<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git, branch v4.4.252</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Linux 4.4.252</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2021-01-17T12:55:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4328b0f47a72b408ff9038a79817b3698281914f'/>
<id>4328b0f47a72b408ff9038a79817b3698281914f</id>
<content type='text'>
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Pavel Machek (CIP) &lt;pavel@denx.de&gt;
Link: https://lore.kernel.org/r/20210115121955.112329537@linuxfoundation.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>
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Pavel Machek (CIP) &lt;pavel@denx.de&gt;
Link: https://lore.kernel.org/r/20210115121955.112329537@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: drop bogus skb with CHECKSUM_PARTIAL and offset beyond end of trimmed packet</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Vasily Averin</name>
<email>vvs@virtuozzo.com</email>
</author>
<published>2020-12-14T19:07:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2555bb2a5163e3741d5dd5916f3a9f0228750aca'/>
<id>2555bb2a5163e3741d5dd5916f3a9f0228750aca</id>
<content type='text'>
commit 54970a2fbb673f090b7f02d7f57b10b2e0707155 upstream.

syzbot reproduces BUG_ON in skb_checksum_help():
tun creates (bogus) skb with huge partial-checksummed area and
small ip packet inside. Then ip_rcv trims the skb based on size
of internal ip packet, after that csum offset points beyond of
trimmed skb. Then checksum_tg() called via netfilter hook
triggers BUG_ON:

        offset = skb_checksum_start_offset(skb);
        BUG_ON(offset &gt;= skb_headlen(skb));

To work around the problem this patch forces pskb_trim_rcsum_slow()
to return -EINVAL in described scenario. It allows its callers to
drop such kind of packets.

Link: https://syzkaller.appspot.com/bug?id=b419a5ca95062664fe1a60b764621eb4526e2cd0
Reported-by: syzbot+7010af67ced6105e5ab6@syzkaller.appspotmail.com
Signed-off-by: Vasily Averin &lt;vvs@virtuozzo.com&gt;
Acked-by: Willem de Bruijn &lt;willemb@google.com&gt;
Link: https://lore.kernel.org/r/1b2494af-2c56-8ee2-7bc0-923fcad1cdf8@virtuozzo.com
Signed-off-by: Jakub Kicinski &lt;kuba@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 54970a2fbb673f090b7f02d7f57b10b2e0707155 upstream.

syzbot reproduces BUG_ON in skb_checksum_help():
tun creates (bogus) skb with huge partial-checksummed area and
small ip packet inside. Then ip_rcv trims the skb based on size
of internal ip packet, after that csum offset points beyond of
trimmed skb. Then checksum_tg() called via netfilter hook
triggers BUG_ON:

        offset = skb_checksum_start_offset(skb);
        BUG_ON(offset &gt;= skb_headlen(skb));

To work around the problem this patch forces pskb_trim_rcsum_slow()
to return -EINVAL in described scenario. It allows its callers to
drop such kind of packets.

Link: https://syzkaller.appspot.com/bug?id=b419a5ca95062664fe1a60b764621eb4526e2cd0
Reported-by: syzbot+7010af67ced6105e5ab6@syzkaller.appspotmail.com
Signed-off-by: Vasily Averin &lt;vvs@virtuozzo.com&gt;
Acked-by: Willem de Bruijn &lt;willemb@google.com&gt;
Link: https://lore.kernel.org/r/1b2494af-2c56-8ee2-7bc0-923fcad1cdf8@virtuozzo.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>block: fix use-after-free in disk_part_iter_next</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2020-12-21T04:33:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a09652089d496a4ecb925e2cb95a6523f22ae538'/>
<id>a09652089d496a4ecb925e2cb95a6523f22ae538</id>
<content type='text'>
commit aebf5db917055b38f4945ed6d621d9f07a44ff30 upstream.

Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&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 aebf5db917055b38f4945ed6d621d9f07a44ff30 upstream.

Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/intel: Fix memleak in intel_irq_remapping_alloc</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Dinghao Liu</name>
<email>dinghao.liu@zju.edu.cn</email>
</author>
<published>2021-01-05T05:18:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5453054e2da78cfaf1ec9d18e906702db852b2c'/>
<id>d5453054e2da78cfaf1ec9d18e906702db852b2c</id>
<content type='text'>
commit ff2b46d7cff80d27d82f7f3252711f4ca1666129 upstream.

When irq_domain_get_irq_data() or irqd_cfg() fails
at i == 0, data allocated by kzalloc() has not been
freed before returning, which leads to memleak.

Fixes: b106ee63abcc ("irq_remapping/vt-d: Enhance Intel IR driver to support hierarchical irqdomains")
Signed-off-by: Dinghao Liu &lt;dinghao.liu@zju.edu.cn&gt;
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210105051837.32118-1-dinghao.liu@zju.edu.cn
Signed-off-by: Will Deacon &lt;will@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 ff2b46d7cff80d27d82f7f3252711f4ca1666129 upstream.

When irq_domain_get_irq_data() or irqd_cfg() fails
at i == 0, data allocated by kzalloc() has not been
freed before returning, which leads to memleak.

Fixes: b106ee63abcc ("irq_remapping/vt-d: Enhance Intel IR driver to support hierarchical irqdomains")
Signed-off-by: Dinghao Liu &lt;dinghao.liu@zju.edu.cn&gt;
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210105051837.32118-1-dinghao.liu@zju.edu.cn
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>block: rsxx: select CONFIG_CRC32</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2021-01-03T21:42:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1a64b912a3a01859e1d6ad524ff7e73ab9d0bb18'/>
<id>1a64b912a3a01859e1d6ad524ff7e73ab9d0bb18</id>
<content type='text'>
commit 36a106a4c1c100d55ba3d32a21ef748cfcd4fa99 upstream.

Without crc32, the driver fails to link:

arm-linux-gnueabi-ld: drivers/block/rsxx/config.o: in function `rsxx_load_config':
config.c:(.text+0x124): undefined reference to `crc32_le'

Fixes: 8722ff8cdbfa ("block: IBM RamSan 70/80 device driver")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&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 36a106a4c1c100d55ba3d32a21ef748cfcd4fa99 upstream.

Without crc32, the driver fails to link:

arm-linux-gnueabi-ld: drivers/block/rsxx/config.o: in function `rsxx_load_config':
config.c:(.text+0x124): undefined reference to `crc32_le'

Fixes: 8722ff8cdbfa ("block: IBM RamSan 70/80 device driver")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>wil6210: select CONFIG_CRC32</title>
<updated>2021-01-17T12:55:14+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2021-01-03T21:36:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=885a02f6957a318862e281167fbdd9c853d530d8'/>
<id>885a02f6957a318862e281167fbdd9c853d530d8</id>
<content type='text'>
commit e186620d7bf11b274b985b839c38266d7918cc05 upstream.

Without crc32, the driver fails to link:

arm-linux-gnueabi-ld: drivers/net/wireless/ath/wil6210/fw.o: in function `wil_fw_verify':
fw.c:(.text+0x74c): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/wireless/ath/wil6210/fw.o:fw.c:(.text+0x758): more undefined references to `crc32_le' follow

Fixes: 151a9706503f ("wil6210: firmware download")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.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 e186620d7bf11b274b985b839c38266d7918cc05 upstream.

Without crc32, the driver fails to link:

arm-linux-gnueabi-ld: drivers/net/wireless/ath/wil6210/fw.o: in function `wil_fw_verify':
fw.c:(.text+0x74c): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/wireless/ath/wil6210/fw.o:fw.c:(.text+0x758): more undefined references to `crc32_le' follow

Fixes: 151a9706503f ("wil6210: firmware download")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get()</title>
<updated>2021-01-17T12:55:13+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2021-01-05T10:19:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=20acb9de26d6f8c187401b27a86daef2a7b70cdf'/>
<id>20acb9de26d6f8c187401b27a86daef2a7b70cdf</id>
<content type='text'>
commit 943bdd0cecad06da8392a33093230e30e501eccc upstream.

Currently there is an unlikely case where cpufreq_cpu_get() returns a
NULL policy and this will cause a NULL pointer dereference later on.

Fix this by passing the policy to transition_frequency_fidvid() from
the caller and hence eliminating the need for the cpufreq_cpu_get()
and cpufreq_cpu_put().

Thanks to Viresh Kumar for suggesting the fix.

Addresses-Coverity: ("Dereference null return")
Fixes: b43a7ffbf33b ("cpufreq: Notify all policy-&gt;cpus in cpufreq_notify_transition()")
Suggested-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 943bdd0cecad06da8392a33093230e30e501eccc upstream.

Currently there is an unlikely case where cpufreq_cpu_get() returns a
NULL policy and this will cause a NULL pointer dereference later on.

Fix this by passing the policy to transition_frequency_fidvid() from
the caller and hence eliminating the need for the cpufreq_cpu_get()
and cpufreq_cpu_put().

Thanks to Viresh Kumar for suggesting the fix.

Addresses-Coverity: ("Dereference null return")
Fixes: b43a7ffbf33b ("cpufreq: Notify all policy-&gt;cpus in cpufreq_notify_transition()")
Suggested-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>spi: pxa2xx: Fix use-after-free on unbind</title>
<updated>2021-01-17T12:55:13+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2020-12-07T08:17:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d474e3f5edbbb79470d35f77669c7da5ea16a42'/>
<id>5d474e3f5edbbb79470d35f77669c7da5ea16a42</id>
<content type='text'>
commit 5626308bb94d9f930aa5f7c77327df4c6daa7759 upstream

pxa2xx_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master/slave() helper
which keeps the private data accessible until the driver has unbound.

Fixes: 32e5b57232c0 ("spi: pxa2xx: Fix controller unregister order")
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+: 32e5b57232c0: spi: pxa2xx: Fix controller unregister order
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+
Link: https://lore.kernel.org/r/5764b04d4a6e43069ebb7808f64c2f774ac6f193.1607286887.git.lukas@wunner.de
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5626308bb94d9f930aa5f7c77327df4c6daa7759 upstream

pxa2xx_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master/slave() helper
which keeps the private data accessible until the driver has unbound.

Fixes: 32e5b57232c0 ("spi: pxa2xx: Fix controller unregister order")
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+: 32e5b57232c0: spi: pxa2xx: Fix controller unregister order
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.17+
Link: https://lore.kernel.org/r/5764b04d4a6e43069ebb7808f64c2f774ac6f193.1607286887.git.lukas@wunner.de
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ubifs: wbuf: Don't leak kernel memory to flash</title>
<updated>2021-01-17T12:55:13+00:00</updated>
<author>
<name>Richard Weinberger</name>
<email>richard@nod.at</email>
</author>
<published>2020-11-16T21:05:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b0260231660261a9b7b2eaaea5188baba163f81f'/>
<id>b0260231660261a9b7b2eaaea5188baba163f81f</id>
<content type='text'>
commit 20f1431160c6b590cdc269a846fc5a448abf5b98 upstream

Write buffers use a kmalloc()'ed buffer, they can leak
up to seven bytes of kernel memory to flash if writes are not
aligned.
So use ubifs_pad() to fill these gaps with padding bytes.
This was never a problem while scanning because the scanner logic
manually aligns node lengths and skips over these gaps.

Cc: &lt;stable@vger.kernel.org&gt;
Fixes: 1e51764a3c2ac05a2 ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
Reviewed-by: Zhihao Cheng &lt;chengzhihao1@huawei.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 20f1431160c6b590cdc269a846fc5a448abf5b98 upstream

Write buffers use a kmalloc()'ed buffer, they can leak
up to seven bytes of kernel memory to flash if writes are not
aligned.
So use ubifs_pad() to fill these gaps with padding bytes.
This was never a problem while scanning because the scanner logic
manually aligns node lengths and skips over these gaps.

Cc: &lt;stable@vger.kernel.org&gt;
Fixes: 1e51764a3c2ac05a2 ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
Reviewed-by: Zhihao Cheng &lt;chengzhihao1@huawei.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vmlinux.lds.h: Add PGO and AutoFDO input sections</title>
<updated>2021-01-17T12:55:13+00:00</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2020-08-21T19:42:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b60abd189e520ac975d8921d052c2dea130c89b2'/>
<id>b60abd189e520ac975d8921d052c2dea130c89b2</id>
<content type='text'>
commit eff8728fe69880d3f7983bec3fb6cea4c306261f upstream.

Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too.

When compiling with profiling information (collected via PGO
instrumentations or AutoFDO sampling), Clang will separate code into
.text.hot, .text.unlikely, or .text.unknown sections based on profiling
information. After D79600 (clang-11), these sections will have a
trailing `.` suffix, ie.  .text.hot., .text.unlikely., .text.unknown..

When using -ffunction-sections together with profiling infomation,
either explicitly (FGKASLR) or implicitly (LTO), code may be placed in
sections following the convention:
.text.hot.&lt;foo&gt;, .text.unlikely.&lt;bar&gt;, .text.unknown.&lt;baz&gt;
where &lt;foo&gt;, &lt;bar&gt;, and &lt;baz&gt; are functions.  (This produces one section
per function; we generally try to merge these all back via linker script
so that we don't have 50k sections).

For the above cases, we need to teach our linker scripts that such
sections might exist and that we'd explicitly like them grouped
together, otherwise we can wind up with code outside of the
_stext/_etext boundaries that might not be mapped properly for some
architectures, resulting in boot failures.

If the linker script is not told about possible input sections, then
where the section is placed as output is a heuristic-laiden mess that's
non-portable between linkers (ie. BFD and LLD), and has resulted in many
hard to debug bugs.  Kees Cook is working on cleaning this up by adding
--orphan-handling=warn linker flag used in ARCH=powerpc to additional
architectures. In the case of linker scripts, borrowing from the Zen of
Python: explicit is better than implicit.

Also, ld.bfd's internal linker script considers .text.hot AND
.text.hot.* to be part of .text, as well as .text.unlikely and
.text.unlikely.*. I didn't see support for .text.unknown.*, and didn't
see Clang producing such code in our kernel builds, but I see code in
LLVM that can produce such section names if profiling information is
missing. That may point to a larger issue with generating or collecting
profiles, but I would much rather be safe and explicit than have to
debug yet another issue related to orphan section placement.

Reported-by: Jian Cai &lt;jiancai@google.com&gt;
Suggested-by: Fāng-ruì Sòng &lt;maskray@google.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Tested-by: Luis Lozano &lt;llozano@google.com&gt;
Tested-by: Manoj Gupta &lt;manojgupta@google.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655
Link: https://reviews.llvm.org/D79600
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760
Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.org

Debugged-by: Luis Lozano &lt;llozano@google.com&gt;
[nc: Fix conflicts around lack of TEXT_MAIN, NOINSTR_TEXT, and
     .text..refcount]
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit eff8728fe69880d3f7983bec3fb6cea4c306261f upstream.

Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too.

When compiling with profiling information (collected via PGO
instrumentations or AutoFDO sampling), Clang will separate code into
.text.hot, .text.unlikely, or .text.unknown sections based on profiling
information. After D79600 (clang-11), these sections will have a
trailing `.` suffix, ie.  .text.hot., .text.unlikely., .text.unknown..

When using -ffunction-sections together with profiling infomation,
either explicitly (FGKASLR) or implicitly (LTO), code may be placed in
sections following the convention:
.text.hot.&lt;foo&gt;, .text.unlikely.&lt;bar&gt;, .text.unknown.&lt;baz&gt;
where &lt;foo&gt;, &lt;bar&gt;, and &lt;baz&gt; are functions.  (This produces one section
per function; we generally try to merge these all back via linker script
so that we don't have 50k sections).

For the above cases, we need to teach our linker scripts that such
sections might exist and that we'd explicitly like them grouped
together, otherwise we can wind up with code outside of the
_stext/_etext boundaries that might not be mapped properly for some
architectures, resulting in boot failures.

If the linker script is not told about possible input sections, then
where the section is placed as output is a heuristic-laiden mess that's
non-portable between linkers (ie. BFD and LLD), and has resulted in many
hard to debug bugs.  Kees Cook is working on cleaning this up by adding
--orphan-handling=warn linker flag used in ARCH=powerpc to additional
architectures. In the case of linker scripts, borrowing from the Zen of
Python: explicit is better than implicit.

Also, ld.bfd's internal linker script considers .text.hot AND
.text.hot.* to be part of .text, as well as .text.unlikely and
.text.unlikely.*. I didn't see support for .text.unknown.*, and didn't
see Clang producing such code in our kernel builds, but I see code in
LLVM that can produce such section names if profiling information is
missing. That may point to a larger issue with generating or collecting
profiles, but I would much rather be safe and explicit than have to
debug yet another issue related to orphan section placement.

Reported-by: Jian Cai &lt;jiancai@google.com&gt;
Suggested-by: Fāng-ruì Sòng &lt;maskray@google.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Tested-by: Luis Lozano &lt;llozano@google.com&gt;
Tested-by: Manoj Gupta &lt;manojgupta@google.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655
Link: https://reviews.llvm.org/D79600
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760
Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.org

Debugged-by: Luis Lozano &lt;llozano@google.com&gt;
[nc: Fix conflicts around lack of TEXT_MAIN, NOINSTR_TEXT, and
     .text..refcount]
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
