Skip to content

L
linux
Switch branch/tag
  1. 22 Oct, 2015 32 commits
  3. 03 Oct, 2015 8 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.1.10 · 27f1b7fe
      Greg Kroah-Hartman authored
      27f1b7fe
    • Kyle Evans's avatar
      hp-wmi: limit hotkey enable · 85695fdc
      Kyle Evans authored 
      commit 8a1513b4 upstream.

Do not write initialize magic on systems that do not have
feature query 0xb. Fixes Bug #82451.

Redefine FEATURE_QUERY to align with 0xb and FEATURE2 with 0xd
for code clearity.

Add a new test function, hp_wmi_bios_2008_later() & simplify
hp_wmi_bios_2009_later(), which fixes a bug in cases where
an improper value is returned. Probably also fixes Bug #69131.

Add missing __init tag.
Signed-off-by: default avatarKyle Evans <kvans32@gmail.com>
Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      85695fdc
    • Luis Henriques's avatar
      zram: fix possible use after free in zcomp_create() · 6e3105d5
      Luis Henriques authored 
      commit 3aaf14da upstream.

zcomp_create() verifies the success of zcomp_strm_{multi,single}_create()
through comp->stream, which can potentially be pointing to memory that
was freed if these functions returned an error.

While at it, replace a 'ERR_PTR(-ENOMEM)' by a more generic
'ERR_PTR(error)' as in the future zcomp_strm_{multi,siggle}_create()
could return other error codes.  Function documentation updated
accordingly.

Fixes: beca3ec7 ("zram: add multi stream functionality")
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
Acked-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6e3105d5
    • Herbert Xu's avatar
      netlink: Replace rhash_portid with bound · d4862367
      Herbert Xu authored 
      [ Upstream commit da314c99 ]

On Mon, Sep 21, 2015 at 02:20:22PM -0400, Tejun Heo wrote:
>
> store_release and load_acquire are different from the usual memory
> barriers and can't be paired this way.  You have to pair store_release
> and load_acquire.  Besides, it isn't a particularly good idea to

OK I've decided to drop the acquire/release helpers as they don't
help us at all and simply pessimises the code by using full memory
barriers (on some architectures) where only a write or read barrier
is needed.

> depend on memory barriers embedded in other data structures like the
> above.  Here, especially, rhashtable_insert() would have write barrier
> *before* the entry is hashed not necessarily *after*, which means that
> in the above case, a socket which appears to have set bound to a
> reader might not visible when the reader tries to look up the socket
> on the hashtable.

But you are right we do need an explicit write barrier here to
ensure that the hashing is visible.

> There's no reason to be overly smart here.  This isn't a crazy hot
> path, write barriers tend to be very cheap, store_release more so.
> Please just do smp_store_release() and note what it's paired with.

It's not about being overly smart.  It's about actually understanding
what's going on with the code.  I've seen too many instances of
people simply sprinkling synchronisation primitives around without
any knowledge of what is happening underneath, which is just a recipe
for creating hard-to-debug races.

> > @@ -1539,7 +1546,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
> >  		}
> >  	}
> >
> > -	if (!nlk->portid) {
> > +	if (!nlk->bound) {
>
> I don't think you can skip load_acquire here just because this is the
> second deref of the variable.  That doesn't change anything.  Race
> condition could still happen between the first and second tests and
> skipping the second would lead to the same kind of bug.

The reason this one is OK is because we do not use nlk->portid or
try to get nlk from the hash table before we return to user-space.

However, there is a real bug here that none of these acquire/release
helpers discovered.  The two bound tests here used to be a single
one.  Now that they are separate it is entirely possible for another
thread to come in the middle and bind the socket.  So we need to
repeat the portid check in order to maintain consistency.

> > @@ -1587,7 +1594,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
> >  	    !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
> >  		return -EPERM;
> >
> > -	if (!nlk->portid)
> > +	if (!nlk->bound)
>
> Don't we need load_acquire here too?  Is this path holding a lock
> which makes that unnecessary?

Ditto.

---8<---
The commit 1f770c0a ("netlink:
Fix autobind race condition that leads to zero port ID") created
some new races that can occur due to inconcsistencies between the
two port IDs.

Tejun is right that a barrier is unavoidable.  Therefore I am
reverting to the original patch that used a boolean to indicate
that a user netlink socket has been bound.

Barriers have been added where necessary to ensure that a valid
portid and the hashed socket is visible.

I have also changed netlink_insert to only return EBUSY if the
socket is bound to a portid different to the requested one.  This
combined with only reading nlk->bound once in netlink_bind fixes
a race where two threads that bind the socket at the same time
with different port IDs may both succeed.

Fixes: 1f770c0a ("netlink: Fix autobind race condition that leads to zero port ID")
Reported-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Nacked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d4862367
    • Herbert Xu's avatar
      netlink: Fix autobind race condition that leads to zero port ID · 4e277624
      Herbert Xu authored 
      [ Upstream commit 1f770c0a ]

The commit c0bb07df ("netlink:
Reset portid after netlink_insert failure") introduced a race
condition where if two threads try to autobind the same socket
one of them may end up with a zero port ID.  This led to kernel
deadlocks that were observed by multiple people.

This patch reverts that commit and instead fixes it by introducing
a separte rhash_portid variable so that the real portid is only set
after the socket has been successfully hashed.

Fixes: c0bb07df ("netlink: Reset portid after netlink_insert failure")
Reported-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4e277624
    • Stas Sergeev's avatar
      mvneta: use inband status only when explicitly enabled · d6001764
      Stas Sergeev authored 
      [ Upstream commit f8af8e6e in net-next tree,
  will be pushed to Linus very soon. ]

The commit 898b2970 ("mvneta: implement SGMII-based in-band link state
signaling") implemented the link parameters auto-negotiation unconditionally.
Unfortunately it appears that some HW that implements SGMII protocol,
doesn't generate the inband status, so it is not possible to auto-negotiate
anything with such HW.

This patch enables the auto-negotiation only if explicitly requested with
the 'managed' DT property.

This patch fixes the following regression:
https://lkml.org/lkml/2015/7/8/865Signed-off-by: default avatarStas Sergeev <stsp@users.sourceforge.net>

CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6001764
    • Stas Sergeev's avatar
      of_mdio: add new DT property 'managed' to specify the PHY management type · ebfd3e10
      Stas Sergeev authored 
      [ Upstream commit 4cba5c21 in net-next tree,
  will be pushed to Linus very soon. ]

Currently the PHY management type is selected by the MAC driver arbitrary.
The decision is based on the presence of the "fixed-link" node and on a
will of the driver's authors.
This caused a regression recently, when mvneta driver suddenly started
to use the in-band status for auto-negotiation on fixed links.
It appears the auto-negotiation may not work when expected by the MAC driver.
Sebastien Rannou explains:
<< Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
inband status) is connected to the switch through QSGMII, and in this context
we are on the media side of the PHY. >>
https://lkml.org/lkml/2015/7/10/206

This patch introduces the new string property 'managed' that allows
the user to set the management type explicitly.
The supported values are:
"auto" - default. Uses either MDIO or nothing, depending on the presence
of the fixed-link node
"in-band-status" - use in-band status
Signed-off-by: default avatarStas Sergeev <stsp@users.sourceforge.net>

CC: Rob Herring <robh+dt@kernel.org>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Florian Fainelli <f.fainelli@gmail.com>
CC: Grant Likely <grant.likely@linaro.org>
CC: devicetree@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ebfd3e10
    • Stas Sergeev's avatar
      net: phy: fixed_phy: handle link-down case · 282117ac
      Stas Sergeev authored 
      [ Upstream 868a4215 in net-next tree,
  will be pushed to Linus very soon. ]

fixed_phy_register() currently hardcodes the fixed PHY link to 1, and
expects to find a "speed" parameter to provide correct information
towards the fixed PHY consumer.

In a subsequent change, where we allow "managed" (e.g: (RS)GMII in-band
status auto-negotiation) fixed PHYs, none of these parameters can be
provided since they will be auto-negotiated, hence, we just provide a
zero-initialized fixed_phy_status to fixed_phy_register() which makes it
fail when we call fixed_phy_update_regs() since status.speed = 0 which
makes us hit the "default" label and error out.

Without this change, we would also see potentially inconsistent
speed/duplex parameters for fixed PHYs when the link is DOWN.

CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: default avatarStas Sergeev <stsp@users.sourceforge.net>
[florian: add more background to why this is correct and desirable]
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      282117ac
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7