<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools, branch v6.4.15</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>selftests/mm: FOLL_LONGTERM need to be updated to 0x100</title>
<updated>2023-08-30T12:52:36+00:00</updated>
<author>
<name>Ayush Jain</name>
<email>ayush.jain3@amd.com</email>
</author>
<published>2023-08-08T12:43:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2dcc0e4b3c1c085e361191ea44c567129f3ef466'/>
<id>2dcc0e4b3c1c085e361191ea44c567129f3ef466</id>
<content type='text'>
commit 1738b949625c7e17a454b25de33f1f415da3db69 upstream.

After commit 2c2241081f7d ("mm/gup: move private gup FOLL_ flags to
internal.h") FOLL_LONGTERM flag value got updated from 0x10000 to 0x100 at
include/linux/mm_types.h.

As hmm.hmm_device_private.hmm_gup_test uses FOLL_LONGTERM Updating same
here as well.

Before this change test goes in an infinite assert loop in
hmm.hmm_device_private.hmm_gup_test
==========================================================
 RUN           hmm.hmm_device_private.hmm_gup_test ...
hmm-tests.c:1962:hmm_gup_test:Expected HMM_DMIRROR_PROT_WRITE..
..(2) == m[2] (34)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
...
==========================================================

 Call Trace:
 &lt;TASK&gt;
 ? sched_clock+0xd/0x20
 ? __lock_acquire.constprop.0+0x120/0x6c0
 ? ktime_get+0x2c/0xd0
 ? sched_clock+0xd/0x20
 ? local_clock+0x12/0xd0
 ? lock_release+0x26e/0x3b0
 pin_user_pages_fast+0x4c/0x70
 gup_test_ioctl+0x4ff/0xbb0
 ? gup_test_ioctl+0x68c/0xbb0
 __x64_sys_ioctl+0x99/0xd0
 do_syscall_64+0x60/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? irqentry_exit_to_user_mode+0xd/0x20
 ? irqentry_exit+0x3f/0x50
 ? exc_page_fault+0x96/0x200
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
 RIP: 0033:0x7f6aaa31aaff

After this change test is able to pass successfully.

Link: https://lkml.kernel.org/r/20230808124347.79163-1-ayush.jain3@amd.com
Fixes: 2c2241081f7d ("mm/gup: move private gup FOLL_ flags to internal.h")
Signed-off-by: Ayush Jain &lt;ayush.jain3@amd.com&gt;
Reviewed-by: Raghavendra K T &lt;raghavendra.kt@amd.com&gt;
Reviewed-by: John Hubbard &lt;jhubbard@nvidia.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.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 1738b949625c7e17a454b25de33f1f415da3db69 upstream.

After commit 2c2241081f7d ("mm/gup: move private gup FOLL_ flags to
internal.h") FOLL_LONGTERM flag value got updated from 0x10000 to 0x100 at
include/linux/mm_types.h.

As hmm.hmm_device_private.hmm_gup_test uses FOLL_LONGTERM Updating same
here as well.

Before this change test goes in an infinite assert loop in
hmm.hmm_device_private.hmm_gup_test
==========================================================
 RUN           hmm.hmm_device_private.hmm_gup_test ...
hmm-tests.c:1962:hmm_gup_test:Expected HMM_DMIRROR_PROT_WRITE..
..(2) == m[2] (34)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
hmm-tests.c:157:hmm_gup_test:Expected ret (-1) == 0 (0)
...
==========================================================

 Call Trace:
 &lt;TASK&gt;
 ? sched_clock+0xd/0x20
 ? __lock_acquire.constprop.0+0x120/0x6c0
 ? ktime_get+0x2c/0xd0
 ? sched_clock+0xd/0x20
 ? local_clock+0x12/0xd0
 ? lock_release+0x26e/0x3b0
 pin_user_pages_fast+0x4c/0x70
 gup_test_ioctl+0x4ff/0xbb0
 ? gup_test_ioctl+0x68c/0xbb0
 __x64_sys_ioctl+0x99/0xd0
 do_syscall_64+0x60/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? syscall_exit_to_user_mode+0x2a/0x50
 ? do_syscall_64+0x6d/0x90
 ? irqentry_exit_to_user_mode+0xd/0x20
 ? irqentry_exit+0x3f/0x50
 ? exc_page_fault+0x96/0x200
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
 RIP: 0033:0x7f6aaa31aaff

After this change test is able to pass successfully.

Link: https://lkml.kernel.org/r/20230808124347.79163-1-ayush.jain3@amd.com
Fixes: 2c2241081f7d ("mm/gup: move private gup FOLL_ flags to internal.h")
Signed-off-by: Ayush Jain &lt;ayush.jain3@amd.com&gt;
Reviewed-by: Raghavendra K T &lt;raghavendra.kt@amd.com&gt;
Reviewed-by: John Hubbard &lt;jhubbard@nvidia.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: bonding: do not set port down before adding to bond</title>
<updated>2023-08-30T12:52:32+00:00</updated>
<author>
<name>Hangbin Liu</name>
<email>liuhangbin@gmail.com</email>
</author>
<published>2023-08-17T08:24:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=be7d58c9a203d1aa68451ff624e639e7a3807bcb'/>
<id>be7d58c9a203d1aa68451ff624e639e7a3807bcb</id>
<content type='text'>
[ Upstream commit be809424659c2844a2d7ab653aacca4898538023 ]

Before adding a port to bond, it need to be set down first. In the
lacpdu test the author set the port down specifically. But commit
a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
changed the operation order, the kernel will set the port down _after_
adding to bond. So all the ports will be down at last and the test failed.

In fact, the veth interfaces are already inactive when added. This
means there's no need to set them down again before adding to the bond.
Let's just remove the link down operation.

Fixes: a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
Reported-by: Zhengchao Shao &lt;shaozhengchao@huawei.com&gt;
Closes: https://lore.kernel.org/netdev/a0ef07c7-91b0-94bd-240d-944a330fcabd@huawei.com/
Signed-off-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Link: https://lore.kernel.org/r/20230817082459.1685972-1-liuhangbin@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 be809424659c2844a2d7ab653aacca4898538023 ]

Before adding a port to bond, it need to be set down first. In the
lacpdu test the author set the port down specifically. But commit
a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
changed the operation order, the kernel will set the port down _after_
adding to bond. So all the ports will be down at last and the test failed.

In fact, the veth interfaces are already inactive when added. This
means there's no need to set them down again before adding to the bond.
Let's just remove the link down operation.

Fixes: a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
Reported-by: Zhengchao Shao &lt;shaozhengchao@huawei.com&gt;
Closes: https://lore.kernel.org/netdev/a0ef07c7-91b0-94bd-240d-944a330fcabd@huawei.com/
Signed-off-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Link: https://lore.kernel.org/r/20230817082459.1685972-1-liuhangbin@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: mlxsw: Fix test failure on Spectrum-4</title>
<updated>2023-08-30T12:52:30+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2023-08-17T13:58:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b457f312e78e9199a1be5363b76e792181c09f91'/>
<id>b457f312e78e9199a1be5363b76e792181c09f91</id>
<content type='text'>
[ Upstream commit f520489e99a35b0a5257667274fbe9afd2d8c50b ]

Remove assumptions about shared buffer cell size and instead query the
cell size from devlink. Adjust the test to send small packets that fit
inside a single cell.

Tested on Spectrum-{1,2,3,4}.

Fixes: 4735402173e6 ("mlxsw: spectrum: Extend to support Spectrum-4 ASIC")
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Petr Machata &lt;petrm@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Link: https://lore.kernel.org/r/f7dfbf3c4d1cb23838d9eb99bab09afaa320c4ca.1692268427.git.petrm@nvidia.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 f520489e99a35b0a5257667274fbe9afd2d8c50b ]

Remove assumptions about shared buffer cell size and instead query the
cell size from devlink. Adjust the test to send small packets that fit
inside a single cell.

Tested on Spectrum-{1,2,3,4}.

Fixes: 4735402173e6 ("mlxsw: spectrum: Extend to support Spectrum-4 ASIC")
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Petr Machata &lt;petrm@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Link: https://lore.kernel.org/r/f7dfbf3c4d1cb23838d9eb99bab09afaa320c4ca.1692268427.git.petrm@nvidia.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>Revert "perf report: Append inlines to non-DWARF callchains"</title>
<updated>2023-08-23T15:32:56+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@kernel.org</email>
</author>
<published>2023-08-01T21:42:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1fc26cc6637cf55e995469a90b5d0c10129897f'/>
<id>c1fc26cc6637cf55e995469a90b5d0c10129897f</id>
<content type='text'>
commit c0b067588a4836b762cfc6a4c83f122ca1dbb93a upstream.

This reverts commit 46d21ec067490ab9cdcc89b9de5aae28786a8b8e.

The tests were made with a specific workload, further tests on a
recently updated fedora 38 system with a system wide perf.data file
shows 'perf report' taking excessive time resolving inlines in vmlinux,
so lets revert this until a full investigation and improvement on the
addr2line support code is made.

Reported-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Acked-by: Artem Savkov &lt;asavkov@redhat.com&gt;
Tested-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/ZMl8VyhdwhClTM5g@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.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 c0b067588a4836b762cfc6a4c83f122ca1dbb93a upstream.

This reverts commit 46d21ec067490ab9cdcc89b9de5aae28786a8b8e.

The tests were made with a specific workload, further tests on a
recently updated fedora 38 system with a system wide perf.data file
shows 'perf report' taking excessive time resolving inlines in vmlinux,
so lets revert this until a full investigation and improvement on the
addr2line support code is made.

Reported-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Acked-by: Artem Savkov &lt;asavkov@redhat.com&gt;
Tested-by: Jesper Dangaard Brouer &lt;hawk@kernel.org&gt;
Cc: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/ZMl8VyhdwhClTM5g@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests: mirror_gre_changes: Tighten up the TTL test match</title>
<updated>2023-08-23T15:32:44+00:00</updated>
<author>
<name>Petr Machata</name>
<email>petrm@nvidia.com</email>
</author>
<published>2023-08-11T15:59:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e75311fa503de45b4b25d8b5ba89f1b92914e8e5'/>
<id>e75311fa503de45b4b25d8b5ba89f1b92914e8e5</id>
<content type='text'>
[ Upstream commit 855067defa36b1f9effad8c219d9a85b655cf500 ]

This test verifies whether the encapsulated packets have the correct
configured TTL. It does so by sending ICMP packets through the test
topology and mirroring them to a gretap netdevice. On a busy host
however, more than just the test ICMP packets may end up flowing
through the topology, get mirrored, and counted. This leads to
potential spurious failures as the test observes much more mirrored
packets than the sent test packets, and assumes a bug.

Fix this by tightening up the mirror action match. Change it from
matchall to a flower classifier matching on ICMP packets specifically.

Fixes: 45315673e0c5 ("selftests: forwarding: Test changes in mirror-to-gretap")
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Tested-by: Mirsad Todorovac &lt;mirsad.todorovac@alu.unizg.hr&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&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 855067defa36b1f9effad8c219d9a85b655cf500 ]

This test verifies whether the encapsulated packets have the correct
configured TTL. It does so by sending ICMP packets through the test
topology and mirroring them to a gretap netdevice. On a busy host
however, more than just the test ICMP packets may end up flowing
through the topology, get mirrored, and counted. This leads to
potential spurious failures as the test observes much more mirrored
packets than the sent test packets, and assumes a bug.

Fix this by tightening up the mirror action match. Change it from
matchall to a flower classifier matching on ICMP packets specifically.

Fixes: 45315673e0c5 ("selftests: forwarding: Test changes in mirror-to-gretap")
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Tested-by: Mirsad Todorovac &lt;mirsad.todorovac@alu.unizg.hr&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&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>
<entry>
<title>x86/retpoline,kprobes: Skip optprobe check for indirect jumps with retpolines and IBT</title>
<updated>2023-08-23T15:32:41+00:00</updated>
<author>
<name>Petr Pavlu</name>
<email>petr.pavlu@suse.com</email>
</author>
<published>2023-07-11T09:19:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc4d07ddc4ff462b78be77edd8ad9f0c4fe38395'/>
<id>dc4d07ddc4ff462b78be77edd8ad9f0c4fe38395</id>
<content type='text'>
commit 833fd800bf56b74d39d71d3f5936dffb3e0409c6 upstream.

The kprobes optimization check can_optimize() calls
insn_is_indirect_jump() to detect indirect jump instructions in
a target function. If any is found, creating an optprobe is disallowed
in the function because the jump could be from a jump table and could
potentially land in the middle of the target optprobe.

With retpolines, insn_is_indirect_jump() additionally looks for calls to
indirect thunks which the compiler potentially used to replace original
jumps. This extra check is however unnecessary because jump tables are
disabled when the kernel is built with retpolines. The same is currently
the case with IBT.

Based on this observation, remove the logic to look for calls to
indirect thunks and skip the check for indirect jumps altogether if the
kernel is built with retpolines or IBT. Remove subsequently the symbols
__indirect_thunk_start and __indirect_thunk_end which are no longer
needed.

Dropping this logic indirectly fixes a problem where the range
[__indirect_thunk_start, __indirect_thunk_end] wrongly included also the
return thunk. It caused that machines which used the return thunk as
a mitigation and didn't have it patched by any alternative ended up not
being able to use optprobes in any regular function.

Fixes: 0b53c374b9ef ("x86/retpoline: Use -mfunction-return")
Suggested-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Suggested-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Petr Pavlu &lt;petr.pavlu@suse.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Link: https://lore.kernel.org/r/20230711091952.27944-3-petr.pavlu@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 833fd800bf56b74d39d71d3f5936dffb3e0409c6 upstream.

The kprobes optimization check can_optimize() calls
insn_is_indirect_jump() to detect indirect jump instructions in
a target function. If any is found, creating an optprobe is disallowed
in the function because the jump could be from a jump table and could
potentially land in the middle of the target optprobe.

With retpolines, insn_is_indirect_jump() additionally looks for calls to
indirect thunks which the compiler potentially used to replace original
jumps. This extra check is however unnecessary because jump tables are
disabled when the kernel is built with retpolines. The same is currently
the case with IBT.

Based on this observation, remove the logic to look for calls to
indirect thunks and skip the check for indirect jumps altogether if the
kernel is built with retpolines or IBT. Remove subsequently the symbols
__indirect_thunk_start and __indirect_thunk_end which are no longer
needed.

Dropping this logic indirectly fixes a problem where the range
[__indirect_thunk_start, __indirect_thunk_end] wrongly included also the
return thunk. It caused that machines which used the return thunk as
a mitigation and didn't have it patched by any alternative ended up not
being able to use optprobes in any regular function.

Fixes: 0b53c374b9ef ("x86/retpoline: Use -mfunction-return")
Suggested-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Suggested-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Petr Pavlu &lt;petr.pavlu@suse.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Link: https://lore.kernel.org/r/20230711091952.27944-3-petr.pavlu@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/retpoline,kprobes: Fix position of thunk sections with CONFIG_LTO_CLANG</title>
<updated>2023-08-23T15:32:41+00:00</updated>
<author>
<name>Petr Pavlu</name>
<email>petr.pavlu@suse.com</email>
</author>
<published>2023-07-11T09:19:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aadb82bb7c656edc8ba9bf280eff97f5069d646c'/>
<id>aadb82bb7c656edc8ba9bf280eff97f5069d646c</id>
<content type='text'>
commit 79cd2a11224eab86d6673fe8a11d2046ae9d2757 upstream.

The linker script arch/x86/kernel/vmlinux.lds.S matches the thunk
sections ".text.__x86.*" from arch/x86/lib/retpoline.S as follows:

  .text {
    [...]
    TEXT_TEXT
    [...]
    __indirect_thunk_start = .;
    *(.text.__x86.*)
    __indirect_thunk_end = .;
    [...]
  }

Macro TEXT_TEXT references TEXT_MAIN which normally expands to only
".text". However, with CONFIG_LTO_CLANG, TEXT_MAIN becomes
".text .text.[0-9a-zA-Z_]*" which wrongly matches also the thunk
sections. The output layout is then different than expected. For
instance, the currently defined range [__indirect_thunk_start,
__indirect_thunk_end] becomes empty.

Prevent the problem by using ".." as the first separator, for example,
".text..__x86.indirect_thunk". This pattern is utilized by other
explicit section names which start with one of the standard prefixes,
such as ".text" or ".data", and that need to be individually selected in
the linker script.

  [ nathan: Fix conflicts with SRSO and fold in fix issue brought up by
    Andrew Cooper in post-review:
    https://lore.kernel.org/20230803230323.1478869-1-andrew.cooper3@citrix.com ]

Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO")
Signed-off-by: Petr Pavlu &lt;petr.pavlu@suse.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230711091952.27944-2-petr.pavlu@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 79cd2a11224eab86d6673fe8a11d2046ae9d2757 upstream.

The linker script arch/x86/kernel/vmlinux.lds.S matches the thunk
sections ".text.__x86.*" from arch/x86/lib/retpoline.S as follows:

  .text {
    [...]
    TEXT_TEXT
    [...]
    __indirect_thunk_start = .;
    *(.text.__x86.*)
    __indirect_thunk_end = .;
    [...]
  }

Macro TEXT_TEXT references TEXT_MAIN which normally expands to only
".text". However, with CONFIG_LTO_CLANG, TEXT_MAIN becomes
".text .text.[0-9a-zA-Z_]*" which wrongly matches also the thunk
sections. The output layout is then different than expected. For
instance, the currently defined range [__indirect_thunk_start,
__indirect_thunk_end] becomes empty.

Prevent the problem by using ".." as the first separator, for example,
".text..__x86.indirect_thunk". This pattern is utilized by other
explicit section names which start with one of the standard prefixes,
such as ".text" or ".data", and that need to be individually selected in
the linker script.

  [ nathan: Fix conflicts with SRSO and fold in fix issue brought up by
    Andrew Cooper in post-review:
    https://lore.kernel.org/20230803230323.1478869-1-andrew.cooper3@citrix.com ]

Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO")
Signed-off-by: Petr Pavlu &lt;petr.pavlu@suse.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230711091952.27944-2-petr.pavlu@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>objtool/x86: Fixup frame-pointer vs rethunk</title>
<updated>2023-08-23T15:32:41+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-08-16T11:59:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37e6d8509c19f928386ca3fdddd2209b0da12ae7'/>
<id>37e6d8509c19f928386ca3fdddd2209b0da12ae7</id>
<content type='text'>
commit dbf46008775516f7f25c95b7760041c286299783 upstream.

For stack-validation of a frame-pointer build, objtool validates that
every CALL instruction is preceded by a frame-setup. The new SRSO
return thunks violate this with their RSB stuffing trickery.

Extend the __fentry__ exception to also cover the embedded_insn case
used for this. This cures:

  vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup

Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net
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 dbf46008775516f7f25c95b7760041c286299783 upstream.

For stack-validation of a frame-pointer build, objtool validates that
every CALL instruction is preceded by a frame-setup. The new SRSO
return thunks violate this with their RSB stuffing trickery.

Extend the __fentry__ exception to also cover the embedded_insn case
used for this. This cures:

  vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup

Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu: Rename original retbleed methods</title>
<updated>2023-08-23T15:32:40+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-08-14T11:44:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5c510151d7698f231f68cd35b6ca20774151fa21'/>
<id>5c510151d7698f231f68cd35b6ca20774151fa21</id>
<content type='text'>
commit d025b7bac07a6e90b6b98b487f88854ad9247c39 upstream.

Rename the original retbleed return thunk and untrain_ret to
retbleed_return_thunk() and retbleed_untrain_ret().

No functional changes.

Suggested-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230814121148.909378169@infradead.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 d025b7bac07a6e90b6b98b487f88854ad9247c39 upstream.

Rename the original retbleed return thunk and untrain_ret to
retbleed_return_thunk() and retbleed_untrain_ret().

No functional changes.

Suggested-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230814121148.909378169@infradead.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/cpu: Clean up SRSO return thunk mess</title>
<updated>2023-08-23T15:32:40+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2023-08-14T11:44:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f0d18c28fcb7c7b5b440c1324b054f40a779853'/>
<id>4f0d18c28fcb7c7b5b440c1324b054f40a779853</id>
<content type='text'>
commit d43490d0ab824023e11d0b57d0aeec17a6e0ca13 upstream.

Use the existing configurable return thunk. There is absolute no
justification for having created this __x86_return_thunk alternative.

To clarify, the whole thing looks like:

Zen3/4 does:

  srso_alias_untrain_ret:
	  nop2
	  lfence
	  jmp srso_alias_return_thunk
	  int3

  srso_alias_safe_ret: // aliasses srso_alias_untrain_ret just so
	  add $8, %rsp
	  ret
	  int3

  srso_alias_return_thunk:
	  call srso_alias_safe_ret
	  ud2

While Zen1/2 does:

  srso_untrain_ret:
	  movabs $foo, %rax
	  lfence
	  call srso_safe_ret           (jmp srso_return_thunk ?)
	  int3

  srso_safe_ret: // embedded in movabs instruction
	  add $8,%rsp
          ret
          int3

  srso_return_thunk:
	  call srso_safe_ret
	  ud2

While retbleed does:

  zen_untrain_ret:
	  test $0xcc, %bl
	  lfence
	  jmp zen_return_thunk
          int3

  zen_return_thunk: // embedded in the test instruction
	  ret
          int3

Where Zen1/2 flush the BTB entry using the instruction decoder trick
(test,movabs) Zen3/4 use BTB aliasing. SRSO adds a return sequence
(srso_safe_ret()) which forces the function return instruction to
speculate into a trap (UD2).  This RET will then mispredict and
execution will continue at the return site read from the top of the
stack.

Pick one of three options at boot (evey function can only ever return
once).

  [ bp: Fixup commit message uarch details and add them in a comment in
    the code too. Add a comment about the srso_select_mitigation()
    dependency on retbleed_select_mitigation(). Add moar ifdeffery for
    32-bit builds. Add a dummy srso_untrain_ret_alias() definition for
    32-bit alternatives needing the symbol. ]

Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230814121148.842775684@infradead.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 d43490d0ab824023e11d0b57d0aeec17a6e0ca13 upstream.

Use the existing configurable return thunk. There is absolute no
justification for having created this __x86_return_thunk alternative.

To clarify, the whole thing looks like:

Zen3/4 does:

  srso_alias_untrain_ret:
	  nop2
	  lfence
	  jmp srso_alias_return_thunk
	  int3

  srso_alias_safe_ret: // aliasses srso_alias_untrain_ret just so
	  add $8, %rsp
	  ret
	  int3

  srso_alias_return_thunk:
	  call srso_alias_safe_ret
	  ud2

While Zen1/2 does:

  srso_untrain_ret:
	  movabs $foo, %rax
	  lfence
	  call srso_safe_ret           (jmp srso_return_thunk ?)
	  int3

  srso_safe_ret: // embedded in movabs instruction
	  add $8,%rsp
          ret
          int3

  srso_return_thunk:
	  call srso_safe_ret
	  ud2

While retbleed does:

  zen_untrain_ret:
	  test $0xcc, %bl
	  lfence
	  jmp zen_return_thunk
          int3

  zen_return_thunk: // embedded in the test instruction
	  ret
          int3

Where Zen1/2 flush the BTB entry using the instruction decoder trick
(test,movabs) Zen3/4 use BTB aliasing. SRSO adds a return sequence
(srso_safe_ret()) which forces the function return instruction to
speculate into a trap (UD2).  This RET will then mispredict and
execution will continue at the return site read from the top of the
stack.

Pick one of three options at boot (evey function can only ever return
once).

  [ bp: Fixup commit message uarch details and add them in a comment in
    the code too. Add a comment about the srso_select_mitigation()
    dependency on retbleed_select_mitigation(). Add moar ifdeffery for
    32-bit builds. Add a dummy srso_untrain_ret_alias() definition for
    32-bit alternatives needing the symbol. ]

Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/20230814121148.842775684@infradead.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
