<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch, branch v5.2.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc/pseries: Fix oops in hotplug memory notifier</title>
<updated>2019-07-26T07:11:09+00:00</updated>
<author>
<name>Nathan Lynch</name>
<email>nathanl@linux.ibm.com</email>
</author>
<published>2019-06-07T05:04:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a63f2ef2082312a7678187296e67d2cb1273ad63'/>
<id>a63f2ef2082312a7678187296e67d2cb1273ad63</id>
<content type='text'>
commit 0aa82c482ab2ece530a6f44897b63b274bb43c8e upstream.

During post-migration device tree updates, we can oops in
pseries_update_drconf_memory() if the source device tree has an
ibm,dynamic-memory-v2 property and the destination has a
ibm,dynamic_memory (v1) property. The notifier processes an "update"
for the ibm,dynamic-memory property but it's really an add in this
scenario. So make sure the old property object is there before
dereferencing it.

Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Nathan Lynch &lt;nathanl@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 0aa82c482ab2ece530a6f44897b63b274bb43c8e upstream.

During post-migration device tree updates, we can oops in
pseries_update_drconf_memory() if the source device tree has an
ibm,dynamic-memory-v2 property and the destination has a
ibm,dynamic_memory (v1) property. The notifier processes an "update"
for the ibm,dynamic-memory property but it's really an add in this
scenario. So make sure the old property object is there before
dereferencing it.

Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Nathan Lynch &lt;nathanl@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Fix xive=off command line</title>
<updated>2019-07-26T07:11:09+00:00</updated>
<author>
<name>Greg Kurz</name>
<email>groug@kaod.org</email>
</author>
<published>2019-05-15T10:05:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dd29ff8324260ae702227e5aba53f78efeec29c7'/>
<id>dd29ff8324260ae702227e5aba53f78efeec29c7</id>
<content type='text'>
commit a3bf9fbdad600b1e4335dd90979f8d6072e4f602 upstream.

On POWER9, if the hypervisor supports XIVE exploitation mode, the
guest OS will unconditionally requests for the XIVE interrupt mode
even if XIVE was deactivated with the kernel command line xive=off.
Later on, when the spapr XIVE init code handles xive=off, it disables
XIVE and tries to fall back on the legacy mode XICS.

This discrepency causes a kernel panic because the hypervisor is
configured to provide the XIVE interrupt mode to the guest :

  kernel BUG at arch/powerpc/sysdev/xics/xics-common.c:135!
  ...
  NIP xics_smp_probe+0x38/0x98
  LR  xics_smp_probe+0x2c/0x98
  Call Trace:
    xics_smp_probe+0x2c/0x98 (unreliable)
    pSeries_smp_probe+0x40/0xa0
    smp_prepare_cpus+0x62c/0x6ec
    kernel_init_freeable+0x148/0x448
    kernel_init+0x2c/0x148
    ret_from_kernel_thread+0x5c/0x68

Look for xive=off during prom_init and don't ask for XIVE in this
case. One exception though: if the host only supports XIVE, we still
want to boot so we ignore xive=off.

Similarly, have the spapr XIVE init code to looking at the interrupt
mode negotiated during CAS, and ignore xive=off if the hypervisor only
supports XIVE.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.20
Reported-by: Pavithra R. Prakash &lt;pavrampu@in.ibm.com&gt;
Signed-off-by: Greg Kurz &lt;groug@kaod.org&gt;
Reviewed-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 a3bf9fbdad600b1e4335dd90979f8d6072e4f602 upstream.

On POWER9, if the hypervisor supports XIVE exploitation mode, the
guest OS will unconditionally requests for the XIVE interrupt mode
even if XIVE was deactivated with the kernel command line xive=off.
Later on, when the spapr XIVE init code handles xive=off, it disables
XIVE and tries to fall back on the legacy mode XICS.

This discrepency causes a kernel panic because the hypervisor is
configured to provide the XIVE interrupt mode to the guest :

  kernel BUG at arch/powerpc/sysdev/xics/xics-common.c:135!
  ...
  NIP xics_smp_probe+0x38/0x98
  LR  xics_smp_probe+0x2c/0x98
  Call Trace:
    xics_smp_probe+0x2c/0x98 (unreliable)
    pSeries_smp_probe+0x40/0xa0
    smp_prepare_cpus+0x62c/0x6ec
    kernel_init_freeable+0x148/0x448
    kernel_init+0x2c/0x148
    ret_from_kernel_thread+0x5c/0x68

Look for xive=off during prom_init and don't ask for XIVE in this
case. One exception though: if the host only supports XIVE, we still
want to boot so we ignore xive=off.

Similarly, have the spapr XIVE init code to looking at the interrupt
mode negotiated during CAS, and ignore xive=off if the hypervisor only
supports XIVE.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.20
Reported-by: Pavithra R. Prakash &lt;pavrampu@in.ibm.com&gt;
Signed-off-by: Greg Kurz &lt;groug@kaod.org&gt;
Reviewed-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/powernv: Fix stale iommu table base after VFIO</title>
<updated>2019-07-26T07:11:09+00:00</updated>
<author>
<name>Alexey Kardashevskiy</name>
<email>aik@ozlabs.ru</email>
</author>
<published>2019-06-28T06:53:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=82150014031da71a4ead7092550c1a1de037816a'/>
<id>82150014031da71a4ead7092550c1a1de037816a</id>
<content type='text'>
commit 5636427d087a55842c1a199dfb839e6545d30e5d upstream.

The powernv platform uses @dma_iommu_ops for non-bypass DMA. These ops
need an iommu_table pointer which is stored in
dev-&gt;archdata.iommu_table_base. It is initialized during
pcibios_setup_device() which handles boot time devices. However when a
device is taken from the system in order to pass it through, the
default IOMMU table is destroyed but the pointer in a device is not
updated; also when a device is returned back to the system, a new
table pointer is not stored in dev-&gt;archdata.iommu_table_base either.
So when a just returned device tries using IOMMU, it crashes on
accessing stale iommu_table or its members.

This calls set_iommu_table_base() when the default window is created.
Note it used to be there before but was wrongly removed (see "fixes").
It did not appear before as these days most devices simply use bypass.

This adds set_iommu_table_base(NULL) when a device is taken from the
system to make it clear that IOMMU DMA cannot be used past that point.

Fixes: c4e9d3c1e65a ("powerpc/powernv/pseries: Rework device adding to IOMMU groups")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 5636427d087a55842c1a199dfb839e6545d30e5d upstream.

The powernv platform uses @dma_iommu_ops for non-bypass DMA. These ops
need an iommu_table pointer which is stored in
dev-&gt;archdata.iommu_table_base. It is initialized during
pcibios_setup_device() which handles boot time devices. However when a
device is taken from the system in order to pass it through, the
default IOMMU table is destroyed but the pointer in a device is not
updated; also when a device is returned back to the system, a new
table pointer is not stored in dev-&gt;archdata.iommu_table_base either.
So when a just returned device tries using IOMMU, it crashes on
accessing stale iommu_table or its members.

This calls set_iommu_table_base() when the default window is created.
Note it used to be there before but was wrongly removed (see "fixes").
It did not appear before as these days most devices simply use bypass.

This adds set_iommu_table_base(NULL) when a device is taken from the
system to make it clear that IOMMU DMA cannot be used past that point.

Fixes: c4e9d3c1e65a ("powerpc/powernv/pseries: Rework device adding to IOMMU groups")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2019-07-02T10:58:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d71acd3f404e65b4cfcbdd3ae096c15c847d7d04'/>
<id>d71acd3f404e65b4cfcbdd3ae096c15c847d7d04</id>
<content type='text'>
commit f5a9e488d62360c91c5770bd55a0b40e419a71ce upstream.

commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
reimplemented book3S code to pltform/powernv/idle.c. But when doing so
missed to add the per-thread LDBAR update in the core_woken path of
the power9_idle_stop(). Patch fixes the same.

Fixes: 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20190702105836.26695-1-maddy@linux.vnet.ibm.com
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 f5a9e488d62360c91c5770bd55a0b40e419a71ce upstream.

commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
reimplemented book3S code to pltform/powernv/idle.c. But when doing so
missed to add the per-thread LDBAR update in the core_woken path of
the power9_idle_stop(). Patch fixes the same.

Fixes: 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20190702105836.26695-1-maddy@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/powernv/npu: Fix reference leak</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Greg Kurz</name>
<email>groug@kaod.org</email>
</author>
<published>2019-04-19T15:34:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=03eccf2da689022410fb70164111ac13766c1b68'/>
<id>03eccf2da689022410fb70164111ac13766c1b68</id>
<content type='text'>
commit 02c5f5394918b9b47ff4357b1b18335768cd867d upstream.

Since 902bdc57451c, get_pci_dev() calls pci_get_domain_bus_and_slot(). This
has the effect of incrementing the reference count of the PCI device, as
explained in drivers/pci/search.c:

 * Given a PCI domain, bus, and slot/function number, the desired PCI
 * device is located in the list of PCI devices. If the device is
 * found, its reference count is increased and this function returns a
 * pointer to its data structure.  The caller must decrement the
 * reference count by calling pci_dev_put().  If no device is found,
 * %NULL is returned.

Nothing was done to call pci_dev_put() and the reference count of GPU and
NPU PCI devices rockets up.

A natural way to fix this would be to teach the callers about the change,
so that they call pci_dev_put() when done with the pointer. This turns
out to be quite intrusive, as it affects many paths in npu-dma.c,
pci-ioda.c and vfio_pci_nvlink2.c. Also, the issue appeared in 4.16 and
some affected code got moved around since then: it would be problematic
to backport the fix to stable releases.

All that code never cared for reference counting anyway. Call pci_dev_put()
from get_pci_dev() to revert to the previous behavior.

Fixes: 902bdc57451c ("powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn")
Cc: stable@vger.kernel.org # v4.16
Signed-off-by: Greg Kurz &lt;groug@kaod.org&gt;
Reviewed-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 02c5f5394918b9b47ff4357b1b18335768cd867d upstream.

Since 902bdc57451c, get_pci_dev() calls pci_get_domain_bus_and_slot(). This
has the effect of incrementing the reference count of the PCI device, as
explained in drivers/pci/search.c:

 * Given a PCI domain, bus, and slot/function number, the desired PCI
 * device is located in the list of PCI devices. If the device is
 * found, its reference count is increased and this function returns a
 * pointer to its data structure.  The caller must decrement the
 * reference count by calling pci_dev_put().  If no device is found,
 * %NULL is returned.

Nothing was done to call pci_dev_put() and the reference count of GPU and
NPU PCI devices rockets up.

A natural way to fix this would be to teach the callers about the change,
so that they call pci_dev_put() when done with the pointer. This turns
out to be quite intrusive, as it affects many paths in npu-dma.c,
pci-ioda.c and vfio_pci_nvlink2.c. Also, the issue appeared in 4.16 and
some affected code got moved around since then: it would be problematic
to backport the fix to stable releases.

All that code never cared for reference counting anyway. Call pci_dev_put()
from get_pci_dev() to revert to the previous behavior.

Fixes: 902bdc57451c ("powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn")
Cc: stable@vger.kernel.org # v4.16
Signed-off-by: Greg Kurz &lt;groug@kaod.org&gt;
Reviewed-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/watchpoint: Restore NV GPRs while returning from exception</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Ravi Bangoria</name>
<email>ravi.bangoria@linux.ibm.com</email>
</author>
<published>2019-06-13T03:30:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2df756cdaf3d3c031bfa81d0d5dd03f1a86111ba'/>
<id>2df756cdaf3d3c031bfa81d0d5dd03f1a86111ba</id>
<content type='text'>
commit f474c28fbcbe42faca4eb415172c07d76adcb819 upstream.

powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:

  # cat /proc/kallsyms | grep kthread_create_list
  c00000000121c8b8 d kthread_create_list

Add watchpoint on kthread_create_list-&gt;prev:

  # perf record -e mem:0xc00000000121c8c0

Run some workload such that new kthread gets invoked. eg, I just
logged out from console:

  list_add corruption. next-&gt;prev should be prev (c000000001214e00), \
	but was c00000000121c8b8. (next=c00000000121c8b8).
  WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
  CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
  ...
  NIP __list_add_valid+0xb4/0xc0
  LR __list_add_valid+0xb0/0xc0
  Call Trace:
  __list_add_valid+0xb0/0xc0 (unreliable)
  __kthread_create_on_node+0xe0/0x260
  kthread_create_on_node+0x34/0x50
  create_worker+0xe8/0x260
  worker_thread+0x444/0x560
  kthread+0x160/0x1a0
  ret_from_kernel_thread+0x5c/0x70

List corruption happened because it uses 'load into non-volatile
register' instruction:

Snippet from __kthread_create_on_node:

  c000000000136be8:     addis   r29,r2,-19
  c000000000136bec:     ld      r29,31424(r29)
        if (!__list_add_valid(new, prev, next))
  c000000000136bf0:     mr      r3,r30
  c000000000136bf4:     mr      r5,r28
  c000000000136bf8:     mr      r4,r29
  c000000000136bfc:     bl      c00000000059a2f8 &lt;__list_add_valid+0x8&gt;

Register state from WARN_ON():

  GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
  GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
  GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
  GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
  GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
  GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
  GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
  GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0

Watchpoint hit at 0xc000000000136bec.

  addis   r29,r2,-19
   =&gt; r29 = 0xc000000001344e00 + (-19 &lt;&lt; 16)
   =&gt; r29 = 0xc000000001214e00

  ld      r29,31424(r29)
   =&gt; r29 = *(0xc000000001214e00 + 31424)
   =&gt; r29 = *(0xc00000000121c8c0)

0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.

Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 f474c28fbcbe42faca4eb415172c07d76adcb819 upstream.

powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:

  # cat /proc/kallsyms | grep kthread_create_list
  c00000000121c8b8 d kthread_create_list

Add watchpoint on kthread_create_list-&gt;prev:

  # perf record -e mem:0xc00000000121c8c0

Run some workload such that new kthread gets invoked. eg, I just
logged out from console:

  list_add corruption. next-&gt;prev should be prev (c000000001214e00), \
	but was c00000000121c8b8. (next=c00000000121c8b8).
  WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
  CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
  ...
  NIP __list_add_valid+0xb4/0xc0
  LR __list_add_valid+0xb0/0xc0
  Call Trace:
  __list_add_valid+0xb0/0xc0 (unreliable)
  __kthread_create_on_node+0xe0/0x260
  kthread_create_on_node+0x34/0x50
  create_worker+0xe8/0x260
  worker_thread+0x444/0x560
  kthread+0x160/0x1a0
  ret_from_kernel_thread+0x5c/0x70

List corruption happened because it uses 'load into non-volatile
register' instruction:

Snippet from __kthread_create_on_node:

  c000000000136be8:     addis   r29,r2,-19
  c000000000136bec:     ld      r29,31424(r29)
        if (!__list_add_valid(new, prev, next))
  c000000000136bf0:     mr      r3,r30
  c000000000136bf4:     mr      r5,r28
  c000000000136bf8:     mr      r4,r29
  c000000000136bfc:     bl      c00000000059a2f8 &lt;__list_add_valid+0x8&gt;

Register state from WARN_ON():

  GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
  GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
  GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
  GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
  GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
  GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
  GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
  GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0

Watchpoint hit at 0xc000000000136bec.

  addis   r29,r2,-19
   =&gt; r29 = 0xc000000001344e00 + (-19 &lt;&lt; 16)
   =&gt; r29 = 0xc000000001214e00

  ld      r29,31424(r29)
   =&gt; r29 = *(0xc000000001214e00 + 31424)
   =&gt; r29 = *(0xc00000000121c8c0)

0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.

Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/mm/32s: fix condition that is always true</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Andreas Schwab</name>
<email>schwab@linux-m68k.org</email>
</author>
<published>2019-06-17T21:22:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f6a2e40dc9edb9b5a32639fa20834cc3bd0d692'/>
<id>9f6a2e40dc9edb9b5a32639fa20834cc3bd0d692</id>
<content type='text'>
commit 46c2478af610efb3212b8b08f74389d69899ef70 upstream.

Move a misplaced paren that makes the condition always true.

Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 46c2478af610efb3212b8b08f74389d69899ef70 upstream.

Move a misplaced paren that makes the condition always true.

Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/32s: fix suspend/resume when IBATs 4-7 are used</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2019-06-17T21:42:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1d2ee2a5757e2e04e90a3d777b391cf7bb8f99b1'/>
<id>1d2ee2a5757e2e04e90a3d777b391cf7bb8f99b1</id>
<content type='text'>
commit 6ecb78ef56e08d2119d337ae23cb951a640dc52d upstream.

Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping
kernel text. But the suspend/restore functions only save/restore
BATs 0 to 3, and clears BATs 4 to 7.

Make suspend and restore functions respectively save and reload
the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature.

Reported-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&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 6ecb78ef56e08d2119d337ae23cb951a640dc52d upstream.

Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping
kernel text. But the suspend/restore functions only save/restore
BATs 0 to 3, and clears BATs 4 to 7.

Make suspend and restore functions respectively save and reload
the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature.

Reported-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: Fix kernel panic due invalid values in IAOQ0 or IAOQ1</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2019-07-16T19:43:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fd0a71299589acfff968fff4fa590707b11383ba'/>
<id>fd0a71299589acfff968fff4fa590707b11383ba</id>
<content type='text'>
commit 10835c854685393a921b68f529bf740fa7c9984d upstream.

On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.

This patch prevents such modifications by always setting the two lowest bits to
one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are
modified via ptrace calls in the native and compat ptrace paths.

Link: https://bugs.gentoo.org/481768
Reported-by: Jeroen Roovers &lt;jer@gentoo.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Rolf Eike Beer &lt;eike-kernel@sf-tec.de&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 10835c854685393a921b68f529bf740fa7c9984d upstream.

On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.

This patch prevents such modifications by always setting the two lowest bits to
one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are
modified via ptrace calls in the native and compat ptrace paths.

Link: https://bugs.gentoo.org/481768
Reported-by: Jeroen Roovers &lt;jer@gentoo.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Rolf Eike Beer &lt;eike-kernel@sf-tec.de&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: Avoid kernel panic triggered by invalid kprobe</title>
<updated>2019-07-26T07:11:08+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2019-07-16T19:16:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1ca14ff51d9c2b336042160eb38909f78f7253eb'/>
<id>1ca14ff51d9c2b336042160eb38909f78f7253eb</id>
<content type='text'>
commit 59a783dbc0d5fd6792aabff933055373b6dcbf2a upstream.

When running gdb I was able to trigger this kernel panic:

 Kernel Fault: Code=26 (Data memory access rights trap) at addr 0000000000000060
 CPU: 0 PID: 1401 Comm: gdb-crash Not tainted 5.2.0-rc7-64bit+ #1053

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
 PSW: 00001000000001000000000000001111 Not tainted
 r00-03  000000000804000f 0000000040dee1a0 0000000040c78cf0 00000000b8d50160
 r04-07  0000000040d2b1a0 000000004360a098 00000000bbbe87b8 0000000000000003
 r08-11  00000000fac20a70 00000000fac24160 00000000fac1bbe0 0000000000000000
 r12-15  00000000fabfb79a 00000000fac244a4 0000000000010000 0000000000000001
 r16-19  00000000bbbe87b8 00000000f8f02910 0000000000010034 0000000000000000
 r20-23  00000000fac24630 00000000fac24630 000000006474e552 00000000fac1aa52
 r24-27  0000000000000028 00000000bbbe87b8 00000000bbbe87b8 0000000040d2b1a0
 r28-31  0000000000000000 00000000b8d501c0 00000000b8d501f0 0000000003424000
 sr00-03  0000000000423000 0000000000000000 0000000000000000 0000000000423000
 sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

 IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040c78cf0 0000000040c78cf4
  IIR: 539f00c0    ISR: 0000000000000000  IOR: 0000000000000060
  CPU:        0   CR30: 00000000b8d50000 CR31: 00000000d22345e2
  ORIG_R28: 0000000040250798
  IAOQ[0]: parisc_kprobe_ss_handler+0x58/0x170
  IAOQ[1]: parisc_kprobe_ss_handler+0x5c/0x170
  RP(r2): parisc_kprobe_ss_handler+0x58/0x170
 Backtrace:
  [&lt;0000000040206ff8&gt;] handle_interruption+0x178/0xbb8
 Kernel panic - not syncing: Kernel Fault

Avoid this panic by checking the return value of kprobe_running() and
skip kprobe if none is currently active.

Cc: &lt;stable@vger.kernel.org&gt; # v5.2
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Tested-by: Rolf Eike Beer &lt;eike-kernel@sf-tec.de&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 59a783dbc0d5fd6792aabff933055373b6dcbf2a upstream.

When running gdb I was able to trigger this kernel panic:

 Kernel Fault: Code=26 (Data memory access rights trap) at addr 0000000000000060
 CPU: 0 PID: 1401 Comm: gdb-crash Not tainted 5.2.0-rc7-64bit+ #1053

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
 PSW: 00001000000001000000000000001111 Not tainted
 r00-03  000000000804000f 0000000040dee1a0 0000000040c78cf0 00000000b8d50160
 r04-07  0000000040d2b1a0 000000004360a098 00000000bbbe87b8 0000000000000003
 r08-11  00000000fac20a70 00000000fac24160 00000000fac1bbe0 0000000000000000
 r12-15  00000000fabfb79a 00000000fac244a4 0000000000010000 0000000000000001
 r16-19  00000000bbbe87b8 00000000f8f02910 0000000000010034 0000000000000000
 r20-23  00000000fac24630 00000000fac24630 000000006474e552 00000000fac1aa52
 r24-27  0000000000000028 00000000bbbe87b8 00000000bbbe87b8 0000000040d2b1a0
 r28-31  0000000000000000 00000000b8d501c0 00000000b8d501f0 0000000003424000
 sr00-03  0000000000423000 0000000000000000 0000000000000000 0000000000423000
 sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

 IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040c78cf0 0000000040c78cf4
  IIR: 539f00c0    ISR: 0000000000000000  IOR: 0000000000000060
  CPU:        0   CR30: 00000000b8d50000 CR31: 00000000d22345e2
  ORIG_R28: 0000000040250798
  IAOQ[0]: parisc_kprobe_ss_handler+0x58/0x170
  IAOQ[1]: parisc_kprobe_ss_handler+0x5c/0x170
  RP(r2): parisc_kprobe_ss_handler+0x58/0x170
 Backtrace:
  [&lt;0000000040206ff8&gt;] handle_interruption+0x178/0xbb8
 Kernel panic - not syncing: Kernel Fault

Avoid this panic by checking the return value of kprobe_running() and
skip kprobe if none is currently active.

Cc: &lt;stable@vger.kernel.org&gt; # v5.2
Acked-by: Sven Schnelle &lt;svens@stackframe.org&gt;
Tested-by: Rolf Eike Beer &lt;eike-kernel@sf-tec.de&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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