<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arm64/kernel/head.S, branch linux-4.9.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>arm64: sysreg: Move to use definitions for all the SCTLR bits</title>
<updated>2022-01-11T12:38:12+00:00</updated>
<author>
<name>James Morse</name>
<email>james.morse@arm.com</email>
</author>
<published>2022-01-07T19:43:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ad130eec63fef3d6a20885ea9d76b195f126dd54'/>
<id>ad130eec63fef3d6a20885ea9d76b195f126dd54</id>
<content type='text'>
commit 7a00d68ebe5f07cb1db17e7fedfd031f0d87e8bb upstream.

__cpu_setup() configures SCTLR_EL1 using some hard coded hex masks,
and el2_setup() duplicates some this when setting RES1 bits.

Lets make this the same as KVM's hyp_init, which uses named bits.

First, we add definitions for all the SCTLR_EL{1,2} bits, the RES{1,0}
bits, and those we want to set or clear.

Add a build_bug checks to ensures all bits are either set or clear.
This means we don't need to preserve endian-ness configuration
generated elsewhere.

Finally, move the head.S and proc.S users of these hard-coded masks
over to the macro versions.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.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 7a00d68ebe5f07cb1db17e7fedfd031f0d87e8bb upstream.

__cpu_setup() configures SCTLR_EL1 using some hard coded hex masks,
and el2_setup() duplicates some this when setting RES1 bits.

Lets make this the same as KVM's hyp_init, which uses named bits.

First, we add definitions for all the SCTLR_EL{1,2} bits, the RES{1,0}
bits, and those we want to set or clear.

Add a build_bug checks to ensures all bits are either set or clear.
This means we don't need to preserve endian-ness configuration
generated elsewhere.

Finally, move the head.S and proc.S users of these hard-coded masks
over to the macro versions.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: move !VHE work to end of el2_setup</title>
<updated>2022-01-11T12:38:12+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2022-01-07T19:43:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0f6d14f246616e141c5d35778eedc8b13f1f8bbb'/>
<id>0f6d14f246616e141c5d35778eedc8b13f1f8bbb</id>
<content type='text'>
commit d61c97a7773d0848b4bf5c4697855c7ce117362c upstream.

We only need to initialise sctlr_el1 if we're installing an EL2 stub, so
we may as well defer this until we're doing so. Similarly, we can defer
intialising CPTR_EL2 until then, as we do not access any trapped
functionality as part of el2_setup.

This patch modified el2_setup accordingly, allowing us to remove a
branch and simplify the code flow.

Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.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 d61c97a7773d0848b4bf5c4697855c7ce117362c upstream.

We only need to initialise sctlr_el1 if we're installing an EL2 stub, so
we may as well defer this until we're doing so. Similarly, we can defer
intialising CPTR_EL2 until then, as we do not access any trapped
functionality as part of el2_setup.

This patch modified el2_setup accordingly, allowing us to remove a
branch and simplify the code flow.

Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: reduce el2_setup branching</title>
<updated>2022-01-11T12:38:12+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2022-01-07T19:43:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=231f1acaa260d3886a40d25916d69f9ecbfab78a'/>
<id>231f1acaa260d3886a40d25916d69f9ecbfab78a</id>
<content type='text'>
commit 3ad47d055aa88d9f4189253f5b5c485f4c4626b2 upstream.

The early el2_setup code is a little convoluted, with two branches where
one would do. This makes the code more painful to read than is
necessary.

We can remove a branch and simplify the logic by moving the early return
in the booted-at-EL1 case earlier in the function. This separates it
from all the setup logic that only makes sense for EL2.

Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.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 3ad47d055aa88d9f4189253f5b5c485f4c4626b2 upstream.

The early el2_setup code is a little convoluted, with two branches where
one would do. This makes the code more painful to read than is
necessary.

We can remove a branch and simplify the logic by moving the early return
in the booted-at-EL1 case earlier in the function. This separates it
from all the setup logic that only makes sense for EL2.

Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Add missing ISB after invalidating TLB in __primary_switch</title>
<updated>2021-03-03T16:44:40+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2021-02-24T09:37:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3fcbf957c111b84c9f07d59464835004133507b'/>
<id>b3fcbf957c111b84c9f07d59464835004133507b</id>
<content type='text'>
[ Upstream commit 9d41053e8dc115c92b8002c3db5f545d7602498b ]

Although there has been a bit of back and forth on the subject, it
appears that invalidating TLBs requires an ISB instruction when FEAT_ETS
is not implemented by the CPU.

From the bible:

  | In an implementation that does not implement FEAT_ETS, a TLB
  | maintenance instruction executed by a PE, PEx, can complete at any
  | time after it is issued, but is only guaranteed to be finished for a
  | PE, PEx, after the execution of DSB by the PEx followed by a Context
  | synchronization event

Add the missing ISB in __primary_switch, just in case.

Fixes: 3c5e9f238bc4 ("arm64: head.S: move KASLR processing out of __enable_mmu()")
Suggested-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20210224093738.3629662-3-maz@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9d41053e8dc115c92b8002c3db5f545d7602498b ]

Although there has been a bit of back and forth on the subject, it
appears that invalidating TLBs requires an ISB instruction when FEAT_ETS
is not implemented by the CPU.

From the bible:

  | In an implementation that does not implement FEAT_ETS, a TLB
  | maintenance instruction executed by a PE, PEx, can complete at any
  | time after it is issued, but is only guaranteed to be finished for a
  | PE, PEx, after the execution of DSB by the PEx followed by a Context
  | synchronization event

Add the missing ISB in __primary_switch, just in case.

Fixes: 3c5e9f238bc4 ("arm64: head.S: move KASLR processing out of __enable_mmu()")
Suggested-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20210224093738.3629662-3-maz@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Fix size of __early_cpu_boot_status</title>
<updated>2020-04-13T08:32:58+00:00</updated>
<author>
<name>Arun KS</name>
<email>arunks@codeaurora.org</email>
</author>
<published>2019-04-30T10:35:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f903a196c4a585bbd6ca26d29fc080681bbc6f78'/>
<id>f903a196c4a585bbd6ca26d29fc080681bbc6f78</id>
<content type='text'>
commit 61cf61d81e326163ce1557ceccfca76e11d0e57c upstream.

__early_cpu_boot_status is of type long. Use quad
assembler directive to allocate proper size.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Arun KS &lt;arunks@codeaurora.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Lee Jones &lt;lee.jones@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 61cf61d81e326163ce1557ceccfca76e11d0e57c upstream.

__early_cpu_boot_status is of type long. Use quad
assembler directive to allocate proper size.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Arun KS &lt;arunks@codeaurora.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Lee Jones &lt;lee.jones@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Prevent mismatched 52-bit VA support</title>
<updated>2019-12-05T14:34:16+00:00</updated>
<author>
<name>Steve Capper</name>
<email>steve.capper@arm.com</email>
</author>
<published>2018-12-06T22:50:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4afc01a8d44d49617eab567b4bcc6c8d00bdd385'/>
<id>4afc01a8d44d49617eab567b4bcc6c8d00bdd385</id>
<content type='text'>
[ Upstream commit a96a33b1ca57dbea4285893dedf290aeb8eb090b ]

For cases where there is a mismatch in ARMv8.2-LVA support between CPUs
we have to be careful in allowing secondary CPUs to boot if 52-bit
virtual addresses have already been enabled on the boot CPU.

This patch adds code to the secondary startup path. If the boot CPU has
enabled 52-bit VAs then ID_AA64MMFR2_EL1 is checked to see if the
secondary can also enable 52-bit support. If not, the secondary is
prevented from booting and an error message is displayed indicating why.

Technically this patch could be implemented using the cpufeature code
when considering 52-bit userspace support. However, we employ low level
checks here as the cpufeature code won't be able to run if we have
mismatched 52-bit kernel va support.

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: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a96a33b1ca57dbea4285893dedf290aeb8eb090b ]

For cases where there is a mismatch in ARMv8.2-LVA support between CPUs
we have to be careful in allowing secondary CPUs to boot if 52-bit
virtual addresses have already been enabled on the boot CPU.

This patch adds code to the secondary startup path. If the boot CPU has
enabled 52-bit VAs then ID_AA64MMFR2_EL1 is checked to see if the
secondary can also enable 52-bit support. If not, the secondary is
prevented from booting and an error message is displayed indicating why.

Technically this patch could be implemented using the cpufeature code
when considering 52-bit userspace support. However, we employ low level
checks here as the cpufeature code won't be able to run if we have
mismatched 52-bit kernel va support.

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: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Relax GIC version check during early boot</title>
<updated>2019-03-23T12:19:43+00:00</updated>
<author>
<name>Vladimir Murzin</name>
<email>vladimir.murzin@arm.com</email>
</author>
<published>2019-02-20T11:43:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=46043c108a37631f0b741ca2574d343ab39d8f67'/>
<id>46043c108a37631f0b741ca2574d343ab39d8f67</id>
<content type='text'>
[ Upstream commit 74698f6971f25d045301139413578865fc2bd8f9 ]

Updates to the GIC architecture allow ID_AA64PFR0_EL1.GIC to have
values other than 0 or 1. At the moment, Linux is quite strict in the
way it handles this field at early boot stage (cpufeature is fine) and
will refuse to use the system register CPU interface if it doesn't
find the value 1.

Fixes: 021f653791ad17e03f98aaa7fb933816ae16f161 ("irqchip: gic-v3: Initial support for GICv3")
Reported-by: Chase Conklin &lt;Chase.Conklin@arm.com&gt;
Reviewed-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 74698f6971f25d045301139413578865fc2bd8f9 ]

Updates to the GIC architecture allow ID_AA64PFR0_EL1.GIC to have
values other than 0 or 1. At the moment, Linux is quite strict in the
way it handles this field at early boot stage (cpufeature is fine) and
will refuse to use the system register CPU interface if it doesn't
find the value 1.

Fixes: 021f653791ad17e03f98aaa7fb933816ae16f161 ("irqchip: gic-v3: Initial support for GICv3")
Reported-by: Chase Conklin &lt;Chase.Conklin@arm.com&gt;
Reviewed-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64/kvm: consistently handle host HCR_EL2 flags</title>
<updated>2019-01-23T07:10:53+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2019-01-18T17:56:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cd350ae3c8923b7ab625283d59178c0debf5687e'/>
<id>cd350ae3c8923b7ab625283d59178c0debf5687e</id>
<content type='text'>
[ Backport of upstream commit 4eaed6aa2c628101246bcabc91b203bfac1193f8 ]

In KVM we define the configuration of HCR_EL2 for a VHE HOST in
HCR_HOST_VHE_FLAGS, but we don't have a similar definition for the
non-VHE host flags, and open-code HCR_RW. Further, in head.S we
open-code the flags for VHE and non-VHE configurations.

In future, we're going to want to configure more flags for the host, so
lets add a HCR_HOST_NVHE_FLAGS defintion, and consistently use both
HCR_HOST_VHE_FLAGS and HCR_HOST_NVHE_FLAGS in the kvm code and head.S.

We now use mov_q to generate the HCR_EL2 value, as we use when
configuring other registers in head.S.

Reviewed-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Reviewed-by: Richard Henderson &lt;richard.henderson@linaro.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
[kristina: backport to 4.9.y: adjust context]
Signed-off-by: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Backport of upstream commit 4eaed6aa2c628101246bcabc91b203bfac1193f8 ]

In KVM we define the configuration of HCR_EL2 for a VHE HOST in
HCR_HOST_VHE_FLAGS, but we don't have a similar definition for the
non-VHE host flags, and open-code HCR_RW. Further, in head.S we
open-code the flags for VHE and non-VHE configurations.

In future, we're going to want to configure more flags for the host, so
lets add a HCR_HOST_NVHE_FLAGS defintion, and consistently use both
HCR_HOST_VHE_FLAGS and HCR_HOST_NVHE_FLAGS in the kvm code and head.S.

We now use mov_q to generate the HCR_EL2 value, as we use when
configuring other registers in head.S.

Reviewed-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Reviewed-by: Richard Henderson &lt;richard.henderson@linaro.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
[kristina: backport to 4.9.y: adjust context]
Signed-off-by: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: idmap: Use "awx" flags for .idmap.text .pushsection directives</title>
<updated>2018-04-08T10:12:56+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2018-04-03T11:09:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=574e44dc36676a13af084a9d5f42cc71a59b8066'/>
<id>574e44dc36676a13af084a9d5f42cc71a59b8066</id>
<content type='text'>
commit 439e70e27a51 upstream.

The identity map is mapped as both writeable and executable by the
SWAPPER_MM_MMUFLAGS and this is relied upon by the kpti code to manage
a synchronisation flag. Update the .pushsection flags to reflect the
actual mapping attributes.

Reported-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Alex Shi &lt;alex.shi@linaro.org&gt; [v4.9 backport]
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt; [v4.9 backport]
Tested-by: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Greg Hackmann &lt;ghackmann@google.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 439e70e27a51 upstream.

The identity map is mapped as both writeable and executable by the
SWAPPER_MM_MMUFLAGS and this is relied upon by the kpti code to manage
a synchronisation flag. Update the .pushsection flags to reflect the
actual mapping attributes.

Reported-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Alex Shi &lt;alex.shi@linaro.org&gt; [v4.9 backport]
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt; [v4.9 backport]
Tested-by: Will Deacon &lt;will.deacon@arm.com&gt;
Tested-by: Greg Hackmann &lt;ghackmann@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Make sure SPsel is always set</title>
<updated>2017-10-05T07:44:02+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2017-09-26T14:57:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7dbd64284b18423c7c81ceb6911de472d1bbadcf'/>
<id>7dbd64284b18423c7c81ceb6911de472d1bbadcf</id>
<content type='text'>
commit 5371513fb338fb9989c569dc071326d369d6ade8 upstream.

When the kernel is entered at EL2 on an ARMv8.0 system, we construct
the EL1 pstate and make sure this uses the the EL1 stack pointer
(we perform an exception return to EL1h).

But if the kernel is either entered at EL1 or stays at EL2 (because
we're on a VHE-capable system), we fail to set SPsel, and use whatever
stack selection the higher exception level has choosen for us.

Let's not take any chance, and make sure that SPsel is set to one
before we decide the mode we're going to run in.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@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 5371513fb338fb9989c569dc071326d369d6ade8 upstream.

When the kernel is entered at EL2 on an ARMv8.0 system, we construct
the EL1 pstate and make sure this uses the the EL1 stack pointer
(we perform an exception return to EL1h).

But if the kernel is either entered at EL1 or stays at EL2 (because
we're on a VHE-capable system), we fail to set SPsel, and use whatever
stack selection the higher exception level has choosen for us.

Let's not take any chance, and make sure that SPsel is set to one
before we decide the mode we're going to run in.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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