<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/sh, branch v3.12.65</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>sh: fix copy_from_user()</title>
<updated>2016-09-29T09:14:33+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2016-08-22T03:39:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=49e361884efedb0786751217b0da7f78c263265e'/>
<id>49e361884efedb0786751217b0da7f78c263265e</id>
<content type='text'>
commit 6e050503a150b2126620c1a1e9b3a368fcd51eac upstream.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6e050503a150b2126620c1a1e9b3a368fcd51eac upstream.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sh64: failing __get_user() should zero</title>
<updated>2016-09-29T09:14:29+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2016-08-22T03:33:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=b5687db2c83a4a83a910fc255583cf4be6669a93'/>
<id>b5687db2c83a4a83a910fc255583cf4be6669a93</id>
<content type='text'>
commit c6852389228df9fb3067f94f3b651de2a7921b36 upstream.

It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c6852389228df9fb3067f94f3b651de2a7921b36 upstream.

It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sh64: fix __NR_fgetxattr</title>
<updated>2016-02-15T16:07:48+00:00</updated>
<author>
<name>Dmitry V. Levin</name>
<email>ldv@altlinux.org</email>
</author>
<published>2015-12-11T21:41:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=afa6ea6ad1bef53a8ac1b6c4ce7437371d46f251'/>
<id>afa6ea6ad1bef53a8ac1b6c4ce7437371d46f251</id>
<content type='text'>
commit 2d33fa1059da4c8e816627a688d950b613ec0474 upstream.

According to arch/sh/kernel/syscalls_64.S and common sense, __NR_fgetxattr
has to be defined to 259, but it doesn't.  Instead, it's defined to 269,
which is of course used by another syscall, __NR_sched_setaffinity in this
case.

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&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: Jiri Slaby &lt;jslaby@suse.cz&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2d33fa1059da4c8e816627a688d950b613ec0474 upstream.

According to arch/sh/kernel/syscalls_64.S and common sense, __NR_fgetxattr
has to be defined to 259, but it doesn't.  Instead, it's defined to 269,
which is of course used by another syscall, __NR_sched_setaffinity in this
case.

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&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: Jiri Slaby &lt;jslaby@suse.cz&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h</title>
<updated>2015-10-28T15:37:39+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2013-11-06T13:57:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=35377f1656fdb8fba54c70eb4d27bf16356b1468'/>
<id>35377f1656fdb8fba54c70eb4d27bf16356b1468</id>
<content type='text'>
commit 93ea02bb84354370e51de803a9405f171f3edf88 upstream.

We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.

Suggested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reviewed-by: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@polymtl.ca&gt;
Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Cc: Michael Neuling &lt;mikey@neuling.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Victor Kaplansky &lt;VICTORK@il.ibm.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 93ea02bb84354370e51de803a9405f171f3edf88 upstream.

We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.

Suggested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reviewed-by: "Paul E. McKenney" &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@polymtl.ca&gt;
Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Michael Ellerman &lt;michael@ellerman.id.au&gt;
Cc: Michael Neuling &lt;mikey@neuling.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Victor Kaplansky &lt;VICTORK@il.ibm.com&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nosave: consolidate __nosave_{begin,end} in &lt;asm/sections.h&gt;</title>
<updated>2015-05-04T09:49:04+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert@linux-m68k.org</email>
</author>
<published>2014-10-09T22:30:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f2efcbce549440344368ee59910b698d039852b5'/>
<id>f2efcbce549440344368ee59910b698d039852b5</id>
<content type='text'>
commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream.

The different architectures used their own (and different) declarations:

    extern __visible const void __nosave_begin, __nosave_end;
    extern const void __nosave_begin, __nosave_end;
    extern long __nosave_begin, __nosave_end;

Consolidate them using the first variant in &lt;asm/sections.h&gt;.

Signed-off-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
[js -- port to 3.12: arm does not have hibernation yet]
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream.

The different architectures used their own (and different) declarations:

    extern __visible const void __nosave_begin, __nosave_end;
    extern const void __nosave_begin, __nosave_end;
    extern long __nosave_begin, __nosave_end;

Consolidate them using the first variant in &lt;asm/sections.h&gt;.

Signed-off-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
[js -- port to 3.12: arm does not have hibernation yet]
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/hugetlb: reduce arch dependent code around follow_huge_*</title>
<updated>2015-03-16T10:09:27+00:00</updated>
<author>
<name>Naoya Horiguchi</name>
<email>n-horiguchi@ah.jp.nec.com</email>
</author>
<published>2015-02-11T23:25:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a59e2c71bf4901512137c9aaf88d2a95961577e1'/>
<id>a59e2c71bf4901512137c9aaf88d2a95961577e1</id>
<content type='text'>
commit 61f77eda9bbf0d2e922197ed2dcf88638a639ce5 upstream.

Currently we have many duplicates in definitions around
follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
patch tries to remove the m.  The basic idea is to put the default
implementation for these functions in mm/hugetlb.c as weak symbols
(regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement
arch-specific code only when the arch needs it.

For follow_huge_addr(), only powerpc and ia64 have their own
implementation, and in all other architectures this function just returns
ERR_PTR(-EINVAL).  So this patch sets returning ERR_PTR(-EINVAL) as
default.

As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
always return 0 in your architecture (like in ia64 or sparc,) it's never
called (the callsite is optimized away) no matter how implemented it is.
So in such architectures, we don't need arch-specific implementation.

In some architecture (like mips, s390 and tile,) their current
arch-specific follow_huge_(pmd|pud)() are effectively identical with the
common code, so this patch lets these architecture use the common code.

One exception is metag, where pmd_huge() could return non-zero but it
expects follow_huge_pmd() to always return NULL.  This means that we need
arch-specific implementation which returns NULL.  This behavior looks
strange to me (because non-zero pmd_huge() implies that the architecture
supports PMD-based hugepage, so follow_huge_pmd() can/should return some
relevant value,) but that's beyond this cleanup patch, so let's keep it.

Justification of non-trivial changes:
- in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
  patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
  is true when follow_huge_pmd() can be called (note that pmd_huge() has
  the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
- in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
  code. This patch forces these archs use PMD_MASK, but it's OK because
  they are identical in both archs.
  In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
  In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
  PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
  PTE_ORDER is always 0, so these are identical.

Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Mel Gorman &lt;mel@csn.ul.ie&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.cz&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Luiz Capitulino &lt;lcapitulino@redhat.com&gt;
Cc: Nishanth Aravamudan &lt;nacc@linux.vnet.ibm.com&gt;
Cc: Lee Schermerhorn &lt;lee.schermerhorn@hp.com&gt;
Cc: Steve Capper &lt;steve.capper@linaro.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 61f77eda9bbf0d2e922197ed2dcf88638a639ce5 upstream.

Currently we have many duplicates in definitions around
follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
patch tries to remove the m.  The basic idea is to put the default
implementation for these functions in mm/hugetlb.c as weak symbols
(regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement
arch-specific code only when the arch needs it.

For follow_huge_addr(), only powerpc and ia64 have their own
implementation, and in all other architectures this function just returns
ERR_PTR(-EINVAL).  So this patch sets returning ERR_PTR(-EINVAL) as
default.

As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
always return 0 in your architecture (like in ia64 or sparc,) it's never
called (the callsite is optimized away) no matter how implemented it is.
So in such architectures, we don't need arch-specific implementation.

In some architecture (like mips, s390 and tile,) their current
arch-specific follow_huge_(pmd|pud)() are effectively identical with the
common code, so this patch lets these architecture use the common code.

One exception is metag, where pmd_huge() could return non-zero but it
expects follow_huge_pmd() to always return NULL.  This means that we need
arch-specific implementation which returns NULL.  This behavior looks
strange to me (because non-zero pmd_huge() implies that the architecture
supports PMD-based hugepage, so follow_huge_pmd() can/should return some
relevant value,) but that's beyond this cleanup patch, so let's keep it.

Justification of non-trivial changes:
- in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
  patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
  is true when follow_huge_pmd() can be called (note that pmd_huge() has
  the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
- in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
  code. This patch forces these archs use PMD_MASK, but it's OK because
  they are identical in both archs.
  In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
  In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
  PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
  PTE_ORDER is always 0, so these are identical.

Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Mel Gorman &lt;mel@csn.ul.ie&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.cz&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Luiz Capitulino &lt;lcapitulino@redhat.com&gt;
Cc: Nishanth Aravamudan &lt;nacc@linux.vnet.ibm.com&gt;
Cc: Lee Schermerhorn &lt;lee.schermerhorn@hp.com&gt;
Cc: Steve Capper &lt;steve.capper@linaro.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vm: add VM_FAULT_SIGSEGV handling support</title>
<updated>2015-03-12T16:31:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-01-29T18:51:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=1868445f57222c177ff2b3ea31f002c1b7eabb08'/>
<id>1868445f57222c177ff2b3ea31f002c1b7eabb08</id>
<content type='text'>
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Tested-by: Jan Engelhardt &lt;jengelh@inai.de&gt;
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Tested-by: Jan Engelhardt &lt;jengelh@inai.de&gt;
Acked-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt; # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hugetlb: restrict hugepage_migration_support() to x86_64</title>
<updated>2014-07-02T10:06:08+00:00</updated>
<author>
<name>Naoya Horiguchi</name>
<email>n-horiguchi@ah.jp.nec.com</email>
</author>
<published>2014-06-04T23:05:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=79e24e2ea96ce5e7c3aa2865d7ff0887f6f53daf'/>
<id>79e24e2ea96ce5e7c3aa2865d7ff0887f6f53daf</id>
<content type='text'>
commit c177c81e09e517bbf75b67762cdab1b83aba6976 upstream.

Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Reported-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Russell King &lt;rmk@arm.linux.org.uk&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Miller &lt;davem@davemloft.net&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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c177c81e09e517bbf75b67762cdab1b83aba6976 upstream.

Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Reported-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Russell King &lt;rmk@arm.linux.org.uk&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Miller &lt;davem@davemloft.net&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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sh: fix format string bug in stack tracer</title>
<updated>2014-05-15T07:55:35+00:00</updated>
<author>
<name>Matt Fleming</name>
<email>matt.fleming@intel.com</email>
</author>
<published>2014-04-03T21:46:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=3937fa5f06d7a2b60545bf52b7b7379a970a6a8a'/>
<id>3937fa5f06d7a2b60545bf52b7b7379a970a6a8a</id>
<content type='text'>
commit a0c32761e73c9999cbf592b702f284221fea8040 upstream.

Kees reported the following error:

   arch/sh/kernel/dumpstack.c: In function 'print_trace_address':
   arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no format arguments [-Werror=format-security]

Use the "%s" format so that it's impossible to interpret 'data' as a
format string.

Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Reported-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a0c32761e73c9999cbf592b702f284221fea8040 upstream.

Kees reported the following error:

   arch/sh/kernel/dumpstack.c: In function 'print_trace_address':
   arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no format arguments [-Werror=format-security]

Use the "%s" format so that it's impossible to interpret 'data' as a
format string.

Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Reported-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.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: Jiri Slaby &lt;jslaby@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch/sh/kernel/kgdb.c: add missing #include &lt;linux/sched.h&gt;</title>
<updated>2014-02-13T21:50:09+00:00</updated>
<author>
<name>Wanlong Gao</name>
<email>gaowanlong@cn.fujitsu.com</email>
</author>
<published>2014-01-21T23:48:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=550c4ce2935b242bd3c61b436444cee1f27ef8ee'/>
<id>550c4ce2935b242bd3c61b436444cee1f27ef8ee</id>
<content type='text'>
commit 53a52f17d96c8d47c79a7dafa81426317e89c7c1 upstream.

  arch/sh/kernel/kgdb.c: In function 'sleeping_thread_to_gdb_regs':
  arch/sh/kernel/kgdb.c:225:32: error: implicit declaration of function 'task_stack_page' [-Werror=implicit-function-declaration]
  arch/sh/kernel/kgdb.c:242:23: error: dereferencing pointer to incomplete type
  arch/sh/kernel/kgdb.c:243:22: error: dereferencing pointer to incomplete type
  arch/sh/kernel/kgdb.c: In function 'singlestep_trap_handler':
  arch/sh/kernel/kgdb.c:310:27: error: 'SIGTRAP' undeclared (first use in this function)
  arch/sh/kernel/kgdb.c:310:27: note: each undeclared identifier is reported only once for each function it appears in

This was introduced by commit 16559ae48c76 ("kgdb: remove #include
&lt;linux/serial_8250.h&gt; from kgdb.h").

[geert@linux-m68k.org: reworded and reformatted]
Signed-off-by: Wanlong Gao &lt;gaowanlong@cn.fujitsu.com&gt;
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@linux-m68k.org&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 53a52f17d96c8d47c79a7dafa81426317e89c7c1 upstream.

  arch/sh/kernel/kgdb.c: In function 'sleeping_thread_to_gdb_regs':
  arch/sh/kernel/kgdb.c:225:32: error: implicit declaration of function 'task_stack_page' [-Werror=implicit-function-declaration]
  arch/sh/kernel/kgdb.c:242:23: error: dereferencing pointer to incomplete type
  arch/sh/kernel/kgdb.c:243:22: error: dereferencing pointer to incomplete type
  arch/sh/kernel/kgdb.c: In function 'singlestep_trap_handler':
  arch/sh/kernel/kgdb.c:310:27: error: 'SIGTRAP' undeclared (first use in this function)
  arch/sh/kernel/kgdb.c:310:27: note: each undeclared identifier is reported only once for each function it appears in

This was introduced by commit 16559ae48c76 ("kgdb: remove #include
&lt;linux/serial_8250.h&gt; from kgdb.h").

[geert@linux-m68k.org: reworded and reformatted]
Signed-off-by: Wanlong Gao &lt;gaowanlong@cn.fujitsu.com&gt;
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@linux-m68k.org&gt;
Reported-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
