<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include, branch v6.1.55</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ata: libata: disallow dev-initiated LPM transitions to unsupported states</title>
<updated>2023-09-23T09:11:12+00:00</updated>
<author>
<name>Niklas Cassel</name>
<email>niklas.cassel@wdc.com</email>
</author>
<published>2023-09-04T20:42:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a3517ee1d4e625bdf262dbad5d76d9df4fac83a4'/>
<id>a3517ee1d4e625bdf262dbad5d76d9df4fac83a4</id>
<content type='text'>
commit 24e0e61db3cb86a66824531989f1df80e0939f26 upstream.

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Slumber state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Partial state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that
a device is not allowed to initiate transitions to power states which are
unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the
corresponding bit in PxSCTL.IPM such that agressive link power management
cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp.
However, only libahci has the ability to read the CAP/CAP2 register to see
if these features are supported. Therefore, in order to not introduce any
regressions on ata_piix or libata-pmp, create flags that indicate that the
respective feature is NOT supported. This way, the behavior for ata_piix
and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

Signed-off-by: Niklas Cassel &lt;niklas.cassel@wdc.com&gt;
Fixes: 1152b2617a6e ("libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 24e0e61db3cb86a66824531989f1df80e0939f26 upstream.

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Slumber state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Partial state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that
a device is not allowed to initiate transitions to power states which are
unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the
corresponding bit in PxSCTL.IPM such that agressive link power management
cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp.
However, only libahci has the ability to read the CAP/CAP2 register to see
if these features are supported. Therefore, in order to not introduce any
regressions on ata_piix or libata-pmp, create flags that indicate that the
respective feature is NOT supported. This way, the behavior for ata_piix
and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

Signed-off-by: Niklas Cassel &lt;niklas.cassel@wdc.com&gt;
Fixes: 1152b2617a6e ("libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/ibt: Suppress spurious ENDBR</title>
<updated>2023-09-23T09:11:09+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-08-02T10:55:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e9b8e266105a6ef495ddc817b5d924c5915d8017'/>
<id>e9b8e266105a6ef495ddc817b5d924c5915d8017</id>
<content type='text'>
[ Upstream commit 25e73b7e3f72a25aa30cbb2eecb49036e0acf066 ]

It was reported that under certain circumstances GCC emits ENDBR
instructions for _THIS_IP_ usage. Specifically, when it appears at the
start of a basic block -- but not elsewhere.

Since _THIS_IP_ is never used for control flow, these ENDBR
instructions are completely superfluous. Override the _THIS_IP_
definition for x86_64 to avoid this.

Less ENDBR instructions is better.

Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits")
Reported-by: David Kaplan &lt;David.Kaplan@amd.com&gt;
Reviewed-by: Andrew Cooper &lt;andrew.cooper3@citrix.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
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 25e73b7e3f72a25aa30cbb2eecb49036e0acf066 ]

It was reported that under certain circumstances GCC emits ENDBR
instructions for _THIS_IP_ usage. Specifically, when it appears at the
start of a basic block -- but not elsewhere.

Since _THIS_IP_ is never used for control flow, these ENDBR
instructions are completely superfluous. Override the _THIS_IP_
definition for x86_64 to avoid this.

Less ENDBR instructions is better.

Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits")
Reported-by: David Kaplan &lt;David.Kaplan@amd.com&gt;
Reviewed-by: Andrew Cooper &lt;andrew.cooper3@citrix.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: factor out a bvec_set_page helper</title>
<updated>2023-09-23T09:11:08+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2023-02-03T15:06:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00cf1dc13c1f5207693abe59d6e26d8fd0ed7673'/>
<id>00cf1dc13c1f5207693abe59d6e26d8fd0ed7673</id>
<content type='text'>
[ Upstream commit d58cdfae6a22e5079656c487aad669597a0635c8 ]

Add a helper to initialize a bvec based of a page pointer.  This will help
removing various open code bvec initializations.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230203150634.3199647-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 1f0bbf28940c ("nvmet-tcp: pass iov_len instead of sg-&gt;length to bvec_set_page()")
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 d58cdfae6a22e5079656c487aad669597a0635c8 ]

Add a helper to initialize a bvec based of a page pointer.  This will help
removing various open code bvec initializations.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230203150634.3199647-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 1f0bbf28940c ("nvmet-tcp: pass iov_len instead of sg-&gt;length to bvec_set_page()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-buf: Add unlocked variant of attachment-mapping functions</title>
<updated>2023-09-23T09:11:08+00:00</updated>
<author>
<name>Dmitry Osipenko</name>
<email>dmitry.osipenko@collabora.com</email>
</author>
<published>2022-10-17T17:22:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4539ff7a48d898bfb9c97c54bee8fd568db9d8b'/>
<id>b4539ff7a48d898bfb9c97c54bee8fd568db9d8b</id>
<content type='text'>
[ Upstream commit 19d6634d8789573a9212ce78dbb4348ffd4f7f78 ]

Add unlocked variant of dma_buf_map/unmap_attachment() that will
be used by drivers that don't take the reservation lock explicitly.

Acked-by: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-3-dmitry.osipenko@collabora.com
Stable-dep-of: a2cb9cd6a394 ("misc: fastrpc: Fix incorrect DMA mapping unmap request")
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 19d6634d8789573a9212ce78dbb4348ffd4f7f78 ]

Add unlocked variant of dma_buf_map/unmap_attachment() that will
be used by drivers that don't take the reservation lock explicitly.

Acked-by: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-3-dmitry.osipenko@collabora.com
Stable-dep-of: a2cb9cd6a394 ("misc: fastrpc: Fix incorrect DMA mapping unmap request")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: chipidea: add workaround for chipidea PEC bug</title>
<updated>2023-09-23T09:11:07+00:00</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-08-09T02:44:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=91f400233edc1354e80b9f6b9370dc1d0e11095b'/>
<id>91f400233edc1354e80b9f6b9370dc1d0e11095b</id>
<content type='text'>
[ Upstream commit 12e6ac69cc7e7d3367599ae26a92a0f9a18bc728 ]

Some NXP processors using ChipIdea USB IP have a bug when frame babble is
detected.

Issue description:
In USB camera test, our controller is host in HS mode. In ISOC IN, when
device sends data across the micro frame, it causes the babble in host
controller. This will clear the PE bit. In spec, it also requires to set
the PEC bit and then set the PCI bit. Without the PCI interrupt, the
software does not know the PE is cleared.

This will add a flag CI_HDRC_HAS_PORTSC_PEC_MISSED to some impacted
platform datas. And the ehci host driver will assert PEC by SW when
specific conditions are satisfied.

Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Link: https://lore.kernel.org/r/20230809024432.535160-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 12e6ac69cc7e7d3367599ae26a92a0f9a18bc728 ]

Some NXP processors using ChipIdea USB IP have a bug when frame babble is
detected.

Issue description:
In USB camera test, our controller is host in HS mode. In ISOC IN, when
device sends data across the micro frame, it causes the babble in host
controller. This will clear the PE bit. In spec, it also requires to set
the PEC bit and then set the PCI bit. Without the PCI interrupt, the
software does not know the PE is cleared.

This will add a flag CI_HDRC_HAS_PORTSC_PEC_MISSED to some impacted
platform datas. And the ehci host driver will assert PEC by SW when
specific conditions are satisfied.

Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Link: https://lore.kernel.org/r/20230809024432.535160-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: ebtables: fix fortify warnings in size_entry_mwt()</title>
<updated>2023-09-23T09:11:03+00:00</updated>
<author>
<name>GONG, Ruiqi</name>
<email>gongruiqi1@huawei.com</email>
</author>
<published>2023-08-09T07:45:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=28b07e30bc1465fdc0d71919739310ec311abe42'/>
<id>28b07e30bc1465fdc0d71919739310ec311abe42</id>
<content type='text'>
[ Upstream commit a7ed3465daa240bdf01a5420f64336fee879c09d ]

When compiling with gcc 13 and CONFIG_FORTIFY_SOURCE=y, the following
warning appears:

In function ‘fortify_memcpy_chk’,
    inlined from ‘size_entry_mwt’ at net/bridge/netfilter/ebtables.c:2118:2:
./include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Werror=attribute-warning]
  592 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The compiler is complaining:

memcpy(&amp;offsets[1], &amp;entry-&gt;watchers_offset,
                       sizeof(offsets) - sizeof(offsets[0]));

where memcpy reads beyong &amp;entry-&gt;watchers_offset to copy
{watchers,target,next}_offset altogether into offsets[]. Silence the
warning by wrapping these three up via struct_group().

Signed-off-by: GONG, Ruiqi &lt;gongruiqi1@huawei.com&gt;
Reviewed-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.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 a7ed3465daa240bdf01a5420f64336fee879c09d ]

When compiling with gcc 13 and CONFIG_FORTIFY_SOURCE=y, the following
warning appears:

In function ‘fortify_memcpy_chk’,
    inlined from ‘size_entry_mwt’ at net/bridge/netfilter/ebtables.c:2118:2:
./include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Werror=attribute-warning]
  592 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The compiler is complaining:

memcpy(&amp;offsets[1], &amp;entry-&gt;watchers_offset,
                       sizeof(offsets) - sizeof(offsets[0]));

where memcpy reads beyong &amp;entry-&gt;watchers_offset to copy
{watchers,target,next}_offset altogether into offsets[]. Silence the
warning by wrapping these three up via struct_group().

Signed-off-by: GONG, Ruiqi &lt;gongruiqi1@huawei.com&gt;
Reviewed-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hw_breakpoint: fix single-stepping when using bpf_overflow_handler</title>
<updated>2023-09-23T09:11:00+00:00</updated>
<author>
<name>Tomislav Novak</name>
<email>tnovak@meta.com</email>
</author>
<published>2023-06-05T19:19:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc1d81ee9312dee73544ec88d356e644edd5c413'/>
<id>dc1d81ee9312dee73544ec88d356e644edd5c413</id>
<content type='text'>
[ Upstream commit d11a69873d9a7435fe6a48531e165ab80a8b1221 ]

Arm platforms use is_default_overflow_handler() to determine if the
hw_breakpoint code should single-step over the breakpoint trigger or
let the custom handler deal with it.

Since bpf_overflow_handler() currently isn't recognized as a default
handler, attaching a BPF program to a PERF_TYPE_BREAKPOINT event causes
it to keep firing (the instruction triggering the data abort exception
is never skipped). For example:

  # bpftrace -e 'watchpoint:0x10000:4:w { print("hit") }' -c ./test
  Attaching 1 probe...
  hit
  hit
  [...]
  ^C

(./test performs a single 4-byte store to 0x10000)

This patch replaces the check with uses_default_overflow_handler(),
which accounts for the bpf_overflow_handler() case by also testing
if one of the perf_event_output functions gets invoked indirectly,
via orig_default_handler.

Signed-off-by: Tomislav Novak &lt;tnovak@meta.com&gt;
Tested-by: Samuel Gosselin &lt;sgosselin@google.com&gt; # arm64
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/linux-arm-kernel/20220923203644.2731604-1-tnovak@fb.com/
Link: https://lore.kernel.org/r/20230605191923.1219974-1-tnovak@meta.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d11a69873d9a7435fe6a48531e165ab80a8b1221 ]

Arm platforms use is_default_overflow_handler() to determine if the
hw_breakpoint code should single-step over the breakpoint trigger or
let the custom handler deal with it.

Since bpf_overflow_handler() currently isn't recognized as a default
handler, attaching a BPF program to a PERF_TYPE_BREAKPOINT event causes
it to keep firing (the instruction triggering the data abort exception
is never skipped). For example:

  # bpftrace -e 'watchpoint:0x10000:4:w { print("hit") }' -c ./test
  Attaching 1 probe...
  hit
  hit
  [...]
  ^C

(./test performs a single 4-byte store to 0x10000)

This patch replaces the check with uses_default_overflow_handler(),
which accounts for the bpf_overflow_handler() case by also testing
if one of the perf_event_output functions gets invoked indirectly,
via orig_default_handler.

Signed-off-by: Tomislav Novak &lt;tnovak@meta.com&gt;
Tested-by: Samuel Gosselin &lt;sgosselin@google.com&gt; # arm64
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/linux-arm-kernel/20220923203644.2731604-1-tnovak@fb.com/
Link: https://lore.kernel.org/r/20230605191923.1219974-1-tnovak@meta.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09</title>
<updated>2023-09-23T09:11:00+00:00</updated>
<author>
<name>Yicong Yang</name>
<email>yangyicong@hisilicon.com</email>
</author>
<published>2023-08-14T12:40:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9d9b5cbc12f49fbdbbc454383981039005af8211'/>
<id>9d9b5cbc12f49fbdbbc454383981039005af8211</id>
<content type='text'>
[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel/fork: beware of __put_task_struct() calling context</title>
<updated>2023-09-23T09:11:00+00:00</updated>
<author>
<name>Wander Lairson Costa</name>
<email>wander@redhat.com</email>
</author>
<published>2023-06-14T12:23:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3b1107abdc2cabdf2044683fc2fa9743a7da5ccc'/>
<id>3b1107abdc2cabdf2044683fc2fa9743a7da5ccc</id>
<content type='text'>
[ Upstream commit d243b34459cea30cfe5f3a9b2feb44e7daff9938 ]

Under PREEMPT_RT, __put_task_struct() indirectly acquires sleeping
locks. Therefore, it can't be called from an non-preemptible context.

One practical example is splat inside inactive_task_timer(), which is
called in a interrupt context:

  CPU: 1 PID: 2848 Comm: life Kdump: loaded Tainted: G W ---------
   Hardware name: HP ProLiant DL388p Gen8, BIOS P70 07/15/2012
   Call Trace:
   dump_stack_lvl+0x57/0x7d
   mark_lock_irq.cold+0x33/0xba
   mark_lock+0x1e7/0x400
   mark_usage+0x11d/0x140
   __lock_acquire+0x30d/0x930
   lock_acquire.part.0+0x9c/0x210
   rt_spin_lock+0x27/0xe0
   refill_obj_stock+0x3d/0x3a0
   kmem_cache_free+0x357/0x560
   inactive_task_timer+0x1ad/0x340
   __run_hrtimer+0x8a/0x1a0
   __hrtimer_run_queues+0x91/0x130
   hrtimer_interrupt+0x10f/0x220
   __sysvec_apic_timer_interrupt+0x7b/0xd0
   sysvec_apic_timer_interrupt+0x4f/0xd0
   asm_sysvec_apic_timer_interrupt+0x12/0x20
   RIP: 0033:0x7fff196bf6f5

Instead of calling __put_task_struct() directly, we defer it using
call_rcu(). A more natural approach would use a workqueue, but since
in PREEMPT_RT, we can't allocate dynamic memory from atomic context,
the code would become more complex because we would need to put the
work_struct instance in the task_struct and initialize it when we
allocate a new task_struct.

The issue is reproducible with stress-ng:

  while true; do
      stress-ng --sched deadline --sched-period 1000000000 \
	      --sched-runtime 800000000 --sched-deadline \
	      1000000000 --mmapfork 23 -t 20
  done

Reported-by: Hu Chunyu &lt;chuhu@redhat.com&gt;
Suggested-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Suggested-by: Valentin Schneider &lt;vschneid@redhat.com&gt;
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Wander Lairson Costa &lt;wander@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20230614122323.37957-2-wander@redhat.com
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 d243b34459cea30cfe5f3a9b2feb44e7daff9938 ]

Under PREEMPT_RT, __put_task_struct() indirectly acquires sleeping
locks. Therefore, it can't be called from an non-preemptible context.

One practical example is splat inside inactive_task_timer(), which is
called in a interrupt context:

  CPU: 1 PID: 2848 Comm: life Kdump: loaded Tainted: G W ---------
   Hardware name: HP ProLiant DL388p Gen8, BIOS P70 07/15/2012
   Call Trace:
   dump_stack_lvl+0x57/0x7d
   mark_lock_irq.cold+0x33/0xba
   mark_lock+0x1e7/0x400
   mark_usage+0x11d/0x140
   __lock_acquire+0x30d/0x930
   lock_acquire.part.0+0x9c/0x210
   rt_spin_lock+0x27/0xe0
   refill_obj_stock+0x3d/0x3a0
   kmem_cache_free+0x357/0x560
   inactive_task_timer+0x1ad/0x340
   __run_hrtimer+0x8a/0x1a0
   __hrtimer_run_queues+0x91/0x130
   hrtimer_interrupt+0x10f/0x220
   __sysvec_apic_timer_interrupt+0x7b/0xd0
   sysvec_apic_timer_interrupt+0x4f/0xd0
   asm_sysvec_apic_timer_interrupt+0x12/0x20
   RIP: 0033:0x7fff196bf6f5

Instead of calling __put_task_struct() directly, we defer it using
call_rcu(). A more natural approach would use a workqueue, but since
in PREEMPT_RT, we can't allocate dynamic memory from atomic context,
the code would become more complex because we would need to put the
work_struct instance in the task_struct and initialize it when we
allocate a new task_struct.

The issue is reproducible with stress-ng:

  while true; do
      stress-ng --sched deadline --sched-period 1000000000 \
	      --sched-runtime 800000000 --sched-deadline \
	      1000000000 --mmapfork 23 -t 20
  done

Reported-by: Hu Chunyu &lt;chuhu@redhat.com&gt;
Suggested-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Suggested-by: Valentin Schneider &lt;vschneid@redhat.com&gt;
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Wander Lairson Costa &lt;wander@redhat.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20230614122323.37957-2-wander@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: Fix bind() regression for v4-mapped-v6 wildcard address.</title>
<updated>2023-09-19T10:28:10+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2023-09-11T18:36:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=63830afece934aa94cdbc9610598829d05d81a00'/>
<id>63830afece934aa94cdbc9610598829d05d81a00</id>
<content type='text'>
[ Upstream commit aa99e5f87bd54db55dd37cb130bd5eb55933027f ]

Andrei Vagin reported bind() regression with strace logs.

If we bind() a TCPv6 socket to ::FFFF:0.0.0.0 and then bind() a TCPv4
socket to 127.0.0.1, the 2nd bind() should fail but now succeeds.

  from socket import *

  s1 = socket(AF_INET6, SOCK_STREAM)
  s1.bind(('::ffff:0.0.0.0', 0))

  s2 = socket(AF_INET, SOCK_STREAM)
  s2.bind(('127.0.0.1', s1.getsockname()[1]))

During the 2nd bind(), if tb-&gt;family is AF_INET6 and sk-&gt;sk_family is
AF_INET in inet_bind2_bucket_match_addr_any(), we still need to check
if tb has the v4-mapped-v6 wildcard address.

The example above does not work after commit 5456262d2baa ("net: Fix
incorrect address comparison when searching for a bind2 bucket"), but
the blamed change is not the commit.

Before the commit, the leading zeros of ::FFFF:0.0.0.0 were treated
as 0.0.0.0, and the sequence above worked by chance.  Technically, this
case has been broken since bhash2 was introduced.

Note that if we bind() two sockets to 127.0.0.1 and then ::FFFF:0.0.0.0,
the 2nd bind() fails properly because we fall back to using bhash to
detect conflicts for the v4-mapped-v6 address.

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Reported-by: Andrei Vagin &lt;avagin@google.com&gt;
Closes: https://lore.kernel.org/netdev/ZPuYBOFC8zsK6r9T@google.com/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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 aa99e5f87bd54db55dd37cb130bd5eb55933027f ]

Andrei Vagin reported bind() regression with strace logs.

If we bind() a TCPv6 socket to ::FFFF:0.0.0.0 and then bind() a TCPv4
socket to 127.0.0.1, the 2nd bind() should fail but now succeeds.

  from socket import *

  s1 = socket(AF_INET6, SOCK_STREAM)
  s1.bind(('::ffff:0.0.0.0', 0))

  s2 = socket(AF_INET, SOCK_STREAM)
  s2.bind(('127.0.0.1', s1.getsockname()[1]))

During the 2nd bind(), if tb-&gt;family is AF_INET6 and sk-&gt;sk_family is
AF_INET in inet_bind2_bucket_match_addr_any(), we still need to check
if tb has the v4-mapped-v6 wildcard address.

The example above does not work after commit 5456262d2baa ("net: Fix
incorrect address comparison when searching for a bind2 bucket"), but
the blamed change is not the commit.

Before the commit, the leading zeros of ::FFFF:0.0.0.0 were treated
as 0.0.0.0, and the sequence above worked by chance.  Technically, this
case has been broken since bhash2 was introduced.

Note that if we bind() two sockets to 127.0.0.1 and then ::FFFF:0.0.0.0,
the 2nd bind() fails properly because we fall back to using bhash to
detect conflicts for the v4-mapped-v6 address.

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Reported-by: Andrei Vagin &lt;avagin@google.com&gt;
Closes: https://lore.kernel.org/netdev/ZPuYBOFC8zsK6r9T@google.com/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
