<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch, branch v4.4.236</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>s390: don't trace preemption in percpu macros</title>
<updated>2020-09-12T09:45:27+00:00</updated>
<author>
<name>Sven Schnelle</name>
<email>svens@linux.ibm.com</email>
</author>
<published>2020-08-20T07:48:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d1d027fc79035930ef838dc51b324a9a835809a3'/>
<id>d1d027fc79035930ef838dc51b324a9a835809a3</id>
<content type='text'>
[ Upstream commit 1196f12a2c960951d02262af25af0bb1775ebcc2 ]

Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context}
to per-cpu variables") the lockdep code itself uses percpu variables. This
leads to recursions because the percpu macros are calling preempt_enable()
which might call trace_preempt_on().

Signed-off-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Reviewed-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.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 1196f12a2c960951d02262af25af0bb1775ebcc2 ]

Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context}
to per-cpu variables") the lockdep code itself uses percpu variables. This
leads to recursions because the percpu macros are calling preempt_enable()
which might call trace_preempt_on().

Signed-off-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Reviewed-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/spufs: add CONFIG_COREDUMP dependency</title>
<updated>2020-09-03T09:19:25+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2020-07-06T13:22:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d7bf4ae5b98909ab7bf4e700da36ea7e52959503'/>
<id>d7bf4ae5b98909ab7bf4e700da36ea7e52959503</id>
<content type='text'>
[ Upstream commit b648a5132ca3237a0f1ce5d871fff342b0efcf8a ]

The kernel test robot pointed out a slightly different error message
after recent commit 5456ffdee666 ("powerpc/spufs: simplify spufs core
dumping") to spufs for a configuration that never worked:

   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_proxydma_info_dump':
&gt;&gt; file.c:(.text+0x4c68): undefined reference to `.dump_emit'
   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_dma_info_dump':
   file.c:(.text+0x4d70): undefined reference to `.dump_emit'
   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_wbox_info_dump':
   file.c:(.text+0x4df4): undefined reference to `.dump_emit'

Add a Kconfig dependency to prevent this from happening again.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Jeremy Kerr &lt;jk@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200706132302.3885935-1-arnd@arndb.de
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 b648a5132ca3237a0f1ce5d871fff342b0efcf8a ]

The kernel test robot pointed out a slightly different error message
after recent commit 5456ffdee666 ("powerpc/spufs: simplify spufs core
dumping") to spufs for a configuration that never worked:

   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_proxydma_info_dump':
&gt;&gt; file.c:(.text+0x4c68): undefined reference to `.dump_emit'
   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_dma_info_dump':
   file.c:(.text+0x4d70): undefined reference to `.dump_emit'
   powerpc64-linux-ld: arch/powerpc/platforms/cell/spufs/file.o: in function `.spufs_wbox_info_dump':
   file.c:(.text+0x4df4): undefined reference to `.dump_emit'

Add a Kconfig dependency to prevent this from happening again.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Jeremy Kerr &lt;jk@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200706132302.3885935-1-arnd@arndb.de
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mips/vdso: Fix resource leaks in genvdso.c</title>
<updated>2020-09-03T09:19:24+00:00</updated>
<author>
<name>Peng Fan</name>
<email>fanpeng@loongson.cn</email>
</author>
<published>2020-07-14T12:30:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a43f5de749e72a960003264833dab4407af00fbd'/>
<id>a43f5de749e72a960003264833dab4407af00fbd</id>
<content type='text'>
[ Upstream commit a859647b4e6bfeb192284d27d24b6a0c914cae1d ]

Close "fd" before the return of map_vdso() and close "out_file"
in main().

Signed-off-by: Peng Fan &lt;fanpeng@loongson.cn&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&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 a859647b4e6bfeb192284d27d24b6a0c914cae1d ]

Close "fd" before the return of map_vdso() and close "out_file"
in main().

Signed-off-by: Peng Fan &lt;fanpeng@loongson.cn&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Do not initiate shutdown when system is running on UPS</title>
<updated>2020-09-03T09:19:22+00:00</updated>
<author>
<name>Vasant Hegde</name>
<email>hegdevasant@linux.vnet.ibm.com</email>
</author>
<published>2020-08-27T07:43:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fe9184c3b534d95b9ee8d5996081d43936d468fd'/>
<id>fe9184c3b534d95b9ee8d5996081d43936d468fd</id>
<content type='text'>
commit 90a9b102eddf6a3f987d15f4454e26a2532c1c98 upstream.

As per PAPR we have to look for both EPOW sensor value and event
modifier to identify the type of event and take appropriate action.

In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes":

  SYSTEM_SHUTDOWN 3

  The system must be shut down. An EPOW-aware OS logs the EPOW error
  log information, then schedules the system to be shut down to begin
  after an OS defined delay internal (default is 10 minutes.)

Then in section 10.3.2.2.8 there is table 146 "Platform Event Log
Format, Version 6, EPOW Section", which includes the "EPOW Event
Modifier":

  For EPOW sensor value = 3
  0x01 = Normal system shutdown with no additional delay
  0x02 = Loss of utility power, system is running on UPS/Battery
  0x03 = Loss of system critical functions, system should be shutdown
  0x04 = Ambient temperature too high
  All other values = reserved

We have a user space tool (rtas_errd) on LPAR to monitor for
EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown
after predefined time. It also starts monitoring for any new EPOW
events. If it receives "Power restored" event before predefined time
it will cancel the shutdown. Otherwise after predefined time it will
shutdown the system.

Commit 79872e35469b ("powerpc/pseries: All events of
EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of
the "on UPS/Battery" case, to immediately shutdown the system. This
breaks existing setups that rely on the userspace tool to delay
shutdown and let the system run on the UPS.

Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Vasant Hegde &lt;hegdevasant@linux.vnet.ibm.com&gt;
[mpe: Massage change log and add PAPR references]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com
Signed-off-by: Vasant Hegde &lt;hegdevasant@linux.vnet.ibm.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>
commit 90a9b102eddf6a3f987d15f4454e26a2532c1c98 upstream.

As per PAPR we have to look for both EPOW sensor value and event
modifier to identify the type of event and take appropriate action.

In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes":

  SYSTEM_SHUTDOWN 3

  The system must be shut down. An EPOW-aware OS logs the EPOW error
  log information, then schedules the system to be shut down to begin
  after an OS defined delay internal (default is 10 minutes.)

Then in section 10.3.2.2.8 there is table 146 "Platform Event Log
Format, Version 6, EPOW Section", which includes the "EPOW Event
Modifier":

  For EPOW sensor value = 3
  0x01 = Normal system shutdown with no additional delay
  0x02 = Loss of utility power, system is running on UPS/Battery
  0x03 = Loss of system critical functions, system should be shutdown
  0x04 = Ambient temperature too high
  All other values = reserved

We have a user space tool (rtas_errd) on LPAR to monitor for
EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown
after predefined time. It also starts monitoring for any new EPOW
events. If it receives "Power restored" event before predefined time
it will cancel the shutdown. Otherwise after predefined time it will
shutdown the system.

Commit 79872e35469b ("powerpc/pseries: All events of
EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of
the "on UPS/Battery" case, to immediately shutdown the system. This
breaks existing setups that rely on the userspace tool to delay
shutdown and let the system run on the UPS.

Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Vasant Hegde &lt;hegdevasant@linux.vnet.ibm.com&gt;
[mpe: Massage change log and add PAPR references]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com
Signed-off-by: Vasant Hegde &lt;hegdevasant@linux.vnet.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm/arm64: Don't reschedule in unmap_stage2_range()</title>
<updated>2020-08-26T08:27:10+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2020-08-24T11:28:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1dee8b843cba4cd7b4d5d454e24ad16d88046bed'/>
<id>1dee8b843cba4cd7b4d5d454e24ad16d88046bed</id>
<content type='text'>
Upstream commits fdfe7cbd5880 ("KVM: Pass MMU notifier range flags to
kvm_unmap_hva_range()") and b5331379bc62 ("KVM: arm64: Only reschedule
if MMU_NOTIFIER_RANGE_BLOCKABLE is not set") fix a "sleeping from invalid
context" BUG caused by unmap_stage2_range() attempting to reschedule when
called on the OOM path.

Unfortunately, these patches rely on the MMU notifier callback being
passed knowledge about whether or not blocking is permitted, which was
introduced in 4.19. Rather than backport this considerable amount of
infrastructure just for KVM on arm, instead just remove the conditional
reschedule.

Cc: &lt;stable@vger.kernel.org&gt; # v4.4 only
Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Acked-by: Marc Zyngier &lt;maz@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>
Upstream commits fdfe7cbd5880 ("KVM: Pass MMU notifier range flags to
kvm_unmap_hva_range()") and b5331379bc62 ("KVM: arm64: Only reschedule
if MMU_NOTIFIER_RANGE_BLOCKABLE is not set") fix a "sleeping from invalid
context" BUG caused by unmap_stage2_range() attempting to reschedule when
called on the OOM path.

Unfortunately, these patches rely on the MMU notifier callback being
passed knowledge about whether or not blocking is permitted, which was
introduced in 4.19. Rather than backport this considerable amount of
infrastructure just for KVM on arm, instead just remove the conditional
reschedule.

Cc: &lt;stable@vger.kernel.org&gt; # v4.4 only
Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Acked-by: Marc Zyngier &lt;maz@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Allow 4224 bytes of stack expansion for the signal frame</title>
<updated>2020-08-26T08:27:09+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2020-07-24T09:25:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fabab559053d5e3f762e52d913cf689a9f242037'/>
<id>fabab559053d5e3f762e52d913cf689a9f242037</id>
<content type='text'>
commit 63dee5df43a31f3844efabc58972f0a206ca4534 upstream.

We have powerpc specific logic in our page fault handling to decide if
an access to an unmapped address below the stack pointer should expand
the stack VMA.

The code was originally added in 2004 "ported from 2.4". The rough
logic is that the stack is allowed to grow to 1MB with no extra
checking. Over 1MB the access must be within 2048 bytes of the stack
pointer, or be from a user instruction that updates the stack pointer.

The 2048 byte allowance below the stack pointer is there to cover the
288 byte "red zone" as well as the "about 1.5kB" needed by the signal
delivery code.

Unfortunately since then the signal frame has expanded, and is now
4224 bytes on 64-bit kernels with transactional memory enabled. This
means if a process has consumed more than 1MB of stack, and its stack
pointer lies less than 4224 bytes from the next page boundary, signal
delivery will fault when trying to expand the stack and the process
will see a SEGV.

The total size of the signal frame is the size of struct rt_sigframe
(which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on
64-bit).

The 2048 byte allowance was correct until 2008 as the signal frame
was:

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1440 */
        /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */
        long unsigned int          _unused[2];           /*  1440    16 */
        unsigned int               tramp[6];             /*  1456    24 */
        struct siginfo *           pinfo;                /*  1480     8 */
        void *                     puc;                  /*  1488     8 */
        struct siginfo     info;                         /*  1496   128 */
        /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */
        char                       abigap[288];          /*  1624   288 */

        /* size: 1920, cachelines: 15, members: 7 */
        /* padding: 8 */
};

1920 + 128 = 2048

Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore,
ptrace and signal support") (Jul 2008) the signal frame expanded to
2304 bytes:

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */	&lt;--
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        long unsigned int          _unused[2];           /*  1696    16 */
        unsigned int               tramp[6];             /*  1712    24 */
        struct siginfo *           pinfo;                /*  1736     8 */
        void *                     puc;                  /*  1744     8 */
        struct siginfo     info;                         /*  1752   128 */
        /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */
        char                       abigap[288];          /*  1880   288 */

        /* size: 2176, cachelines: 17, members: 7 */
        /* padding: 8 */
};

2176 + 128 = 2304

At this point we should have been exposed to the bug, though as far as
I know it was never reported. I no longer have a system old enough to
easily test on.

Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a
grow-down stack segment") caused our stack expansion code to never
trigger, as there was always a VMA found for a write up to PAGE_SIZE
below r1.

That meant the bug was hidden as we continued to expand the signal
frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory
state to the signal context") (Feb 2013):

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        struct ucontext    uc_transact;                  /*  1696  1696 */	&lt;--
        /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */
        long unsigned int          _unused[2];           /*  3392    16 */
        unsigned int               tramp[6];             /*  3408    24 */
        struct siginfo *           pinfo;                /*  3432     8 */
        void *                     puc;                  /*  3440     8 */
        struct siginfo     info;                         /*  3448   128 */
        /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */
        char                       abigap[288];          /*  3576   288 */

        /* size: 3872, cachelines: 31, members: 8 */
        /* padding: 8 */
        /* last cacheline: 32 bytes */
};

3872 + 128 = 4000

And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit
userspace to 512 bytes") (Feb 2014):

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        struct ucontext    uc_transact;                  /*  1696  1696 */
        /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */
        long unsigned int          _unused[2];           /*  3392    16 */
        unsigned int               tramp[6];             /*  3408    24 */
        struct siginfo *           pinfo;                /*  3432     8 */
        void *                     puc;                  /*  3440     8 */
        struct siginfo     info;                         /*  3448   128 */
        /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */
        char                       abigap[512];          /*  3576   512 */	&lt;--

        /* size: 4096, cachelines: 32, members: 8 */
        /* padding: 8 */
};

4096 + 128 = 4224

Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard
gap, between vmas") exposed us to the existing bug, because it changed
the stack VMA to be the correct/real size, meaning our stack expansion
code is now triggered.

Fix it by increasing the allowance to 4224 bytes.

Hard-coding 4224 is obviously unsafe against future expansions of the
signal frame in the same way as the existing code. We can't easily use
sizeof() because the signal frame structure is not in a header. We
will either fix that, or rip out all the custom stack expansion
checking logic entirely.

Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support")
Cc: stable@vger.kernel.org # v2.6.27+
Reported-by: Tom Lane &lt;tgl@sss.pgh.pa.us&gt;
Tested-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au
Signed-off-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 63dee5df43a31f3844efabc58972f0a206ca4534 upstream.

We have powerpc specific logic in our page fault handling to decide if
an access to an unmapped address below the stack pointer should expand
the stack VMA.

The code was originally added in 2004 "ported from 2.4". The rough
logic is that the stack is allowed to grow to 1MB with no extra
checking. Over 1MB the access must be within 2048 bytes of the stack
pointer, or be from a user instruction that updates the stack pointer.

The 2048 byte allowance below the stack pointer is there to cover the
288 byte "red zone" as well as the "about 1.5kB" needed by the signal
delivery code.

Unfortunately since then the signal frame has expanded, and is now
4224 bytes on 64-bit kernels with transactional memory enabled. This
means if a process has consumed more than 1MB of stack, and its stack
pointer lies less than 4224 bytes from the next page boundary, signal
delivery will fault when trying to expand the stack and the process
will see a SEGV.

The total size of the signal frame is the size of struct rt_sigframe
(which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on
64-bit).

The 2048 byte allowance was correct until 2008 as the signal frame
was:

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1440 */
        /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */
        long unsigned int          _unused[2];           /*  1440    16 */
        unsigned int               tramp[6];             /*  1456    24 */
        struct siginfo *           pinfo;                /*  1480     8 */
        void *                     puc;                  /*  1488     8 */
        struct siginfo     info;                         /*  1496   128 */
        /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */
        char                       abigap[288];          /*  1624   288 */

        /* size: 1920, cachelines: 15, members: 7 */
        /* padding: 8 */
};

1920 + 128 = 2048

Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore,
ptrace and signal support") (Jul 2008) the signal frame expanded to
2304 bytes:

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */	&lt;--
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        long unsigned int          _unused[2];           /*  1696    16 */
        unsigned int               tramp[6];             /*  1712    24 */
        struct siginfo *           pinfo;                /*  1736     8 */
        void *                     puc;                  /*  1744     8 */
        struct siginfo     info;                         /*  1752   128 */
        /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */
        char                       abigap[288];          /*  1880   288 */

        /* size: 2176, cachelines: 17, members: 7 */
        /* padding: 8 */
};

2176 + 128 = 2304

At this point we should have been exposed to the bug, though as far as
I know it was never reported. I no longer have a system old enough to
easily test on.

Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a
grow-down stack segment") caused our stack expansion code to never
trigger, as there was always a VMA found for a write up to PAGE_SIZE
below r1.

That meant the bug was hidden as we continued to expand the signal
frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory
state to the signal context") (Feb 2013):

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        struct ucontext    uc_transact;                  /*  1696  1696 */	&lt;--
        /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */
        long unsigned int          _unused[2];           /*  3392    16 */
        unsigned int               tramp[6];             /*  3408    24 */
        struct siginfo *           pinfo;                /*  3432     8 */
        void *                     puc;                  /*  3440     8 */
        struct siginfo     info;                         /*  3448   128 */
        /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */
        char                       abigap[288];          /*  3576   288 */

        /* size: 3872, cachelines: 31, members: 8 */
        /* padding: 8 */
        /* last cacheline: 32 bytes */
};

3872 + 128 = 4000

And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit
userspace to 512 bytes") (Feb 2014):

struct rt_sigframe {
        struct ucontext    uc;                           /*     0  1696 */
        /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */
        struct ucontext    uc_transact;                  /*  1696  1696 */
        /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */
        long unsigned int          _unused[2];           /*  3392    16 */
        unsigned int               tramp[6];             /*  3408    24 */
        struct siginfo *           pinfo;                /*  3432     8 */
        void *                     puc;                  /*  3440     8 */
        struct siginfo     info;                         /*  3448   128 */
        /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */
        char                       abigap[512];          /*  3576   512 */	&lt;--

        /* size: 4096, cachelines: 32, members: 8 */
        /* padding: 8 */
};

4096 + 128 = 4224

Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard
gap, between vmas") exposed us to the existing bug, because it changed
the stack VMA to be the correct/real size, meaning our stack expansion
code is now triggered.

Fix it by increasing the allowance to 4224 bytes.

Hard-coding 4224 is obviously unsafe against future expansions of the
signal frame in the same way as the existing code. We can't easily use
sizeof() because the signal frame structure is not in a header. We
will either fix that, or rip out all the custom stack expansion
checking logic entirely.

Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support")
Cc: stable@vger.kernel.org # v2.6.27+
Reported-by: Tom Lane &lt;tgl@sss.pgh.pa.us&gt;
Tested-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au
Signed-off-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>alpha: fix annotation of io{read,write}{16,32}be()</title>
<updated>2020-08-26T08:27:09+00:00</updated>
<author>
<name>Luc Van Oostenryck</name>
<email>luc.vanoostenryck@gmail.com</email>
</author>
<published>2020-08-12T01:33:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d0f13ebd32e13f18675a28368c1345dd1d463296'/>
<id>d0f13ebd32e13f18675a28368c1345dd1d463296</id>
<content type='text'>
[ Upstream commit bd72866b8da499e60633ff28f8a4f6e09ca78efe ]

These accessors must be used to read/write a big-endian bus.  The value
returned or written is native-endian.

However, these accessors are defined using be{16,32}_to_cpu() or
cpu_to_be{16,32}() to make the endian conversion but these expect a
__be{16,32} when none is present.  Keeping them would need a force cast
that would solve nothing at all.

So, do the conversion using swab{16,32}, like done in asm-generic for
similar situations.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: http://lkml.kernel.org/r/20200622114232.80039-1-luc.vanoostenryck@gmail.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.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 bd72866b8da499e60633ff28f8a4f6e09ca78efe ]

These accessors must be used to read/write a big-endian bus.  The value
returned or written is native-endian.

However, these accessors are defined using be{16,32}_to_cpu() or
cpu_to_be{16,32}() to make the endian conversion but these expect a
__be{16,32} when none is present.  Keeping them would need a force cast
that would solve nothing at all.

So, do the conversion using swab{16,32}, like done in asm-generic for
similar situations.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Luc Van Oostenryck &lt;luc.vanoostenryck@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: http://lkml.kernel.org/r/20200622114232.80039-1-luc.vanoostenryck@gmail.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>m68knommu: fix overwriting of bits in ColdFire V3 cache control</title>
<updated>2020-08-26T08:27:08+00:00</updated>
<author>
<name>Greg Ungerer</name>
<email>gerg@linux-m68k.org</email>
</author>
<published>2020-06-13T07:17:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=650504dcda62b6878c87fcc47bad8702e39d009f'/>
<id>650504dcda62b6878c87fcc47bad8702e39d009f</id>
<content type='text'>
[ Upstream commit bdee0e793cea10c516ff48bf3ebb4ef1820a116b ]

The Cache Control Register (CACR) of the ColdFire V3 has bits that
control high level caching functions, and also enable/disable the use
of the alternate stack pointer register (the EUSP bit) to provide
separate supervisor and user stack pointer registers. The code as
it is today will blindly clear the EUSP bit on cache actions like
invalidation. So it is broken for this case - and that will result
in failed booting (interrupt entry and exit processing will be
completely hosed).

This only affects ColdFire V3 parts that support the alternate stack
register (like the 5329 for example) - generally speaking new parts do,
older parts don't. It has no impact on ColdFire V3 parts with the single
stack pointer, like the 5307 for example.

Fix the cache bit defines used, so they maintain the EUSP bit when
carrying out cache actions through the CACR register.

Signed-off-by: Greg Ungerer &lt;gerg@linux-m68k.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 bdee0e793cea10c516ff48bf3ebb4ef1820a116b ]

The Cache Control Register (CACR) of the ColdFire V3 has bits that
control high level caching functions, and also enable/disable the use
of the alternate stack pointer register (the EUSP bit) to provide
separate supervisor and user stack pointer registers. The code as
it is today will blindly clear the EUSP bit on cache actions like
invalidation. So it is broken for this case - and that will result
in failed booting (interrupt entry and exit processing will be
completely hosed).

This only affects ColdFire V3 parts that support the alternate stack
register (like the 5329 for example) - generally speaking new parts do,
older parts don't. It has no impact on ColdFire V3 parts with the single
stack pointer, like the 5307 for example.

Fix the cache bit defines used, so they maintain the EUSP bit when
carrying out cache actions through the CACR register.

Signed-off-by: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sh: landisk: Add missing initialization of sh_io_port_base</title>
<updated>2020-08-21T08:53:07+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2020-08-14T12:42:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=56fd8add9de311704d88629c5bd297b7ff92bae8'/>
<id>56fd8add9de311704d88629c5bd297b7ff92bae8</id>
<content type='text'>
[ Upstream commit 0c64a0dce51faa9c706fdf1f957d6f19878f4b81 ]

The Landisk setup code maps the CF IDE area using ioremap_prot(), and
passes the resulting virtual addresses to the pata_platform driver,
disguising them as I/O port addresses.  Hence the pata_platform driver
translates them again using ioport_map().
As CONFIG_GENERIC_IOMAP=n, and CONFIG_HAS_IOPORT_MAP=y, the
SuperH-specific mapping code in arch/sh/kernel/ioport.c translates
I/O port addresses to virtual addresses by adding sh_io_port_base, which
defaults to -1, thus breaking the assumption of an identity mapping.

Fix this by setting sh_io_port_base to zero.

Fixes: 37b7a97884ba64bf ("sh: machvec IO death.")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.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 0c64a0dce51faa9c706fdf1f957d6f19878f4b81 ]

The Landisk setup code maps the CF IDE area using ioremap_prot(), and
passes the resulting virtual addresses to the pata_platform driver,
disguising them as I/O port addresses.  Hence the pata_platform driver
translates them again using ioport_map().
As CONFIG_GENERIC_IOMAP=n, and CONFIG_HAS_IOPORT_MAP=y, the
SuperH-specific mapping code in arch/sh/kernel/ioport.c translates
I/O port addresses to virtual addresses by adding sh_io_port_base, which
defaults to -1, thus breaking the assumption of an identity mapping.

Fix this by setting sh_io_port_base to zero.

Fixes: 37b7a97884ba64bf ("sh: machvec IO death.")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Rich Felker &lt;dalias@libc.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pseries: Fix 64 bit logical memory block panic</title>
<updated>2020-08-21T08:53:06+00:00</updated>
<author>
<name>Anton Blanchard</name>
<email>anton@ozlabs.org</email>
</author>
<published>2020-07-15T00:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0511e6969c32455cbc9cea968325b9d2d0f94e0e'/>
<id>0511e6969c32455cbc9cea968325b9d2d0f94e0e</id>
<content type='text'>
commit 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream.

Booting with a 4GB LMB size causes us to panic:

  qemu-system-ppc64: OS terminated: OS panic:
      Memory block size not suitable: 0x0

Fix pseries_memory_block_size() to handle 64 bit LMBs.

Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard &lt;anton@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org
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 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream.

Booting with a 4GB LMB size causes us to panic:

  qemu-system-ppc64: OS terminated: OS panic:
      Memory block size not suitable: 0x0

Fix pseries_memory_block_size() to handle 64 bit LMBs.

Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard &lt;anton@ozlabs.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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