<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/asm-generic, branch v4.9.202</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.9.202</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.9.202'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2019-08-25T08:51:50Z</updated>
<entry>
<title>asm-generic: fix -Wtype-limits compiler warnings</title>
<updated>2019-08-25T08:51:50Z</updated>
<author>
<name>Qian Cai</name>
<email>cai@lca.pw</email>
</author>
<published>2019-08-03T04:49:19Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=912420e5252c6867d3c3c3ad7a69ca59e5fc48c8'/>
<id>urn:sha1:912420e5252c6867d3c3c3ad7a69ca59e5fc48c8</id>
<content type='text'>
[ Upstream commit cbedfe11347fe418621bd188d58a206beb676218 ]

Commit d66acc39c7ce ("bitops: Optimise get_order()") introduced a
compilation warning because "rx_frag_size" is an "ushort" while
PAGE_SHIFT here is 16.

The commit changed the get_order() to be a multi-line macro where
compilers insist to check all statements in the macro even when
__builtin_constant_p(rx_frag_size) will return false as "rx_frag_size"
is a module parameter.

In file included from ./arch/powerpc/include/asm/page_64.h:107,
                 from ./arch/powerpc/include/asm/page.h:242,
                 from ./arch/powerpc/include/asm/mmu.h:132,
                 from ./arch/powerpc/include/asm/lppaca.h:47,
                 from ./arch/powerpc/include/asm/paca.h:17,
                 from ./arch/powerpc/include/asm/current.h:13,
                 from ./include/linux/thread_info.h:21,
                 from ./arch/powerpc/include/asm/processor.h:39,
                 from ./include/linux/prefetch.h:15,
                 from drivers/net/ethernet/emulex/benet/be_main.c:14:
drivers/net/ethernet/emulex/benet/be_main.c: In function 'be_rx_cqs_create':
./include/asm-generic/getorder.h:54:9: warning: comparison is always
true due to limited range of data type [-Wtype-limits]
   (((n) &lt; (1UL &lt;&lt; PAGE_SHIFT)) ? 0 :  \
         ^
drivers/net/ethernet/emulex/benet/be_main.c:3138:33: note: in expansion
of macro 'get_order'
  adapter-&gt;big_page_size = (1 &lt;&lt; get_order(rx_frag_size)) * PAGE_SIZE;
                                 ^~~~~~~~~

Fix it by moving all of this multi-line macro into a proper function,
and killing __get_order() off.

[akpm@linux-foundation.org: remove __get_order() altogether]
[cai@lca.pw: v2]
  Link: http://lkml.kernel.org/r/1564000166-31428-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/1563914986-26502-1-git-send-email-cai@lca.pw
Fixes: d66acc39c7ce ("bitops: Optimise get_order()")
Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Reviewed-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Jakub Jelinek &lt;jakub@redhat.com&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: James Y Knight &lt;jyknight@google.com&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>
</entry>
<entry>
<title>bug.h: work around GCC PR82365 in BUG()</title>
<updated>2019-07-10T07:55:44Z</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2018-02-21T22:45:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=074d0aaec0c61ab19099a1d31d08c7552ed97a16'/>
<id>urn:sha1:074d0aaec0c61ab19099a1d31d08c7552ed97a16</id>
<content type='text'>
[ Upstream commit 173a3efd3edb2ef6ef07471397c5f542a360e9c1 ]

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;	[arch/arc]
Tested-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;	[arch/arc]
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Christopher Li &lt;sparse@chrisli.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: "Steven Rostedt (VMware)" &lt;rostedt@goodmis.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&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;
[removed cris chunks - gregkh]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>locking/qspinlock: Pull in asm/byteorder.h to ensure correct endianness</title>
<updated>2019-01-26T08:38:36Z</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2019-01-24T18:54:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4b527f25a4ac64c0d17c882cdf8322be66f31611'/>
<id>urn:sha1:4b527f25a4ac64c0d17c882cdf8322be66f31611</id>
<content type='text'>
This commit is not required upstream, but is required for the 4.9.y
stable series.

Upstream commit 101110f6271c ("Kbuild: always define endianess in
kconfig.h") ensures that either __LITTLE_ENDIAN or __BIG_ENDIAN is
defined to reflect the endianness of the target CPU architecture
regardless of whether or not &lt;asm/byteorder.h&gt; has been #included. The
upstream definition of 'struct qspinlock' relies on this property.

Unfortunately, the 4.9.y stable series does not provide this guarantee,
so the 'spin_unlock()' routine can erroneously treat the underlying
lockword as big-endian on little-endian architectures using native
qspinlock (i.e. x86_64 without PV) if the caller has not included
&lt;asm/byteorder.h&gt;. This can lead to hangs such as the one in
'i915_gem_request()' reported via bugzilla:

  https://bugzilla.kernel.org/show_bug.cgi?id=202063

Fix the issue by ensuring that &lt;asm/byteorder.h&gt; is #included in
&lt;asm/qspinlock_types.h&gt;, where 'struct qspinlock' is defined.

Cc: &lt;stable@vger.kernel.org&gt; # 4.9
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
[will: wrote commit message]
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>locking/qspinlock: Fix build for anonymous union in older GCC compilers</title>
<updated>2018-12-21T13:11:34Z</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2018-06-22T00:35:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c6bcf40f769294a80c64213f9175ccd408d64532'/>
<id>urn:sha1:c6bcf40f769294a80c64213f9175ccd408d64532</id>
<content type='text'>
[ Upstream commit 6cc65be4f6f2a7186af8f3e09900787c7912dad2 ]

One of my tests compiles the kernel with gcc 4.5.3, and I hit the
following build error:

  include/linux/semaphore.h: In function 'sema_init':
  include/linux/semaphore.h:35:17: error: unknown field 'val' specified in initializer
  include/linux/semaphore.h:35:17: warning: missing braces around initializer
  include/linux/semaphore.h:35:17: warning: (near initialization for '(anonymous).raw_lock.&lt;anonymous&gt;.val')

I bisected it down to:

 625e88be1f41 ("locking/qspinlock: Merge 'struct __qspinlock' into 'struct qspinlock'")

... which makes qspinlock have an anonymous union, which makes initializing it special
for older compilers. By adding strategic brackets, it makes the build
happy again.

Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 625e88be1f41 ("locking/qspinlock: Merge 'struct __qspinlock' into 'struct qspinlock'")
Link: http://lkml.kernel.org/r/20180621203526.172ab5c4@vmware.local.home
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>locking/qspinlock: Merge 'struct __qspinlock' into 'struct qspinlock'</title>
<updated>2018-12-21T13:11:33Z</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-12-18T22:10:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=60668f3cddf1b25a954b198cade0ce726a6853ab'/>
<id>urn:sha1:60668f3cddf1b25a954b198cade0ce726a6853ab</id>
<content type='text'>
commit 625e88be1f41b53cec55827c984e4a89ea8ee9f9 upstream.

'struct __qspinlock' provides a handy union of fields so that
subcomponents of the lockword can be accessed by name, without having to
manage shifts and masks explicitly and take endianness into account.

This is useful in qspinlock.h and also potentially in arch headers, so
move the 'struct __qspinlock' into 'struct qspinlock' and kill the extra
definition.

Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Waiman Long &lt;longman@redhat.com&gt;
Acked-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1524738868-31318-3-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ioremap: Update pgtable free interfaces with addr</title>
<updated>2018-08-17T18:59:29Z</updated>
<author>
<name>Chintan Pandya</name>
<email>cpandya@codeaurora.org</email>
</author>
<published>2018-06-27T14:13:47Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6e6b637779d78fd7d32e4e19d59cfe815e68857c'/>
<id>urn:sha1:6e6b637779d78fd7d32e4e19d59cfe815e68857c</id>
<content type='text'>
commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream.

The following kernel panic was observed on ARM64 platform due to a stale
TLB entry.

 1. ioremap with 4K size, a valid pte page table is set.
 2. iounmap it, its pte entry is set to 0.
 3. ioremap the same address with 2M size, update its pmd entry with
    a new value.
 4. CPU may hit an exception because the old pmd entry is still in TLB,
    which leads to a kernel panic.

Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page
table") has addressed this panic by falling to pte mappings in the above
case on ARM64.

To support pmd mappings in all cases, TLB purge needs to be performed
in this case on ARM64.

Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page()
so that TLB purge can be added later in seprate patches.

[toshi.kani@hpe.com: merge changes, rewrite patch description]
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Chintan Pandya &lt;cpandya@codeaurora.org&gt;
Signed-off-by: Toshi Kani &lt;toshi.kani@hpe.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: stable@vger.kernel.org
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>x86/speculation/l1tf: Unbreak !__HAVE_ARCH_PFN_MODIFY_ALLOWED architectures</title>
<updated>2018-08-15T16:14:55Z</updated>
<author>
<name>Jiri Kosina</name>
<email>jkosina@suse.cz</email>
</author>
<published>2018-07-14T19:56:13Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b4f17de89e7aaecfc67a173ca8607899ee8707c3'/>
<id>urn:sha1:b4f17de89e7aaecfc67a173ca8607899ee8707c3</id>
<content type='text'>
commit 6c26fcd2abfe0a56bbd95271fce02df2896cfd24 upstream.

pfn_modify_allowed() and arch_has_pfn_modify_check() are outside of the
!__ASSEMBLY__ section in include/asm-generic/pgtable.h, which confuses
assembler on archs that don't have __HAVE_ARCH_PFN_MODIFY_ALLOWED (e.g.
ia64) and breaks build:

    include/asm-generic/pgtable.h: Assembler messages:
    include/asm-generic/pgtable.h:538: Error: Unknown opcode `static inline bool pfn_modify_allowed(unsigned long pfn,pgprot_t prot)'
    include/asm-generic/pgtable.h:540: Error: Unknown opcode `return true'
    include/asm-generic/pgtable.h:543: Error: Unknown opcode `static inline bool arch_has_pfn_modify_check(void)'
    include/asm-generic/pgtable.h:545: Error: Unknown opcode `return false'
    arch/ia64/kernel/entry.S:69: Error: `mov' does not fit into bundle

Move those two static inlines into the !__ASSEMBLY__ section so that they
don't confuse the asm build pass.

Fixes: 42e4089c7890 ("x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings")
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
[groeck: Context changes]
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings</title>
<updated>2018-08-15T16:14:45Z</updated>
<author>
<name>Andi Kleen</name>
<email>ak@linux.intel.com</email>
</author>
<published>2018-06-13T22:48:27Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7c5b42f82c13365b8284b5945f5ffa9f88380dd7'/>
<id>urn:sha1:7c5b42f82c13365b8284b5945f5ffa9f88380dd7</id>
<content type='text'>
commit 42e4089c7890725fcd329999252dc489b72f2921 upstream

For L1TF PROT_NONE mappings are protected by inverting the PFN in the page
table entry. This sets the high bits in the CPU's address space, thus
making sure to point to not point an unmapped entry to valid cached memory.

Some server system BIOSes put the MMIO mappings high up in the physical
address space. If such an high mapping was mapped to unprivileged users
they could attack low memory by setting such a mapping to PROT_NONE. This
could happen through a special device driver which is not access
protected. Normal /dev/mem is of course access protected.

To avoid this forbid PROT_NONE mappings or mprotect for high MMIO mappings.

Valid page mappings are allowed because the system is then unsafe anyways.

It's not expected that users commonly use PROT_NONE on MMIO. But to
minimize any impact this is only enforced if the mapping actually refers to
a high MMIO address (defined as the MAX_PA-1 bit being set), and also skip
the check for root.

For mmaps this is straight forward and can be handled in vm_insert_pfn and
in remap_pfn_range().

For mprotect it's a bit trickier. At the point where the actual PTEs are
accessed a lot of state has been changed and it would be difficult to undo
on an error. Since this is a uncommon case use a separate early page talk
walk pass for MMIO PROT_NONE mappings that checks for this condition
early. For non MMIO and non PROT_NONE there are no changes.

[dwmw2: Backport to 4.9]

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Acked-by: Dave Hansen &lt;dave.hansen@intel.com&gt;
Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>asm-generic: provide generic_pmdp_establish()</title>
<updated>2018-05-30T05:50:23Z</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2018-02-01T00:17:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=038ab51ea036e255c614e1c5f58a8c08799ddd64'/>
<id>urn:sha1:038ab51ea036e255c614e1c5f58a8c08799ddd64</id>
<content type='text'>
[ Upstream commit c58f0bb77ed8bf93dfdde762b01cb67eebbdfc29 ]

Patch series "Do not lose dirty bit on THP pages", v4.

Vlastimil noted that pmdp_invalidate() is not atomic and we can lose
dirty and access bits if CPU sets them after pmdp dereference, but
before set_pmd_at().

The bug can lead to data loss, but the race window is tiny and I haven't
seen any reports that suggested that it happens in reality.  So I don't
think it worth sending it to stable.

Unfortunately, there's no way to address the issue in a generic way.  We
need to fix all architectures that support THP one-by-one.

All architectures that have THP supported have to provide atomic
pmdp_invalidate() that returns previous value.

If generic implementation of pmdp_invalidate() is used, architecture
needs to provide atomic pmdp_estabish().

pmdp_estabish() is not used out-side generic implementation of
pmdp_invalidate() so far, but I think this can change in the future.

This patch (of 12):

This is an implementation of pmdp_establish() that is only suitable for
an architecture that doesn't have hardware dirty/accessed bits.  In this
case we can't race with CPU which sets these bits and non-atomic
approach is fine.

Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Daney &lt;david.daney@cavium.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nitin Gupta &lt;nitin.m.gupta@oracle.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&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;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>futex: Remove duplicated code and fix undefined behaviour</title>
<updated>2018-05-19T08:27:00Z</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2017-08-24T07:31:05Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=81da9f87ad9d5b77014f0d11946ffbc887bdec70'/>
<id>urn:sha1:81da9f87ad9d5b77014f0d11946ffbc887bdec70</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>
</entry>
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