<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arm64/kernel, branch v6.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2023-02-18T18:10:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-18T18:10:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c2822b116e300ca6e3b7f98623deb760a93a1d2'/>
<id>0c2822b116e300ca6e3b7f98623deb760a93a1d2</id>
<content type='text'>
Pull arm64 regression fix from Will Deacon:
 "Apologies for the _extremely_ late pull request here, but we had a
  'perf' (i.e. CPU PMU) regression on the Apple M1 reported on Wednesday
  [1] which was introduced by bd2756811766 ("perf: Rewrite core context
  handling") during the merge window.

  Mark and I looked into this and noticed an additional problem caused
  by the same patch, where the 'CHAIN' event (used to combine two
  adjacent 32-bit counters into a single 64-bit counter) was not being
  filtered correctly. Mark posted a series on Thursday [2] which
  addresses both of these regressions and I queued it the same day.

  The changes are small, self-contained and have been confirmed to fix
  the original regression.

  Summary:

   - Fix 'perf' regression for non-standard CPU PMU hardware (i.e. Apple
     M1)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: perf: reject CHAIN events at creation time
  arm_pmu: fix event CPU filtering
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull arm64 regression fix from Will Deacon:
 "Apologies for the _extremely_ late pull request here, but we had a
  'perf' (i.e. CPU PMU) regression on the Apple M1 reported on Wednesday
  [1] which was introduced by bd2756811766 ("perf: Rewrite core context
  handling") during the merge window.

  Mark and I looked into this and noticed an additional problem caused
  by the same patch, where the 'CHAIN' event (used to combine two
  adjacent 32-bit counters into a single 64-bit counter) was not being
  filtered correctly. Mark posted a series on Thursday [2] which
  addresses both of these regressions and I queued it the same day.

  The changes are small, self-contained and have been confirmed to fix
  the original regression.

  Summary:

   - Fix 'perf' regression for non-standard CPU PMU hardware (i.e. Apple
     M1)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: perf: reject CHAIN events at creation time
  arm_pmu: fix event CPU filtering
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: perf: reject CHAIN events at creation time</title>
<updated>2023-02-16T21:23:52+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2023-02-16T14:12:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=853e2dac25c15f7431dfe59805de1bada34c96e9'/>
<id>853e2dac25c15f7431dfe59805de1bada34c96e9</id>
<content type='text'>
Currently it's possible for a user to open CHAIN events arbitrarily,
which we previously tried to rule out in commit:

  ca2b497253ad01c8 ("arm64: perf: Reject stand-alone CHAIN events for PMUv3")

Which allowed the events to be opened, but prevented them from being
scheduled by by using an arm_pmu::filter_match hook to reject the
relevant events.

The CHAIN event filtering in the arm_pmu::filter_match hook was silently
removed in commit:

  bd27568117664b8b ("perf: Rewrite core context handling")

As a result, it's now possible for users to open CHAIN events, and for
these to be installed arbitrarily.

Fix this by rejecting CHAIN events at creation time. This avoids the
creation of events which will never count, and doesn't require using the
dynamic filtering.

Attempting to open a CHAIN event (0x1e) will now be rejected:

| # ./perf stat -e armv8_pmuv3/config=0x1e/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|    &lt;not supported&gt;      armv8_pmuv3/config=0x1e/
|
|        0.002197470 seconds time elapsed
|
|        0.000000000 seconds user
|        0.002294000 seconds sys

Other events (e.g. CPU_CYCLES / 0x11) will open as usual:

| # ./perf stat -e armv8_pmuv3/config=0x11/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|            2538761      armv8_pmuv3/config=0x11/
|
|        0.002227330 seconds time elapsed
|
|        0.002369000 seconds user
|        0.000000000 seconds sys

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20230216141240.3833272-3-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently it's possible for a user to open CHAIN events arbitrarily,
which we previously tried to rule out in commit:

  ca2b497253ad01c8 ("arm64: perf: Reject stand-alone CHAIN events for PMUv3")

Which allowed the events to be opened, but prevented them from being
scheduled by by using an arm_pmu::filter_match hook to reject the
relevant events.

The CHAIN event filtering in the arm_pmu::filter_match hook was silently
removed in commit:

  bd27568117664b8b ("perf: Rewrite core context handling")

As a result, it's now possible for users to open CHAIN events, and for
these to be installed arbitrarily.

Fix this by rejecting CHAIN events at creation time. This avoids the
creation of events which will never count, and doesn't require using the
dynamic filtering.

Attempting to open a CHAIN event (0x1e) will now be rejected:

| # ./perf stat -e armv8_pmuv3/config=0x1e/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|    &lt;not supported&gt;      armv8_pmuv3/config=0x1e/
|
|        0.002197470 seconds time elapsed
|
|        0.000000000 seconds user
|        0.002294000 seconds sys

Other events (e.g. CPU_CYCLES / 0x11) will open as usual:

| # ./perf stat -e armv8_pmuv3/config=0x11/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|            2538761      armv8_pmuv3/config=0x11/
|
|        0.002227330 seconds time elapsed
|
|        0.002369000 seconds user
|        0.000000000 seconds sys

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20230216141240.3833272-3-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm_pmu: fix event CPU filtering</title>
<updated>2023-02-16T21:23:52+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2023-02-16T14:12:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=61d03862734360aad470019f160d484403a3923e'/>
<id>61d03862734360aad470019f160d484403a3923e</id>
<content type='text'>
Janne reports that perf has been broken on Apple M1 as of commit:

  bd27568117664b8b ("perf: Rewrite core context handling")

That commit replaced the pmu::filter_match() callback with
pmu::filter(), whose return value has the opposite polarity, with true
implying events should be ignored rather than scheduled. While an
attempt was made to update the logic in armv8pmu_filter() and
armpmu_filter() accordingly, the return value remains inverted in a
couple of cases:

* If the arm_pmu does not have an arm_pmu::filter() callback,
  armpmu_filter() will always return whether the CPU is supported rather
  than whether the CPU is not supported.

  As a result, the perf core will not schedule events on supported CPUs,
  resulting in a loss of events. Additionally, the perf core will
  attempt to schedule events on unsupported CPUs, but this will be
  rejected by armpmu_add(), which may result in a loss of events from
  other PMUs on those unsupported CPUs.

* If the arm_pmu does have an arm_pmu::filter() callback, and
  armpmu_filter() is called on a CPU which is not supported by the
  arm_pmu, armpmu_filter() will return false rather than true.

  As a result, the perf core will attempt to schedule events on
  unsupported CPUs, but this will be rejected by armpmu_add(), which may
  result in a loss of events from other PMUs on those unsupported CPUs.

This means a loss of events can be seen with any arm_pmu driver, but
with the ARMv8 PMUv3 driver (which is the only arm_pmu driver with an
arm_pmu::filter() callback) the event loss will be more limited and may
go unnoticed, which is how this issue evaded testing so far.

Fix the CPU filtering by performing this consistently in
armpmu_filter(), and remove the redundant arm_pmu::filter() callback and
armv8pmu_filter() implementation.

Commit bd2756811766 also silently removed the CHAIN event filtering from
armv8pmu_filter(), which will be addressed by a separate patch without
using the filter callback.

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: Janne Grunau &lt;j@jannau.net&gt;
Link: https://lore.kernel.org/asahi/20230215-arm_pmu_m1_regression-v1-1-f5a266577c8d@jannau.net/
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Asahi Lina &lt;lina@asahilina.net&gt;
Cc: Eric Curtin &lt;ecurtin@redhat.com&gt;
Tested-by: Janne Grunau &lt;j@jannau.net&gt;
Link: https://lore.kernel.org/r/20230216141240.3833272-2-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Janne reports that perf has been broken on Apple M1 as of commit:

  bd27568117664b8b ("perf: Rewrite core context handling")

That commit replaced the pmu::filter_match() callback with
pmu::filter(), whose return value has the opposite polarity, with true
implying events should be ignored rather than scheduled. While an
attempt was made to update the logic in armv8pmu_filter() and
armpmu_filter() accordingly, the return value remains inverted in a
couple of cases:

* If the arm_pmu does not have an arm_pmu::filter() callback,
  armpmu_filter() will always return whether the CPU is supported rather
  than whether the CPU is not supported.

  As a result, the perf core will not schedule events on supported CPUs,
  resulting in a loss of events. Additionally, the perf core will
  attempt to schedule events on unsupported CPUs, but this will be
  rejected by armpmu_add(), which may result in a loss of events from
  other PMUs on those unsupported CPUs.

* If the arm_pmu does have an arm_pmu::filter() callback, and
  armpmu_filter() is called on a CPU which is not supported by the
  arm_pmu, armpmu_filter() will return false rather than true.

  As a result, the perf core will attempt to schedule events on
  unsupported CPUs, but this will be rejected by armpmu_add(), which may
  result in a loss of events from other PMUs on those unsupported CPUs.

This means a loss of events can be seen with any arm_pmu driver, but
with the ARMv8 PMUv3 driver (which is the only arm_pmu driver with an
arm_pmu::filter() callback) the event loss will be more limited and may
go unnoticed, which is how this issue evaded testing so far.

Fix the CPU filtering by performing this consistently in
armpmu_filter(), and remove the redundant arm_pmu::filter() callback and
armv8pmu_filter() implementation.

Commit bd2756811766 also silently removed the CHAIN event filtering from
armv8pmu_filter(), which will be addressed by a separate patch without
using the filter callback.

Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: Janne Grunau &lt;j@jannau.net&gt;
Link: https://lore.kernel.org/asahi/20230215-arm_pmu_m1_regression-v1-1-f5a266577c8d@jannau.net/
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Asahi Lina &lt;lina@asahilina.net&gt;
Cc: Eric Curtin &lt;ecurtin@redhat.com&gt;
Tested-by: Janne Grunau &lt;j@jannau.net&gt;
Link: https://lore.kernel.org/r/20230216141240.3833272-2-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi</title>
<updated>2023-01-23T19:46:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-01-23T19:46:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9946f0981ff8698848ee79d739f432a2a3e68eed'/>
<id>9946f0981ff8698848ee79d739f432a2a3e68eed</id>
<content type='text'>
Pull EFI fixes from Ard Biesheuvel:
 "Another couple of EFI fixes, of which the first two were already in
  -next when I sent out the previous PR, but they caused some issues on
  non-EFI boots so I let them simmer for a bit longer.

   - ensure the EFI ResetSystem and ACPI PRM calls are recognized as
     users of the EFI runtime, and therefore protected against
     exceptions

   - account for the EFI runtime stack in the stacktrace code

   - remove Matthew Garrett's MAINTAINERS entry for efivarfs"

* tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Remove Matthew Garrett as efivarfs maintainer
  arm64: efi: Account for the EFI runtime stack in stack unwinder
  arm64: efi: Avoid workqueue to check whether EFI runtime is live
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull EFI fixes from Ard Biesheuvel:
 "Another couple of EFI fixes, of which the first two were already in
  -next when I sent out the previous PR, but they caused some issues on
  non-EFI boots so I let them simmer for a bit longer.

   - ensure the EFI ResetSystem and ACPI PRM calls are recognized as
     users of the EFI runtime, and therefore protected against
     exceptions

   - account for the EFI runtime stack in the stacktrace code

   - remove Matthew Garrett's MAINTAINERS entry for efivarfs"

* tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Remove Matthew Garrett as efivarfs maintainer
  arm64: efi: Account for the EFI runtime stack in stack unwinder
  arm64: efi: Avoid workqueue to check whether EFI runtime is live
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: efi: Account for the EFI runtime stack in stack unwinder</title>
<updated>2023-01-16T14:27:31+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2022-12-09T11:10:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7ea55715c421d22c1b63f7129cae6a654091b695'/>
<id>7ea55715c421d22c1b63f7129cae6a654091b695</id>
<content type='text'>
The EFI runtime services run from a dedicated stack now, and so the
stack unwinder needs to be informed about this.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The EFI runtime services run from a dedicated stack now, and so the
stack unwinder needs to be informed about this.

Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: efi: Avoid workqueue to check whether EFI runtime is live</title>
<updated>2023-01-16T14:27:31+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2022-10-28T14:39:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8a9a1a18731eb123e35f48176380a18b9782845e'/>
<id>8a9a1a18731eb123e35f48176380a18b9782845e</id>
<content type='text'>
Comparing current_work() against efi_rts_work.work is sufficient to
decide whether current is currently running EFI runtime services code at
any level in its call stack.

However, there are other potential users of the EFI runtime stack, such
as the ACPI subsystem, which may invoke efi_call_virt_pointer()
directly, and so any sync exceptions occurring in firmware during those
calls are currently misidentified.

So instead, let's check whether the stashed value of the thread stack
pointer points into current's thread stack. This can only be the case if
current was interrupted while running EFI runtime code. Note that this
implies that we should clear the stashed value after switching back, to
avoid false positives.

Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Comparing current_work() against efi_rts_work.work is sufficient to
decide whether current is currently running EFI runtime services code at
any level in its call stack.

However, there are other potential users of the EFI runtime stack, such
as the ACPI subsystem, which may invoke efi_call_virt_pointer()
directly, and so any sync exceptions occurring in firmware during those
calls are currently misidentified.

So instead, let's check whether the stashed value of the thread stack
pointer points into current's thread stack. This can only be the case if
current was interrupted while running EFI runtime code. Note that this
implies that we should clear the stashed value after switching back, to
avoid false positives.

Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'efi-fixes-for-v6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi</title>
<updated>2023-01-13T16:37:10+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-01-13T16:37:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0bf913e07b377cfc288cfe488ca30b7d67059d8a'/>
<id>0bf913e07b377cfc288cfe488ca30b7d67059d8a</id>
<content type='text'>
Pull EFI fixes from Ard Biesheuvel:

 - avoid a potential crash on the efi_subsys_init() error path

 - use more appropriate error code for runtime services calls issued
   after a crash in the firmware occurred

 - avoid READ_ONCE() for accessing firmware tables that may appear
   misaligned in memory

* tag 'efi-fixes-for-v6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: tpm: Avoid READ_ONCE() for accessing the event log
  efi: rt-wrapper: Add missing include
  efi: fix userspace infinite retry read efivars after EFI runtime services page fault
  efi: fix NULL-deref in init error path
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull EFI fixes from Ard Biesheuvel:

 - avoid a potential crash on the efi_subsys_init() error path

 - use more appropriate error code for runtime services calls issued
   after a crash in the firmware occurred

 - avoid READ_ONCE() for accessing firmware tables that may appear
   misaligned in memory

* tag 'efi-fixes-for-v6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: tpm: Avoid READ_ONCE() for accessing the event log
  efi: rt-wrapper: Add missing include
  efi: fix userspace infinite retry read efivars after EFI runtime services page fault
  efi: fix NULL-deref in init error path
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: rt-wrapper: Add missing include</title>
<updated>2023-01-09T11:42:56+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2023-01-09T11:41:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=18bba1843fc7f264f58c9345d00827d082f9c558'/>
<id>18bba1843fc7f264f58c9345d00827d082f9c558</id>
<content type='text'>
Add the missing #include of asm/assembler.h, which is where the ldr_l
macro is defined.

Fixes: ff7a167961d1b97e ("arm64: efi: Execute runtime services from a dedicated stack")
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the missing #include of asm/assembler.h, which is where the ldr_l
macro is defined.

Fixes: ff7a167961d1b97e ("arm64: efi: Execute runtime services from a dedicated stack")
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption</title>
<updated>2023-01-06T17:14:55+00:00</updated>
<author>
<name>Anshuman Khandual</name>
<email>anshuman.khandual@arm.com</email>
</author>
<published>2023-01-02T06:16:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5db568e748f6fb7d0d2e1bff4c2698ad4f50b982'/>
<id>5db568e748f6fb7d0d2e1bff4c2698ad4f50b982</id>
<content type='text'>
If a Cortex-A715 cpu sees a page mapping permissions change from executable
to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers, on the
next instruction abort caused by permission fault.

Only user-space does executable to non-executable permission transition via
mprotect() system call which calls ptep_modify_prot_start() and ptep_modify
_prot_commit() helpers, while changing the page mapping. The platform code
can override these helpers via __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION.

Work around the problem via doing a break-before-make TLB invalidation, for
all executable user space mappings, that go through mprotect() system call.
This overrides ptep_modify_prot_start() and ptep_modify_prot_commit(), via
defining HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION on the platform thus giving
an opportunity to intercept user space exec mappings, and do the necessary
TLB invalidation. Similar interceptions are also implemented for HugeTLB.

Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Link: https://lore.kernel.org/r/20230102061651.34745-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a Cortex-A715 cpu sees a page mapping permissions change from executable
to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers, on the
next instruction abort caused by permission fault.

Only user-space does executable to non-executable permission transition via
mprotect() system call which calls ptep_modify_prot_start() and ptep_modify
_prot_commit() helpers, while changing the page mapping. The platform code
can override these helpers via __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION.

Work around the problem via doing a break-before-make TLB invalidation, for
all executable user space mappings, that go through mprotect() system call.
This overrides ptep_modify_prot_start() and ptep_modify_prot_commit(), via
defining HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION on the platform thus giving
an opportunity to intercept user space exec mappings, and do the necessary
TLB invalidation. Similar interceptions are also implemented for HugeTLB.

Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Link: https://lore.kernel.org/r/20230102061651.34745-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64/signal: Always allocate SVE signal frames on SME only systems</title>
<updated>2023-01-05T15:31:18+00:00</updated>
<author>
<name>Mark Brown</name>
<email>broonie@kernel.org</email>
</author>
<published>2022-12-27T17:12:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f26cd7372160da2eba31061d7943348ab9f2c01d'/>
<id>f26cd7372160da2eba31061d7943348ab9f2c01d</id>
<content type='text'>
Currently we only allocate space for SVE signal frames on systems that
support SVE, meaning that SME only systems do not allocate a signal frame
for streaming mode SVE state. Change the check so space is allocated if
either feature is supported.

Fixes: 85ed24dad290 ("arm64/sme: Implement streaming SVE signal handling")
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20221223-arm64-fix-sme-only-v1-3-938d663f69e5@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently we only allocate space for SVE signal frames on systems that
support SVE, meaning that SME only systems do not allocate a signal frame
for streaming mode SVE state. Change the check so space is allocated if
either feature is supported.

Fixes: 85ed24dad290 ("arm64/sme: Implement streaming SVE signal handling")
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20221223-arm64-fix-sme-only-v1-3-938d663f69e5@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
