calls update_persistent_clock(),
if the architecture defines an update_persistent_clock64() to replace
and remove its update_persistent_clock() version, when building the
kernel the linker will throw an undefined symbol error, that is, any
arch that switches to update_persistent_clock64() will have this issue.
To solve the issue, we add the common weak update_persistent_clock().
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Two issues were found on an IMX6 development board without an
enabled RTC device(resulting in the boot time and monotonic
time being initialized to 0).
Issue 1:exportfs -a generate:
"exportfs: /opt/nfs/arm does not support NFS export"
Issue 2:cat /proc/stat:
"btime 4294967236"
The same issues can be reproduced on x86 after running the
following code:
int main(void)
{
struct timeval val;
int ret;
val.tv_sec = 0;
val.tv_usec = 0;
ret = settimeofday(&val, NULL);
return 0;
}
Two issues are different symptoms of same problem:
The reason is a positive wall_to_monotonic pushes boot time back
to the time before Epoch, and getboottime will return negative
value.
In symptom 1:
negative boot time cause get_expiry() to overflow time_t
when input expire time is 2147483647, then cache_flush()
always clears entries just added in ip_map_parse.
In symptom 2:
show_stat() uses "unsigned long" to print negative btime
value returned by getboottime.
This patch fix the problem by prohibiting time from being set to a value which
would cause a negative boot time. As a result one can't set the CLOCK_REALTIME
time prior to (1970 + system uptime).
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Wang YanQing <udknight@gmail.com>
[jstultz: reworded commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
timespec_trunc() avoids rounding if granularity <= nanoseconds-per-jiffie
(or TICK_NSEC). This optimization assumes that:
1. current_kernel_time().tv_nsec is already rounded to TICK_NSEC (i.e.
with HZ=1000 you'd get 1000000, 2000000, 3000000... but never 1000001).
This is no longer true (probably since hrtimers introduced in 2.6.16).
2. TICK_NSEC is evenly divisible by all possible granularities. This may
be true for HZ=100, 250, 1000, but obviously not for HZ=300 /
TICK_NSEC=3333333 (introduced in 2.6.20).
Thus, sub-second portions of in-core file times are not rounded to on-disk
granularity. I.e. file times may change when the inode is re-read from disk
or when the file system is remounted.
This affects all file systems with file time granularities > 1 ns and < 1s,
e.g. CEPH (1000 ns), UDF (1000 ns), CIFS (100 ns), NTFS (100 ns) and FUSE
(configurable from user mode via struct fuse_init_out.time_gran).
Steps to reproduce with e.g. UDF:
$ dd if=/dev/zero of=udfdisk count=10000 && mkudffs udfdisk
$ mkdir udf && mount udfdisk udf
$ touch udf/test && stat -c %y udf/test
2015-06-09 10:22:56.130006767 +0200
$ umount udf && mount udfdisk udf
$ stat -c %y udf/test
2015-06-09 10:22:56.130006000 +0200
Remounting truncates the mtime to 1 µs.
Fix the rounding in timespec_trunc() and update the documentation.
timespec_trunc() is exclusively used to calculate inode's [acm]time (mostly
via current_fs_time()), and always with super_block.s_time_gran as second
argument. So this can safely be changed without side effects.
Note: This does _not_ fix the issue for FAT's 2 second mtime resolution,
as super_block.s_time_gran isn't prepared to handle different ctime /
mtime / atime resolutions nor resolutions > 1 second.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
I noticed for non-monotonic timers in timer_list, some of the
output looked a little confusing.
For example:
#1: <0000000000000000>, posix_timer_fn, S:01, hrtimer_start_range_ns, leap-a-day/2360
# expires at 1434412800000000000-1434412800000000000 nsecs [in 1434410725062375469 to 1434410725062375469 nsecs]
You'll note the relative time till the expiration "[in xxx to
yyy nsecs]" is incorrect. This is because its printing the delta
between CLOCK_MONOTONIC time to the CLOCK_REALTIME expiration.
This patch fixes this issue by adding the clock offset to the
"now" time which we use to calculate the delta.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Pull locking fix from Ingo Molnar:
"A single fix for a locking self-test crash"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/pvqspinlock: Fix kernel panic in locking-selftest
Existing users of ioremap_cache() are mapping memory that is known in
advance to not have i/o side effects. These users are forced to cast
away the __iomem annotation, or otherwise neglect to fix the sparse
errors thrown when dereferencing pointers to this memory. Provide
memremap() as a non __iomem annotated ioremap_*() in the case when
ioremap is otherwise a pointer to cacheable memory. Empirically,
ioremap_<cacheable-type>() call sites are seeking memory-like semantics
(e.g. speculative reads, and prefetching permitted).
memremap() is a break from the ioremap implementation pattern of adding
a new memremap_<type>() for each mapping type and having silent
compatibility fall backs. Instead, the implementation defines flags
that are passed to the central memremap() and if a mapping type is not
supported by an arch memremap returns NULL.
We introduce a memremap prototype as a trivial wrapper of
ioremap_cache() and ioremap_wt(). Later, once all ioremap_cache() and
ioremap_wt() usage has been removed from drivers we teach archs to
implement arch_memremap() with the ability to strictly enforce the
mapping type.
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Move certificate handling out of the kernel/ directory and into a certs/
directory to get all the weird stuff in one place and move the generated
signing keys into this directory.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Conflicts:
drivers/net/ethernet/cavium/Kconfig
The cavium conflict was overlapping dependency
changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
The Intel build-bot detected a sparse warning with with a patch I posted a
couple of days ago that was accepted in the audit/next tree:
Subject: [linux-next:master 6689/6751] kernel/audit_watch.c:543:36: sparse: dereference of noderef expression
Date: Friday, August 07, 2015, 06:57:55 PM
From: kbuild test robot <fengguang.wu@intel.com>
tree: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: e6455bc5b91f41f842f30465c9193320f0568707
commit: 2e3a8aeb63e5335d4f837d453787c71bcb479796 [6689/6751] Merge remote- tracking branch 'audit/next'
sparse warnings: (new ones prefixed by >>)
>> kernel/audit_watch.c:543:36: sparse: dereference of noderef expression
kernel/audit_watch.c:544:28: sparse: dereference of noderef expression
34d99af5 Richard Guy Briggs 2015-08-05 541 int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark)
34d99af5 Richard Guy Briggs 2015-08-05 542 {
34d99af5 Richard Guy Briggs 2015-08-05 @543 unsigned long ino = tsk->mm- >exe_file->f_inode->i_ino;
34d99af5 Richard Guy Briggs 2015-08-05 544 dev_t dev = tsk->mm->exe_file- >f_inode->i_sb->s_dev;
:::::: The code at line 543 was first introduced by commit
:::::: 34d99af52a audit: implement audit by executable
tsk->mm->exe_file requires RCU access. The warning was reproduceable by adding
"C=1 CF=-D__CHECK_ENDIAN__" to the build command, and verified eliminated with
this patch.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
The code that places signals in signal queues computes the uids, gids,
and pids at the time the signals are enqueued. Which means that tasks
that share signal queues must be in the same pid and user namespaces.
Sharing signal handlers is fine, but bizarre.
So make the code in fork and userns_install clearer by only testing
for what is functionally necessary.
Also update the comment in unshare about unsharing a user namespace to
be a little more explicit and make a little more sense.
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In the logic in the initial commit of unshare made creating a new
thread group for a process, contingent upon creating a new memory
address space for that process. That is wrong. Two separate
processes in different thread groups can share a memory address space
and clone allows creation of such proceses.
This is significant because it was observed that mm_users > 1 does not
mean that a process is multi-threaded, as reading /proc/PID/maps
temporarily increments mm_users, which allows other processes to
(accidentally) interfere with unshare() calls.
Correct the check in check_unshare_flags() to test for
!thread_group_empty() for CLONE_THREAD, CLONE_SIGHAND, and CLONE_VM.
For sighand->count > 1 for CLONE_SIGHAND and CLONE_VM.
For !current_is_single_threaded instead of mm_users > 1 for CLONE_VM.
By using the correct checks in unshare this removes the possibility of
an accidental denial of service attack.
Additionally using the correct checks in unshare ensures that only an
explicit unshare(CLONE_VM) can possibly trigger the slow path of
current_is_single_threaded(). As an explict unshare(CLONE_VM) is
pointless it is not expected there are many applications that make
that call.
Cc: stable@vger.kernel.org
Fixes: b2e0d98705 userns: Implement unshare of the user namespace
Reported-by: Ricky Zhou <rickyz@chromium.org>
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
A PKCS#7 or CMS message can have per-signature authenticated attributes
that are digested as a lump and signed by the authorising key for that
signature. If such attributes exist, the content digest isn't itself
signed, but rather it is included in a special authattr which then
contributes to the signature.
Further, we already require the master message content type to be
pkcs7_signedData - but there's also a separate content type for the data
itself within the SignedData object and this must be repeated inside the
authattrs for each signer [RFC2315 9.2, RFC5652 11.1].
We should really validate the authattrs if they exist or forbid them
entirely as appropriate. To this end:
(1) Alter the PKCS#7 parser to reject any message that has more than one
signature where at least one signature has authattrs and at least one
that does not.
(2) Validate authattrs if they are present and strongly restrict them.
Only the following authattrs are permitted and all others are
rejected:
(a) contentType. This is checked to be an OID that matches the
content type in the SignedData object.
(b) messageDigest. This must match the crypto digest of the data.
(c) signingTime. If present, we check that this is a valid, parseable
UTCTime or GeneralTime and that the date it encodes fits within
the validity window of the matching X.509 cert.
(d) S/MIME capabilities. We don't check the contents.
(e) Authenticode SP Opus Info. We don't check the contents.
(f) Authenticode Statement Type. We don't check the contents.
The message is rejected if (a) or (b) are missing. If the message is
an Authenticode type, the message is rejected if (e) is missing; if
not Authenticode, the message is rejected if (d) - (f) are present.
The S/MIME capabilities authattr (d) unfortunately has to be allowed
to support kernels already signed by the pesign program. This only
affects kexec. sign-file suppresses them (CMS_NOSMIMECAP).
The message is also rejected if an authattr is given more than once or
if it contains more than one element in its set of values.
(3) Add a parameter to pkcs7_verify() to select one of the following
restrictions and pass in the appropriate option from the callers:
(*) VERIFYING_MODULE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
forbids authattrs. sign-file sets CMS_NOATTR. We could be more
flexible and permit authattrs optionally, but only permit minimal
content.
(*) VERIFYING_FIRMWARE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
requires authattrs. In future, this will require an attribute
holding the target firmware name in addition to the minimal set.
(*) VERIFYING_UNSPECIFIED_SIGNATURE
This requires that the SignedData content type be pkcs7-data but
allows either no authattrs or only permits the minimal set.
(*) VERIFYING_KEXEC_PE_SIGNATURE
This only supports the Authenticode SPC_INDIRECT_DATA content type
and requires at least an SpcSpOpusInfo authattr in addition to the
minimal set. It also permits an SPC_STATEMENT_TYPE authattr (and
an S/MIME capabilities authattr because the pesign program doesn't
remove these).
(*) VERIFYING_KEY_SIGNATURE
(*) VERIFYING_KEY_SELF_SIGNATURE
These are invalid in this context but are included for later use
when limiting the use of X.509 certs.
(4) The pkcs7_test key type is given a module parameter to select between
the above options for testing purposes. For example:
echo 1 >/sys/module/pkcs7_test_key/parameters/usage
keyctl padd pkcs7_test foo @s </tmp/stuff.pkcs7
will attempt to check the signature on stuff.pkcs7 as if it contains a
firmware blob (1 being VERIFYING_FIRMWARE_SIGNATURE).
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Fix up the dependencies somewhat too, while we're at it.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Pull RCU changes from Paul E. McKenney:
- The combination of tree geometry-initialization simplifications
and OS-jitter-reduction changes to expedited grace periods.
These two are stacked due to the large number of conflicts
that would otherwise result.
[ With one addition, a temporary commit to silence a lockdep false
positive. Additional changes to the expedited grace-period
primitives (queued for 4.4) remove the cause of this false
positive, and therefore include a revert of this temporary commit. ]
- Documentation updates.
- Torture-test updates.
- Miscellaneous fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "dl_boosted" flag is set by comparing *absolute* deadlines
(c.f., rt_mutex_setprio()).
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438782979-9057-2-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The comment is "misleading"; fix it by adapting a comment from
push_rt_tasks().
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438782979-9057-1-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change the calling context of sched_class::set_cpus_allowed() such
that we can assume the task is inactive.
This allows us to easily make changes that affect accounting done by
enqueue/dequeue. This does in fact completely remove
set_cpus_allowed_rt() and greatly reduces set_cpus_allowed_dl().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.667516139@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Give every class a set_cpus_allowed() method, this enables some small
optimization in the RT,DL implementation by avoiding a double
cpumask_weight() call.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.614517487@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because sched_setscheduler() checks p->flags & PF_NO_SETAFFINITY
without locks, a caller might observe an old value and race with the
set_cpus_allowed_ptr() call from __kthread_bind() and effectively undo
it:
__kthread_bind()
do_set_cpus_allowed()
<SYSCALL>
sched_setaffinity()
if (p->flags & PF_NO_SETAFFINITIY)
set_cpus_allowed_ptr()
p->flags |= PF_NO_SETAFFINITY
Fix the bug by putting everything under the regular scheduler locks.
This also closes a hole in the serialization of task_struct::{nr_,}cpus_allowed.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.545640346@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Current code ensures that a task has a normalized vruntime when switching away
from the fair class, but it does not ensure the task has a non-normalized
vruntime when switching back to the fair class.
This is an example breaking this consistency:
1. a task is in fair class and !queued
2. changes its class to RT class (still !queued)
3. changes its class to fair class again (still !queued)
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439197375-27927-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Systems which have all nodes at a distance of at most 1 hop should be
identified as 'NUMA_DIRECT'.
However, the scheduler incorrectly identifies it as 'NUMA_BACKPLANE'.
This is because 'n' is assigned to sched_max_numa_distance but the
code (mis)interprets it to mean 'number of hops'.
Rik had actually used sched_domains_numa_levels for detecting a
'NUMA_DIRECT' topology:
http://marc.info/?l=linux-kernel&m=141279712429834&w=2
But that was changed when he removed the hops table in the
subsequent version:
http://marc.info/?l=linux-kernel&m=141353106106771&w=2
Fixing the issue here.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1439256048-3748-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The qrwlock implementation is slightly heavy in its use of memory
barriers, mainly through the use of _cmpxchg() and _return() atomics, which
imply full barrier semantics.
This patch modifies the qrwlock code to use the more relaxed atomic
routines so that we can reduce the unnecessary barrier overhead on
weakly-ordered architectures.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hp.com
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1438880084-18856-7-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A question [1] was raised about the use of page::private in AUX buffer
allocations, so let's add a clarification about its intended use.
The private field and flag are used by perf's rb_alloc_aux() path to
tell the pmu driver the size of each high-order allocation, so that the
driver can program those appropriately into its hardware. This only
matters for PMUs that don't support hardware scatter tables. Otherwise,
every page in the buffer is just a page.
This patch adds a comment about the private field to the AUX buffer
allocation path.
[1] http://marc.info/?l=linux-kernel&m=143803696607968
Reported-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@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/1438063204-665-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I ran the perf fuzzer, which triggered some WARN()s which are due to
trying to stop/restart an event on the wrong CPU.
Use the normal IPI pattern to ensure we run the code on the correct CPU.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bad7192b84 ("perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Eric Dumazet