<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arm64, branch v4.9.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls</title>
<updated>2018-01-23T18:57:09+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2018-01-16T10:23:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ddfaa7acd7a27355200457eb56767cf5fcafc1d0'/>
<id>ddfaa7acd7a27355200457eb56767cf5fcafc1d0</id>
<content type='text'>
commit acfb3b883f6d6a4b5d27ad7fdded11f6a09ae6dd upstream.

KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.

Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.

Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.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 acfb3b883f6d6a4b5d27ad7fdded11f6a09ae6dd upstream.

KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.

Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.

Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Initialise high_memory global variable earlier</title>
<updated>2017-12-25T13:23:36+00:00</updated>
<author>
<name>Steve Capper</name>
<email>steve.capper@arm.com</email>
</author>
<published>2017-12-04T14:13:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb95f1caee6177da78c8fa9a54bcd3695c903b97'/>
<id>bb95f1caee6177da78c8fa9a54bcd3695c903b97</id>
<content type='text'>
commit f24e5834a2c3f6c5f814a417f858226f0a010ade upstream.

The high_memory global variable is used by
cma_declare_contiguous(.) before it is defined.

We don't notice this as we compute __pa(high_memory - 1), and it looks
like we're processing a VA from the direct linear map.

This problem becomes apparent when we flip the kernel virtual address
space and the linear map is moved to the bottom of the kernel VA space.

This patch moves the initialisation of high_memory before it used.

Fixes: f7426b983a6a ("mm: cma: adjust address limit to avoid hitting low/high memory boundary")
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.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 f24e5834a2c3f6c5f814a417f858226f0a010ade upstream.

The high_memory global variable is used by
cma_declare_contiguous(.) before it is defined.

We don't notice this as we compute __pa(high_memory - 1), and it looks
like we're processing a VA from the direct linear map.

This problem becomes apparent when we flip the kernel virtual address
space and the linear map is moved to the bottom of the kernel VA space.

This patch moves the initialisation of high_memory before it used.

Fixes: f7426b983a6a ("mm: cma: adjust address limit to avoid hitting low/high memory boundary")
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: prevent regressions in compressed kernel image size when upgrading to binutils 2.27</title>
<updated>2017-12-20T09:07:31+00:00</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2017-10-27T16:33:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b7ada2c0ea291e7bf22b51745afd9f1ccfc91292'/>
<id>b7ada2c0ea291e7bf22b51745afd9f1ccfc91292</id>
<content type='text'>
[ Upstream commit fd9dde6abcb9bfe6c6bee48834e157999f113971 ]

Upon upgrading to binutils 2.27, we found that our lz4 and gzip
compressed kernel images were significantly larger, resulting is 10ms
boot time regressions.

As noted by Rahul:
"aarch64 binaries uses RELA relocations, where each relocation entry
includes an addend value. This is similar to x86_64.  On x86_64, the
addend values are also stored at the relocation offset for relative
relocations. This is an optimization: in the case where code does not
need to be relocated, the loader can simply skip processing relative
relocations.  In binutils-2.25, both bfd and gold linkers did this for
x86_64, but only the gold linker did this for aarch64.  The kernel build
here is using the bfd linker, which stored zeroes at the relocation
offsets for relative relocations.  Since a set of zeroes compresses
better than a set of non-zero addend values, this behavior was resulting
in much better lz4 compression.

The bfd linker in binutils-2.27 is now storing the actual addend values
at the relocation offsets. The behavior is now consistent with what it
does for x86_64 and what gold linker does for both architectures.  The
change happened in this upstream commit:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613
Since a bunch of zeroes got replaced by non-zero addend values, we see
the side effect of lz4 compressed image being a bit bigger.

To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs"
flag can be used:
$ LDFLAGS="--no-apply-dynamic-relocs" make
With this flag, the compressed image size is back to what it was with
binutils-2.25.

If the kernel is using ASLR, there aren't additional runtime costs to
--no-apply-dynamic-relocs, as the relocations will need to be applied
again anyway after the kernel is relocated to a random address.

If the kernel is not using ASLR, then presumably the current default
behavior of the linker is better. Since the static linker performed the
dynamic relocs, and the kernel is not moved to a different address at
load time, it can skip applying the relocations all over again."

Some measurements:

$ ld -v
GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117
                    ^
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb

$ ld -v
GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315
                    ^
pre patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb

post patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb

By Siqi's measurement w/ gzip:
binutils 2.27 with this patch (with --no-apply-dynamic-relocs):
Image 41535488
Image.gz 13404067

binutils 2.27 without this patch (without --no-apply-dynamic-relocs):
Image 41535488
Image.gz 14125516

Any compression scheme should be able to get better results from the
longer runs of zeros, not just GZIP and LZ4.

10ms boot time savings isn't anything to get excited about, but users of
arm64+compression+bfd-2.27 should not have to pay a penalty for no
runtime improvement.

Reported-by: Gopinath Elanchezhian &lt;gelanchezhian@google.com&gt;
Reported-by: Sindhuri Pentyala &lt;spentyala@google.com&gt;
Reported-by: Wei Wang &lt;wvw@google.com&gt;
Suggested-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Suggested-by: Rahul Chaudhry &lt;rahulchaudhry@google.com&gt;
Suggested-by: Siqi Lin &lt;siqilin@google.com&gt;
Suggested-by: Stephen Hines &lt;srhines@google.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
[will: added comment to Makefile]
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&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 fd9dde6abcb9bfe6c6bee48834e157999f113971 ]

Upon upgrading to binutils 2.27, we found that our lz4 and gzip
compressed kernel images were significantly larger, resulting is 10ms
boot time regressions.

As noted by Rahul:
"aarch64 binaries uses RELA relocations, where each relocation entry
includes an addend value. This is similar to x86_64.  On x86_64, the
addend values are also stored at the relocation offset for relative
relocations. This is an optimization: in the case where code does not
need to be relocated, the loader can simply skip processing relative
relocations.  In binutils-2.25, both bfd and gold linkers did this for
x86_64, but only the gold linker did this for aarch64.  The kernel build
here is using the bfd linker, which stored zeroes at the relocation
offsets for relative relocations.  Since a set of zeroes compresses
better than a set of non-zero addend values, this behavior was resulting
in much better lz4 compression.

The bfd linker in binutils-2.27 is now storing the actual addend values
at the relocation offsets. The behavior is now consistent with what it
does for x86_64 and what gold linker does for both architectures.  The
change happened in this upstream commit:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613
Since a bunch of zeroes got replaced by non-zero addend values, we see
the side effect of lz4 compressed image being a bit bigger.

To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs"
flag can be used:
$ LDFLAGS="--no-apply-dynamic-relocs" make
With this flag, the compressed image size is back to what it was with
binutils-2.25.

If the kernel is using ASLR, there aren't additional runtime costs to
--no-apply-dynamic-relocs, as the relocations will need to be applied
again anyway after the kernel is relocated to a random address.

If the kernel is not using ASLR, then presumably the current default
behavior of the linker is better. Since the static linker performed the
dynamic relocs, and the kernel is not moved to a different address at
load time, it can skip applying the relocations all over again."

Some measurements:

$ ld -v
GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117
                    ^
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb

$ ld -v
GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315
                    ^
pre patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb

post patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb

By Siqi's measurement w/ gzip:
binutils 2.27 with this patch (with --no-apply-dynamic-relocs):
Image 41535488
Image.gz 13404067

binutils 2.27 without this patch (without --no-apply-dynamic-relocs):
Image 41535488
Image.gz 14125516

Any compression scheme should be able to get better results from the
longer runs of zeros, not just GZIP and LZ4.

10ms boot time savings isn't anything to get excited about, but users of
arm64+compression+bfd-2.27 should not have to pay a penalty for no
runtime improvement.

Reported-by: Gopinath Elanchezhian &lt;gelanchezhian@google.com&gt;
Reported-by: Sindhuri Pentyala &lt;spentyala@google.com&gt;
Reported-by: Wei Wang &lt;wvw@google.com&gt;
Suggested-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Suggested-by: Rahul Chaudhry &lt;rahulchaudhry@google.com&gt;
Suggested-by: Siqi Lin &lt;siqilin@google.com&gt;
Suggested-by: Stephen Hines &lt;srhines@google.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
[will: added comment to Makefile]
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&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>arm64: KVM: Survive unknown traps from guests</title>
<updated>2017-12-14T08:28:19+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2017-02-20T12:30:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aafb72d2ed5579208191cfc3fb9425570c1303ce'/>
<id>aafb72d2ed5579208191cfc3fb9425570c1303ce</id>
<content type='text'>
[ Upstream commit ba4dd156eabdca93501d92a980ba27fa5f4bbd27 ]

Currently we BUG() if we see an ESR_EL2.EC value we don't recognise. As
configurable disables/enables are added to the architecture (controlled
by RES1/RES0 bits respectively), with associated synchronous exceptions,
it may be possible for a guest to trigger exceptions with classes that
we don't recognise.

While we can't service these exceptions in a manner useful to the guest,
we can avoid bringing down the host. Per ARM DDI 0487A.k_iss10775, page
D7-1937, EC values within the range 0x00 - 0x2c are reserved for future
use with synchronous exceptions, and EC values within the range 0x2d -
0x3f may be used for either synchronous or asynchronous exceptions.

The patch makes KVM handle any unknown EC by injecting an UNDEFINED
exception into the guest, with a corresponding (ratelimited) warning in
the host dmesg. We could later improve on this with with a new (opt-in)
exit to the host userspace.

Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&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 ba4dd156eabdca93501d92a980ba27fa5f4bbd27 ]

Currently we BUG() if we see an ESR_EL2.EC value we don't recognise. As
configurable disables/enables are added to the architecture (controlled
by RES1/RES0 bits respectively), with associated synchronous exceptions,
it may be possible for a guest to trigger exceptions with classes that
we don't recognise.

While we can't service these exceptions in a manner useful to the guest,
we can avoid bringing down the host. Per ARM DDI 0487A.k_iss10775, page
D7-1937, EC values within the range 0x00 - 0x2c are reserved for future
use with synchronous exceptions, and EC values within the range 0x2d -
0x3f may be used for either synchronous or asynchronous exceptions.

The patch makes KVM handle any unknown EC by injecting an UNDEFINED
exception into the guest, with a corresponding (ratelimited) warning in
the host dmesg. We could later improve on this with with a new (opt-in)
exit to the host userspace.

Cc: Dave Martin &lt;dave.martin@arm.com&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&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>arm64: fpsimd: Prevent registers leaking from dead tasks</title>
<updated>2017-12-14T08:28:14+00:00</updated>
<author>
<name>Dave Martin</name>
<email>Dave.Martin@arm.com</email>
</author>
<published>2017-12-05T14:56:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a39224199e97e2f49870933f8a9caaaa1edf736c'/>
<id>a39224199e97e2f49870933f8a9caaaa1edf736c</id>
<content type='text'>
commit 071b6d4a5d343046f253a5a8835d477d93992002 upstream.

Currently, loading of a task's fpsimd state into the CPU registers
is skipped if that task's state is already present in the registers
of that CPU.

However, the code relies on the struct fpsimd_state * (and by
extension struct task_struct *) to unambiguously identify a task.

There is a particular case in which this doesn't work reliably:
when a task exits, its task_struct may be recycled to describe a
new task.

Consider the following scenario:

 1) Task P loads its fpsimd state onto cpu C.
        per_cpu(fpsimd_last_state, C) := P;
        P-&gt;thread.fpsimd_state.cpu := C;

 2) Task X is scheduled onto C and loads its fpsimd state on C.
        per_cpu(fpsimd_last_state, C) := X;
        X-&gt;thread.fpsimd_state.cpu := C;

 3) X exits, causing X's task_struct to be freed.

 4) P forks a new child T, which obtains X's recycled task_struct.
	T == X.
	T-&gt;thread.fpsimd_state.cpu == C (inherited from P).

 5) T is scheduled on C.
	T's fpsimd state is not loaded, because
	per_cpu(fpsimd_last_state, C) == T (== X) &amp;&amp;
	T-&gt;thread.fpsimd_state.cpu == C.

        (This is the check performed by fpsimd_thread_switch().)

So, T gets X's registers because the last registers loaded onto C
were those of X, in (2).

This patch fixes the problem by ensuring that the sched-in check
fails in (5): fpsimd_flush_task_state(T) is called when T is
forked, so that T-&gt;thread.fpsimd_state.cpu == C cannot be true.
This relies on the fact that T is not schedulable until after
copy_thread() completes.

Once T's fpsimd state has been loaded on some CPU C there may still
be other cpus D for which per_cpu(fpsimd_last_state, D) ==
&amp;X-&gt;thread.fpsimd_state.  But D is necessarily != C in this case,
and the check in (5) must fail.

An alternative fix would be to do refcounting on task_struct.  This
would result in each CPU holding a reference to the last task whose
fpsimd state was loaded there.  It's not clear whether this is
preferable, and it involves higher overhead than the fix proposed
in this patch.  It would also move all the task_struct freeing
work into the context switch critical section, or otherwise some
deferred cleanup mechanism would need to be introduced, neither of
which seems obviously justified.

Fixes: 005f78cd8849 ("arm64: defer reloading a task's FPSIMD state to userland resume")
Signed-off-by: Dave Martin &lt;Dave.Martin@arm.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
[will: word-smithed the comment so it makes more sense]
Signed-off-by: Will Deacon &lt;will.deacon@arm.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 071b6d4a5d343046f253a5a8835d477d93992002 upstream.

Currently, loading of a task's fpsimd state into the CPU registers
is skipped if that task's state is already present in the registers
of that CPU.

However, the code relies on the struct fpsimd_state * (and by
extension struct task_struct *) to unambiguously identify a task.

There is a particular case in which this doesn't work reliably:
when a task exits, its task_struct may be recycled to describe a
new task.

Consider the following scenario:

 1) Task P loads its fpsimd state onto cpu C.
        per_cpu(fpsimd_last_state, C) := P;
        P-&gt;thread.fpsimd_state.cpu := C;

 2) Task X is scheduled onto C and loads its fpsimd state on C.
        per_cpu(fpsimd_last_state, C) := X;
        X-&gt;thread.fpsimd_state.cpu := C;

 3) X exits, causing X's task_struct to be freed.

 4) P forks a new child T, which obtains X's recycled task_struct.
	T == X.
	T-&gt;thread.fpsimd_state.cpu == C (inherited from P).

 5) T is scheduled on C.
	T's fpsimd state is not loaded, because
	per_cpu(fpsimd_last_state, C) == T (== X) &amp;&amp;
	T-&gt;thread.fpsimd_state.cpu == C.

        (This is the check performed by fpsimd_thread_switch().)

So, T gets X's registers because the last registers loaded onto C
were those of X, in (2).

This patch fixes the problem by ensuring that the sched-in check
fails in (5): fpsimd_flush_task_state(T) is called when T is
forked, so that T-&gt;thread.fpsimd_state.cpu == C cannot be true.
This relies on the fact that T is not schedulable until after
copy_thread() completes.

Once T's fpsimd state has been loaded on some CPU C there may still
be other cpus D for which per_cpu(fpsimd_last_state, D) ==
&amp;X-&gt;thread.fpsimd_state.  But D is necessarily != C in this case,
and the check in (5) must fail.

An alternative fix would be to do refcounting on task_struct.  This
would result in each CPU holding a reference to the last task whose
fpsimd state was loaded there.  It's not clear whether this is
preferable, and it involves higher overhead than the fix proposed
in this patch.  It would also move all the task_struct freeing
work into the context switch critical section, or otherwise some
deferred cleanup mechanism would need to be introduced, neither of
which seems obviously justified.

Fixes: 005f78cd8849 ("arm64: defer reloading a task's FPSIMD state to userland resume")
Signed-off-by: Dave Martin &lt;Dave.Martin@arm.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
[will: word-smithed the comment so it makes more sense]
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: KVM: fix VTTBR_BADDR_MASK BUG_ON off-by-one</title>
<updated>2017-12-14T08:28:14+00:00</updated>
<author>
<name>Kristina Martsenko</name>
<email>kristina.martsenko@arm.com</email>
</author>
<published>2017-11-16T17:58:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=63fba9ff76f0ef8af6009903ccc903bd5cee9876'/>
<id>63fba9ff76f0ef8af6009903ccc903bd5cee9876</id>
<content type='text'>
commit 26aa7b3b1c0fb3f1a6176a0c1847204ef4355693 upstream.

VTTBR_BADDR_MASK is used to sanity check the size and alignment of the
VTTBR address. It seems to currently be off by one, thereby only
allowing up to 47-bit addresses (instead of 48-bit) and also
insufficiently checking the alignment. This patch fixes it.

As an example, with 4k pages, before this patch we have:

  PHYS_MASK_SHIFT = 48
  VTTBR_X = 37 - 24 = 13
  VTTBR_BADDR_SHIFT = 13 - 1 = 12
  VTTBR_BADDR_MASK = ((1 &lt;&lt; 35) - 1) &lt;&lt; 12 = 0x00007ffffffff000

Which is wrong, because the mask doesn't allow bit 47 of the VTTBR
address to be set, and only requires the address to be 12-bit (4k)
aligned, while it actually needs to be 13-bit (8k) aligned because we
concatenate two 4k tables.

With this patch, the mask becomes 0x0000ffffffffe000, which is what we
want.

Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions")
Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
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<pre>
commit 26aa7b3b1c0fb3f1a6176a0c1847204ef4355693 upstream.

VTTBR_BADDR_MASK is used to sanity check the size and alignment of the
VTTBR address. It seems to currently be off by one, thereby only
allowing up to 47-bit addresses (instead of 48-bit) and also
insufficiently checking the alignment. This patch fixes it.

As an example, with 4k pages, before this patch we have:

  PHYS_MASK_SHIFT = 48
  VTTBR_X = 37 - 24 = 13
  VTTBR_BADDR_SHIFT = 13 - 1 = 12
  VTTBR_BADDR_MASK = ((1 &lt;&lt; 35) - 1) &lt;&lt; 12 = 0x00007ffffffff000

Which is wrong, because the mask doesn't allow bit 47 of the VTTBR
address to be set, and only requires the address to be 12-bit (4k)
aligned, while it actually needs to be 13-bit (8k) aligned because we
concatenate two 4k tables.

With this patch, the mask becomes 0x0000ffffffffe000, which is what we
want.

Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions")
Reviewed-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Implement arch-specific pte_access_permitted()</title>
<updated>2017-11-30T08:39:01+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2017-10-26T17:36:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e5380004ee78a6090a52a6b8deb44577ec70daa8'/>
<id>e5380004ee78a6090a52a6b8deb44577ec70daa8</id>
<content type='text'>
commit 6218f96c58dbf44a06aeaf767aab1f54fc397838 upstream.

The generic pte_access_permitted() implementation only checks for
pte_present() (together with the write permission where applicable).
However, for both kernel ptes and PROT_NONE mappings pte_present() also
returns true on arm64 even though such mappings are not user accessible.
Additionally, arm64 now supports execute-only user permission
(PROT_EXEC) which is implemented by clearing the PTE_USER bit.

With this patch the arm64 implementation of pte_access_permitted()
checks for the PTE_VALID and PTE_USER bits together with writable access
if applicable.

Reported-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.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 6218f96c58dbf44a06aeaf767aab1f54fc397838 upstream.

The generic pte_access_permitted() implementation only checks for
pte_present() (together with the write permission where applicable).
However, for both kernel ptes and PROT_NONE mappings pte_present() also
returns true on arm64 even though such mappings are not user accessible.
Additionally, arm64 now supports execute-only user permission
(PROT_EXEC) which is implemented by clearing the PTE_USER bit.

With this patch the arm64 implementation of pte_access_permitted()
checks for the PTE_VALID and PTE_USER bits together with writable access
if applicable.

Reported-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: dts: NS2: reserve memory for Nitro firmware</title>
<updated>2017-11-21T08:23:26+00:00</updated>
<author>
<name>Jon Mason</name>
<email>jon.mason@broadcom.com</email>
</author>
<published>2016-12-05T23:12:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d820f84e169fa3e83e1f28a0cc4ca5a1770a9c4'/>
<id>5d820f84e169fa3e83e1f28a0cc4ca5a1770a9c4</id>
<content type='text'>
[ Upstream commit 0cc878d678444392ca2a31350f89f489593ef5bb ]

Nitro firmware is loaded into memory by the bootloader at a specific
location.  Set this memory range aside to prevent the kernel from using
it.

Signed-off-by: Jon Mason &lt;jon.mason@broadcom.com&gt;
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&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 0cc878d678444392ca2a31350f89f489593ef5bb ]

Nitro firmware is loaded into memory by the bootloader at a specific
location.  Set this memory range aside to prevent the kernel from using
it.

Signed-off-by: Jon Mason &lt;jon.mason@broadcom.com&gt;
Signed-off-by: Florian Fainelli &lt;f.fainelli@gmail.com&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>arm64: dma-mapping: Only swizzle DMA ops for IOMMU_DOMAIN_DMA</title>
<updated>2017-11-15T14:53:13+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2017-01-06T10:49:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dea9c75f3f624056b666fa9d9b931cd09715b3dd'/>
<id>dea9c75f3f624056b666fa9d9b931cd09715b3dd</id>
<content type='text'>
[ Upstream commit 4a8d8a14c0d08c2437cb80c05e88f6cc1ca3fb2c ]

The arm64 DMA-mapping implementation sets the DMA ops to the IOMMU DMA
ops if we detect that an IOMMU is present for the master and the DMA
ranges are valid.

In the case when the IOMMU domain for the device is not of type
IOMMU_DOMAIN_DMA, then we have no business swizzling the ops, since
we're not in control of the underlying address space. This patch leaves
the DMA ops alone for masters attached to non-DMA IOMMU domains.

Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&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 4a8d8a14c0d08c2437cb80c05e88f6cc1ca3fb2c ]

The arm64 DMA-mapping implementation sets the DMA ops to the IOMMU DMA
ops if we detect that an IOMMU is present for the master and the DMA
ranges are valid.

In the case when the IOMMU domain for the device is not of type
IOMMU_DOMAIN_DMA, then we have no business swizzling the ops, since
we're not in control of the underlying address space. This patch leaves
the DMA ops alone for masters attached to non-DMA IOMMU domains.

Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&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>arm/arm64: kvm: Disable branch profiling in HYP code</title>
<updated>2017-11-08T09:08:32+00:00</updated>
<author>
<name>Julien Thierry</name>
<email>julien.thierry@arm.com</email>
</author>
<published>2017-10-20T11:34:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e059fc3c36c01cf7c67e3177132e18d16278630a'/>
<id>e059fc3c36c01cf7c67e3177132e18d16278630a</id>
<content type='text'>
commit f9b269f3098121b5d54aaf822e0898c8ed1d3fec upstream.

When HYP code runs into branch profiling code, it attempts to jump to
unmapped memory, causing a HYP Panic.

Disable the branch profiling for code designed to run at HYP mode.

Signed-off-by: Julien Thierry &lt;julien.thierry@arm.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.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 f9b269f3098121b5d54aaf822e0898c8ed1d3fec upstream.

When HYP code runs into branch profiling code, it attempts to jump to
unmapped memory, causing a HYP Panic.

Disable the branch profiling for code designed to run at HYP mode.

Signed-off-by: Julien Thierry &lt;julien.thierry@arm.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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