<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/sh, branch v4.4.151</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>sh: New gcc support</title>
<updated>2018-06-06T14:46:20+00:00</updated>
<author>
<name>Yoshinori Sato</name>
<email>ysato@users.sourceforge.jp</email>
</author>
<published>2015-06-20T05:02:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f8c42dfbf6d8a88f7856b7551910fdb57c2a14b4'/>
<id>f8c42dfbf6d8a88f7856b7551910fdb57c2a14b4</id>
<content type='text'>
commit 940d4113f3306e07a1f86541489b686d1a979d54 upstream.

New gcc (4.8 or later) used new shift helper functions.
So we need added new helper to private libgcc.

Signed-off-by: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&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 940d4113f3306e07a1f86541489b686d1a979d54 upstream.

New gcc (4.8 or later) used new shift helper functions.
So we need added new helper to private libgcc.

Signed-off-by: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sh: fix debug trap failure to process signals before return to user</title>
<updated>2018-05-30T05:49:07+00:00</updated>
<author>
<name>Rich Felker</name>
<email>dalias@libc.org</email>
</author>
<published>2018-03-16T00:01:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8971f3183b7e55591244e0c2d3e56a18c0d03f52'/>
<id>8971f3183b7e55591244e0c2d3e56a18c0d03f52</id>
<content type='text'>
[ Upstream commit 96a598996f6ac518ac79839ecbb17c91af91f4f7 ]

When responding to a debug trap (breakpoint) in userspace, the
kernel's trap handler raised SIGTRAP but returned from the trap via a
code path that ignored pending signals, resulting in an infinite loop
re-executing the trapping instruction.

Signed-off-by: Rich Felker &lt;dalias@libc.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 96a598996f6ac518ac79839ecbb17c91af91f4f7 ]

When responding to a debug trap (breakpoint) in userspace, the
kernel's trap handler raised SIGTRAP but returned from the trap via a
code path that ignored pending signals, resulting in an infinite loop
re-executing the trapping instruction.

Signed-off-by: Rich Felker &lt;dalias@libc.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>2018-05-26T06:48:50+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.toradex.cn/cgit/linux-toradex.git/commit/?id=177a981885cf9588ca5cbcaf2ce65ab0d4b4abb3'/>
<id>177a981885cf9588ca5cbcaf2ce65ab0d4b4abb3</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>SolutionEngine771x: fix Ether platform data</title>
<updated>2018-03-03T09:19:45+00:00</updated>
<author>
<name>Sergei Shtylyov</name>
<email>sergei.shtylyov@cogentembedded.com</email>
</author>
<published>2018-01-06T18:53:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7f102d7af10cdbc9a90abb635c790f1071765421'/>
<id>7f102d7af10cdbc9a90abb635c790f1071765421</id>
<content type='text'>
[ Upstream commit 195e2addbce09e5afbc766efc1e6567c9ce840d3 ]

The 'sh_eth' driver's probe() method would fail  on the SolutionEngine7710
board and crash on SolutionEngine7712 board  as the platform code is
hopelessly behind the driver's platform data --  it passes the PHY address
instead of 'struct sh_eth_plat_data *'; pass the latter to the driver in
order to fix the bug...

Fixes: 71557a37adb5 ("[netdrvr] sh_eth: Add SH7619 support")
Signed-off-by: Sergei Shtylyov &lt;sergei.shtylyov@cogentembedded.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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 195e2addbce09e5afbc766efc1e6567c9ce840d3 ]

The 'sh_eth' driver's probe() method would fail  on the SolutionEngine7710
board and crash on SolutionEngine7712 board  as the platform code is
hopelessly behind the driver's platform data --  it passes the PHY address
instead of 'struct sh_eth_plat_data *'; pass the latter to the driver in
order to fix the bug...

Fixes: 71557a37adb5 ("[netdrvr] sh_eth: Add SH7619 support")
Signed-off-by: Sergei Shtylyov &lt;sergei.shtylyov@cogentembedded.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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>signal/sh: Ensure si_signo is initialized in do_divide_error</title>
<updated>2018-02-16T19:09:46+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2017-07-24T22:30:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fbc1425f4544371b5fe20b9a93f73b85c08dfe29'/>
<id>fbc1425f4544371b5fe20b9a93f73b85c08dfe29</id>
<content type='text'>
commit 0e88bb002a9b2ee8cc3cc9478ce2dc126f849696 upstream.

Set si_signo.

Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: linux-sh@vger.kernel.org
Fixes: 0983b31849bb ("sh: Wire up division and address error exceptions on SH-2A.")
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.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>
commit 0e88bb002a9b2ee8cc3cc9478ce2dc126f849696 upstream.

Set si_signo.

Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: linux-sh@vger.kernel.org
Fixes: 0983b31849bb ("sh: Wire up division and address error exceptions on SH-2A.")
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: sh-sci: Fix register offsets for the IRDA serial port</title>
<updated>2017-11-15T16:13:10+00:00</updated>
<author>
<name>Laurent Pinchart</name>
<email>laurent.pinchart+renesas@ideasonboard.com</email>
</author>
<published>2017-01-11T14:43:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6450c9a96ff368f1a652215d1e0814343e4fa2e2'/>
<id>6450c9a96ff368f1a652215d1e0814343e4fa2e2</id>
<content type='text'>
[ Upstream commit a752ba18af8285e3eeda572f40dddaebff0c3621 ]

Even though most of its registers are 8-bit wide, the IRDA has two
16-bit registers that make it a 16-bit peripheral and not a 8-bit
peripheral with addresses shifted by one. Fix the registers offset in
the driver and the platform data regshift value.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart+renesas@ideasonboard.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.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 a752ba18af8285e3eeda572f40dddaebff0c3621 ]

Even though most of its registers are 8-bit wide, the IRDA has two
16-bit registers that make it a 16-bit peripheral and not a 8-bit
peripheral with addresses shifted by one. Fix the registers offset in
the driver and the platform data regshift value.

Signed-off-by: Laurent Pinchart &lt;laurent.pinchart+renesas@ideasonboard.com&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: larger stack guard gap, between vmas</title>
<updated>2017-06-26T05:13:11+00:00</updated>
<author>
<name>Hugh Dickins</name>
<email>hughd@google.com</email>
</author>
<published>2017-06-19T11:03:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4b359430674caa2c98d0049a6941f157d2a33741'/>
<id>4b359430674caa2c98d0049a6941f157d2a33741</id>
<content type='text'>
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Original-patch-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Tested-by: Helge Deller &lt;deller@gmx.de&gt; # parisc
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes]
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
[gkh: minor build fixes for 4.4]
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 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Original-patch-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Tested-by: Helge Deller &lt;deller@gmx.de&gt; # parisc
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes]
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
[gkh: minor build fixes for 4.4]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sh: fix copy_from_user()</title>
<updated>2016-09-24T08:07:44+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.toradex.cn/cgit/linux-toradex.git/commit/?id=df243b41c66ebad9361bfb75fa022dd168ffb394'/>
<id>df243b41c66ebad9361bfb75fa022dd168ffb394</id>
<content type='text'>
commit 6e050503a150b2126620c1a1e9b3a368fcd51eac upstream.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.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 6e050503a150b2126620c1a1e9b3a368fcd51eac upstream.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sh64: failing __get_user() should zero</title>
<updated>2016-09-24T08:07:44+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.toradex.cn/cgit/linux-toradex.git/commit/?id=9ce4d2bd802d99a39b424408c9633dac047c0b32'/>
<id>9ce4d2bd802d99a39b424408c9633dac047c0b32</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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sched/preempt, sh: kmap_coherent relies on disabled preemption</title>
<updated>2016-04-12T16:08:36+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>dahi@linux.vnet.ibm.com</email>
</author>
<published>2016-02-29T08:19:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=10595c57f4682b096d6ac6dd2212ac889f08d9f4'/>
<id>10595c57f4682b096d6ac6dd2212ac889f08d9f4</id>
<content type='text'>
commit b15d53d009558d14c4f394a6d1fa2039c7f45c43 upstream.

kmap_coherent needs disabled preemption to not schedule in the critical
section, just like kmap_coherent on mips and kmap_atomic in general.

Fixes: 8222dbe21e79 "sched/preempt, mm/fault: Decouple preemption from the page fault logic"
Reported-by: Hans Verkuil &lt;hverkuil@xs4all.nl&gt;
Signed-off-by: David Hildenbrand &lt;dahi@linux.vnet.ibm.com&gt;
Tested-by: Hans Verkuil &lt;hans.verkuil@cisco.com&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.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 b15d53d009558d14c4f394a6d1fa2039c7f45c43 upstream.

kmap_coherent needs disabled preemption to not schedule in the critical
section, just like kmap_coherent on mips and kmap_atomic in general.

Fixes: 8222dbe21e79 "sched/preempt, mm/fault: Decouple preemption from the page fault logic"
Reported-by: Hans Verkuil &lt;hverkuil@xs4all.nl&gt;
Signed-off-by: David Hildenbrand &lt;dahi@linux.vnet.ibm.com&gt;
Tested-by: Hans Verkuil &lt;hans.verkuil@cisco.com&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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