<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/hexagon/include, branch linux-4.9.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>hexagon: parenthesize registers in asm predicates</title>
<updated>2020-01-23T07:19:37+00:00</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2020-01-04T20:59:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a63c9fe36c58cacac4e73c8d153482c0dad227c0'/>
<id>a63c9fe36c58cacac4e73c8d153482c0dad227c0</id>
<content type='text'>
[ Upstream commit 780a0cfda9006a9a22d6473c2d4c527f5c68eb2e ]

Hexagon requires that register predicates in assembly be parenthesized.

Link: https://github.com/ClangBuiltLinux/linux/issues/754
Link: http://lkml.kernel.org/r/20191209222956.239798-3-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Suggested-by: Sid Manning &lt;sidneym@codeaurora.org&gt;
Acked-by: Brian Cain &lt;bcain@codeaurora.org&gt;
Cc: Lee Jones &lt;lee.jones@linaro.org&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Tuowen Zhao &lt;ztuowen@gmail.com&gt;
Cc: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Cc: Allison Randal &lt;allison@lohutok.net&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Richard Fontana &lt;rfontana@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 780a0cfda9006a9a22d6473c2d4c527f5c68eb2e ]

Hexagon requires that register predicates in assembly be parenthesized.

Link: https://github.com/ClangBuiltLinux/linux/issues/754
Link: http://lkml.kernel.org/r/20191209222956.239798-3-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Suggested-by: Sid Manning &lt;sidneym@codeaurora.org&gt;
Acked-by: Brian Cain &lt;bcain@codeaurora.org&gt;
Cc: Lee Jones &lt;lee.jones@linaro.org&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Tuowen Zhao &lt;ztuowen@gmail.com&gt;
Cc: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Cc: Allison Randal &lt;allison@lohutok.net&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Richard Fontana &lt;rfontana@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hexagon: modify ffs() and fls() to return int</title>
<updated>2018-10-10T06:53:21+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2018-07-22T23:03:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3c751807c9d25c548c91eed58d3bf7cb128d9853'/>
<id>3c751807c9d25c548c91eed58d3bf7cb128d9853</id>
<content type='text'>
[ Upstream commit 5c41aaad409c097cf1ef74f2c649fed994744ef5 ]

Building drivers/mtd/nand/raw/nandsim.c on arch/hexagon/ produces a
printk format build warning.  This is due to hexagon's ffs() being
coded as returning long instead of int.

Fix the printk format warning by changing all of hexagon's ffs() and
fls() functions to return int instead of long.  The variables that
they return are already int instead of long.  This return type
matches the return type in &lt;asm-generic/bitops/&gt;.

../drivers/mtd/nand/raw/nandsim.c: In function 'init_nandsim':
../drivers/mtd/nand/raw/nandsim.c:760:2: warning: format '%u' expects argument of type 'unsigned int', but argument 2 has type 'long int' [-Wformat]

There are no ffs() or fls() allmodconfig build errors after making this
change.

Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: linux-hexagon@vger.kernel.org
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Patch-mainline: linux-kernel @ 07/22/2018, 16:03
Signed-off-by: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5c41aaad409c097cf1ef74f2c649fed994744ef5 ]

Building drivers/mtd/nand/raw/nandsim.c on arch/hexagon/ produces a
printk format build warning.  This is due to hexagon's ffs() being
coded as returning long instead of int.

Fix the printk format warning by changing all of hexagon's ffs() and
fls() functions to return int instead of long.  The variables that
they return are already int instead of long.  This return type
matches the return type in &lt;asm-generic/bitops/&gt;.

../drivers/mtd/nand/raw/nandsim.c: In function 'init_nandsim':
../drivers/mtd/nand/raw/nandsim.c:760:2: warning: format '%u' expects argument of type 'unsigned int', but argument 2 has type 'long int' [-Wformat]

There are no ffs() or fls() allmodconfig build errors after making this
change.

Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: linux-hexagon@vger.kernel.org
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Patch-mainline: linux-kernel @ 07/22/2018, 16:03
Signed-off-by: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>futex: Remove duplicated code and fix undefined behaviour</title>
<updated>2018-05-19T08:27:00+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2017-08-24T07:31:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=81da9f87ad9d5b77014f0d11946ffbc887bdec70'/>
<id>81da9f87ad9d5b77014f0d11946ffbc887bdec70</id>
<content type='text'>
commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; [s390]
Acked-by: Chris Metcalf &lt;cmetcalf@mellanox.com&gt; [for tile]
Reviewed-by: Darren Hart (VMware) &lt;dvhart@infradead.org&gt;
Reviewed-by: Will Deacon &lt;will.deacon@arm.com&gt; [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson &lt;stefan.kristiansson@saunalahti.fi&gt;
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings &lt;ben.hutchings@codethink.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; [s390]
Acked-by: Chris Metcalf &lt;cmetcalf@mellanox.com&gt; [for tile]
Reviewed-by: Darren Hart (VMware) &lt;dvhart@infradead.org&gt;
Reviewed-by: Will Deacon &lt;will.deacon@arm.com&gt; [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson &lt;stefan.kristiansson@saunalahti.fi&gt;
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings &lt;ben.hutchings@codethink.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>hexagon: fix strncpy_from_user() error return</title>
<updated>2016-09-13T21:49:39+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2016-08-19T01:16:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f35c1e0671728d1c9abc405d05ef548b5fcb2fc4'/>
<id>f35c1e0671728d1c9abc405d05ef548b5fcb2fc4</id>
<content type='text'>
It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).

Cc: stable@vger.kernel.org
Acked-by: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).

Cc: stable@vger.kernel.org
Acked-by: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-mapping: use unsigned long for dma_attrs</title>
<updated>2016-08-04T12:50:07+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>k.kozlowski@samsung.com</email>
</author>
<published>2016-08-03T20:46:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00085f1efa387a8ce100e3734920f7639c80caa3'/>
<id>00085f1efa387a8ce100e3734920f7639c80caa3</id>
<content type='text'>
The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski &lt;k.kozlowski@samsung.com&gt;
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Acked-by: Hans-Christian Noren Egtvedt &lt;egtvedt@samfundet.no&gt;
Acked-by: Mark Salter &lt;msalter@redhat.com&gt; [c6x]
Acked-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt; [cris]
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt; [drm]
Reviewed-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Acked-by: Joerg Roedel &lt;jroedel@suse.de&gt; [iommu]
Acked-by: Fabien Dessenne &lt;fabien.dessenne@st.com&gt; [bdisp]
Reviewed-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt; [vb2-core]
Acked-by: David Vrabel &lt;david.vrabel@citrix.com&gt; [xen]
Acked-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt; [xen swiotlb]
Acked-by: Joerg Roedel &lt;jroedel@suse.de&gt; [iommu]
Acked-by: Richard Kuo &lt;rkuo@codeaurora.org&gt; [hexagon]
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt; [m68k]
Acked-by: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt; [s390]
Acked-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Acked-by: Hans-Christian Noren Egtvedt &lt;egtvedt@samfundet.no&gt; [avr32]
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt; [arc]
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt; [arm64 and dma-iommu]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski &lt;k.kozlowski@samsung.com&gt;
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Acked-by: Hans-Christian Noren Egtvedt &lt;egtvedt@samfundet.no&gt;
Acked-by: Mark Salter &lt;msalter@redhat.com&gt; [c6x]
Acked-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt; [cris]
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt; [drm]
Reviewed-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Acked-by: Joerg Roedel &lt;jroedel@suse.de&gt; [iommu]
Acked-by: Fabien Dessenne &lt;fabien.dessenne@st.com&gt; [bdisp]
Reviewed-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt; [vb2-core]
Acked-by: David Vrabel &lt;david.vrabel@citrix.com&gt; [xen]
Acked-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt; [xen swiotlb]
Acked-by: Joerg Roedel &lt;jroedel@suse.de&gt; [iommu]
Acked-by: Richard Kuo &lt;rkuo@codeaurora.org&gt; [hexagon]
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt; [m68k]
Acked-by: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt; [s390]
Acked-by: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Acked-by: Hans-Christian Noren Egtvedt &lt;egtvedt@samfundet.no&gt; [avr32]
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt; [arc]
Acked-by: Robin Murphy &lt;robin.murphy@arm.com&gt; [arm64 and dma-iommu]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2016-07-25T19:41:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-07-25T19:41:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c86ad14d305d2429c3da19462440bac50c183def'/>
<id>c86ad14d305d2429c3da19462440bac50c183def</id>
<content type='text'>
Pull locking updates from Ingo Molnar:
 "The locking tree was busier in this cycle than the usual pattern - a
  couple of major projects happened to coincide.

  The main changes are:

   - implement the atomic_fetch_{add,sub,and,or,xor}() API natively
     across all SMP architectures (Peter Zijlstra)

   - add atomic_fetch_{inc/dec}() as well, using the generic primitives
     (Davidlohr Bueso)

   - optimize various aspects of rwsems (Jason Low, Davidlohr Bueso,
     Waiman Long)

   - optimize smp_cond_load_acquire() on arm64 and implement LSE based
     atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
     on arm64 (Will Deacon)

   - introduce smp_acquire__after_ctrl_dep() and fix various barrier
     mis-uses and bugs (Peter Zijlstra)

   - after discovering ancient spin_unlock_wait() barrier bugs in its
     implementation and usage, strengthen its semantics and update/fix
     usage sites (Peter Zijlstra)

   - optimize mutex_trylock() fastpath (Peter Zijlstra)

   - ... misc fixes and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API
  locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire()
  locking/static_keys: Fix non static symbol Sparse warning
  locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec()
  locking/atomic, arch/tile: Fix tilepro build
  locking/atomic, arch/m68k: Remove comment
  locking/atomic, arch/arc: Fix build
  locking/Documentation: Clarify limited control-dependency scope
  locking/atomic, arch/rwsem: Employ atomic_long_fetch_add()
  locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire()
  locking/atomic, arch/mips: Convert to _relaxed atomics
  locking/atomic, arch/alpha: Convert to _relaxed atomics
  locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions
  locking/atomic: Remove linux/atomic.h:atomic_fetch_or()
  locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
  locking/atomic: Fix atomic64_relaxed() bits
  locking/atomic, arch/xtensa: Implement atomic_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking updates from Ingo Molnar:
 "The locking tree was busier in this cycle than the usual pattern - a
  couple of major projects happened to coincide.

  The main changes are:

   - implement the atomic_fetch_{add,sub,and,or,xor}() API natively
     across all SMP architectures (Peter Zijlstra)

   - add atomic_fetch_{inc/dec}() as well, using the generic primitives
     (Davidlohr Bueso)

   - optimize various aspects of rwsems (Jason Low, Davidlohr Bueso,
     Waiman Long)

   - optimize smp_cond_load_acquire() on arm64 and implement LSE based
     atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
     on arm64 (Will Deacon)

   - introduce smp_acquire__after_ctrl_dep() and fix various barrier
     mis-uses and bugs (Peter Zijlstra)

   - after discovering ancient spin_unlock_wait() barrier bugs in its
     implementation and usage, strengthen its semantics and update/fix
     usage sites (Peter Zijlstra)

   - optimize mutex_trylock() fastpath (Peter Zijlstra)

   - ... misc fixes and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API
  locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire()
  locking/static_keys: Fix non static symbol Sparse warning
  locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec()
  locking/atomic, arch/tile: Fix tilepro build
  locking/atomic, arch/m68k: Remove comment
  locking/atomic, arch/arc: Fix build
  locking/Documentation: Clarify limited control-dependency scope
  locking/atomic, arch/rwsem: Employ atomic_long_fetch_add()
  locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire()
  locking/atomic, arch/mips: Convert to _relaxed atomics
  locking/atomic, arch/alpha: Convert to _relaxed atomics
  locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions
  locking/atomic: Remove linux/atomic.h:atomic_fetch_or()
  locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
  locking/atomic: Fix atomic64_relaxed() bits
  locking/atomic, arch/xtensa: Implement atomic_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>tree wide: get rid of __GFP_REPEAT for order-0 allocations part I</title>
<updated>2016-06-25T00:23:52+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2016-06-24T21:48:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=32d6bd9059f265f617f6502c68dfbcae7e515add'/>
<id>32d6bd9059f265f617f6502c68dfbcae7e515add</id>
<content type='text'>
This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&amp;paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt; [for tile]
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: John Crispin &lt;blogic@openwrt.org&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&amp;paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chen Liqin &lt;liqin.linux@gmail.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt; [for tile]
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: John Crispin &lt;blogic@openwrt.org&gt;
Cc: Lennox Wu &lt;lennox.wu@gmail.com&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/atomic: Remove linux/atomic.h:atomic_fetch_or()</title>
<updated>2016-06-16T08:48:32+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2016-04-17T22:58:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b53d6bedbe781974097fd8c38263f6cc78ff9ea7'/>
<id>b53d6bedbe781974097fd8c38263f6cc78ff9ea7</id>
<content type='text'>
Since all architectures have this implemented now natively, remove this
dead code.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since all architectures have this implemented now natively, remove this
dead code.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/atomic, arch/hexagon: Implement atomic_fetch_{add,sub,and,or,xor}()</title>
<updated>2016-06-16T08:48:25+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2016-04-17T23:16:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4be7dd393515615430a4d07ca1ffceaf2a331620'/>
<id>4be7dd393515615430a4d07ca1ffceaf2a331620</id>
<content type='text'>
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-hexagon@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-hexagon@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/spinlock, arch: Update and fix spin_unlock_wait() implementations</title>
<updated>2016-06-14T09:55:15+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2016-05-26T08:35:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=726328d92a42b6d4b76078e2659f43067f82c4e8'/>
<id>726328d92a42b6d4b76078e2659f43067f82c4e8</id>
<content type='text'>
This patch updates/fixes all spin_unlock_wait() implementations.

The update is in semantics; where it previously was only a control
dependency, we now upgrade to a full load-acquire to match the
store-release from the spin_unlock() we waited on. This ensures that
when spin_unlock_wait() returns, we're guaranteed to observe the full
critical section we waited on.

This fixes a number of spin_unlock_wait() users that (not
unreasonably) rely on this.

I also fixed a number of ticket lock versions to only wait on the
current lock holder, instead of for a full unlock, as this is
sufficient.

Furthermore; again for ticket locks; I added an smp_rmb() in between
the initial ticket load and the spin loop testing the current value
because I could not convince myself the address dependency is
sufficient, esp. if the loads are of different sizes.

I'm more than happy to remove this smp_rmb() again if people are
certain the address dependency does indeed work as expected.

Note: PPC32 will be fixed independently

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: chris@zankel.net
Cc: cmetcalf@mellanox.com
Cc: davem@davemloft.net
Cc: dhowells@redhat.com
Cc: james.hogan@imgtec.com
Cc: jejb@parisc-linux.org
Cc: linux@armlinux.org.uk
Cc: mpe@ellerman.id.au
Cc: ralf@linux-mips.org
Cc: realmz6@gmail.com
Cc: rkuo@codeaurora.org
Cc: rth@twiddle.net
Cc: schwidefsky@de.ibm.com
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Cc: ysato@users.sourceforge.jp
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch updates/fixes all spin_unlock_wait() implementations.

The update is in semantics; where it previously was only a control
dependency, we now upgrade to a full load-acquire to match the
store-release from the spin_unlock() we waited on. This ensures that
when spin_unlock_wait() returns, we're guaranteed to observe the full
critical section we waited on.

This fixes a number of spin_unlock_wait() users that (not
unreasonably) rely on this.

I also fixed a number of ticket lock versions to only wait on the
current lock holder, instead of for a full unlock, as this is
sufficient.

Furthermore; again for ticket locks; I added an smp_rmb() in between
the initial ticket load and the spin loop testing the current value
because I could not convince myself the address dependency is
sufficient, esp. if the loads are of different sizes.

I'm more than happy to remove this smp_rmb() again if people are
certain the address dependency does indeed work as expected.

Note: PPC32 will be fixed independently

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: chris@zankel.net
Cc: cmetcalf@mellanox.com
Cc: davem@davemloft.net
Cc: dhowells@redhat.com
Cc: james.hogan@imgtec.com
Cc: jejb@parisc-linux.org
Cc: linux@armlinux.org.uk
Cc: mpe@ellerman.id.au
Cc: ralf@linux-mips.org
Cc: realmz6@gmail.com
Cc: rkuo@codeaurora.org
Cc: rth@twiddle.net
Cc: schwidefsky@de.ibm.com
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Cc: ysato@users.sourceforge.jp
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
