vfs: In d_path don't call d_dname on a mount point

Aditya Kali (adityakali@google.com) wrote:
> Commit bf056bfa80596a5d14b26b17276a56a0dcb080e5:
> "proc: Fix the namespace inode permission checks." converted
> the namespace files into symlinks. The same commit changed
> the way namespace bind mounts appear in /proc/mounts:
>   $ mount --bind /proc/self/ns/ipc /mnt/ipc
> Originally:
>   $ cat /proc/mounts | grep ipc
>   proc /mnt/ipc proc rw,nosuid,nodev,noexec 0 0
>
> After commit bf056bfa80596a5d14b26b17276a56a0dcb080e5:
>   $ cat /proc/mounts | grep ipc
>   proc ipc:[4026531839] proc rw,nosuid,nodev,noexec 0 0
>
> This breaks userspace which expects the 2nd field in
> /proc/mounts to be a valid path.

The symlink /proc/<pid>/ns/{ipc,mnt,net,pid,user,uts} point to
dentries allocated with d_alloc_pseudo that we can mount, and
that have interesting names printed out with d_dname.

When these files are bind mounted /proc/mounts is not currently
displaying the mount point correctly because d_dname is called instead
of just displaying the path where the file is mounted.

Solve this by adding an explicit check to distinguish mounted pseudo
inodes and unmounted pseudo inodes.  Unmounted pseudo inodes always
use mount of their filesstem as the mnt_root  in their path making
these two cases easy to distinguish.

CC: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reported-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
fork:  Allow CLONE_PARENT after setns(CLONE_NEWPID)

Serge Hallyn <serge.hallyn@ubuntu.com> writes:
> Hi Oleg,
>
> commit 40a0d32d1eaffe6aac7324ca92604b6b3977eb0e :
> "fork: unify and tighten up CLONE_NEWUSER/CLONE_NEWPID checks"
> breaks lxc-attach in 3.12.  That code forks a child which does
> setns() and then does a clone(CLONE_PARENT).  That way the
> grandchild can be in the right namespaces (which the child was
> not) and be a child of the original task, which is the monitor.
>
> lxc-attach in 3.11 was working fine with no side effects that I
> could see.  Is there a real danger in allowing CLONE_PARENT
> when current->nsproxy->pidns_for_children is not our pidns,
> or was this done out of an "over-abundance of caution"?  Can we
> safely revert that new extra check?

The two fundamental things I know we can not allow are:
- A shared signal queue aka CLONE_THREAD.  Because we compute the pid
  and uid of the signal when we place it in the queue.

- Changing the pid and by extention pid_namespace of an existing
  process.

From a parents perspective there is nothing special about the pid
namespace, to deny CLONE_PARENT, because the parent simply won't know or
care.

From the childs perspective all that is special really are shared signal
queues.

User mode threading with CLONE_PARENT|CLONE_VM|CLONE_SIGHAND and tasks
in different pid namespaces is almost certainly going to break because
it is complicated.  But shared signal handlers can look at per thread
information to know which pid namespace a process is in, so I don't know
of any reason not to support CLONE_PARENT|CLONE_VM|CLONE_SIGHAND threads
at the kernel level.  It would be absolutely stupid to implement but
that is a different thing.

So hmm.

Because it can do no harm, and because it is a regression let's remove
the CLONE_PARENT check and send it stable.

Cc: stable@vger.kernel.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
vfs: Fix a regression in mounting proc

Gao feng <gaofeng@cn.fujitsu.com> reported that commit
e51db73532955dc5eaba4235e62b74b460709d5b
userns: Better restrictions on when proc and sysfs can be mounted
caused a regression on mounting a new instance of proc in a mount
namespace created with user namespace privileges, when binfmt_misc
is mounted on /proc/sys/fs/binfmt_misc.

This is an unintended regression caused by the absolutely bogus empty
directory check in fs_fully_visible.  The check fs_fully_visible replaced
didn't even bother to attempt to verify proc was fully visible and
hiding proc files with any kind of mount is rare.  So for now fix
the userspace regression by allowing directory with nlink == 1
as /proc/sys/fs/binfmt_misc has.

I will have a better patch but it is not stable material, or
last minute kernel material.  So it will have to wait.

Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Tested-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
mfd: rtsx_pcr: Disable interrupts before cancelling delayed works

This fixes a kernel panic when resuming from suspend to RAM.
Without this fix an interrupt hits after the delayed work is canceled
and thus requeues it. So we end up freeing an armed timer.

Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
writeback: Fix data corruption on NFS

Commit 4f8ad655dbc8 "writeback: Refactor writeback_single_inode()" added
a condition to skip clean inode. However this is wrong in WB_SYNC_ALL
mode because there we also want to wait for outstanding writeback on
possibly clean inode. This was causing occasional data corruption issues
on NFS because it uses sync_inode() to make sure all outstanding writes
are flushed to the server before truncating the inode and with
sync_inode() returning prematurely file was sometimes extended back
by an outstanding write after it was truncated.

So modify the test to also check for pages under writeback in
WB_SYNC_ALL mode.

CC: stable@vger.kernel.org # >= 3.5
Fixes: 4f8ad655dbc82cf05d2edc11e66b78a42d38bf93
Reported-and-tested-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
ARM: shmobile: armadillo: Fix coherent DMA mask

Commit 4dcfa60071b3d23f0181f27d8519f12e37cefbb9 ("ARM: DMA-API: better
handing of DMA masks for coherent allocations") added an additional
check to the coherent DMA mask that results in an error when the mask is
larger than what dma_addr_t can address.

Set the LCDC coherent DMA mask to DMA_BIT_MASK(32) instead of ~0 to fix
the problem.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
ARM: shmobile: kzm9g: Fix coherent DMA mask

Commit 4dcfa60071b3d23f0181f27d8519f12e37cefbb9 ("ARM: DMA-API: better
handing of DMA masks for coherent allocations") added an additional
check to the coherent DMA mask that results in an error when the mask is
larger than what dma_addr_t can address.

Set the LCDC coherent DMA mask to DMA_BIT_MASK(32) instead of ~0 to fix
the problem.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
ARM: shmobile: mackerel: Fix coherent DMA mask

Commit 4dcfa60071b3d23f0181f27d8519f12e37cefbb9 ("ARM: DMA-API: better
handing of DMA masks for coherent allocations") added an additional
check to the coherent DMA mask that results in an error when the mask is
larger than what dma_addr_t can address.

Set the LCDC coherent DMA mask to DMA_BIT_MASK(32) instead of ~0 to fix
the problem.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
clocksource: cadence_ttc: Fix mutex taken inside interrupt context

When the kernel is compiled with:
CONFIG_HIGH_RES_TIMERS=no
CONFIG_HZ_PERIODIC=yes
CONFIG_DEBUG_ATOMIC_SLEEP=yes

The following WARN appears:

WARNING: CPU: 1 PID: 0 at linux/kernel/mutex.c:856 mutex_trylock+0x70/0x1fc()
DEBUG_LOCKS_WARN_ON(in_interrupt())
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.12.0-xilinx-dirty #93
[<c0014a78>] (unwind_backtrace+0x0/0x11c) from [<c0011b6c>] (show_stack+0x10/0x14)
[<c0011b6c>] (show_stack+0x10/0x14) from [<c039120c>] (dump_stack+0x7c/0xc0)
[<c039120c>] (dump_stack+0x7c/0xc0) from [<c001fda4>] (warn_slowpath_common+0x60/0x84)
[<c001fda4>] (warn_slowpath_common+0x60/0x84) from [<c001fe48>] (warn_slowpath_fmt+0x2c/0x3c)
[<c001fe48>] (warn_slowpath_fmt+0x2c/0x3c) from [<c0392658>] (mutex_trylock+0x70/0x1fc)
[<c0392658>] (mutex_trylock+0x70/0x1fc) from [<c02dfc08>] (clk_prepare_lock+0xc/0xe4)
[<c02dfc08>] (clk_prepare_lock+0xc/0xe4) from [<c02e099c>] (clk_get_rate+0xc/0x44)
[<c02e099c>] (clk_get_rate+0xc/0x44) from [<c02d0394>] (ttc_set_mode+0x34/0x78)
[<c02d0394>] (ttc_set_mode+0x34/0x78) from [<c005f794>] (clockevents_set_mode+0x28/0x5c)
[<c005f794>] (clockevents_set_mode+0x28/0x5c) from [<c00607fc>] (tick_broadcast_on_off+0x190/0x1c0)
[<c00607fc>] (tick_broadcast_on_off+0x190/0x1c0) from [<c005f168>] (clockevents_notify+0x58/0x1ac)
[<c005f168>] (clockevents_notify+0x58/0x1ac) from [<c02b99dc>] (cpuidle_setup_broadcast_timer+0x20/0x24)
[<c02b99dc>] (cpuidle_setup_broadcast_timer+0x20/0x24) from [<c006cd04>] (generic_smp_call_function_single_interrupt+0)
[<c006cd04>] (generic_smp_call_function_single_interrupt+0xe0/0x130) from [<c00138c8>] (handle_IPI+0x88/0x118)
[<c00138c8>] (handle_IPI+0x88/0x118) from [<c0008504>] (gic_handle_irq+0x58/0x60)
[<c0008504>] (gic_handle_irq+0x58/0x60) from [<c0012644>] (__irq_svc+0x44/0x78)
Exception stack(0xef099fa0 to 0xef099fe8)
9fa0: 00000001 ef092100 00000000 ef092100 ef098000 00000015 c0399f2c c0579d74
9fc0: 0000406a 413fc090 00000000 00000000 00000000 ef099fe8 c00666ec c000f46c
9fe0: 20000113 ffffffff
[<c0012644>] (__irq_svc+0x44/0x78) from [<c000f46c>] (arch_cpu_idle+0x34/0x3c)
[<c000f46c>] (arch_cpu_idle+0x34/0x3c) from [<c0053980>] (cpu_startup_entry+0xa8/0x10c)
[<c0053980>] (cpu_startup_entry+0xa8/0x10c) from [<000085a4>] (0x85a4)

We are in an interrupt context (IPI) and we are calling clk_get_rate in the
set_mode function which in turn ends up by getting a mutex... Even if that
does not hang, it is a potential kernel deadlock.

It is not allowed to call clk_get_rate() from interrupt context. To
avoid such calls the timer input frequency is stored in the driver's
data struct which makes it accessible to the driver in any context.

[dlezcano] completed the changelog with the WARN trace and added a more
detailed description. Tested on zync zc702.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
clk: samsung: exynos4: Correct SRC_MFC register

The SRC_MFC register offset was incorrect, which could cause have caused
wrong calculation of rate of sclk_mfc clock, that could in turn lead to
incorrect operation of MFC. This patch corrects it.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
[t.figa: Updated patch description]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clk: exynos5250: fix sysmmu_mfc{l,r} gate clocks

The gate clocks for the MFC sysmmus appear to be flipped, i.e.
GATE_IP_MFC[2] gates sysmmu_mfcl and GATE_IP_MFC[1] gates sysmmu_mfcr.
Fix this so that the MFC will start up.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clk: samsung: exynos5250: Fix ACP gate register offset

The CLK_GATE_IP_ACP register offset is incorrectly listed making
definition of g2d clock incorrect, which may lead to system failures
when trying to use G2D on systems on which firmware gates this clock
by default. Fix this and the register ordering as well.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
[t.figa: Updated patch description.]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clk: samsung: exynos5250: Add MDMA0 clocks

Adds gate clock for MDMA0 on Exynos5250 SoC. This is needed to ensure
that the clock is enabled when MDMA0 is used on systems on which
firmware gates the clockby default.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
[t.figa: Updated patch description.]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ARM: dts: exynos5250: Fix MDMA0 clock number

Due to incorrect clock specified in MDMA0 node, using MDMA0 controller
could cause system failures, due to wrong clock being controlled. This
patch fixes this by specifying correct clock.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
[t.figa: Corrected commit message and description.]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clk: samsung: exynos5250: Add CLK_IGNORE_UNUSED flag for the sysreg clock

The sysreg (system register) generates control signals for various blocks
like disp1blk, i2c, mipi, usb etc. However, it gets disabled as an unused
clock at boot-up. This can lead to failures in operation of above blocks,
because they can not be configured properly if this clock is disabled.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
[t.figa: Updated patch description.]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clk: exynos: File scope reg_save array should depend on PM_SLEEP

Move reg_save[] into CONFIG_PM_SLEEP dependency block as it is used only
by suspend and resume functions.

This fixes the warning on CONFIG_PM_SLEEP=n:
drivers/clk/samsung/clk-exynos-audss.c:29:22: warning: ‘reg_save’ defined but not used [-Wunused-variable]

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ahci: add PCI ID for Marvell 88SE9170 SATA controller

This patch adds support for the PCI ID provided by the Marvell 88SE9170
SATA controller.

Signed-off-by: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
sata_sis: missing PM support

sata_sis has no suspend/resume methods. The default ones will do fine and
are needed on some systems.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge tag 'renesas-fixes3-for-v3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes

From Simon Horman:
Third Round of Renesas ARM based SoC Fixes for v3.13

* sh7372 (SH-Mobile AP4) based Mackerel board
  r8a773a0 (SH-Mobile AG5) based kzm9g board
  r8a7740 (R-Mobile A1) based Armadillo board

  - Correct coherent DMA mask

    This resolves regressions introduced by 4dcfa60071b3d23f
    ("ARM: DMA-API: better handing of DMA masks for coherent allocations")
    in v3.12-rc1.

* tag 'renesas-fixes3-for-v3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  ARM: shmobile: mackerel: Fix coherent DMA mask
  ARM: shmobile: kzm9g: Fix coherent DMA mask
  ARM: shmobile: armadillo: Fix coherent DMA mask

Signed-off-by: Olof Johansson <olof@lixom.net>
ACPI / AC: change notification handler type to ACPI_ALL_NOTIFY

With kernel 3.13rc5 there are no AC adapter notifications on my laptop.

Commit cc8ef5270734 "ACPI / AC: convert ACPI ac driver to platform bus"
changed the driver to listen to device notifications only. However, AML
code on my laptop notifies the driver with zero event.

This patch changes the driver to listen to all events again.

Fixes: cc8ef5270734 (ACPI / AC: convert ACPI ac driver to platform bus)
References: https://bugzilla.kernel.org/show_bug.cgi?id=67821
Signed-off-by: Alexander Mezin <mezin.alexander@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>