<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v6.5.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>memfd: replace ratcheting feature from vm.memfd_noexec with hierarchy</title>
<updated>2023-09-13T07:53:57+00:00</updated>
<author>
<name>Aleksa Sarai</name>
<email>cyphar@cyphar.com</email>
</author>
<published>2023-08-14T08:41:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a39eb58a57848570d0ed0ab715c64278b42c8aed'/>
<id>a39eb58a57848570d0ed0ab715c64278b42c8aed</id>
<content type='text'>
[ Upstream commit 9876cfe8ec1cb3c88de31f4d58d57b0e7e22bcc4 ]

This sysctl has the very unusual behaviour of not allowing any user (even
CAP_SYS_ADMIN) to reduce the restriction setting, meaning that if you were
to set this sysctl to a more restrictive option in the host pidns you
would need to reboot your machine in order to reset it.

The justification given in [1] is that this is a security feature and thus
it should not be possible to disable.  Aside from the fact that we have
plenty of security-related sysctls that can be disabled after being
enabled (fs.protected_symlinks for instance), the protection provided by
the sysctl is to stop users from being able to create a binary and then
execute it.  A user with CAP_SYS_ADMIN can trivially do this without
memfd_create(2):

  % cat mount-memfd.c
  #include &lt;fcntl.h&gt;
  #include &lt;string.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;unistd.h&gt;
  #include &lt;linux/mount.h&gt;

  #define SHELLCODE "#!/bin/echo this file was executed from this totally private tmpfs:"

  int main(void)
  {
  	int fsfd = fsopen("tmpfs", FSOPEN_CLOEXEC);
  	assert(fsfd &gt;= 0);
  	assert(!fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 2));

  	int dfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
  	assert(dfd &gt;= 0);

  	int execfd = openat(dfd, "exe", O_CREAT | O_RDWR | O_CLOEXEC, 0782);
  	assert(execfd &gt;= 0);
  	assert(write(execfd, SHELLCODE, strlen(SHELLCODE)) == strlen(SHELLCODE));
  	assert(!close(execfd));

  	char *execpath = NULL;
  	char *argv[] = { "bad-exe", NULL }, *envp[] = { NULL };
  	execfd = openat(dfd, "exe", O_PATH | O_CLOEXEC);
  	assert(execfd &gt;= 0);
  	assert(asprintf(&amp;execpath, "/proc/self/fd/%d", execfd) &gt; 0);
  	assert(!execve(execpath, argv, envp));
  }
  % ./mount-memfd
  this file was executed from this totally private tmpfs: /proc/self/fd/5
  %

Given that it is possible for CAP_SYS_ADMIN users to create executable
binaries without memfd_create(2) and without touching the host filesystem
(not to mention the many other things a CAP_SYS_ADMIN process would be
able to do that would be equivalent or worse), it seems strange to cause a
fair amount of headache to admins when there doesn't appear to be an
actual security benefit to blocking this.  There appear to be concerns
about confused-deputy-esque attacks[2] but a confused deputy that can
write to arbitrary sysctls is a bigger security issue than executable
memfds.

/* New API */

The primary requirement from the original author appears to be more based
on the need to be able to restrict an entire system in a hierarchical
manner[3], such that child namespaces cannot re-enable executable memfds.

So, implement that behaviour explicitly -- the vm.memfd_noexec scope is
evaluated up the pidns tree to &amp;init_pid_ns and you have the most
restrictive value applied to you.  The new lower limit you can set
vm.memfd_noexec is whatever limit applies to your parent.

Note that a pidns will inherit a copy of the parent pidns's effective
vm.memfd_noexec setting at unshare() time.  This matches the existing
behaviour, and it also ensures that a pidns will never have its
vm.memfd_noexec setting *lowered* behind its back (but it will be raised
if the parent raises theirs).

/* Backwards Compatibility */

As the previous version of the sysctl didn't allow you to lower the
setting at all, there are no backwards compatibility issues with this
aspect of the change.

However it should be noted that now that the setting is completely
hierarchical.  Previously, a cloned pidns would just copy the current
pidns setting, meaning that if the parent's vm.memfd_noexec was changed it
wouldn't propoagate to existing pid namespaces.  Now, the restriction
applies recursively.  This is a uAPI change, however:

 * The sysctl is very new, having been merged in 6.3.
 * Several aspects of the sysctl were broken up until this patchset and
   the other patchset by Jeff Xu last month.

And thus it seems incredibly unlikely that any real users would run into
this issue. In the worst case, if this causes userspace isues we could
make it so that modifying the setting follows the hierarchical rules but
the restriction checking uses the cached copy.

[1]: https://lore.kernel.org/CABi2SkWnAgHK1i6iqSqPMYuNEhtHBkO8jUuCvmG3RmUB5TKHJw@mail.gmail.com/
[2]: https://lore.kernel.org/CALmYWFs_dNCzw_pW1yRAo4bGCPEtykroEQaowNULp7svwMLjOg@mail.gmail.com/
[3]: https://lore.kernel.org/CALmYWFuahdUF7cT4cm7_TGLqPanuHXJ-hVSfZt7vpTnc18DPrw@mail.gmail.com/

Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-4-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Dominique Martinet &lt;asmadeus@codewreck.org&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Daniel Verkamp &lt;dverkamp@chromium.org&gt;
Cc: Jeff Xu &lt;jeffxu@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&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 9876cfe8ec1cb3c88de31f4d58d57b0e7e22bcc4 ]

This sysctl has the very unusual behaviour of not allowing any user (even
CAP_SYS_ADMIN) to reduce the restriction setting, meaning that if you were
to set this sysctl to a more restrictive option in the host pidns you
would need to reboot your machine in order to reset it.

The justification given in [1] is that this is a security feature and thus
it should not be possible to disable.  Aside from the fact that we have
plenty of security-related sysctls that can be disabled after being
enabled (fs.protected_symlinks for instance), the protection provided by
the sysctl is to stop users from being able to create a binary and then
execute it.  A user with CAP_SYS_ADMIN can trivially do this without
memfd_create(2):

  % cat mount-memfd.c
  #include &lt;fcntl.h&gt;
  #include &lt;string.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;unistd.h&gt;
  #include &lt;linux/mount.h&gt;

  #define SHELLCODE "#!/bin/echo this file was executed from this totally private tmpfs:"

  int main(void)
  {
  	int fsfd = fsopen("tmpfs", FSOPEN_CLOEXEC);
  	assert(fsfd &gt;= 0);
  	assert(!fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 2));

  	int dfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
  	assert(dfd &gt;= 0);

  	int execfd = openat(dfd, "exe", O_CREAT | O_RDWR | O_CLOEXEC, 0782);
  	assert(execfd &gt;= 0);
  	assert(write(execfd, SHELLCODE, strlen(SHELLCODE)) == strlen(SHELLCODE));
  	assert(!close(execfd));

  	char *execpath = NULL;
  	char *argv[] = { "bad-exe", NULL }, *envp[] = { NULL };
  	execfd = openat(dfd, "exe", O_PATH | O_CLOEXEC);
  	assert(execfd &gt;= 0);
  	assert(asprintf(&amp;execpath, "/proc/self/fd/%d", execfd) &gt; 0);
  	assert(!execve(execpath, argv, envp));
  }
  % ./mount-memfd
  this file was executed from this totally private tmpfs: /proc/self/fd/5
  %

Given that it is possible for CAP_SYS_ADMIN users to create executable
binaries without memfd_create(2) and without touching the host filesystem
(not to mention the many other things a CAP_SYS_ADMIN process would be
able to do that would be equivalent or worse), it seems strange to cause a
fair amount of headache to admins when there doesn't appear to be an
actual security benefit to blocking this.  There appear to be concerns
about confused-deputy-esque attacks[2] but a confused deputy that can
write to arbitrary sysctls is a bigger security issue than executable
memfds.

/* New API */

The primary requirement from the original author appears to be more based
on the need to be able to restrict an entire system in a hierarchical
manner[3], such that child namespaces cannot re-enable executable memfds.

So, implement that behaviour explicitly -- the vm.memfd_noexec scope is
evaluated up the pidns tree to &amp;init_pid_ns and you have the most
restrictive value applied to you.  The new lower limit you can set
vm.memfd_noexec is whatever limit applies to your parent.

Note that a pidns will inherit a copy of the parent pidns's effective
vm.memfd_noexec setting at unshare() time.  This matches the existing
behaviour, and it also ensures that a pidns will never have its
vm.memfd_noexec setting *lowered* behind its back (but it will be raised
if the parent raises theirs).

/* Backwards Compatibility */

As the previous version of the sysctl didn't allow you to lower the
setting at all, there are no backwards compatibility issues with this
aspect of the change.

However it should be noted that now that the setting is completely
hierarchical.  Previously, a cloned pidns would just copy the current
pidns setting, meaning that if the parent's vm.memfd_noexec was changed it
wouldn't propoagate to existing pid namespaces.  Now, the restriction
applies recursively.  This is a uAPI change, however:

 * The sysctl is very new, having been merged in 6.3.
 * Several aspects of the sysctl were broken up until this patchset and
   the other patchset by Jeff Xu last month.

And thus it seems incredibly unlikely that any real users would run into
this issue. In the worst case, if this causes userspace isues we could
make it so that modifying the setting follows the hierarchical rules but
the restriction checking uses the cached copy.

[1]: https://lore.kernel.org/CABi2SkWnAgHK1i6iqSqPMYuNEhtHBkO8jUuCvmG3RmUB5TKHJw@mail.gmail.com/
[2]: https://lore.kernel.org/CALmYWFs_dNCzw_pW1yRAo4bGCPEtykroEQaowNULp7svwMLjOg@mail.gmail.com/
[3]: https://lore.kernel.org/CALmYWFuahdUF7cT4cm7_TGLqPanuHXJ-hVSfZt7vpTnc18DPrw@mail.gmail.com/

Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-4-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Dominique Martinet &lt;asmadeus@codewreck.org&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Daniel Verkamp &lt;dverkamp@chromium.org&gt;
Cc: Jeff Xu &lt;jeffxu@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&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>memfd: do not -EACCES old memfd_create() users with vm.memfd_noexec=2</title>
<updated>2023-09-13T07:53:57+00:00</updated>
<author>
<name>Aleksa Sarai</name>
<email>cyphar@cyphar.com</email>
</author>
<published>2023-08-14T08:40:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5a597636caa749dcaaae841a17c12325b9f56e4'/>
<id>d5a597636caa749dcaaae841a17c12325b9f56e4</id>
<content type='text'>
[ Upstream commit 202e14222fadb246dfdf182e67de1518e86a1e20 ]

Given the difficulty of auditing all of userspace to figure out whether
every memfd_create() user has switched to passing MFD_EXEC and
MFD_NOEXEC_SEAL flags, it seems far less distruptive to make it possible
for older programs that don't make use of executable memfds to run under
vm.memfd_noexec=2.  Otherwise, a small dependency change can result in
spurious errors.  For programs that don't use executable memfds, passing
MFD_NOEXEC_SEAL is functionally a no-op and thus having the same

In addition, every failure under vm.memfd_noexec=2 needs to print to the
kernel log so that userspace can figure out where the error came from.
The concerns about pr_warn_ratelimited() spam that caused the switch to
pr_warn_once()[1,2] do not apply to the vm.memfd_noexec=2 case.

This is a user-visible API change, but as it allows programs to do
something that would be blocked before, and the sysctl itself was broken
and recently released, it seems unlikely this will cause any issues.

[1]: https://lore.kernel.org/Y5yS8wCnuYGLHMj4@x1n/
[2]: https://lore.kernel.org/202212161233.85C9783FB@keescook/

Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-2-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Dominique Martinet &lt;asmadeus@codewreck.org&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Daniel Verkamp &lt;dverkamp@chromium.org&gt;
Cc: Jeff Xu &lt;jeffxu@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&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 202e14222fadb246dfdf182e67de1518e86a1e20 ]

Given the difficulty of auditing all of userspace to figure out whether
every memfd_create() user has switched to passing MFD_EXEC and
MFD_NOEXEC_SEAL flags, it seems far less distruptive to make it possible
for older programs that don't make use of executable memfds to run under
vm.memfd_noexec=2.  Otherwise, a small dependency change can result in
spurious errors.  For programs that don't use executable memfds, passing
MFD_NOEXEC_SEAL is functionally a no-op and thus having the same

In addition, every failure under vm.memfd_noexec=2 needs to print to the
kernel log so that userspace can figure out where the error came from.
The concerns about pr_warn_ratelimited() spam that caused the switch to
pr_warn_once()[1,2] do not apply to the vm.memfd_noexec=2 case.

This is a user-visible API change, but as it allows programs to do
something that would be blocked before, and the sysctl itself was broken
and recently released, it seems unlikely this will cause any issues.

[1]: https://lore.kernel.org/Y5yS8wCnuYGLHMj4@x1n/
[2]: https://lore.kernel.org/202212161233.85C9783FB@keescook/

Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-2-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Dominique Martinet &lt;asmadeus@codewreck.org&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Cc: Daniel Verkamp &lt;dverkamp@chromium.org&gt;
Cc: Jeff Xu &lt;jeffxu@google.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&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>arm64: sdei: abort running SDEI handlers during crash</title>
<updated>2023-09-13T07:53:55+00:00</updated>
<author>
<name>D Scott Phillips</name>
<email>scott@os.amperecomputing.com</email>
</author>
<published>2023-06-27T00:29:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4ed3664fbc7ab23fed55b6a1f2dd6af71ff7e51d'/>
<id>4ed3664fbc7ab23fed55b6a1f2dd6af71ff7e51d</id>
<content type='text'>
commit 5cd474e57368f0957c343bb21e309cf82826b1ef upstream.

Interrupts are blocked in SDEI context, per the SDEI spec: "The client
interrupts cannot preempt the event handler." If we crashed in the SDEI
handler-running context (as with ACPI's AGDI) then we need to clean up the
SDEI state before proceeding to the crash kernel so that the crash kernel
can have working interrupts.

Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME
the handler, discarding the interrupted context.

Fixes: f5df26961853 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking")
Signed-off-by: D Scott Phillips &lt;scott@os.amperecomputing.com&gt;
Cc: stable@vger.kernel.org
Reviewed-by: James Morse &lt;james.morse@arm.com&gt;
Tested-by: Mihai Carabas &lt;mihai.carabas@oracle.com&gt;
Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com
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 5cd474e57368f0957c343bb21e309cf82826b1ef upstream.

Interrupts are blocked in SDEI context, per the SDEI spec: "The client
interrupts cannot preempt the event handler." If we crashed in the SDEI
handler-running context (as with ACPI's AGDI) then we need to clean up the
SDEI state before proceeding to the crash kernel so that the crash kernel
can have working interrupts.

Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME
the handler, discarding the interrupted context.

Fixes: f5df26961853 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking")
Signed-off-by: D Scott Phillips &lt;scott@os.amperecomputing.com&gt;
Cc: stable@vger.kernel.org
Reviewed-by: James Morse &lt;james.morse@arm.com&gt;
Tested-by: Mihai Carabas &lt;mihai.carabas@oracle.com&gt;
Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com
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>net: handle ARPHRD_PPP in dev_is_mac_header_xmit()</title>
<updated>2023-09-13T07:53:54+00:00</updated>
<author>
<name>Nicolas Dichtel</name>
<email>nicolas.dichtel@6wind.com</email>
</author>
<published>2023-08-23T13:41:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d68331f61768488941c792f13b00b371da3ab2b6'/>
<id>d68331f61768488941c792f13b00b371da3ab2b6</id>
<content type='text'>
commit a4f39c9f14a634e4cd35fcd338c239d11fcc73fc upstream.

The goal is to support a bpf_redirect() from an ethernet device (ingress)
to a ppp device (egress).
The l2 header is added automatically by the ppp driver, thus the ethernet
header should be removed.

CC: stable@vger.kernel.org
Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper")
Signed-off-by: Nicolas Dichtel &lt;nicolas.dichtel@6wind.com&gt;
Tested-by: Siwar Zitouni &lt;siwar.zitouni@6wind.com&gt;
Reviewed-by: Guillaume Nault &lt;gnault@redhat.com&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 a4f39c9f14a634e4cd35fcd338c239d11fcc73fc upstream.

The goal is to support a bpf_redirect() from an ethernet device (ingress)
to a ppp device (egress).
The l2 header is added automatically by the ppp driver, thus the ethernet
header should be removed.

CC: stable@vger.kernel.org
Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper")
Signed-off-by: Nicolas Dichtel &lt;nicolas.dichtel@6wind.com&gt;
Tested-by: Siwar Zitouni &lt;siwar.zitouni@6wind.com&gt;
Reviewed-by: Guillaume Nault &lt;gnault@redhat.com&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>mfd: rz-mtu3: Link time dependencies</title>
<updated>2023-09-13T07:53:47+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2023-07-19T09:02:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c27237437b95b5afcf89d84fdc44b04ceecfe0a2'/>
<id>c27237437b95b5afcf89d84fdc44b04ceecfe0a2</id>
<content type='text'>
[ Upstream commit 10d3340441bd0db857fc7fcb1733a800acf47a3d ]

The new set of drivers for RZ/G2L MTU3a tries to enable compile-testing the
individual client drivers even when the MFD portion is disabled but gets it
wrong, causing a link failure when the core is in a loadable module but the
other drivers are built-in:

x86_64-linux-ld: drivers/pwm/pwm-rz-mtu3.o: in function `rz_mtu3_pwm_apply':
pwm-rz-mtu3.c:(.text+0x4bf): undefined reference to `rz_mtu3_8bit_ch_write'
x86_64-linux-ld: pwm-rz-mtu3.c:(.text+0x509): undefined reference to `rz_mtu3_disable'

arm-linux-gnueabi-ld: drivers/counter/rz-mtu3-cnt.o: in function `rz_mtu3_cascade_counts_enable_get':
rz-mtu3-cnt.c:(.text+0xbec): undefined reference to `rz_mtu3_shared_reg_read'

It seems better not to add the extra complexity here but instead just use
a normal hard dependency, so remove the #else portion in the header along
with the "|| COMPILE_TEST". This could also be fixed by having slightly more
elaborate Kconfig dependencies or using the cursed 'IS_REACHABLE()' helper,
but in practice it's already possible to compile-test all these drivers
by enabling the mtd portion.

Fixes: 254d3a727421c ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
Fixes: 0be8907359df4 ("counter: Add Renesas RZ/G2L MTU3a counter driver")
Fixes: 654c293e1687b ("mfd: Add Renesas RZ/G2L MTU3a core driver")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Thierry Reding &lt;thierry.reding@gmail.com&gt;
Reviewed-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/r/20230719090430.1925182-1-arnd@kernel.org
Signed-off-by: Lee Jones &lt;lee@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 10d3340441bd0db857fc7fcb1733a800acf47a3d ]

The new set of drivers for RZ/G2L MTU3a tries to enable compile-testing the
individual client drivers even when the MFD portion is disabled but gets it
wrong, causing a link failure when the core is in a loadable module but the
other drivers are built-in:

x86_64-linux-ld: drivers/pwm/pwm-rz-mtu3.o: in function `rz_mtu3_pwm_apply':
pwm-rz-mtu3.c:(.text+0x4bf): undefined reference to `rz_mtu3_8bit_ch_write'
x86_64-linux-ld: pwm-rz-mtu3.c:(.text+0x509): undefined reference to `rz_mtu3_disable'

arm-linux-gnueabi-ld: drivers/counter/rz-mtu3-cnt.o: in function `rz_mtu3_cascade_counts_enable_get':
rz-mtu3-cnt.c:(.text+0xbec): undefined reference to `rz_mtu3_shared_reg_read'

It seems better not to add the extra complexity here but instead just use
a normal hard dependency, so remove the #else portion in the header along
with the "|| COMPILE_TEST". This could also be fixed by having slightly more
elaborate Kconfig dependencies or using the cursed 'IS_REACHABLE()' helper,
but in practice it's already possible to compile-test all these drivers
by enabling the mtd portion.

Fixes: 254d3a727421c ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
Fixes: 0be8907359df4 ("counter: Add Renesas RZ/G2L MTU3a counter driver")
Fixes: 654c293e1687b ("mfd: Add Renesas RZ/G2L MTU3a core driver")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Thierry Reding &lt;thierry.reding@gmail.com&gt;
Reviewed-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/r/20230719090430.1925182-1-arnd@kernel.org
Signed-off-by: Lee Jones &lt;lee@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvmem: core: Return NULL when no nvmem layout is found</title>
<updated>2023-09-13T07:53:45+00:00</updated>
<author>
<name>Miquel Raynal</name>
<email>miquel.raynal@bootlin.com</email>
</author>
<published>2023-08-23T13:27:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9529b1c5c38f481c74440b3f018ea3d20d5d3320'/>
<id>9529b1c5c38f481c74440b3f018ea3d20d5d3320</id>
<content type='text'>
[ Upstream commit 81e1d9a39569d315f747c2af19ce502cd08645ed ]

Currently, of_nvmem_layout_get_container() returns NULL on error, or an
error pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. We
should likely avoid this kind of mix for two reasons: to clarify the
intend and anyway fix the !CONFIG_OF which will likely always if we use
this helper somewhere else. Let's just return NULL when no layout is
found, we don't need an error value here.

Link: https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
Fixes: 266570f496b9 ("nvmem: core: introduce NVMEM layouts")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/
Signed-off-by: Miquel Raynal &lt;miquel.raynal@bootlin.com&gt;
Reviewed-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Srinivas Kandagatla &lt;srinivas.kandagatla@linaro.org&gt;
Link: https://lore.kernel.org/r/20230823132744.350618-21-srinivas.kandagatla@linaro.org
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 81e1d9a39569d315f747c2af19ce502cd08645ed ]

Currently, of_nvmem_layout_get_container() returns NULL on error, or an
error pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. We
should likely avoid this kind of mix for two reasons: to clarify the
intend and anyway fix the !CONFIG_OF which will likely always if we use
this helper somewhere else. Let's just return NULL when no layout is
found, we don't need an error value here.

Link: https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
Fixes: 266570f496b9 ("nvmem: core: introduce NVMEM layouts")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/
Signed-off-by: Miquel Raynal &lt;miquel.raynal@bootlin.com&gt;
Reviewed-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Srinivas Kandagatla &lt;srinivas.kandagatla@linaro.org&gt;
Link: https://lore.kernel.org/r/20230823132744.350618-21-srinivas.kandagatla@linaro.org
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>HID: input: Support devices sending Eraser without Invert</title>
<updated>2023-09-13T07:53:41+00:00</updated>
<author>
<name>Illia Ostapyshyn</name>
<email>ostapyshyn@sra.uni-hannover.de</email>
</author>
<published>2023-06-13T15:26:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6360b396e81b5295aa9ee3d4f9af13b9bbbbac65'/>
<id>6360b396e81b5295aa9ee3d4f9af13b9bbbbac65</id>
<content type='text'>
[ Upstream commit 276e14e6c3993317257e1787e93b7166fbc30905 ]

Some digitizers (notably XP-Pen Artist 24) do not report the Invert
usage when erasing.  This causes the device to be permanently stuck with
the BTN_TOOL_RUBBER tool after sending Eraser, as Invert is the only
usage that can release the tool.  In this state, Touch and Inrange are
no longer reported to userspace, rendering the pen unusable.

Prior to commit 87562fcd1342 ("HID: input: remove the need for
HID_QUIRK_INVERT"), BTN_TOOL_RUBBER was never set and Eraser events were
simply translated into BTN_TOUCH without causing an inconsistent state.

Introduce HID_QUIRK_NOINVERT for such digitizers and detect them during
hidinput_configure_usage().  This quirk causes the tool to be released
as soon as Eraser is reported as not set.  Set BTN_TOOL_RUBBER in
input-&gt;keybit when mapping Eraser.

Fixes: 87562fcd1342 ("HID: input: remove the need for HID_QUIRK_INVERT")
Co-developed-by: Nils Fuhler &lt;nils@nilsfuhler.de&gt;
Signed-off-by: Nils Fuhler &lt;nils@nilsfuhler.de&gt;
Signed-off-by: Illia Ostapyshyn &lt;ostapyshyn@sra.uni-hannover.de&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&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 276e14e6c3993317257e1787e93b7166fbc30905 ]

Some digitizers (notably XP-Pen Artist 24) do not report the Invert
usage when erasing.  This causes the device to be permanently stuck with
the BTN_TOOL_RUBBER tool after sending Eraser, as Invert is the only
usage that can release the tool.  In this state, Touch and Inrange are
no longer reported to userspace, rendering the pen unusable.

Prior to commit 87562fcd1342 ("HID: input: remove the need for
HID_QUIRK_INVERT"), BTN_TOOL_RUBBER was never set and Eraser events were
simply translated into BTN_TOUCH without causing an inconsistent state.

Introduce HID_QUIRK_NOINVERT for such digitizers and detect them during
hidinput_configure_usage().  This quirk causes the tool to be released
as soon as Eraser is reported as not set.  Set BTN_TOOL_RUBBER in
input-&gt;keybit when mapping Eraser.

Fixes: 87562fcd1342 ("HID: input: remove the need for HID_QUIRK_INVERT")
Co-developed-by: Nils Fuhler &lt;nils@nilsfuhler.de&gt;
Signed-off-by: Nils Fuhler &lt;nils@nilsfuhler.de&gt;
Signed-off-by: Illia Ostapyshyn &lt;ostapyshyn@sra.uni-hannover.de&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kernfs: add stub helper for kernfs_generic_poll()</title>
<updated>2023-09-13T07:53:38+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2023-07-24T12:18:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=568800390f41fdd8733261740cb1f0e80c625d60'/>
<id>568800390f41fdd8733261740cb1f0e80c625d60</id>
<content type='text'>
[ Upstream commit 79038a99445f69c5d28494dd4f8c6f0509f65b2e ]

In some randconfig builds, kernfs ends up being disabled, so there is no prototype
for kernfs_generic_poll()

In file included from kernel/sched/build_utility.c:97:
kernel/sched/psi.c:1479:3: error: implicit declaration of function 'kernfs_generic_poll' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
                kernfs_generic_poll(t-&gt;of, wait);
                ^

Add a stub helper for it, as we have it for other kernfs functions.

Fixes: aff037078ecae ("sched/psi: use kernfs polling functions for PSI trigger polling")
Fixes: 147e1a97c4a0b ("fs: kernfs: add poll file operation")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Chengming Zhou &lt;zhouchengming@bytedance.com&gt;
Link: https://lore.kernel.org/r/20230724121823.1357562-1-arnd@kernel.org
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 79038a99445f69c5d28494dd4f8c6f0509f65b2e ]

In some randconfig builds, kernfs ends up being disabled, so there is no prototype
for kernfs_generic_poll()

In file included from kernel/sched/build_utility.c:97:
kernel/sched/psi.c:1479:3: error: implicit declaration of function 'kernfs_generic_poll' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
                kernfs_generic_poll(t-&gt;of, wait);
                ^

Add a stub helper for it, as we have it for other kernfs functions.

Fixes: aff037078ecae ("sched/psi: use kernfs polling functions for PSI trigger polling")
Fixes: 147e1a97c4a0b ("fs: kernfs: add poll file operation")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Chengming Zhou &lt;zhouchengming@bytedance.com&gt;
Link: https://lore.kernel.org/r/20230724121823.1357562-1-arnd@kernel.org
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>PCI: Add locking to RMW PCI Express Capability Register accessors</title>
<updated>2023-09-13T07:53:30+00:00</updated>
<author>
<name>Ilpo Järvinen</name>
<email>ilpo.jarvinen@linux.intel.com</email>
</author>
<published>2023-07-17T12:04:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=47e7a6529b5e0626d76f45432c7710073e5b6a44'/>
<id>47e7a6529b5e0626d76f45432c7710073e5b6a44</id>
<content type='text'>
[ Upstream commit 5e70d0acf0825f439079736080350371f8d6699a ]

Many places in the kernel write the Link Control and Root Control PCI
Express Capability Registers without proper concurrency control and this
could result in losing the changes one of the writers intended to make.

Add pcie_cap_lock spinlock into the struct pci_dev and use it to protect
bit changes made in the RMW capability accessors. Protect only a selected
set of registers by differentiating the RMW accessor internally to
locked/unlocked variants using a wrapper which has the same signature as
pcie_capability_clear_and_set_word(). As the Capability Register (pos)
given to the wrapper is always a constant, the compiler should be able to
simplify all the dead-code away.

So far only the Link Control Register (ASPM, hotplug, link retraining,
various drivers) and the Root Control Register (AER &amp; PME) seem to
require RMW locking.

Suggested-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: c7f486567c1d ("PCI PM: PCIe PME root port service driver")
Fixes: f12eb72a268b ("PCI/ASPM: Use PCI Express Capability accessors")
Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support")
Fixes: affa48de8417 ("staging/rdma/hfi1: Add support for enabling/disabling PCIe ASPM")
Fixes: 849a9366cba9 ("misc: rtsx: Add support new chip rts5228 mmc: rtsx: Add support MMC_CAP2_NO_MMC")
Fixes: 3d1e7aa80d1c ("misc: rtsx: Use pcie_capability_clear_and_set_word() for PCI_EXP_LNKCTL")
Fixes: c0e5f4e73a71 ("misc: rtsx: Add support for RTS5261")
Fixes: 3df4fce739e2 ("misc: rtsx: separate aspm mode into MODE_REG and MODE_CFG")
Fixes: 121e9c6b5c4c ("misc: rtsx: modify and fix init_hw function")
Fixes: 19f3bd548f27 ("mfd: rtsx: Remove LCTLR defination")
Fixes: 773ccdfd9cc6 ("mfd: rtsx: Read vendor setting from config space")
Fixes: 8275b77a1513 ("mfd: rts5249: Add support for RTS5250S power saving")
Fixes: 5da4e04ae480 ("misc: rtsx: Add support for RTS5260")
Fixes: 0f49bfbd0f2e ("tg3: Use PCI Express Capability accessors")
Fixes: 5e7dfd0fb94a ("tg3: Prevent corruption at 10 / 100Mbps w CLKREQ")
Fixes: b726e493e8dc ("r8169: sync existing 8168 device hardware start sequences with vendor driver")
Fixes: e6de30d63eb1 ("r8169: more 8168dp support.")
Fixes: 8a06127602de ("Bluetooth: hci_bcm4377: Add new driver for BCM4377 PCIe boards")
Fixes: 6f461f6c7c96 ("e1000e: enable/disable ASPM L0s and L1 and ERT according to hardware errata")
Fixes: 1eae4eb2a1c7 ("e1000e: Disable L1 ASPM power savings for 82573 mobile variants")
Fixes: 8060e169e02f ("ath9k: Enable extended synch for AR9485 to fix L0s recovery issue")
Fixes: 69ce674bfa69 ("ath9k: do btcoex ASPM disabling at initialization time")
Fixes: f37f05503575 ("mt76: mt76x2e: disable pcie_aspm by default")
Link: https://lore.kernel.org/r/20230717120503.15276-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: "Rafael J. Wysocki" &lt;rafael@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 5e70d0acf0825f439079736080350371f8d6699a ]

Many places in the kernel write the Link Control and Root Control PCI
Express Capability Registers without proper concurrency control and this
could result in losing the changes one of the writers intended to make.

Add pcie_cap_lock spinlock into the struct pci_dev and use it to protect
bit changes made in the RMW capability accessors. Protect only a selected
set of registers by differentiating the RMW accessor internally to
locked/unlocked variants using a wrapper which has the same signature as
pcie_capability_clear_and_set_word(). As the Capability Register (pos)
given to the wrapper is always a constant, the compiler should be able to
simplify all the dead-code away.

So far only the Link Control Register (ASPM, hotplug, link retraining,
various drivers) and the Root Control Register (AER &amp; PME) seem to
require RMW locking.

Suggested-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Fixes: c7f486567c1d ("PCI PM: PCIe PME root port service driver")
Fixes: f12eb72a268b ("PCI/ASPM: Use PCI Express Capability accessors")
Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support")
Fixes: affa48de8417 ("staging/rdma/hfi1: Add support for enabling/disabling PCIe ASPM")
Fixes: 849a9366cba9 ("misc: rtsx: Add support new chip rts5228 mmc: rtsx: Add support MMC_CAP2_NO_MMC")
Fixes: 3d1e7aa80d1c ("misc: rtsx: Use pcie_capability_clear_and_set_word() for PCI_EXP_LNKCTL")
Fixes: c0e5f4e73a71 ("misc: rtsx: Add support for RTS5261")
Fixes: 3df4fce739e2 ("misc: rtsx: separate aspm mode into MODE_REG and MODE_CFG")
Fixes: 121e9c6b5c4c ("misc: rtsx: modify and fix init_hw function")
Fixes: 19f3bd548f27 ("mfd: rtsx: Remove LCTLR defination")
Fixes: 773ccdfd9cc6 ("mfd: rtsx: Read vendor setting from config space")
Fixes: 8275b77a1513 ("mfd: rts5249: Add support for RTS5250S power saving")
Fixes: 5da4e04ae480 ("misc: rtsx: Add support for RTS5260")
Fixes: 0f49bfbd0f2e ("tg3: Use PCI Express Capability accessors")
Fixes: 5e7dfd0fb94a ("tg3: Prevent corruption at 10 / 100Mbps w CLKREQ")
Fixes: b726e493e8dc ("r8169: sync existing 8168 device hardware start sequences with vendor driver")
Fixes: e6de30d63eb1 ("r8169: more 8168dp support.")
Fixes: 8a06127602de ("Bluetooth: hci_bcm4377: Add new driver for BCM4377 PCIe boards")
Fixes: 6f461f6c7c96 ("e1000e: enable/disable ASPM L0s and L1 and ERT according to hardware errata")
Fixes: 1eae4eb2a1c7 ("e1000e: Disable L1 ASPM power savings for 82573 mobile variants")
Fixes: 8060e169e02f ("ath9k: Enable extended synch for AR9485 to fix L0s recovery issue")
Fixes: 69ce674bfa69 ("ath9k: do btcoex ASPM disabling at initialization time")
Fixes: f37f05503575 ("mt76: mt76x2e: disable pcie_aspm by default")
Link: https://lore.kernel.org/r/20230717120503.15276-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: don't allow enabling a cache on devices that don't support it</title>
<updated>2023-09-13T07:53:18+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2023-07-07T09:42:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f8f054988894936413d71d81adb22653316227fa'/>
<id>f8f054988894936413d71d81adb22653316227fa</id>
<content type='text'>
[ Upstream commit 43c9835b144c7ce29efe142d662529662a9eb376 ]

Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.

Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.

Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.

Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&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 43c9835b144c7ce29efe142d662529662a9eb376 ]

Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.

Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.

Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.

Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
