<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools, branch v6.2.12</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>selftests: mptcp: userspace pm: uniform verify events</title>
<updated>2023-04-20T10:36:59+00:00</updated>
<author>
<name>Matthieu Baerts</name>
<email>matthieu.baerts@tessares.net</email>
</author>
<published>2023-04-11T20:42:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a096a78d70a012b47d0ab50cfd26905a39506bf8'/>
<id>a096a78d70a012b47d0ab50cfd26905a39506bf8</id>
<content type='text'>
commit 711ae788cbbb82818531b55e32b09518ee09a11a upstream.

Simply adding a "sleep" before checking something is usually not a good
idea because the time that has been picked can not be enough or too
much. The best is to wait for events with a timeout.

In this selftest, 'sleep 0.5' is used more than 40 times. It is always
used before calling a 'verify_*' function except for this
verify_listener_events which has been added later.

At the end, using all these 'sleep 0.5' seems to work: the slow CIs
don't complain so far. Also because it doesn't take too much time, we
can just add two more 'sleep 0.5' to uniform what is done before calling
a 'verify_*' function. For the same reasons, we can also delay a bigger
refactoring to replace all these 'sleep 0.5' by functions waiting for
events instead of waiting for a fix time and hope for the best.

Fixes: 6c73008aa301 ("selftests: mptcp: listener test for userspace PM")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
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 711ae788cbbb82818531b55e32b09518ee09a11a upstream.

Simply adding a "sleep" before checking something is usually not a good
idea because the time that has been picked can not be enough or too
much. The best is to wait for events with a timeout.

In this selftest, 'sleep 0.5' is used more than 40 times. It is always
used before calling a 'verify_*' function except for this
verify_listener_events which has been added later.

At the end, using all these 'sleep 0.5' seems to work: the slow CIs
don't complain so far. Also because it doesn't take too much time, we
can just add two more 'sleep 0.5' to uniform what is done before calling
a 'verify_*' function. For the same reasons, we can also delay a bigger
refactoring to replace all these 'sleep 0.5' by functions waiting for
events instead of waiting for a fix time and hope for the best.

Fixes: 6c73008aa301 ("selftests: mptcp: listener test for userspace PM")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Matthieu Baerts &lt;matthieu.baerts@tessares.net&gt;
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>maple_tree: fix write memory barrier of nodes once dead for RCU mode</title>
<updated>2023-04-20T10:36:58+00:00</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@oracle.com</email>
</author>
<published>2023-02-27T17:36:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2780b421b8da4b2032b0769636851d608ac72125'/>
<id>2780b421b8da4b2032b0769636851d608ac72125</id>
<content type='text'>
[ Upstream commit c13af03de46ba27674dd9fb31a17c0d480081139 ]

During the development of the maple tree, the strategy of freeing multiple
nodes changed and, in the process, the pivots were reused to store
pointers to dead nodes.  To ensure the readers see accurate pivots, the
writers need to mark the nodes as dead and call smp_wmb() to ensure any
readers can identify the node as dead before using the pivot values.

There were two places where the old method of marking the node as dead
without smp_wmb() were being used, which resulted in RCU readers seeing
the wrong pivot value before seeing the node was dead.  Fix this race
condition by using mte_set_node_dead() which has the smp_wmb() call to
ensure the race is closed.

Add a WARN_ON() to the ma_free_rcu() call to ensure all nodes being freed
are marked as dead to ensure there are no other call paths besides the two
updated paths.

This is necessary for the RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-6-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@oracle.com&gt;
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@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 c13af03de46ba27674dd9fb31a17c0d480081139 ]

During the development of the maple tree, the strategy of freeing multiple
nodes changed and, in the process, the pivots were reused to store
pointers to dead nodes.  To ensure the readers see accurate pivots, the
writers need to mark the nodes as dead and call smp_wmb() to ensure any
readers can identify the node as dead before using the pivot values.

There were two places where the old method of marking the node as dead
without smp_wmb() were being used, which resulted in RCU readers seeing
the wrong pivot value before seeing the node was dead.  Fix this race
condition by using mte_set_node_dead() which has the smp_wmb() call to
ensure the race is closed.

Add a WARN_ON() to the ma_free_rcu() call to ensure all nodes being freed
are marked as dead to ensure there are no other call paths besides the two
updated paths.

This is necessary for the RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-6-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@oracle.com&gt;
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Fix progs/find_vma_fail1.c build error.</title>
<updated>2023-04-20T10:36:56+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2023-03-10T20:41:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb484ba17bf9db34ea4f5a3c2157865b45c258f9'/>
<id>bb484ba17bf9db34ea4f5a3c2157865b45c258f9</id>
<content type='text'>
[ Upstream commit 32513d40d908b267508d37994753d9bd1600914b ]

The commit 11e456cae91e ("selftests/bpf: Fix compilation errors: Assign a value to a constant")
fixed the issue cleanly in bpf-next.
This is an alternative fix in bpf tree to avoid merge conflict between bpf and bpf-next.

Signed-off-by: Alexei Starovoitov &lt;ast@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 32513d40d908b267508d37994753d9bd1600914b ]

The commit 11e456cae91e ("selftests/bpf: Fix compilation errors: Assign a value to a constant")
fixed the issue cleanly in bpf-next.
This is an alternative fix in bpf tree to avoid merge conflict between bpf and bpf-next.

Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: add the missing CONFIG_IP_SCTP in net config</title>
<updated>2023-04-20T10:36:55+00:00</updated>
<author>
<name>Xin Long</name>
<email>lucien.xin@gmail.com</email>
</author>
<published>2023-04-12T15:13:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1ac56e2d45af612f89c36508536b5aa3692c3592'/>
<id>1ac56e2d45af612f89c36508536b5aa3692c3592</id>
<content type='text'>
[ Upstream commit 3a0385be133e7091cc9a9a998c7ec712bb9585db ]

The selftest sctp_vrf needs CONFIG_IP_SCTP set in config
when building the kernel, so add it.

Fixes: a61bd7b9fef3 ("selftests: add a selftest for sctp vrf")
Reported-by: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Reviewed-by: Sridhar Samudrala &lt;sridhar.samudrala@intel.com&gt;
Link: https://lore.kernel.org/r/61dddebc4d2dd98fe7fb145e24d4b2430e42b572.1681312386.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@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 3a0385be133e7091cc9a9a998c7ec712bb9585db ]

The selftest sctp_vrf needs CONFIG_IP_SCTP set in config
when building the kernel, so add it.

Fixes: a61bd7b9fef3 ("selftests: add a selftest for sctp vrf")
Reported-by: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Reviewed-by: Sridhar Samudrala &lt;sridhar.samudrala@intel.com&gt;
Link: https://lore.kernel.org/r/61dddebc4d2dd98fe7fb145e24d4b2430e42b572.1681312386.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: openvswitch: adjust datapath NL message declaration</title>
<updated>2023-04-20T10:36:55+00:00</updated>
<author>
<name>Aaron Conole</name>
<email>aconole@redhat.com</email>
</author>
<published>2023-04-12T11:58:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=506c9d946a12e3e19a1de2a813c6e6c57acbae57'/>
<id>506c9d946a12e3e19a1de2a813c6e6c57acbae57</id>
<content type='text'>
[ Upstream commit 306dc21361993f4fe50a15d4db6b1a4de5d0adb0 ]

The netlink message for creating a new datapath takes an array
of ports for the PID creation.  This shouldn't cause much issue
but correct it for future cases where we need to do decode of
datapath information that could include the per-cpu PID map.

Fixes: 25f16c873fb1 ("selftests: add openvswitch selftest suite")
Signed-off-by: Aaron Conole &lt;aconole@redhat.com&gt;
Link: https://lore.kernel.org/r/20230412115828.3991806-1-aconole@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@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 306dc21361993f4fe50a15d4db6b1a4de5d0adb0 ]

The netlink message for creating a new datapath takes an array
of ports for the PID creation.  This shouldn't cause much issue
but correct it for future cases where we need to do decode of
datapath information that could include the per-cpu PID map.

Fixes: 25f16c873fb1 ("selftests: add openvswitch selftest suite")
Signed-off-by: Aaron Conole &lt;aconole@redhat.com&gt;
Link: https://lore.kernel.org/r/20230412115828.3991806-1-aconole@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>maple_tree: remove GFP_ZERO from kmem_cache_alloc() and kmem_cache_alloc_bulk()</title>
<updated>2023-04-13T15:02:57+00:00</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@Oracle.com</email>
</author>
<published>2023-04-11T15:10:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c387104c2d9f4853dc08c51b38f1760f8f1bf01'/>
<id>0c387104c2d9f4853dc08c51b38f1760f8f1bf01</id>
<content type='text'>
commit 541e06b772c1aaffb3b6a245ccface36d7107af2 upstream.

Preallocations are common in the VMA code to avoid allocating under
certain locking conditions.  The preallocations must also cover the
worst-case scenario.  Removing the GFP_ZERO flag from the
kmem_cache_alloc() (and bulk variant) calls will reduce the amount of time
spent zeroing memory that may not be used.  Only zero out the necessary
area to keep track of the allocations in the maple state.  Zero the entire
node prior to using it in the tree.

This required internal changes to node counting on allocation, so the test
code is also updated.

This restores some micro-benchmark performance: up to +9% in mmtests mmap1
by my testing +10% to +20% in mmap, mmapaddr, mmapmany tests reported by
Red Hat

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2149636
Link: https://lkml.kernel.org/r/20230105160427.2988454-1-Liam.Howlett@oracle.com
Cc: stable@vger.kernel.org
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett &lt;Liam.Howlett@oracle.com&gt;
Reported-by: Jirka Hladky &lt;jhladky@redhat.com&gt;
Suggested-by: Matthew Wilcox (Oracle) &lt;willy@infradead.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 541e06b772c1aaffb3b6a245ccface36d7107af2 upstream.

Preallocations are common in the VMA code to avoid allocating under
certain locking conditions.  The preallocations must also cover the
worst-case scenario.  Removing the GFP_ZERO flag from the
kmem_cache_alloc() (and bulk variant) calls will reduce the amount of time
spent zeroing memory that may not be used.  Only zero out the necessary
area to keep track of the allocations in the maple state.  Zero the entire
node prior to using it in the tree.

This required internal changes to node counting on allocation, so the test
code is also updated.

This restores some micro-benchmark performance: up to +9% in mmtests mmap1
by my testing +10% to +20% in mmap, mmapaddr, mmapmany tests reported by
Red Hat

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2149636
Link: https://lkml.kernel.org/r/20230105160427.2988454-1-Liam.Howlett@oracle.com
Cc: stable@vger.kernel.org
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett &lt;Liam.Howlett@oracle.com&gt;
Reported-by: Jirka Hladky &lt;jhladky@redhat.com&gt;
Suggested-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix btf_dump's packed struct determination</title>
<updated>2023-04-06T10:12:48+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2022-12-15T18:36:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78a95870c337b18a21ecd750e134fcaf8ddc1fc8'/>
<id>78a95870c337b18a21ecd750e134fcaf8ddc1fc8</id>
<content type='text'>
[ Upstream commit 4fb877aaa179dcdb1676d55216482febaada457e ]

Fix bug in btf_dump's logic of determining if a given struct type is
packed or not. The notion of "natural alignment" is not needed and is
even harmful in this case, so drop it altogether. The biggest difference
in btf_is_struct_packed() compared to its original implementation is
that we don't really use btf__align_of() to determine overall alignment
of a struct type (because it could be 1 for both packed and non-packed
struct, depending on specifci field definitions), and just use field's
actual alignment to calculate whether any field is requiring packing or
struct's size overall necessitates packing.

Add two simple test cases that demonstrate the difference this change
would make.

Fixes: ea2ce1ba99aa ("libbpf: Fix BTF-to-C converter's padding logic")
Reported-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20221215183605.4149488-1-andrii@kernel.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 4fb877aaa179dcdb1676d55216482febaada457e ]

Fix bug in btf_dump's logic of determining if a given struct type is
packed or not. The notion of "natural alignment" is not needed and is
even harmful in this case, so drop it altogether. The biggest difference
in btf_is_struct_packed() compared to its original implementation is
that we don't really use btf__align_of() to determine overall alignment
of a struct type (because it could be 1 for both packed and non-packed
struct, depending on specifci field definitions), and just use field's
actual alignment to calculate whether any field is requiring packing or
struct's size overall necessitates packing.

Add two simple test cases that demonstrate the difference this change
would make.

Fixes: ea2ce1ba99aa ("libbpf: Fix BTF-to-C converter's padding logic")
Reported-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20221215183605.4149488-1-andrii@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/bpf: Add few corner cases to test padding handling of btf_dump</title>
<updated>2023-04-06T10:12:47+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2022-12-12T21:15:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=19d25ad209bac8b5b2564335bb41e1fceb814da0'/>
<id>19d25ad209bac8b5b2564335bb41e1fceb814da0</id>
<content type='text'>
[ Upstream commit b148c8b9b926e257a59c8eb2cd6fa3adfd443254 ]

Add few hand-crafted cases and few randomized cases found using script
from [0] that tests btf_dump's padding logic.

  [0] https://lore.kernel.org/bpf/85f83c333f5355c8ac026f835b18d15060725fcb.camel@ericsson.com/

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20221212211505.558851-7-andrii@kernel.org
Stable-dep-of: 4fb877aaa179 ("libbpf: Fix btf_dump's packed struct determination")
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 b148c8b9b926e257a59c8eb2cd6fa3adfd443254 ]

Add few hand-crafted cases and few randomized cases found using script
from [0] that tests btf_dump's padding logic.

  [0] https://lore.kernel.org/bpf/85f83c333f5355c8ac026f835b18d15060725fcb.camel@ericsson.com/

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20221212211505.558851-7-andrii@kernel.org
Stable-dep-of: 4fb877aaa179 ("libbpf: Fix btf_dump's packed struct determination")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libbpf: Fix BTF-to-C converter's padding logic</title>
<updated>2023-04-06T10:12:47+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2022-12-12T21:15:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6c55a73fd503062f1bc2f5f760829824dac4cced'/>
<id>6c55a73fd503062f1bc2f5f760829824dac4cced</id>
<content type='text'>
[ Upstream commit ea2ce1ba99aa6a60c8d8a706e3abadf3de372163 ]

Turns out that btf_dump API doesn't handle a bunch of tricky corner
cases, as reported by Per, and further discovered using his testing
Python script ([0]).

This patch revamps btf_dump's padding logic significantly, making it
more correct and also avoiding unnecessary explicit padding, where
compiler would pad naturally. This overall topic turned out to be very
tricky and subtle, there are lots of subtle corner cases. The comments
in the code tries to give some clues, but comments themselves are
supposed to be paired with good understanding of C alignment and padding
rules. Plus some experimentation to figure out subtle things like
whether `long :0;` means that struct is now forced to be long-aligned
(no, it's not, turns out).

Anyways, Per's script, while not completely correct in some known
situations, doesn't show any obvious cases where this logic breaks, so
this is a nice improvement over the previous state of this logic.

Some selftests had to be adjusted to accommodate better use of natural
alignment rules, eliminating some unnecessary padding, or changing it to
`type: 0;` alignment markers.

Note also that for when we are in between bitfields, we emit explicit
bit size, while otherwise we use `: 0`, this feels much more natural in
practice.

Next patch will add few more test cases, found through randomized Per's
script.

  [0] https://lore.kernel.org/bpf/85f83c333f5355c8ac026f835b18d15060725fcb.camel@ericsson.com/

Reported-by: Per Sundström XP &lt;per.xp.sundstrom@ericsson.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20221212211505.558851-6-andrii@kernel.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 ea2ce1ba99aa6a60c8d8a706e3abadf3de372163 ]

Turns out that btf_dump API doesn't handle a bunch of tricky corner
cases, as reported by Per, and further discovered using his testing
Python script ([0]).

This patch revamps btf_dump's padding logic significantly, making it
more correct and also avoiding unnecessary explicit padding, where
compiler would pad naturally. This overall topic turned out to be very
tricky and subtle, there are lots of subtle corner cases. The comments
in the code tries to give some clues, but comments themselves are
supposed to be paired with good understanding of C alignment and padding
rules. Plus some experimentation to figure out subtle things like
whether `long :0;` means that struct is now forced to be long-aligned
(no, it's not, turns out).

Anyways, Per's script, while not completely correct in some known
situations, doesn't show any obvious cases where this logic breaks, so
this is a nice improvement over the previous state of this logic.

Some selftests had to be adjusted to accommodate better use of natural
alignment rules, eliminating some unnecessary padding, or changing it to
`type: 0;` alignment markers.

Note also that for when we are in between bitfields, we emit explicit
bit size, while otherwise we use `: 0`, this feels much more natural in
practice.

Next patch will add few more test cases, found through randomized Per's
script.

  [0] https://lore.kernel.org/bpf/85f83c333f5355c8ac026f835b18d15060725fcb.camel@ericsson.com/

Reported-by: Per Sundström XP &lt;per.xp.sundstrom@ericsson.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20221212211505.558851-6-andrii@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/power turbostat: fix decoding of HWP_STATUS</title>
<updated>2023-04-06T10:12:30+00:00</updated>
<author>
<name>Antti Laakso</name>
<email>antti.laakso@intel.com</email>
</author>
<published>2023-01-25T13:17:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aa1f298b397be89e5192c9a3345def7e81985d54'/>
<id>aa1f298b397be89e5192c9a3345def7e81985d54</id>
<content type='text'>
[ Upstream commit 92c25393586ac799b9b7d9e50434f3c44a7622c4 ]

The "excursion to minimum" information is in bit2
in HWP_STATUS MSR. Fix the bitmask used for
decoding the register.

Signed-off-by: Antti Laakso &lt;antti.laakso@intel.com&gt;
Reviewed-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Signed-off-by: Len Brown &lt;len.brown@intel.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 92c25393586ac799b9b7d9e50434f3c44a7622c4 ]

The "excursion to minimum" information is in bit2
in HWP_STATUS MSR. Fix the bitmask used for
decoding the register.

Signed-off-by: Antti Laakso &lt;antti.laakso@intel.com&gt;
Reviewed-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Signed-off-by: Len Brown &lt;len.brown@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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